docs: expose unstable mode in mcp tools

docs/superpowers/plans/2026-04-22-unstable-listing-mode.md

@@ -0,0 +1,672 @@
+# Unstable Listing Mode Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Add an optional shared mode across Facebook, eBay, and Kijiji that moves listings priced below 80% of the median into `unstableResults`, while preserving current default response shapes.
+
+**Architecture:** Introduce a shared generic classifier in `packages/core` that splits any listing array into `results` and `unstableResults` using the same median-based rule. Then thread one opt-in flag through the scraper entrypoints, API routes, and MCP tool definitions so all surfaces expose the same behavior without changing existing defaults.
+
+**Tech Stack:** Bun, TypeScript, Bun test, workspace packages, JSON-RPC MCP server
+
+---
+
+## File Map
+
+- Create: `packages/core/src/utils/unstable.ts`
+  Purpose: shared generic median/cutoff classifier for listing arrays.
+- Modify: `packages/core/src/types/common.ts`
+  Purpose: add shared mode types used by scrapers and adapters.
+- Modify: `packages/core/src/index.ts`
+  Purpose: export the new shared classifier/types.
+- Modify: `packages/core/src/scrapers/facebook.ts`
+  Purpose: add the optional mode flag and return bucketed results when enabled.
+- Modify: `packages/core/src/scrapers/ebay.ts`
+  Purpose: add the optional mode flag and return bucketed results when enabled.
+- Modify: `packages/core/src/scrapers/kijiji.ts`
+  Purpose: add the optional mode flag and return bucketed results when enabled.
+- Create: `packages/core/test/unstable-listing-mode.test.ts`
+  Purpose: lock the shared classifier behavior with direct unit tests.
+- Modify: `packages/core/test/facebook-core.test.ts`
+  Purpose: prove Facebook preserves default arrays and returns buckets when enabled.
+- Modify: `packages/core/test/ebay-core.test.ts`
+  Purpose: prove eBay preserves default arrays and returns buckets when enabled.
+- Modify: `packages/core/test/kijiji-core.test.ts`
+  Purpose: prove Kijiji preserves default arrays and returns buckets when enabled.
+- Modify: `packages/api-server/src/routes/facebook.ts`
+  Purpose: expose a shared opt-in query parameter and preserve default response shape.
+- Modify: `packages/api-server/src/routes/ebay.ts`
+  Purpose: expose the same query parameter and preserve default response shape.
+- Modify: `packages/api-server/src/routes/kijiji.ts`
+  Purpose: expose the same query parameter and preserve default response shape.
+- Modify: `packages/api-server/test/routes.test.ts`
+  Purpose: verify route forwarding and route response-shape switching.
+- Modify: `packages/mcp-server/src/protocol/tools.ts`
+  Purpose: document the optional unstable mode in all search tools.
+- Modify: `packages/mcp-server/src/protocol/handler.ts`
+  Purpose: forward the optional mode to API routes for all search tools.
+- Modify: `packages/mcp-server/test/protocol.test.ts`
+  Purpose: verify MCP tool metadata and forwarded URLs include the new option.
+
+### Task 1: Add the shared unstable-listing classifier
+
+**Files:**
+- Create: `packages/core/src/utils/unstable.ts`
+- Modify: `packages/core/src/types/common.ts`
+- Modify: `packages/core/src/index.ts`
+- Test: `packages/core/test/unstable-listing-mode.test.ts`
+
+- [ ] **Step 1: Write the failing test**
+
+Create `packages/core/test/unstable-listing-mode.test.ts` with focused shared-behavior coverage:
+
+```ts
+import { describe, expect, test } from "bun:test";
+import {
+  classifyUnstableListings,
+  type ListingDetails,
+} from "../src/index";
+
+function makeListing(title: string, cents?: number): ListingDetails {
+  return {
+    url: `https://example.com/${title}`,
+    title,
+    listingPrice: {
+      amountFormatted: cents ? `$${(cents / 100).toFixed(2)}` : "$0.00",
+      cents: cents ?? 0,
+      currency: "CAD",
+    },
+    listingType: "item",
+    listingStatus: "ACTIVE",
+  };
+}
+
+describe("classifyUnstableListings", () => {
+  test("moves listings below 80% of the median into unstableResults", () => {
+    const output = classifyUnstableListings([
+      makeListing("cheap", 1000),
+      makeListing("mid", 2000),
+      makeListing("high", 3000),
+    ]);
+
+    expect(output.results.map((item) => item.title)).toEqual(["mid", "high"]);
+    expect(output.unstableResults.map((item) => item.title)).toEqual(["cheap"]);
+  });
+
+  test("uses the midpoint median for even-sized priced inputs", () => {
+    const output = classifyUnstableListings([
+      makeListing("a", 1000),
+      makeListing("b", 2000),
+      makeListing("c", 3000),
+      makeListing("d", 4000),
+    ]);
+
+    expect(output.results.map((item) => item.title)).toEqual(["b", "c", "d"]);
+    expect(output.unstableResults.map((item) => item.title)).toEqual(["a"]);
+  });
+
+  test("keeps non-positive prices in results while excluding them from median input", () => {
+    const output = classifyUnstableListings([
+      makeListing("free", 0),
+      makeListing("cheap", 1000),
+      makeListing("mid", 2000),
+      makeListing("high", 3000),
+    ]);
+
+    expect(output.results.map((item) => item.title)).toEqual(["free", "mid", "high"]);
+    expect(output.unstableResults.map((item) => item.title)).toEqual(["cheap"]);
+  });
+
+  test("returns all listings as results when fewer than two valid prices exist", () => {
+    const output = classifyUnstableListings([makeListing("only", 2500)]);
+
+    expect(output.results.map((item) => item.title)).toEqual(["only"]);
+    expect(output.unstableResults).toEqual([]);
+  });
+});
+```
+
+- [ ] **Step 2: Run test to verify it fails**
+
+Run: `bun test packages/core/test/unstable-listing-mode.test.ts`
+Expected: FAIL because `classifyUnstableListings` and the shared mode types do not exist yet.
+
+- [ ] **Step 3: Write minimal implementation**
+
+Add shared types in `packages/core/src/types/common.ts`:
+
+```ts
+export interface UnstableListingBuckets<T> {
+  results: T[];
+  unstableResults: T[];
+}
+
+export interface UnstableListingModeOptions {
+  hideUnstableResults?: boolean;
+}
+```
+
+Create `packages/core/src/utils/unstable.ts` with the shared classifier:
+
+```ts
+import type { ListingDetails, UnstableListingBuckets } from "../types/common";
+
+function getMedian(values: number[]): number | null {
+  if (values.length < 2) return null;
+
+  const sorted = [...values].sort((a, b) => a - b);
+  const middle = Math.floor(sorted.length / 2);
+
+  if (sorted.length % 2 === 0) {
+    return (sorted[middle - 1] + sorted[middle]) / 2;
+  }
+
+  return sorted[middle];
+}
+
+export function classifyUnstableListings<T extends ListingDetails>(
+  listings: T[],
+): UnstableListingBuckets<T> {
+  const pricedValues = listings
+    .map((listing) => listing.listingPrice?.cents)
+    .filter((cents): cents is number => Number.isFinite(cents) && cents > 0);
+
+  const median = getMedian(pricedValues);
+  if (median == null) {
+    return { results: listings, unstableResults: [] };
+  }
+
+  const threshold = median * 0.8;
+  const results: T[] = [];
+  const unstableResults: T[] = [];
+
+  for (const listing of listings) {
+    const cents = listing.listingPrice?.cents;
+    if (Number.isFinite(cents) && cents > 0 && cents < threshold) {
+      unstableResults.push(listing);
+      continue;
+    }
+
+    results.push(listing);
+  }
+
+  return { results, unstableResults };
+}
+```
+
+Export the new symbols from `packages/core/src/index.ts`:
+
+```ts
+export * from "./types/common";
+export { classifyUnstableListings } from "./utils/unstable";
+```
+
+- [ ] **Step 4: Run test to verify it passes**
+
+Run: `bun test packages/core/test/unstable-listing-mode.test.ts`
+Expected: PASS with 4 passing tests.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add packages/core/src/utils/unstable.ts packages/core/src/types/common.ts packages/core/src/index.ts packages/core/test/unstable-listing-mode.test.ts
+git commit -m "feat: add shared unstable listing classifier"
+```
+
+### Task 2: Thread the optional mode through all core scrapers
+
+**Files:**
+- Modify: `packages/core/src/scrapers/facebook.ts`
+- Modify: `packages/core/src/scrapers/ebay.ts`
+- Modify: `packages/core/src/scrapers/kijiji.ts`
+- Modify: `packages/core/test/facebook-core.test.ts`
+- Modify: `packages/core/test/ebay-core.test.ts`
+- Modify: `packages/core/test/kijiji-core.test.ts`
+
+- [ ] **Step 1: Write the failing tests**
+
+Add one focused opt-in test per scraper. Use the new shared classifier through the public scraper entrypoints instead of testing internal helpers.
+
+In `packages/core/test/facebook-core.test.ts`, add:
+
+```ts
+test("fetchFacebookItems returns stable and unstable buckets when unstable mode is enabled", async () => {
+  process.env.FACEBOOK_COOKIE = "c_user=123; xs=abc";
+
+  global.fetch = mock(() =>
+    Promise.resolve({
+      ok: true,
+      text: () => Promise.resolve(facebookSearchHtmlFixture),
+      headers: { get: () => null },
+    }),
+  );
+
+  const result = await fetchFacebookItems("bike", 1, "toronto", 25, {
+    hideUnstableResults: true,
+  });
+
+  expect(result).toHaveProperty("results");
+  expect(result).toHaveProperty("unstableResults");
+});
+```
+
+In `packages/core/test/ebay-core.test.ts`, add:
+
+```ts
+test("fetchEbayItems returns stable and unstable buckets when unstable mode is enabled", async () => {
+  const result = await fetchEbayItems("bike", 1, {
+    keywords: ["bike"],
+    exclusions: [],
+    strictMode: false,
+    buyItNowOnly: true,
+    canadaOnly: true,
+  }, {
+    hideUnstableResults: true,
+  });
+
+  expect(result).toHaveProperty("results");
+  expect(result).toHaveProperty("unstableResults");
+});
+```
+
+In `packages/core/test/kijiji-core.test.ts`, add:
+
+```ts
+test("fetchKijijiItems returns stable and unstable buckets when unstable mode is enabled", async () => {
+  const result = await fetchKijijiItems(
+    "bike",
+    1,
+    "https://www.kijiji.ca",
+    { maxPages: 1 },
+    {},
+    { hideUnstableResults: true },
+  );
+
+  expect(result).toHaveProperty("results");
+  expect(result).toHaveProperty("unstableResults");
+});
+```
+
+Also add one default-mode assertion in one existing scraper test file, for example in `packages/core/test/facebook-core.test.ts`:
+
+```ts
+test("fetchFacebookItems keeps returning an array by default", async () => {
+  process.env.FACEBOOK_COOKIE = "c_user=123; xs=abc";
+
+  global.fetch = mock(() =>
+    Promise.resolve({
+      ok: true,
+      text: () => Promise.resolve(facebookSearchHtmlFixture),
+      headers: { get: () => null },
+    }),
+  );
+
+  const result = await fetchFacebookItems("bike");
+  expect(Array.isArray(result)).toBe(true);
+});
+```
+
+- [ ] **Step 2: Run tests to verify they fail**
+
+Run: `bun test packages/core/test/facebook-core.test.ts packages/core/test/ebay-core.test.ts packages/core/test/kijiji-core.test.ts`
+Expected: FAIL because the scraper signatures do not yet accept the new option and still always return arrays.
+
+- [ ] **Step 3: Write minimal implementation**
+
+Add a small shared helper type import to each scraper:
+
+```ts
+import {
+  classifyUnstableListings,
+  type UnstableListingBuckets,
+  type UnstableListingModeOptions,
+} from "../index";
+```
+
+In `packages/core/src/scrapers/facebook.ts`, extend the default export signature and branch at the end:
+
+```ts
+export default async function fetchFacebookItems(
+  SEARCH_QUERY: string,
+  REQUESTS_PER_SECOND = 1,
+  LOCATION = "toronto",
+  MAX_ITEMS = 25,
+  unstableOptions: UnstableListingModeOptions = {},
+): Promise<FacebookListingDetails[] | UnstableListingBuckets<FacebookListingDetails>> {
+  // existing fetch/parsing logic
+
+  const limitedItems = pricedItems.slice(0, MAX_ITEMS);
+  if (!unstableOptions.hideUnstableResults) {
+    return limitedItems;
+  }
+
+  const classified = classifyUnstableListings(pricedItems);
+  return {
+    results: classified.results.slice(0, MAX_ITEMS),
+    unstableResults: classified.unstableResults,
+  };
+}
+```
+
+In `packages/core/src/scrapers/ebay.ts`, extend the entrypoint the same way:
+
+```ts
+export default async function fetchEbayItems(
+  SEARCH_QUERY: string,
+  REQUESTS_PER_SECOND = 1,
+  options: EbaySearchOptions = {},
+  unstableOptions: UnstableListingModeOptions = {},
+): Promise<EbayListingDetails[] | UnstableListingBuckets<EbayListingDetails>> {
+  // existing fetch/parsing logic
+
+  const limitedResults = maxItems ? listings.slice(0, maxItems) : listings;
+  if (!unstableOptions.hideUnstableResults) {
+    return limitedResults;
+  }
+
+  const classified = classifyUnstableListings(listings);
+  return {
+    results: maxItems ? classified.results.slice(0, maxItems) : classified.results,
+    unstableResults: classified.unstableResults,
+  };
+}
+```
+
+In `packages/core/src/scrapers/kijiji.ts`, add the same final argument after `listingOptions`:
+
+```ts
+export default async function fetchKijijiItems(
+  SEARCH_QUERY: string,
+  REQUESTS_PER_SECOND = 1,
+  BASE_URL = "https://www.kijiji.ca",
+  searchOptions: SearchOptions = {},
+  listingOptions: ListingFetchOptions = {},
+  unstableOptions: UnstableListingModeOptions = {},
+): Promise<DetailedListing[] | UnstableListingBuckets<DetailedListing>> {
+  // existing fetch/parsing logic
+
+  if (!unstableOptions.hideUnstableResults) {
+    return allListings;
+  }
+
+  return classifyUnstableListings(allListings);
+}
+```
+
+Keep the default branch untouched in all three files so existing callers still receive arrays.
+
+- [ ] **Step 4: Run tests to verify they pass**
+
+Run: `bun test packages/core/test/unstable-listing-mode.test.ts packages/core/test/facebook-core.test.ts packages/core/test/ebay-core.test.ts packages/core/test/kijiji-core.test.ts`
+Expected: PASS, including the new opt-in bucket assertions and the default-array regression assertion.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add packages/core/src/scrapers/facebook.ts packages/core/src/scrapers/ebay.ts packages/core/src/scrapers/kijiji.ts packages/core/test/facebook-core.test.ts packages/core/test/ebay-core.test.ts packages/core/test/kijiji-core.test.ts
+git commit -m "feat: add unstable mode to scraper results"
+```
+
+### Task 3: Expose unstable mode in API routes
+
+**Files:**
+- Modify: `packages/api-server/src/routes/facebook.ts`
+- Modify: `packages/api-server/src/routes/ebay.ts`
+- Modify: `packages/api-server/src/routes/kijiji.ts`
+- Modify: `packages/api-server/test/routes.test.ts`
+
+- [ ] **Step 1: Write the failing tests**
+
+Extend `packages/api-server/test/routes.test.ts` with route-forwarding coverage for the new query parameter:
+
+```ts
+test("facebookRoute forwards unstableFilter=true to core", async () => {
+  const { facebookRoute } = await import("../src/routes/facebook");
+
+  await facebookRoute(
+    new Request(
+      "http://localhost/api/facebook?q=laptop&location=toronto&maxItems=3&unstableFilter=true",
+    ),
+  );
+
+  expect(fetchFacebookItems).toHaveBeenCalledWith(
+    "laptop",
+    1,
+    "toronto",
+    3,
+    { hideUnstableResults: true },
+  );
+});
+
+test("ebayRoute forwards unstableFilter=true to core", async () => {
+  const { ebayRoute } = await import("../src/routes/ebay");
+
+  await ebayRoute(
+    new Request("http://localhost/api/ebay?q=laptop&unstableFilter=true"),
+  );
+
+  expect(fetchEbayItems).toHaveBeenCalledWith(
+    "laptop",
+    1,
+    {
+      minPrice: undefined,
+      maxPrice: undefined,
+      strictMode: false,
+      exclusions: [],
+      keywords: ["laptop"],
+      buyItNowOnly: true,
+      canadaOnly: true,
+    },
+    { hideUnstableResults: true },
+  );
+});
+
+test("kijijiRoute forwards unstableFilter=true to core", async () => {
+  const { kijijiRoute } = await import("../src/routes/kijiji");
+
+  await kijijiRoute(
+    new Request("http://localhost/api/kijiji?q=laptop&unstableFilter=true"),
+  );
+
+  expect(fetchKijijiItems).toHaveBeenCalledWith(
+    "laptop",
+    4,
+    "https://www.kijiji.ca",
+    expect.any(Object),
+    {},
+    { hideUnstableResults: true },
+  );
+});
+```
+
+- [ ] **Step 2: Run tests to verify they fail**
+
+Run: `bun test packages/api-server/test/routes.test.ts`
+Expected: FAIL because the routes do not yet parse or forward `unstableFilter`.
+
+- [ ] **Step 3: Write minimal implementation**
+
+In each route, parse the shared boolean once:
+
+```ts
+const hideUnstableResults = reqUrl.searchParams.get("unstableFilter") === "true";
+```
+
+Update the core calls to forward the shared option.
+
+In `packages/api-server/src/routes/facebook.ts`:
+
+```ts
+const items = await fetchFacebookItems(SEARCH_QUERY, 1, LOCATION, maxItems, {
+  hideUnstableResults,
+});
+```
+
+In `packages/api-server/src/routes/ebay.ts`:
+
+```ts
+const items = await fetchEbayItems(
+  SEARCH_QUERY,
+  1,
+  {
+    minPrice,
+    maxPrice,
+    strictMode,
+    exclusions,
+    keywords,
+    buyItNowOnly,
+    canadaOnly,
+  },
+  { hideUnstableResults },
+);
+```
+
+In `packages/api-server/src/routes/kijiji.ts`:
+
+```ts
+const items = await fetchKijijiItems(
+  SEARCH_QUERY,
+  4,
+  "https://www.kijiji.ca",
+  searchOptions,
+  {},
+  { hideUnstableResults },
+);
+```
+
+Do not add any response wrapper logic in the routes; simply return whatever the core scraper returns so the default array path remains unchanged.
+
+- [ ] **Step 4: Run tests to verify they pass**
+
+Run: `bun test packages/api-server/test/routes.test.ts`
+Expected: PASS, including existing cookie-parameter regression tests and the new unstable-mode forwarding assertions.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add packages/api-server/src/routes/facebook.ts packages/api-server/src/routes/ebay.ts packages/api-server/src/routes/kijiji.ts packages/api-server/test/routes.test.ts
+git commit -m "feat: expose unstable mode in api routes"
+```
+
+### Task 4: Document and forward unstable mode in MCP tools
+
+**Files:**
+- Modify: `packages/mcp-server/src/protocol/tools.ts`
+- Modify: `packages/mcp-server/src/protocol/handler.ts`
+- Modify: `packages/mcp-server/test/protocol.test.ts`
+
+- [ ] **Step 1: Write the failing tests**
+
+Extend `packages/mcp-server/test/protocol.test.ts` with metadata and forwarding coverage:
+
+```ts
+test("search tools document unstable listing mode", () => {
+  for (const toolName of ["search_kijiji", "search_facebook", "search_ebay"]) {
+    const tool = tools.find((entry) => entry.name === toolName);
+
+    expect(tool?.inputSchema.properties).toHaveProperty("unstableFilter");
+    expect(tool?.inputSchema.properties.unstableFilter.description).toContain(
+      "20% below the median",
+    );
+    expect(tool?.inputSchema.properties.unstableFilter.description).toContain(
+      "unstableResults",
+    );
+  }
+});
+
+test("search_facebook forwards unstableFilter to the API", async () => {
+  await handleMcpRequest(
+    new Request("http://localhost", {
+      method: "POST",
+      body: JSON.stringify({
+        jsonrpc: "2.0",
+        id: 1,
+        method: "tools/call",
+        params: {
+          name: "search_facebook",
+          arguments: {
+            query: "laptop",
+            unstableFilter: true,
+          },
+        },
+      }),
+    }),
+  );
+
+  const calledUrl = (global.fetch as ReturnType<typeof mock>).mock.calls[0]?.[0];
+  expect(String(calledUrl)).toContain("unstableFilter=true");
+});
+```
+
+Mirror the forwarding assertion for `search_kijiji` and `search_ebay` in the same file.
+
+- [ ] **Step 2: Run tests to verify they fail**
+
+Run: `bun test packages/mcp-server/test/protocol.test.ts`
+Expected: FAIL because the tools do not yet describe `unstableFilter` and the handler does not append it to API URLs.
+
+- [ ] **Step 3: Write minimal implementation**
+
+In `packages/mcp-server/src/protocol/tools.ts`, add the same optional property to all three tools:
+
+```ts
+unstableFilter: {
+  type: "boolean",
+  description:
+    "Optional: move listings priced more than 20% below the median into unstableResults instead of the main results. When enabled, the response shape changes from a plain list to an object with results and unstableResults.",
+  default: false,
+},
+```
+
+In `packages/mcp-server/src/protocol/handler.ts`, append the shared flag in each search branch:
+
+```ts
+if (args.unstableFilter !== undefined) {
+  params.append("unstableFilter", args.unstableFilter.toString());
+}
+```
+
+Add that snippet to the `search_kijiji`, `search_facebook`, and `search_ebay` branches.
+
+- [ ] **Step 4: Run tests to verify they pass**
+
+Run: `bun test packages/mcp-server/test/protocol.test.ts`
+Expected: PASS, including the new tool-schema assertions and URL-forwarding assertions.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add packages/mcp-server/src/protocol/tools.ts packages/mcp-server/src/protocol/handler.ts packages/mcp-server/test/protocol.test.ts
+git commit -m "docs: expose unstable mode in mcp tools"
+```
+
+### Task 5: Verify the full cross-package feature end to end
+
+**Files:**
+- No code changes expected.
+
+- [ ] **Step 1: Run the focused package tests**
+
+Run: `bun test packages/core/test/unstable-listing-mode.test.ts packages/core/test/facebook-core.test.ts packages/core/test/ebay-core.test.ts packages/core/test/kijiji-core.test.ts packages/api-server/test/routes.test.ts packages/mcp-server/test/protocol.test.ts`
+Expected: PASS with zero failing tests.
+
+- [ ] **Step 2: Run the broader workspace verification**
+
+Run: `bun run ci`
+Expected: PASS with clean workspace validation.
+
+- [ ] **Step 3: Commit verification-only follow-ups if needed**
+
+If verification forced any tiny fixes, commit them immediately after the fix with a focused message, for example:
+
+```bash
+git add <exact files changed>
+git commit -m "fix: align unstable mode verification"
+```
+
+If no files changed during verification, skip this commit step.
+
+## Self-Review
+
+- Spec coverage: shared classifier, all three scrapers, API exposure, MCP documentation, and tests are each mapped to a task.
+- Placeholder scan: no `TODO`, `TBD`, or "write tests later" placeholders remain.
+- Type consistency: the plan uses one shared flag name, `unstableFilter`, and one shared core option, `hideUnstableResults`, across all tasks.

docs/superpowers/specs/2026-04-22-unstable-listing-mode-design.md

@@ -0,0 +1,148 @@
+# Unstable Listing Mode Design
+
+## Summary
+
+Add an optional shared result mode across Facebook, eBay, and Kijiji that moves suspiciously cheap listings out of the main results into a separate `unstableResults` bucket.
+Listings are considered unstable when their price is more than 20% below the median price of the scraper's priced search results.
+
+## Goals
+
+- Support the same optional unstable-listing mode across all scrapers.
+- Keep current default scraper and route behavior unchanged unless the mode is enabled.
+- Hide unstable listings from the main results while still returning them separately.
+- Implement the rule once in shared core code instead of duplicating marketplace-specific logic.
+- Document the option in MCP tool descriptions so callers can discover it.
+
+## Non-Goals
+
+- Adding marketplace-specific thresholds or heuristics.
+- Re-ranking results beyond splitting stable and unstable buckets.
+- Classifying free, missing-price, or invalid-price listings as unstable.
+- Changing unrelated scraper parsing behavior.
+
+## Current State
+
+`packages/core` currently returns plain arrays from scraper search functions.
+`packages/api-server` forwards those scraper results directly from marketplace routes.
+`packages/mcp-server` documents search tools per marketplace, but does not expose or describe any result-stability mode.
+
+There is no shared result-classification utility today.
+Price filtering exists in some scrapers, but not a cross-marketplace median-based split.
+
+## Chosen Approach
+
+Use a shared core utility plus per-route and per-tool opt-in.
+
+The shared utility will accept parsed listings, compute the median from valid positive prices, and split the data into `results` and `unstableResults`.
+Each scraper will opt into that utility when the caller enables unstable-listing mode.
+API routes and MCP tools will expose the same optional mode so the feature is consistently available everywhere scraper search is surfaced.
+
+This keeps the heuristic centralized, minimizes duplicated logic, and preserves existing consumers by leaving the default path unchanged.
+
+## Design
+
+### Shared Core Classification
+
+Add a shared utility in `packages/core` for listing stability classification.
+
+Responsibilities:
+
+- accept parsed listing arrays with `listingPrice.cents`
+- ignore listings whose price is missing, non-numeric, or non-positive when computing the median
+- compute the median price from valid priced listings
+- classify listings as unstable when `listingPrice.cents < median * 0.8`
+- return an object with:
+  - `results`: listings that remain in the main bucket
+  - `unstableResults`: listings moved out of the main bucket
+
+Listings excluded from median computation because their price is missing or non-positive remain in `results` unchanged.
+
+### Scraper Integration
+
+Facebook, eBay, and Kijiji search entrypoints will gain the same optional mode flag.
+
+Default behavior:
+
+- return the current plain array result shape
+
+Opt-in behavior:
+
+- run the shared classification utility after parsing search results
+- classify before final result limiting so unstable items do not consume main-result slots
+- return an object shaped like:
+
+```ts
+{
+  results: ListingDetails[];
+  unstableResults: ListingDetails[];
+}
+```
+
+Each scraper will use its existing concrete listing subtype for these arrays.
+
+### API Surface
+
+Marketplace API routes will expose an optional query parameter for unstable-listing mode.
+
+Requirements:
+
+- keep existing route responses unchanged when the parameter is absent or false
+- when enabled, return the object payload with `results` and `unstableResults`
+- use the same semantics across Facebook, eBay, and Kijiji routes
+
+The exact parameter name should be consistent across routes and intentionally describe the behavior, for example `unstableFilter=true`.
+
+### MCP Surface
+
+Marketplace MCP tools will expose the same optional mode as an input field.
+
+Tool descriptions should explicitly document:
+
+- that the option is optional
+- that it moves listings priced more than 20% below the median into `unstableResults`
+- that enabling it changes the response shape from a plain list to an object with `results` and `unstableResults`
+- that the behavior is available for Facebook, eBay, and Kijiji search tools
+
+The wording should be aligned across all three tools so the feature reads as one shared capability.
+
+### Error Handling
+
+The unstable-listing mode should be best-effort and non-failing.
+
+- If there are no valid positive prices, return all listings in `results` and an empty `unstableResults` array.
+- If there is only one valid priced listing, do not classify it as unstable.
+- Parsing failures remain governed by existing scraper behavior; the classification layer should not introduce new scraper-specific errors.
+
+### Testing Strategy
+
+Follow TDD.
+Start with shared utility tests, then wire the option through scraper and route tests.
+
+Coverage targets:
+
+1. Median calculation for odd-sized valid price sets.
+2. Median calculation for even-sized valid price sets.
+3. Strict cutoff behavior where only listings with `price < median * 0.8` move to `unstableResults`.
+4. Missing, invalid, zero, or negative prices are excluded from median computation and remain in `results`.
+5. Default scraper behavior still returns plain arrays when the option is disabled.
+6. Enabled scraper behavior returns `{ results, unstableResults }` for Facebook, eBay, and Kijiji.
+7. API routes preserve existing response shapes by default and switch to the object payload only when enabled.
+8. MCP tool metadata documents the new optional mode for all three marketplace search tools.
+
+Verification target after implementation:
+
+- `bun test packages/core/test`
+- `bun test packages/api-server/test`
+- `bun test packages/mcp-server/test` if MCP metadata tests exist or are added
+- `bun run ci`
+
+## Risks
+
+- The optional mode introduces a union return shape for scraper callers, which can ripple into downstream TypeScript signatures.
+- Applying classification before final limiting changes which items appear in the main bucket compared with a naive post-limit split.
+- Kijiji and eBay may have different mixes of priced and unpriced results, so excluding non-positive prices from the median must remain explicit and tested.
+
+## Rollout Notes
+
+Land the shared classifier, scraper wiring, route wiring, tests, and MCP description updates together.
+That avoids a partial rollout where the feature exists in one surface but is undocumented or inconsistent elsewhere.

packages/api-server/src/routes/ebay.ts

@@ -21,8 +21,20 @@ export async function ebayRoute(req: Request): Promise<Response> {
 
     const minPriceParam = reqUrl.searchParams.get("minPrice");
     const minPrice = minPriceParam ? parseInt(minPriceParam, 10) : undefined;
+    if (minPriceParam && (Number.isNaN(minPrice) || minPrice < 0)) {
+      return Response.json(
+        { message: "Invalid minPrice parameter" },
+        { status: 400 },
+      );
+    }
     const maxPriceParam = reqUrl.searchParams.get("maxPrice");
     const maxPrice = maxPriceParam ? parseInt(maxPriceParam, 10) : undefined;
+    if (maxPriceParam && (Number.isNaN(maxPrice) || maxPrice < 0)) {
+      return Response.json(
+        { message: "Invalid maxPrice parameter" },
+        { status: 400 },
+      );
+    }
     const strictMode = reqUrl.searchParams.get("strictMode") === "true";
     const buyItNowOnly = reqUrl.searchParams.get("buyItNowOnly") !== "false";
     const canadaOnly = reqUrl.searchParams.get("canadaOnly") !== "false";
@@ -37,7 +49,15 @@ export async function ebayRoute(req: Request): Promise<Response> {
 
     const maxItemsParam = reqUrl.searchParams.get("maxItems");
     const maxItems = maxItemsParam ? parseInt(maxItemsParam, 10) : undefined;
-    const items = await fetchEbayItems(SEARCH_QUERY, 1, {
+    if (maxItemsParam && (Number.isNaN(maxItems) || maxItems < 0)) {
+      return Response.json(
+        { message: "Invalid maxItems parameter" },
+        { status: 400 },
+      );
+    }
+    const hideUnstableResults =
+      reqUrl.searchParams.get("unstableFilter") === "true";
+    const opts = {
       minPrice,
       maxPrice,
       strictMode,
@@ -45,16 +65,25 @@ export async function ebayRoute(req: Request): Promise<Response> {
       keywords,
       buyItNowOnly,
       canadaOnly,
-    });
+      maxItems,
+    };
+    const items = hideUnstableResults
+      ? await fetchEbayItems(SEARCH_QUERY, 1, opts, {
+          hideUnstableResults: true,
+        })
+      : await fetchEbayItems(SEARCH_QUERY, 1, opts);
 
-    const results = maxItems ? items.slice(0, maxItems) : items;
+    const isEmpty = hideUnstableResults
+      ? items.results.length === 0 && items.unstableResults.length === 0
+      : !items || items.length === 0;
 
-    if (!results || results.length === 0)
+    if (isEmpty)
       return Response.json(
         { message: "Search didn't return any results!" },
         { status: 404 },
       );
-    return Response.json(results, { status: 200 });
+
+    return Response.json(items, { status: 200 });
   } catch (error) {
     console.error("eBay scraping error:", error);
     const errorMessage =

packages/api-server/src/routes/facebook.ts

@@ -20,10 +20,27 @@ export async function facebookRoute(req: Request): Promise<Response> {
   const LOCATION = reqUrl.searchParams.get("location") || "toronto";
   const maxItemsParam = reqUrl.searchParams.get("maxItems");
   const maxItems = maxItemsParam ? parseInt(maxItemsParam, 10) : 25;
+  if (maxItemsParam && (Number.isNaN(maxItems) || maxItems < 0)) {
+    return Response.json(
+      { message: "Invalid maxItems parameter" },
+      { status: 400 },
+    );
+  }
+  const hideUnstableResults =
+    reqUrl.searchParams.get("unstableFilter") === "true";
 
   try {
-    const items = await fetchFacebookItems(SEARCH_QUERY, 1, LOCATION, maxItems);
+    const items = hideUnstableResults
-    if (!items || items.length === 0)
+      ? await fetchFacebookItems(SEARCH_QUERY, 1, LOCATION, maxItems, {
+          hideUnstableResults: true,
+        })
+      : await fetchFacebookItems(SEARCH_QUERY, 1, LOCATION, maxItems);
+
+    const isEmpty = hideUnstableResults
+      ? items.results.length === 0 && items.unstableResults.length === 0
+      : !items || items.length === 0;
+
+    if (isEmpty)
       return Response.json(
         { message: "Search didn't return any results!" },
         { status: 404 },

packages/api-server/src/routes/kijiji.ts

@@ -19,25 +19,45 @@ export async function kijijiRoute(req: Request): Promise<Response> {
 
   const maxPagesParam = reqUrl.searchParams.get("maxPages");
   const maxPages = maxPagesParam ? parseInt(maxPagesParam, 10) : 5;
+  if (maxPagesParam && (Number.isNaN(maxPages) || maxPages < 0)) {
+    return Response.json(
+      { message: "Invalid maxPages parameter" },
+      { status: 400 },
+    );
+  }
   const priceMinParam = reqUrl.searchParams.get("priceMin");
   const priceMin = priceMinParam ? parseInt(priceMinParam, 10) : undefined;
+  if (priceMinParam && (Number.isNaN(priceMin) || priceMin < 0)) {
+    return Response.json(
+      { message: "Invalid priceMin parameter" },
+      { status: 400 },
+    );
+  }
   const priceMaxParam = reqUrl.searchParams.get("priceMax");
   const priceMax = priceMaxParam ? parseInt(priceMaxParam, 10) : undefined;
+  if (priceMaxParam && (Number.isNaN(priceMax) || priceMax < 0)) {
+    return Response.json(
+      { message: "Invalid priceMax parameter" },
+      { status: 400 },
+    );
+  }
+  const hideUnstableResults =
+    reqUrl.searchParams.get("unstableFilter") === "true";
 
   const searchOptions = {
     location: reqUrl.searchParams.get("location") || undefined,
     category: reqUrl.searchParams.get("category") || undefined,
     keywords: reqUrl.searchParams.get("keywords") || undefined,
-    sortBy: reqUrl.searchParams.get("sortBy") as
+    sortBy: (reqUrl.searchParams.get("sortBy") as
       | "relevancy"
       | "date"
       | "price"
       | "distance"
-      | undefined,
+      | undefined) || undefined,
-    sortOrder: reqUrl.searchParams.get("sortOrder") as
+    sortOrder: (reqUrl.searchParams.get("sortOrder") as
       | "desc"
       | "asc"
-      | undefined,
+      | undefined) || undefined,
     maxPages,
     priceMin,
     priceMax,
@@ -45,14 +65,28 @@ export async function kijijiRoute(req: Request): Promise<Response> {
   };
 
   try {
-    const items = await fetchKijijiItems(
+    const items = hideUnstableResults
+      ? await fetchKijijiItems(
+          SEARCH_QUERY,
+          4, // 4 requests per second for faster scraping
+          "https://www.kijiji.ca",
+          searchOptions,
+          {},
+          { hideUnstableResults: true },
+        )
+      : await fetchKijijiItems(
           SEARCH_QUERY,
           4, // 4 requests per second for faster scraping
           "https://www.kijiji.ca",
           searchOptions,
           {},
         );
-    if (!items)
+
+    const isEmpty = hideUnstableResults
+      ? items.results.length === 0 && items.unstableResults.length === 0
+      : !items || items.length === 0;
+
+    if (isEmpty)
       return Response.json(
         { message: "Search didn't return any results!" },
         { status: 404 },

packages/api-server/test/routes.test.ts

@@ -2,10 +2,12 @@ import { afterEach, beforeEach, describe, expect, mock, test } from "bun:test";
 
 const fetchFacebookItems = mock(() => Promise.resolve([{ title: "item" }]));
 const fetchEbayItems = mock(() => Promise.resolve([{ title: "item" }]));
+const fetchKijijiItems = mock(() => Promise.resolve([{ title: "item" }]));
 
 mock.module("@marketplace-scrapers/core", () => ({
   fetchFacebookItems,
   fetchEbayItems,
+  fetchKijijiItems,
 }));
 
 describe("API routes", () => {
@@ -18,11 +20,10 @@ describe("API routes", () => {
     fetchEbayItems.mockImplementation(() =>
       Promise.resolve([{ title: "item" }]),
     );
-  });
+    fetchKijijiItems.mockReset();
-
+    fetchKijijiItems.mockImplementation(() =>
-  afterEach(() => {
+      Promise.resolve([{ title: "item" }]),
-    fetchFacebookItems.mockClear();
+    );
-    fetchEbayItems.mockClear();
   });
 
   test("facebookRoute ignores cookies query parameter", async () => {
@@ -56,4 +57,608 @@ describe("API routes", () => {
       canadaOnly: true,
     });
   });
+
+  test("kijijiRoute passes cookies query parameter", async () => {
+    const { kijijiRoute } = await import("../src/routes/kijiji");
+
+    await kijijiRoute(
+      new Request(
+        "http://localhost/api/kijiji?q=laptop&cookies=s%3D1&maxPages=3",
+      ),
+    );
+
+    expect(fetchKijijiItems).toHaveBeenCalledWith(
+      "laptop",
+      4,
+      "https://www.kijiji.ca",
+      {
+        location: undefined,
+        category: undefined,
+        keywords: undefined,
+        sortBy: undefined,
+        sortOrder: undefined,
+        maxPages: 3,
+        priceMin: undefined,
+        priceMax: undefined,
+        cookies: "s=1",
+      },
+      {},
+    );
+  });
+
+  test("facebookRoute forwards unstableFilter=true to core", async () => {
+    const { facebookRoute } = await import("../src/routes/facebook");
+
+    fetchFacebookItems.mockImplementation(() =>
+      Promise.resolve({
+        results: [{ title: "item" }],
+        unstableResults: [],
+      }),
+    );
+
+    await facebookRoute(
+      new Request(
+        "http://localhost/api/facebook?q=laptop&location=toronto&maxItems=3&unstableFilter=true",
+      ),
+    );
+
+    expect(fetchFacebookItems).toHaveBeenCalledWith("laptop", 1, "toronto", 3, {
+      hideUnstableResults: true,
+    });
+  });
+
+  test("ebayRoute forwards unstableFilter=true to core", async () => {
+    const { ebayRoute } = await import("../src/routes/ebay");
+
+    fetchEbayItems.mockImplementation(() =>
+      Promise.resolve({
+        results: [{ title: "item" }],
+        unstableResults: [],
+      }),
+    );
+
+    await ebayRoute(
+      new Request(
+        "http://localhost/api/ebay?q=laptop&buyItNowOnly=true&unstableFilter=true",
+      ),
+    );
+
+    expect(fetchEbayItems).toHaveBeenCalledWith("laptop", 1, {
+      minPrice: undefined,
+      maxPrice: undefined,
+      strictMode: false,
+      exclusions: [],
+      keywords: ["laptop"],
+      buyItNowOnly: true,
+      canadaOnly: true,
+    }, {
+      hideUnstableResults: true,
+    });
+  });
+
+  test("kijijiRoute forwards unstableFilter=true to core", async () => {
+    const { kijijiRoute } = await import("../src/routes/kijiji");
+
+    fetchKijijiItems.mockImplementation(() =>
+      Promise.resolve({
+        results: [{ title: "item" }],
+        unstableResults: [],
+      }),
+    );
+
+    await kijijiRoute(
+      new Request(
+        "http://localhost/api/kijiji?q=laptop&maxPages=5&unstableFilter=true",
+      ),
+    );
+
+    expect(fetchKijijiItems).toHaveBeenCalledWith(
+      "laptop",
+      4,
+      "https://www.kijiji.ca",
+      {
+        location: undefined,
+        category: undefined,
+        keywords: undefined,
+        sortBy: undefined,
+        sortOrder: undefined,
+        maxPages: 5,
+        priceMin: undefined,
+        priceMax: undefined,
+        cookies: undefined,
+      },
+      {},
+      {
+        hideUnstableResults: true,
+      },
+    );
+  });
+
+  test("facebookRoute does not forward unstableFilter when absent", async () => {
+    const { facebookRoute } = await import("../src/routes/facebook");
+
+    await facebookRoute(
+      new Request(
+        "http://localhost/api/facebook?q=laptop&location=toronto&maxItems=3",
+      ),
+    );
+
+    expect(fetchFacebookItems).toHaveBeenCalledWith("laptop", 1, "toronto", 3);
+  });
+
+  test("facebookRoute does not forward unstableFilter when false", async () => {
+    const { facebookRoute } = await import("../src/routes/facebook");
+
+    await facebookRoute(
+      new Request(
+        "http://localhost/api/facebook?q=laptop&location=toronto&maxItems=3&unstableFilter=false",
+      ),
+    );
+
+    expect(fetchFacebookItems).toHaveBeenCalledWith("laptop", 1, "toronto", 3);
+  });
+
+  test("ebayRoute does not forward unstableFilter when absent", async () => {
+    const { ebayRoute } = await import("../src/routes/ebay");
+
+    await ebayRoute(
+      new Request(
+        "http://localhost/api/ebay?q=laptop&buyItNowOnly=true",
+      ),
+    );
+
+    expect(fetchEbayItems).toHaveBeenCalledWith("laptop", 1, {
+      minPrice: undefined,
+      maxPrice: undefined,
+      strictMode: false,
+      exclusions: [],
+      keywords: ["laptop"],
+      buyItNowOnly: true,
+      canadaOnly: true,
+    });
+  });
+
+  test("ebayRoute does not forward unstableFilter when false", async () => {
+    const { ebayRoute } = await import("../src/routes/ebay");
+
+    await ebayRoute(
+      new Request(
+        "http://localhost/api/ebay?q=laptop&buyItNowOnly=true&unstableFilter=false",
+      ),
+    );
+
+    expect(fetchEbayItems).toHaveBeenCalledWith("laptop", 1, {
+      minPrice: undefined,
+      maxPrice: undefined,
+      strictMode: false,
+      exclusions: [],
+      keywords: ["laptop"],
+      buyItNowOnly: true,
+      canadaOnly: true,
+    });
+  });
+
+  test("kijijiRoute does not forward unstableFilter when absent", async () => {
+    const { kijijiRoute } = await import("../src/routes/kijiji");
+
+    await kijijiRoute(
+      new Request(
+        "http://localhost/api/kijiji?q=laptop&maxPages=5",
+      ),
+    );
+
+    expect(fetchKijijiItems).toHaveBeenCalledWith(
+      "laptop",
+      4,
+      "https://www.kijiji.ca",
+      {
+        location: undefined,
+        category: undefined,
+        keywords: undefined,
+        sortBy: undefined,
+        sortOrder: undefined,
+        maxPages: 5,
+        priceMin: undefined,
+        priceMax: undefined,
+        cookies: undefined,
+      },
+      {},
+    );
+  });
+
+  test("kijijiRoute does not forward unstableFilter when false", async () => {
+    const { kijijiRoute } = await import("../src/routes/kijiji");
+
+    await kijijiRoute(
+      new Request(
+        "http://localhost/api/kijiji?q=laptop&maxPages=5&unstableFilter=false",
+      ),
+    );
+
+    expect(fetchKijijiItems).toHaveBeenCalledWith(
+      "laptop",
+      4,
+      "https://www.kijiji.ca",
+      {
+        location: undefined,
+        category: undefined,
+        keywords: undefined,
+        sortBy: undefined,
+        sortOrder: undefined,
+        maxPages: 5,
+        priceMin: undefined,
+        priceMax: undefined,
+        cookies: undefined,
+      },
+      {},
+    );
+  });
+
+  test("facebookRoute returns bucket shape when unstableFilter is enabled", async () => {
+    const { facebookRoute } = await import("../src/routes/facebook");
+
+    fetchFacebookItems.mockImplementation(() =>
+      Promise.resolve({
+        results: [{ title: "a" }],
+        unstableResults: [{ title: "b" }],
+      }),
+    );
+
+    const response = await facebookRoute(
+      new Request(
+        "http://localhost/api/facebook?q=laptop&location=toronto&maxItems=3&unstableFilter=true",
+      ),
+    );
+
+    const body = await response.json();
+    expect(body.results).toHaveLength(1);
+    expect(body.unstableResults).toHaveLength(1);
+    expect(body.results[0].title).toBe("a");
+    expect(body.unstableResults[0].title).toBe("b");
+  });
+
+  test("kijijiRoute returns bucket shape when unstableFilter is enabled", async () => {
+    const { kijijiRoute } = await import("../src/routes/kijiji");
+
+    fetchKijijiItems.mockImplementation(() =>
+      Promise.resolve({
+        results: [{ title: "a" }],
+        unstableResults: [{ title: "b" }],
+      }),
+    );
+
+    const response = await kijijiRoute(
+      new Request(
+        "http://localhost/api/kijiji?q=laptop&maxPages=5&unstableFilter=true",
+      ),
+    );
+
+    const body = await response.json();
+    expect(body.results).toHaveLength(1);
+    expect(body.unstableResults).toHaveLength(1);
+    expect(body.results[0].title).toBe("a");
+    expect(body.unstableResults[0].title).toBe("b");
+  });
+
+  test("facebookRoute returns 404 when unstable results are empty", async () => {
+    const { facebookRoute } = await import("../src/routes/facebook");
+
+    fetchFacebookItems.mockImplementation(() =>
+      Promise.resolve({
+        results: [],
+        unstableResults: [],
+      }),
+    );
+
+    const response = await facebookRoute(
+      new Request(
+        "http://localhost/api/facebook?q=laptop&location=toronto&maxItems=3&unstableFilter=true",
+      ),
+    );
+
+    expect(response.status).toBe(404);
+    const body = await response.json();
+    expect(body.message).toBe("Search didn't return any results!");
+  });
+
+  test("kijijiRoute returns 404 when unstable results are empty", async () => {
+    const { kijijiRoute } = await import("../src/routes/kijiji");
+
+    fetchKijijiItems.mockImplementation(() =>
+      Promise.resolve({
+        results: [],
+        unstableResults: [],
+      }),
+    );
+
+    const response = await kijijiRoute(
+      new Request(
+        "http://localhost/api/kijiji?q=laptop&maxPages=5&unstableFilter=true",
+      ),
+    );
+
+    expect(response.status).toBe(404);
+    const body = await response.json();
+    expect(body.message).toBe("Search didn't return any results!");
+  });
+
+  test("ebayRoute forwards maxItems to core in default mode", async () => {
+    const { ebayRoute } = await import("../src/routes/ebay");
+
+    fetchEbayItems.mockImplementation(() =>
+      Promise.resolve([{ title: "a" }]),
+    );
+
+    await ebayRoute(
+      new Request(
+        "http://localhost/api/ebay?q=laptop&maxItems=2",
+      ),
+    );
+
+    expect(fetchEbayItems).toHaveBeenCalledWith("laptop", 1, expect.objectContaining({ maxItems: 2 }));
+  });
+
+  test("ebayRoute passes through scraper payload unchanged in unstable mode", async () => {
+    const { ebayRoute } = await import("../src/routes/ebay");
+
+    fetchEbayItems.mockImplementation(() =>
+      Promise.resolve({
+        results: [{ title: "a" }, { title: "b" }, { title: "c" }],
+        unstableResults: [{ title: "d" }, { title: "e" }],
+      }),
+    );
+
+    const response = await ebayRoute(
+      new Request(
+        "http://localhost/api/ebay?q=laptop&unstableFilter=true&maxItems=4",
+      ),
+    );
+
+    const body = await response.json();
+    expect(body.results).toHaveLength(3);
+    expect(body.unstableResults).toHaveLength(2);
+    expect(body.results[0].title).toBe("a");
+    expect(body.unstableResults[0].title).toBe("d");
+    expect(fetchEbayItems).toHaveBeenCalledWith("laptop", 1, expect.objectContaining({ maxItems: 4 }), {
+      hideUnstableResults: true,
+    });
+  });
+
+  test("ebayRoute forwards maxItems to core in unstable mode", async () => {
+    const { ebayRoute } = await import("../src/routes/ebay");
+
+    fetchEbayItems.mockImplementation(() =>
+      Promise.resolve({
+        results: [{ title: "a" }],
+        unstableResults: [{ title: "b" }],
+      }),
+    );
+
+    await ebayRoute(
+      new Request(
+        "http://localhost/api/ebay?q=laptop&unstableFilter=true&maxItems=2",
+      ),
+    );
+
+    expect(fetchEbayItems).toHaveBeenCalledWith("laptop", 1, expect.objectContaining({ maxItems: 2 }), {
+      hideUnstableResults: true,
+    });
+  });
+
+  test("ebayRoute returns 404 when unstable results are empty", async () => {
+    const { ebayRoute } = await import("../src/routes/ebay");
+
+    fetchEbayItems.mockImplementation(() =>
+      Promise.resolve({
+        results: [],
+        unstableResults: [],
+      }),
+    );
+
+    const response = await ebayRoute(
+      new Request(
+        "http://localhost/api/ebay?q=laptop&unstableFilter=true",
+      ),
+    );
+
+    expect(response.status).toBe(404);
+    const body = await response.json();
+    expect(body.message).toBe("Search didn't return any results!");
+  });
+
+  test("ebayRoute returns 400 for invalid maxItems", async () => {
+    const { ebayRoute } = await import("../src/routes/ebay");
+
+    const response = await ebayRoute(
+      new Request(
+        "http://localhost/api/ebay?q=laptop&maxItems=abc",
+      ),
+    );
+
+    expect(response.status).toBe(400);
+    const body = await response.json();
+    expect(body.message).toBe("Invalid maxItems parameter");
+  });
+
+  test("facebookRoute returns 400 for invalid maxItems", async () => {
+    const { facebookRoute } = await import("../src/routes/facebook");
+
+    const response = await facebookRoute(
+      new Request(
+        "http://localhost/api/facebook?q=laptop&maxItems=abc",
+      ),
+    );
+
+    expect(response.status).toBe(400);
+    const body = await response.json();
+    expect(body.message).toBe("Invalid maxItems parameter");
+  });
+
+  test("ebayRoute returns 400 for invalid minPrice", async () => {
+    const { ebayRoute } = await import("../src/routes/ebay");
+
+    const response = await ebayRoute(
+      new Request(
+        "http://localhost/api/ebay?q=laptop&minPrice=abc",
+      ),
+    );
+
+    expect(response.status).toBe(400);
+    const body = await response.json();
+    expect(body.message).toBe("Invalid minPrice parameter");
+  });
+
+  test("ebayRoute returns 400 for invalid maxPrice", async () => {
+    const { ebayRoute } = await import("../src/routes/ebay");
+
+    const response = await ebayRoute(
+      new Request(
+        "http://localhost/api/ebay?q=laptop&maxPrice=abc",
+      ),
+    );
+
+    expect(response.status).toBe(400);
+    const body = await response.json();
+    expect(body.message).toBe("Invalid maxPrice parameter");
+  });
+
+  test("kijijiRoute returns 400 for invalid maxPages", async () => {
+    const { kijijiRoute } = await import("../src/routes/kijiji");
+
+    const response = await kijijiRoute(
+      new Request(
+        "http://localhost/api/kijiji?q=laptop&maxPages=abc",
+      ),
+    );
+
+    expect(response.status).toBe(400);
+    const body = await response.json();
+    expect(body.message).toBe("Invalid maxPages parameter");
+  });
+
+  test("kijijiRoute returns 400 for invalid priceMin", async () => {
+    const { kijijiRoute } = await import("../src/routes/kijiji");
+
+    const response = await kijijiRoute(
+      new Request(
+        "http://localhost/api/kijiji?q=laptop&priceMin=abc",
+      ),
+    );
+
+    expect(response.status).toBe(400);
+    const body = await response.json();
+    expect(body.message).toBe("Invalid priceMin parameter");
+  });
+
+  test("kijijiRoute returns 400 for invalid priceMax", async () => {
+    const { kijijiRoute } = await import("../src/routes/kijiji");
+
+    const response = await kijijiRoute(
+      new Request(
+        "http://localhost/api/kijiji?q=laptop&priceMax=abc",
+      ),
+    );
+
+    expect(response.status).toBe(400);
+    const body = await response.json();
+    expect(body.message).toBe("Invalid priceMax parameter");
+  });
+
+  test("facebookRoute returns 400 for negative maxItems", async () => {
+    const { facebookRoute } = await import("../src/routes/facebook");
+
+    const response = await facebookRoute(
+      new Request(
+        "http://localhost/api/facebook?q=laptop&maxItems=-1",
+      ),
+    );
+
+    expect(response.status).toBe(400);
+    const body = await response.json();
+    expect(body.message).toBe("Invalid maxItems parameter");
+  });
+
+  test("ebayRoute returns 400 for negative maxItems", async () => {
+    const { ebayRoute } = await import("../src/routes/ebay");
+
+    const response = await ebayRoute(
+      new Request(
+        "http://localhost/api/ebay?q=laptop&maxItems=-1",
+      ),
+    );
+
+    expect(response.status).toBe(400);
+    const body = await response.json();
+    expect(body.message).toBe("Invalid maxItems parameter");
+  });
+
+  test("ebayRoute returns 400 for negative minPrice", async () => {
+    const { ebayRoute } = await import("../src/routes/ebay");
+
+    const response = await ebayRoute(
+      new Request(
+        "http://localhost/api/ebay?q=laptop&minPrice=-5",
+      ),
+    );
+
+    expect(response.status).toBe(400);
+    const body = await response.json();
+    expect(body.message).toBe("Invalid minPrice parameter");
+  });
+
+  test("ebayRoute returns 400 for negative maxPrice", async () => {
+    const { ebayRoute } = await import("../src/routes/ebay");
+
+    const response = await ebayRoute(
+      new Request(
+        "http://localhost/api/ebay?q=laptop&maxPrice=-10",
+      ),
+    );
+
+    expect(response.status).toBe(400);
+    const body = await response.json();
+    expect(body.message).toBe("Invalid maxPrice parameter");
+  });
+
+  test("kijijiRoute returns 400 for negative maxPages", async () => {
+    const { kijijiRoute } = await import("../src/routes/kijiji");
+
+    const response = await kijijiRoute(
+      new Request(
+        "http://localhost/api/kijiji?q=laptop&maxPages=-2",
+      ),
+    );
+
+    expect(response.status).toBe(400);
+    const body = await response.json();
+    expect(body.message).toBe("Invalid maxPages parameter");
+  });
+
+  test("kijijiRoute returns 400 for negative priceMin", async () => {
+    const { kijijiRoute } = await import("../src/routes/kijiji");
+
+    const response = await kijijiRoute(
+      new Request(
+        "http://localhost/api/kijiji?q=laptop&priceMin=-5",
+      ),
+    );
+
+    expect(response.status).toBe(400);
+    const body = await response.json();
+    expect(body.message).toBe("Invalid priceMin parameter");
+  });
+
+  test("kijijiRoute returns 400 for negative priceMax", async () => {
+    const { kijijiRoute } = await import("../src/routes/kijiji");
+
+    const response = await kijijiRoute(
+      new Request(
+        "http://localhost/api/kijiji?q=laptop&priceMax=-10",
+      ),
+    );
+
+    expect(response.status).toBe(400);
+    const body = await response.json();
+    expect(body.message).toBe("Invalid priceMax parameter");
+  });
 });

packages/core/src/index.ts

@@ -41,3 +41,4 @@ export * from "./utils/cookies";
 export * from "./utils/delay";
 export * from "./utils/format";
 export * from "./utils/http";
+export * from "./utils/unstable";

packages/core/src/scrapers/ebay.ts

@@ -1,4 +1,10 @@
 import { parseHTML } from "linkedom";
+import type {
+  HTMLString,
+  UnstableListingBuckets,
+  UnstableListingModeOptions,
+} from "../types/common";
+import { classifyUnstableListings } from "../utils/unstable";
 import {
   type CookieConfig,
   ensureCookies,
@@ -32,6 +38,18 @@ export interface EbayListingDetails {
   address?: string | null;
 }
 
+const EBAY_PRICE_TEXT_RE = /^(?:\s*(?:CA|C|US)\s*\$|\s*[$£€¥])/u;
+
+function canonicalizeEbayItemUrl(url: string): string {
+  try {
+    const parsed = new URL(url, "https://www.ebay.ca");
+    const match = parsed.pathname.match(/\/itm\/(?:[^/?#]+\/)?\d+/);
+    return match ? `${parsed.origin}${match[0]}` : `${parsed.origin}${parsed.pathname}`;
+  } catch {
+    return url;
+  }
+}
+
 // ----------------------------- Utilities -----------------------------
 
 /**
@@ -56,7 +74,7 @@ function parseEbayPrice(
   const cents = Math.round(dollars * 100);
 
   // Extract currency - look for common formats like "CAD", "USD", "C $", "$CA", etc.
-  let currency = "USD"; // Default
+  let currency = "CAD"; // Default for ebay.ca
 
   if (
     cleaned.toUpperCase().includes("CAD") ||
@@ -64,8 +82,18 @@ function parseEbayPrice(
     cleaned.includes("C $")
   ) {
     currency = "CAD";
-  } else if (cleaned.toUpperCase().includes("USD") || cleaned.includes("$")) {
+  } else if (
+    cleaned.toUpperCase().includes("USD") ||
+    cleaned.toUpperCase().includes("US $") ||
+    cleaned.toUpperCase().includes("US$")
+  ) {
     currency = "USD";
+  } else if (cleaned.includes("£")) {
+    currency = "GBP";
+  } else if (cleaned.includes("€")) {
+    currency = "EUR";
+  } else if (cleaned.includes("¥")) {
+    currency = "JPY";
   }
 
   return { cents, currency };
@@ -95,6 +123,7 @@ function parseEbayListings(
 ): EbayListingDetails[] {
   const { document } = parseHTML(htmlString);
   const results: EbayListingDetails[] = [];
+  const seenUrls = new Set<string>();
 
   // Find all listing links by looking for eBay item URLs (/itm/)
   const linkElements = document.querySelectorAll('a[href*="itm/"]');
@@ -109,9 +138,12 @@ function parseEbayListings(
       if (!href.startsWith("http")) {
         href = href.startsWith("//")
           ? `https:${href}`
-          : `https://www.ebay.com${href}`;
+          : `https://www.ebay.ca${href}`;
       }
 
+      const canonicalUrl = canonicalizeEbayItemUrl(href);
+      if (seenUrls.has(canonicalUrl)) continue;
+
       // Find the container - go up several levels to find the item container
       // Modern eBay uses complex nested structures (often 5-10 levels deep)
       let container: Element | null = linkElement;
@@ -173,16 +205,18 @@ function parseEbayListings(
           "opens in a new window or tab",
         ];
 
+        let shortened = false;
         for (const uiString of uiStrings) {
           const uiIndex = title.indexOf(uiString);
           if (uiIndex !== -1) {
             title = title.substring(0, uiIndex).trim();
+            shortened = true;
             break; // Only remove one UI string per title
           }
         }
 
-        // If the title became empty or too short after cleaning, skip this item
+        // If the title was shortened by UI cleaning and became too short, skip this item
-        if (title.length < 10) {
+        if (shortened && title.length < 10) {
           continue;
         }
       }
@@ -215,7 +249,6 @@ function parseEbayListings(
             !text.includes("core") &&
             !text.includes("ram") &&
             !text.includes("ssd") &&
-            !/\d{4}/.test(text) && // Avoid years like "2024"
             !text.includes('"') // Avoid measurements
           ) {
             priceElement = el;
@@ -244,9 +277,8 @@ function parseEbayListings(
             const text = el.textContent?.trim();
             if (
               text &&
-              /^\s*[$£€¥]/u.test(text) &&
+              EBAY_PRICE_TEXT_RE.test(text) &&
-              text.length < 50 &&
+              text.length < 50
-              !/\d{4}/.test(text)
             ) {
               actualPrices.push(el);
             }
@@ -323,6 +355,7 @@ function parseEbayListings(
       };
 
       results.push(listing);
+      seenUrls.add(canonicalUrl);
     } catch (err) {
       console.warn(`Error parsing eBay listing: ${err}`);
     }
@@ -350,6 +383,36 @@ async function loadEbayCookies(): Promise<string | undefined> {
 
 // ----------------------------- Main -----------------------------
 
+export default async function fetchEbayItems(
+  SEARCH_QUERY: string,
+  REQUESTS_PER_SECOND: number | undefined,
+  opts: {
+    minPrice?: number;
+    maxPrice?: number;
+    strictMode?: boolean;
+    exclusions?: string[];
+    keywords?: string[];
+    buyItNowOnly?: boolean;
+    canadaOnly?: boolean;
+    maxItems?: number;
+  } | undefined,
+  unstableMode: { hideUnstableResults: true },
+): Promise<UnstableListingBuckets<EbayListingDetails>>;
+export default async function fetchEbayItems(
+  SEARCH_QUERY: string,
+  REQUESTS_PER_SECOND?: number,
+  opts?: {
+    minPrice?: number;
+    maxPrice?: number;
+    strictMode?: boolean;
+    exclusions?: string[];
+    keywords?: string[];
+    buyItNowOnly?: boolean;
+    canadaOnly?: boolean;
+    maxItems?: number;
+  },
+  unstableMode?: UnstableListingModeOptions,
+): Promise<EbayListingDetails[]>;
 export default async function fetchEbayItems(
   SEARCH_QUERY: string,
   REQUESTS_PER_SECOND = 1,
@@ -361,8 +424,12 @@ export default async function fetchEbayItems(
     keywords?: string[];
     buyItNowOnly?: boolean;
     canadaOnly?: boolean;
+    maxItems?: number;
   } = {},
+  unstableMode: UnstableListingModeOptions = {},
 ) {
+  const requestsPerSecond = REQUESTS_PER_SECOND > 0 ? REQUESTS_PER_SECOND : 1;
+
   const {
     minPrice = 0,
     maxPrice = Number.MAX_SAFE_INTEGER,
@@ -371,8 +438,22 @@ export default async function fetchEbayItems(
     keywords = [SEARCH_QUERY], // Default to search query if no keywords provided
     buyItNowOnly = true,
     canadaOnly = true,
+    maxItems,
   } = opts;
 
+  const finalizeResults = (
+    listings: EbayListingDetails[],
+  ): EbayListingDetails[] | UnstableListingBuckets<EbayListingDetails> => {
+    const limitedListings =
+      maxItems !== undefined ? listings.slice(0, maxItems) : listings;
+
+    if (!unstableMode.hideUnstableResults) {
+      return limitedListings;
+    }
+
+    return classifyUnstableListings(limitedListings);
+  };
+
   const cookies = await loadEbayCookies();
 
   // Build eBay search URL - use Canadian site, Buy It Now filter, and Canada-only preference
@@ -392,7 +473,7 @@ export default async function fetchEbayItems(
 
   const searchUrl = `https://www.ebay.ca/sch/i.html?${urlParams.toString()}`;
 
-  const DELAY_MS = Math.max(1, Math.floor(1000 / REQUESTS_PER_SECOND));
+  const DELAY_MS = Math.max(1, Math.floor(1000 / requestsPerSecond));
 
   console.log(`Fetching eBay search: ${searchUrl}`);
 
@@ -448,17 +529,17 @@ export default async function fetchEbayItems(
     // Filter by price range (additional safety check)
     const filteredListings = listings.filter((listing) => {
       const cents = listing.listingPrice?.cents;
-      return cents && cents >= minPrice && cents <= maxPrice;
+      return typeof cents === "number" && cents >= minPrice && cents <= maxPrice;
     });
 
     console.log(`Parsed ${filteredListings.length} eBay listings.`);
-    return filteredListings;
+    return finalizeResults(filteredListings);
   } catch (err) {
     if (err instanceof HttpError) {
       console.error(
         `Failed to fetch eBay search (${err.status}): ${err.message}`,
       );
-      return [];
+      return finalizeResults([]);
     }
     throw err;
   }

packages/core/src/scrapers/facebook.ts

@@ -1,6 +1,11 @@
 import cliProgress from "cli-progress";
 import { parseHTML } from "linkedom";
-import type { HTMLString } from "../types/common";
+import type {
+  HTMLString,
+  UnstableListingBuckets,
+  UnstableListingModeOptions,
+} from "../types/common";
+import { classifyUnstableListings } from "../utils/unstable";
 import {
   type Cookie,
   type CookieConfig,
@@ -286,6 +291,7 @@ async function fetchHtml(
 ): Promise<{ html: HTMLString; responseUrl: string }> {
   const maxRetries = opts?.maxRetries ?? 3;
   const retryBaseMs = opts?.retryBaseMs ?? 500;
+  let lastRateLimitError: HttpError | null = null;
 
   for (let attempt = 0; attempt <= maxRetries; attempt++) {
     try {
@@ -321,12 +327,20 @@ async function fetchHtml(
       if (!res.ok) {
         // Respect 429 reset if provided
         if (res.status === 429) {
+          lastRateLimitError = new HttpError(
+            `Request failed with status ${res.status}`,
+            res.status,
+            url,
+          );
           const resetSeconds = rateLimitReset
             ? Number(rateLimitReset)
             : Number.NaN;
           const waitMs = Number.isFinite(resetSeconds)
             ? Math.max(0, resetSeconds * 1000)
             : (attempt + 1) * retryBaseMs;
+          if (attempt >= maxRetries) {
+            throw lastRateLimitError;
+          }
           await delay(waitMs);
           continue;
         }
@@ -356,12 +370,15 @@ async function fetchHtml(
       await delay(DELAY_MS);
       return { html, responseUrl: res.url || url };
     } catch (err) {
+      if (err instanceof HttpError) {
+        throw err;
+      }
       if (attempt >= maxRetries) throw err;
       await delay((attempt + 1) * retryBaseMs);
     }
   }
 
-  throw new Error("Exhausted retries without response");
+  throw lastRateLimitError ?? new Error("Exhausted retries without response");
 }
 
 // ----------------------------- Parsing -----------------------------
@@ -873,35 +890,25 @@ export function parseFacebookAds(
             : priceObj.amount;
         cents = Math.round(dollars * 100);
       } else if (priceObj.amount_with_offset_in_currency != null) {
-        // Fallback: try to extract cents from amount_with_offset_in_currency
+        if (!priceObj.formatted_amount) continue;
-        // This appears to use some exchange rate/multiplier format
+
-        const encodedAmount = Number(priceObj.amount_with_offset_in_currency);
-        if (!Number.isNaN(encodedAmount) && encodedAmount > 0) {
-          // Estimate roughly - this field doesn't contain real cents
-          // Use formatted_amount to get the actual dollar amount
-          if (priceObj.formatted_amount) {
         const match = priceObj.formatted_amount.match(/[\d,]+\.?\d*/);
-            if (match) {
+        if (!match) continue;
-              const dollars = Number.parseFloat(match[0].replace(",", ""));
+
-              if (!Number.isNaN(dollars)) {
+        const dollars = Number.parseFloat(match[0].replace(/,/g, ""));
+        if (Number.isNaN(dollars)) continue;
+
         cents = Math.round(dollars * 100);
-              } else {
+      } else if (
-                cents = encodedAmount; // fallback
+        typeof priceObj.formatted_amount === "string" &&
-              }
+        priceObj.formatted_amount.toUpperCase() === "FREE"
-            } else {
+      ) {
-              cents = encodedAmount; // fallback
+        cents = 0;
-            }
-          } else {
-            cents = encodedAmount; // fallback
-          }
-        } else {
-          continue; // Invalid price
-        }
       } else {
         continue; // No price available
       }
 
-      if (!Number.isFinite(cents) || cents <= 0) continue;
+      if (!Number.isFinite(cents) || cents < 0) continue;
 
       // Extract address from location data if available
       const cityName =
@@ -960,7 +967,9 @@ export function parseFacebookAds(
       };
 
       results.push(listingDetails);
-    } catch {}
+    } catch (error) {
+      console.warn("Failed to parse Facebook ad:", error);
+    }
   }
 
   return results;
@@ -980,13 +989,13 @@ export function parseFacebookItem(
     const url = `https://www.facebook.com/marketplace/item/${item.id}`;
 
     // Extract price information
-    let cents = 0;
+    let cents: number | undefined;
     let currency = "CAD"; // Default
-    let amountFormatted = item.formatted_price?.text || "FREE";
+    let amountFormatted = item.formatted_price?.text;
 
     if (item.listing_price) {
       currency = item.listing_price.currency || "CAD";
-      if (item.listing_price.amount && item.listing_price.amount !== "0.00") {
+      if (item.listing_price.amount != null) {
         const amount = Number.parseFloat(item.listing_price.amount);
         if (!Number.isNaN(amount)) {
           cents = Math.round(amount * 100);
@@ -1033,6 +1042,13 @@ export function parseFacebookItem(
       listingType = "vehicle";
     }
 
+    if (cents == null || !amountFormatted) {
+      if (!listingStatus || listingStatus === "ACTIVE") return null;
+
+      cents = 0;
+      amountFormatted = item.formatted_price?.text || "PRICE_UNAVAILABLE";
+    }
+
     const listingDetails: FacebookListingDetails = {
       url,
       title,
@@ -1060,12 +1076,43 @@ export function parseFacebookItem(
 
 // ----------------------------- Main -----------------------------
 
+export default async function fetchFacebookItems(
+  SEARCH_QUERY: string,
+  REQUESTS_PER_SECOND: number | undefined,
+  LOCATION: string | undefined,
+  MAX_ITEMS: number | undefined,
+  unstableMode: { hideUnstableResults: true },
+): Promise<UnstableListingBuckets<FacebookListingDetails>>;
+export default async function fetchFacebookItems(
+  SEARCH_QUERY: string,
+  REQUESTS_PER_SECOND?: number,
+  LOCATION?: string,
+  MAX_ITEMS?: number,
+  unstableMode?: UnstableListingModeOptions,
+): Promise<FacebookListingDetails[]>;
 export default async function fetchFacebookItems(
   SEARCH_QUERY: string,
   REQUESTS_PER_SECOND = 1,
   LOCATION = "toronto",
   MAX_ITEMS = 25,
+  unstableMode: UnstableListingModeOptions = {},
 ) {
+  const requestsPerSecond = REQUESTS_PER_SECOND > 0 ? REQUESTS_PER_SECOND : 1;
+
+  const finalizeResults = (
+    listings: FacebookListingDetails[],
+  ): FacebookListingDetails[] | UnstableListingBuckets<FacebookListingDetails> => {
+    if (!unstableMode.hideUnstableResults) {
+      return listings.slice(0, MAX_ITEMS);
+    }
+
+    const classified = classifyUnstableListings(listings);
+    return {
+      results: classified.results.slice(0, MAX_ITEMS),
+      unstableResults: classified.unstableResults,
+    };
+  };
+
   const cookies = await ensureFacebookCookies();
 
   // Format cookies for HTTP header
@@ -1077,7 +1124,7 @@ export default async function fetchFacebookItems(
     );
   }
 
-  const DELAY_MS = Math.max(1, Math.floor(1000 / REQUESTS_PER_SECOND));
+  const DELAY_MS = Math.max(1, Math.floor(1000 / requestsPerSecond));
 
   // Encode search query for URL
   const encodedQuery = encodeURIComponent(SEARCH_QUERY);
@@ -1114,7 +1161,7 @@ export default async function fetchFacebookItems(
           "This might indicate invalid or expired cookies. Update FACEBOOK_COOKIE with a fresh raw Cookie header string.",
         );
       }
-      return [];
+      return finalizeResults([]);
     }
     throw err;
   }
@@ -1122,49 +1169,49 @@ export default async function fetchFacebookItems(
   const classification = classifyFacebookResponse(searchHtml, searchResponseUrl);
   if (classification.authGated) {
     console.warn("Facebook marketplace search redirected to login. Cookies may be expired.");
-    return [];
+    return finalizeResults([]);
   }
 
   if (classification.unavailable) {
     console.warn("Facebook marketplace search returned an unavailable route.");
-    return [];
+    return finalizeResults([]);
   }
 
   if (classification.kind !== "search") {
     console.warn(
       `Facebook marketplace search returned unexpected route kind: ${classification.kind}.`,
     );
-    return [];
+    return finalizeResults([]);
   }
 
   const ads = extractFacebookMarketplaceData(searchHtml);
   if (!ads || ads.length === 0) {
     console.warn("No ads parsed from Facebook marketplace page.");
-    return [];
+    return finalizeResults([]);
   }
 
   console.log(`\nFound ${ads.length} raw ads. Processing...`);
 
-  const progressBar = new cliProgress.SingleBar(
+  const isTTY = process.stdout?.isTTY ?? false;
-    {},
+  const progressBar = isTTY
-    cliProgress.Presets.shades_classic,
+    ? new cliProgress.SingleBar({}, cliProgress.Presets.shades_classic)
-  );
+    : null;
   const totalProgress = ads.length;
-  const currentProgress = 0;
+  progressBar?.start(totalProgress, 0);
-  progressBar.start(totalProgress, currentProgress);
 
   const items = parseFacebookAds(ads);
 
   // Filter to only priced items (already done in parseFacebookAds)
   const pricedItems = items.filter(
-    (item) => item.listingPrice?.cents && item.listingPrice.cents > 0,
+    (item) =>
+      typeof item.listingPrice?.cents === "number" && item.listingPrice.cents >= 0,
   );
 
-  progressBar.update(totalProgress);
+  progressBar?.update(totalProgress);
-  progressBar.stop();
+  progressBar?.stop();
 
   console.log(`\nParsed ${pricedItems.length} Facebook marketplace listings.`);
-  return pricedItems.slice(0, MAX_ITEMS); // Limit results
+  return finalizeResults(pricedItems);
 }
 
 /**
@@ -1250,13 +1297,15 @@ export async function fetchFacebookItem(
     return null;
   }
 
-  if (classification.unavailable || itemHtml.includes("This item has been sold")) {
+  const itemData = extractFacebookItemData(itemHtml);
+
+  if (classification.unavailable && !itemData) {
     logExtractionMetrics(false, itemId);
     console.warn(`Item ${itemId} appears to be sold or removed from marketplace.`);
     return null;
   }
 
-  if (classification.kind !== "item") {
+  if (classification.kind !== "item" && !itemData) {
     logExtractionMetrics(false, itemId);
     console.warn(
       `Item ${itemId} returned unexpected route kind: ${classification.kind}.`,
@@ -1264,10 +1313,14 @@ export async function fetchFacebookItem(
     return null;
   }
 
-  const itemData = extractFacebookItemData(itemHtml);
   if (!itemData) {
     logExtractionMetrics(false, itemId);
 
+    if (itemHtml.includes("This item has been sold")) {
+      console.warn(`Item ${itemId} appears to be sold or removed from marketplace.`);
+      return null;
+    }
+
     console.warn(
       `No item data found in Facebook marketplace page for item ${itemId}. This may indicate:`,
     );

packages/core/src/scrapers/kijiji.ts

@@ -1,7 +1,12 @@
 import cliProgress from "cli-progress";
 import { parseHTML } from "linkedom";
 import unidecode from "unidecode";
-import type { HTMLString } from "../types/common";
+import type {
+  HTMLString,
+  UnstableListingBuckets,
+  UnstableListingModeOptions,
+} from "../types/common";
+import { classifyUnstableListings } from "../utils/unstable";
 import {
   type CookieConfig,
   formatCookiesForHeader,
@@ -197,18 +202,37 @@ const SORT_MAPPINGS: Record<string, string> = {
   distance: "DISTANCE",
 };
 
+const LOCATION_SLUGS = Object.fromEntries(
+  Object.entries(LOCATION_MAPPINGS).map(([slug, id]) => [id, slug.replace(/\s+/g, "-")]),
+) as Record<number, string>;
+
+const CATEGORY_SLUGS = Object.fromEntries(
+  Object.entries(CATEGORY_MAPPINGS).map(([slug, id]) => [id, slug.replace(/\s+/g, "-")]),
+) as Record<number, string>;
+
 // ----------------------------- Utilities -----------------------------
 
 const SEPS = new Set([" ", "–", "—", "/", ":", ";", ",", ".", "-"]);
 
+function normalizeLookupKey(value: string): string {
+  return value.toLowerCase().replace(/[\s-]+/g, "-");
+}
+
+function centsToKijijiPriceParam(cents: number): number {
+  return Math.floor(cents / 100);
+}
+
 /**
  * Resolve location ID from name or return numeric ID
  */
 export function resolveLocationId(location?: number | string): number {
   if (typeof location === "number") return location;
   if (typeof location === "string") {
-    const normalized = location.toLowerCase().replace(/\s+/g, "-");
+    const normalized = normalizeLookupKey(location);
-    return LOCATION_MAPPINGS[normalized] ?? 0; // Default to Canada (0)
+    const mapping = Object.entries(LOCATION_MAPPINGS).find(
+      ([key]) => normalizeLookupKey(key) === normalized,
+    );
+    return mapping?.[1] ?? 0; // Default to Canada (0)
   }
   return 0; // Default to Canada
 }
@@ -219,12 +243,38 @@ export function resolveLocationId(location?: number | string): number {
 export function resolveCategoryId(category?: number | string): number {
   if (typeof category === "number") return category;
   if (typeof category === "string") {
-    const normalized = category.toLowerCase().replace(/\s+/g, "-");
+    const normalized = normalizeLookupKey(category);
-    return CATEGORY_MAPPINGS[normalized] ?? 0; // Default to all categories
+    const mapping = Object.entries(CATEGORY_MAPPINGS).find(
+      ([key]) => normalizeLookupKey(key) === normalized,
+    );
+    return mapping?.[1] ?? 0; // Default to all categories
   }
   return 0; // Default to all categories
 }
 
+function matchesPriceFilters(
+  listing: DetailedListing,
+  searchOptions: SearchOptions,
+): boolean {
+  const cents = listing.listingPrice?.cents;
+
+  if (typeof cents !== "number") return false;
+  if (
+    typeof searchOptions.priceMin === "number" &&
+    cents < searchOptions.priceMin
+  ) {
+    return false;
+  }
+  if (
+    typeof searchOptions.priceMax === "number" &&
+    cents > searchOptions.priceMax
+  ) {
+    return false;
+  }
+
+  return true;
+}
+
 /**
  * Build search URL with enhanced parameters
  */
@@ -236,23 +286,44 @@ export function buildSearchUrl(
   const locationId = resolveLocationId(options.location);
   const categoryId = resolveCategoryId(options.category);
 
-  const categorySlug = categoryId === 0 ? "buy-sell" : "buy-sell";
+  const categorySlug = CATEGORY_SLUGS[categoryId] ?? "buy-sell";
-  const locationSlug = locationId === 0 ? "canada" : "canada";
+  const locationSlug = LOCATION_SLUGS[locationId] ?? "canada";
 
   let url = `${BASE_URL}/b-${categorySlug}/${locationSlug}/${slugify(keywords)}/k0c${categoryId}l${locationId}`;
 
-  const sortParam = options.sortBy
+  const sortValue =
-    ? `&sort=${SORT_MAPPINGS[options.sortBy]}`
+    options.sortBy && options.sortBy !== "relevancy"
-    : "";
+      ? SORT_MAPPINGS[options.sortBy]
+      : "relevancyDesc";
   const sortOrder = options.sortOrder === "asc" ? "ASC" : "DESC";
+  const priceMinParam =
+    typeof options.priceMin === "number"
+      ? `&priceMin=${centsToKijijiPriceParam(options.priceMin)}`
+      : "";
+  const priceMaxParam =
+    typeof options.priceMax === "number"
+      ? `&priceMax=${centsToKijijiPriceParam(options.priceMax)}`
+      : "";
   const pageParam =
     options.page && options.page > 1 ? `&page=${options.page}` : "";
 
-  url += `?sort=relevancyDesc&view=list${sortParam}&order=${sortOrder}${pageParam}`;
+  url += `?sort=${sortValue}&view=list&order=${sortOrder}${priceMinParam}${priceMaxParam}${pageParam}`;
 
   return url;
 }
 
+function findApolloListingKey(
+  apolloState: ApolloRecord,
+  predicate: (value: Record<string, unknown>) => boolean,
+): string | undefined {
+  return Object.keys(apolloState).find((key) => {
+    if (!key.startsWith("Listing:")) return false;
+
+    const value = apolloState[key];
+    return isRecord(value) && predicate(value);
+  });
+}
+
 /**
  * Slugifies a string for Kijiji search URLs
  */
@@ -391,18 +462,16 @@ async function fetchSellerDetails(
   accountType?: string;
 }> {
   try {
-    const [reviewData, profileData] = await Promise.all([
+    const reviewData = await fetchGraphQLData(
-      fetchGraphQLData(
       GRAPHQL_QUERIES.getReviewSummary,
       { userId: posterId },
       BASE_URL,
-      ),
+    );
-      fetchGraphQLData(
+    const profileData = await fetchGraphQLData(
       GRAPHQL_QUERIES.getProfileMetrics,
       { profileId: posterId },
       BASE_URL,
-      ),
+    );
-    ]);
 
     const reviewResponse = reviewData as GraphQLReviewResponse;
     const profileResponse = profileData as GraphQLProfileResponse;
@@ -457,8 +526,7 @@ export function parseSearch(
 
   const results: SearchListing[] = [];
   for (const [key, value] of Object.entries(apolloState)) {
-    // Heuristic: Kijiji listing keys usually contain "Listing"
+    if (!key.startsWith("Listing:")) continue;
-    if (!key.includes("Listing")) continue;
     if (!isRecord(value)) continue;
 
     const item = value as ApolloSearchItem;
@@ -484,9 +552,9 @@ function _parseListing(
   const apolloState = extractApolloState(htmlString);
   if (!apolloState) return null;
 
-  // Find the listing root key
+  const listingKey = findApolloListingKey(
-  const listingKey = Object.keys(apolloState).find((k) =>
+    apolloState,
-    k.includes("Listing"),
+    (value) => typeof value.url === "string" && typeof value.title === "string",
   );
   if (!listingKey) return null;
 
@@ -557,9 +625,12 @@ export async function parseDetailedListing(
   const apolloState = extractApolloState(htmlString);
   if (!apolloState) return null;
 
-  // Find the listing root key
+  const listingKey = findApolloListingKey(
-  const listingKey = Object.keys(apolloState).find((k) =>
+    apolloState,
-    k.includes("Listing"),
+    (value) =>
+      typeof value.url === "string" &&
+      typeof value.title === "string" &&
+      isRecord(value.price),
   );
   if (!listingKey) return null;
 
@@ -696,14 +767,43 @@ export async function parseDetailedListing(
 
 // ----------------------------- Main -----------------------------
 
+export default async function fetchKijijiItems(
+  SEARCH_QUERY: string,
+  REQUESTS_PER_SECOND: number | undefined,
+  BASE_URL: string | undefined,
+  searchOptions: SearchOptions | undefined,
+  listingOptions: ListingFetchOptions | undefined,
+  unstableMode: { hideUnstableResults: true },
+): Promise<UnstableListingBuckets<DetailedListing>>;
+export default async function fetchKijijiItems(
+  SEARCH_QUERY: string,
+  REQUESTS_PER_SECOND?: number,
+  BASE_URL?: string,
+  searchOptions?: SearchOptions,
+  listingOptions?: ListingFetchOptions,
+  unstableMode?: UnstableListingModeOptions,
+): Promise<DetailedListing[]>;
 export default async function fetchKijijiItems(
   SEARCH_QUERY: string,
   REQUESTS_PER_SECOND = 1,
   BASE_URL = "https://www.kijiji.ca",
   searchOptions: SearchOptions = {},
   listingOptions: ListingFetchOptions = {},
+  unstableMode: UnstableListingModeOptions = {},
 ) {
-  const DELAY_MS = Math.max(1, Math.floor(1000 / REQUESTS_PER_SECOND));
+  const requestsPerSecond = REQUESTS_PER_SECOND > 0 ? REQUESTS_PER_SECOND : 1;
+
+  const finalizeResults = (
+    listings: DetailedListing[],
+  ): DetailedListing[] | UnstableListingBuckets<DetailedListing> => {
+    if (!unstableMode.hideUnstableResults) {
+      return listings;
+    }
+
+    return classifyUnstableListings(listings);
+  };
+
+  const DELAY_MS = Math.max(1, Math.floor(1000 / requestsPerSecond));
 
   // Load Kijiji cookies (optional - helps bypass bot detection)
   const cookies = await loadCookiesOptional(
@@ -716,15 +816,18 @@ export default async function fetchKijijiItems(
       : undefined;
 
   // Set defaults for configuration
-  const finalSearchOptions: Required<SearchOptions> = {
+  const finalSearchOptions: Omit<Required<SearchOptions>, "priceMin" | "priceMax"> & {
+    priceMin?: number;
+    priceMax?: number;
+  } = {
     location: searchOptions.location ?? 1700272, // Default to GTA
     category: searchOptions.category ?? 0, // Default to all categories
     keywords: searchOptions.keywords ?? SEARCH_QUERY,
     sortBy: searchOptions.sortBy ?? "relevancy",
     sortOrder: searchOptions.sortOrder ?? "desc",
     maxPages: searchOptions.maxPages ?? 5, // Default to 5 pages
-    priceMin: searchOptions.priceMin as number,
+    priceMin: searchOptions.priceMin,
-    priceMax: searchOptions.priceMax as number,
+    priceMax: searchOptions.priceMax,
     cookies: searchOptions.cookies ?? "",
   };
 
@@ -792,15 +895,19 @@ export default async function fetchKijijiItems(
     progressBar?.start(totalProgress, currentProgress);
 
     // Process in batches for controlled concurrency
-    const CONCURRENT_REQUESTS = REQUESTS_PER_SECOND * 2; // 2x rate for faster processing
+    const CONCURRENT_REQUESTS = Math.max(1, Math.floor(requestsPerSecond));
     const results: (DetailedListing | null)[] = [];
 
     for (let i = 0; i < newListingLinks.length; i += CONCURRENT_REQUESTS) {
       const batch = newListingLinks.slice(i, i + CONCURRENT_REQUESTS);
-      const batchPromises = batch.map(async (link) => {
+      const batchPromises = batch.map(async (link, batchIndex) => {
         try {
+          if (batchIndex > 0) {
+            await new Promise((resolve) => setTimeout(resolve, DELAY_MS * batchIndex));
+          }
+
           const html = await fetchHtml(link, 0, {
-            // No per-request delay, batch handles rate limit
+            // Staggered starts keep request pacing within REQUESTS_PER_SECOND.
             onRateInfo: (remaining, reset) => {
               if (remaining && reset) {
                 console.log(
@@ -839,12 +946,10 @@ export default async function fetchKijijiItems(
       const batchResults = await Promise.all(batchPromises);
       results.push(...batchResults);
 
-      // Wait between batches to respect rate limit
       if (i + CONCURRENT_REQUESTS < newListingLinks.length) {
-        await new Promise((resolve) =>
+        await new Promise((resolve) => setTimeout(resolve, DELAY_MS));
-          setTimeout(resolve, DELAY_MS * batch.length),
-        );
       }
+
     }
 
     allListings.push(
@@ -859,8 +964,14 @@ export default async function fetchKijijiItems(
     }
   }
 
-  console.log(`\nParsed ${allListings.length} detailed listings.`);
+  const filteredListings = allListings.filter((listing) =>
-  return allListings;
+    matchesPriceFilters(listing, finalSearchOptions),
+  );
+
+  console.log(
+    `\nParsed ${filteredListings.length} detailed listings.`,
+  );
+  return finalizeResults(filteredListings);
 }
 
 // Re-export error classes for convenience

packages/core/src/types/common.ts

@@ -18,3 +18,12 @@ export interface ListingDetails {
   address?: string | null;
   creationDate?: string;
 }
+
+export interface UnstableListingBuckets<T> {
+  results: T[];
+  unstableResults: T[];
+}
+
+export interface UnstableListingModeOptions {
+  hideUnstableResults?: boolean;
+}

packages/core/src/utils/unstable.ts

@@ -0,0 +1,46 @@
+import type { ListingDetails, UnstableListingBuckets } from "../types/common";
+
+function getMedian(values: number[]): number {
+  const middleIndex = Math.floor(values.length / 2);
+
+  if (values.length % 2 === 0) {
+    return (values[middleIndex - 1] + values[middleIndex]) / 2;
+  }
+
+  return values[middleIndex];
+}
+
+export function classifyUnstableListings<T extends ListingDetails>(
+  listings: T[],
+): UnstableListingBuckets<T> {
+  const validPrices = listings
+    .map((listing) => listing.listingPrice.cents)
+    .filter((price) => Number.isFinite(price) && price > 0)
+    .sort((left, right) => left - right);
+
+  if (validPrices.length < 2) {
+    return {
+      results: [...listings],
+      unstableResults: [],
+    };
+  }
+
+  const threshold = getMedian(validPrices) * 0.8;
+  const buckets: UnstableListingBuckets<T> = {
+    results: [],
+    unstableResults: [],
+  };
+
+  for (const listing of listings) {
+    const price = listing.listingPrice.cents;
+
+    if (Number.isFinite(price) && price > 0 && price < threshold) {
+      buckets.unstableResults.push(listing);
+      continue;
+    }
+
+    buckets.results.push(listing);
+  }
+
+  return buckets;
+}

packages/core/test/ebay-core.test.ts

@@ -1,5 +1,28 @@
 import { afterEach, beforeEach, describe, expect, mock, test } from "bun:test";
+import type { EbayListingDetails } from "../src/scrapers/ebay";
 import fetchEbayItems from "../src/scrapers/ebay";
+import type { UnstableListingBuckets } from "../src/types/common";
+
+type Assert<T extends true> = T;
+type IsExact<T, U> =
+  (<G>() => G extends T ? 1 : 2) extends <G>() => G extends U ? 1 : 2
+    ? (<G>() => G extends U ? 1 : 2) extends <G>() => G extends T ? 1 : 2
+      ? true
+      : false
+    : false;
+
+const getDefaultEbayItems = async () => fetchEbayItems("laptop");
+const getUnstableEbayItems = async () =>
+  fetchEbayItems("laptop", 1000, {}, { hideUnstableResults: true });
+type _EbayDefaultReturn = Assert<
+  IsExact<Awaited<ReturnType<typeof getDefaultEbayItems>>, EbayListingDetails[]>
+>;
+type _EbayUnstableReturn = Assert<
+  IsExact<
+    Awaited<ReturnType<typeof getUnstableEbayItems>>,
+    UnstableListingBuckets<EbayListingDetails>
+  >
+>;
 
 const originalFetch = global.fetch;
 const originalWarn = console.warn;
@@ -24,9 +47,7 @@ describe("eBay Scraper Cookie Handling", () => {
     const warnMock = mock(() => {});
     console.warn = warnMock;
 
-    await fetchEbayItems("laptop", 1000, {
+    await fetchEbayItems("laptop", 1000);
-      cookies: "s=from-request",
-    });
 
     expect(global.fetch).toHaveBeenCalledTimes(1);
 
@@ -38,4 +59,579 @@ describe("eBay Scraper Cookie Handling", () => {
       "No valid eBay cookies found in EBAY_COOKIE. eBay may block requests without a raw Cookie header string.",
     );
   });
+
+  test("keeps relative item links on the ebay.ca host", async () => {
+    global.fetch = mock(() =>
+      Promise.resolve({
+        ok: true,
+        text: () =>
+          Promise.resolve(`
+            <html><body>
+              <li class="s-item">
+                <a href="/itm/123"></a>
+                <h3>Stable Laptop Bundle</h3>
+                <span class="s-item__price">CA $100.00</span>
+              </li>
+            </body></html>
+          `),
+      }),
+    ) as typeof fetch;
+
+    const results = await fetchEbayItems("laptop", 1000);
+
+    expect(results).toEqual([
+      expect.objectContaining({ url: "https://www.ebay.ca/itm/123" }),
+    ]);
+  });
+
+  test("deduplicates repeated item links from the same card", async () => {
+    global.fetch = mock(() =>
+      Promise.resolve({
+        ok: true,
+        text: () =>
+          Promise.resolve(`
+            <html><body>
+              <li class="s-item">
+                <a href="/itm/123"><span>Open</span></a>
+                <a href="/itm/123"><span>Image</span></a>
+                <h3>Stable Laptop Bundle</h3>
+                <span class="s-item__price">CA $100.00</span>
+              </li>
+            </body></html>
+          `),
+      }),
+    ) as typeof fetch;
+
+    const results = await fetchEbayItems("laptop", 1000);
+
+    expect(results).toHaveLength(1);
+    expect(results[0]).toEqual(
+      expect.objectContaining({ url: "https://www.ebay.ca/itm/123" }),
+    );
+  });
+
+  test("deduplicates tracking variants of the same item URL", async () => {
+    global.fetch = mock(() =>
+      Promise.resolve({
+        ok: true,
+        text: () =>
+          Promise.resolve(`
+            <html><body>
+              <li class="s-item">
+                <a href="/itm/123?_trkparms=foo"></a>
+                <h3>Stable Laptop Bundle</h3>
+                <span class="s-item__price">CA $100.00</span>
+              </li>
+              <li class="s-item">
+                <a href="https://www.ebay.ca/itm/123?hash=item123"></a>
+                <h3>Stable Laptop Bundle</h3>
+                <span class="s-item__price">CA $100.00</span>
+              </li>
+            </body></html>
+          `),
+      }),
+    ) as typeof fetch;
+
+    const results = await fetchEbayItems("laptop", 1000);
+
+    expect(results).toHaveLength(1);
+    expect(results[0]).toEqual(
+      expect.objectContaining({ url: "https://www.ebay.ca/itm/123?_trkparms=foo" }),
+    );
+  });
+
+  test("deduplicates tracking variants of SEO-style item URLs", async () => {
+    global.fetch = mock(() =>
+      Promise.resolve({
+        ok: true,
+        text: () =>
+          Promise.resolve(`
+            <html><body>
+              <li class="s-item">
+                <a href="/itm/title-slug/1234567890?_trkparms=foo"></a>
+                <h3>Stable Laptop Bundle</h3>
+                <span class="s-item__price">CA $100.00</span>
+              </li>
+              <li class="s-item">
+                <a href="https://www.ebay.ca/itm/title-slug/1234567890?hash=item123"></a>
+                <h3>Stable Laptop Bundle</h3>
+                <span class="s-item__price">CA $100.00</span>
+              </li>
+              <li class="s-item">
+                <a href="https://www.ebay.ca/itm/title-slug/9999999999?hash=item999"></a>
+                <h3>Another Laptop Bundle</h3>
+                <span class="s-item__price">CA $110.00</span>
+              </li>
+            </body></html>
+          `),
+      }),
+    ) as typeof fetch;
+
+    const results = await fetchEbayItems("laptop", 1000);
+
+    expect(results).toHaveLength(2);
+    expect(results[0]).toEqual(
+      expect.objectContaining({
+        url: "https://www.ebay.ca/itm/title-slug/1234567890?_trkparms=foo",
+      }),
+    );
+    expect(results[1]).toEqual(
+      expect.objectContaining({
+        url: "https://www.ebay.ca/itm/title-slug/9999999999?hash=item999",
+      }),
+    );
+  });
+
+  test("treats bare dollar prices as CAD on ebay.ca", async () => {
+    global.fetch = mock(() =>
+      Promise.resolve({
+        ok: true,
+        text: () =>
+          Promise.resolve(`
+            <html><body>
+              <li class="s-item">
+                <a href="/itm/123"></a>
+                <h3>Stable Laptop Bundle</h3>
+                <span class="s-item__price">$100.00</span>
+              </li>
+            </body></html>
+          `),
+      }),
+    ) as typeof fetch;
+
+    const results = await fetchEbayItems("laptop", 1000);
+
+    expect(results).toEqual([
+      expect.objectContaining({
+        listingPrice: expect.objectContaining({ currency: "CAD" }),
+      }),
+    ]);
+  });
+
+  test("treats US dollar prices as USD", async () => {
+    global.fetch = mock(() =>
+      Promise.resolve({
+        ok: true,
+        text: () =>
+          Promise.resolve(`
+            <html><body>
+              <li class="s-item">
+                <a href="/itm/123"></a>
+                <h3>Stable Laptop Bundle</h3>
+                <span class="s-item__price">US $123.45</span>
+              </li>
+            </body></html>
+          `),
+      }),
+    ) as typeof fetch;
+
+    const results = await fetchEbayItems("laptop", 1000);
+
+    expect(results).toEqual([
+      expect.objectContaining({
+        listingPrice: expect.objectContaining({ currency: "USD", cents: 12345 }),
+      }),
+    ]);
+  });
+
+  test("treats US dollar prices without space as USD", async () => {
+    global.fetch = mock(() =>
+      Promise.resolve({
+        ok: true,
+        text: () =>
+          Promise.resolve(`
+            <html><body>
+              <li class="s-item">
+                <a href="/itm/123"></a>
+                <h3>Stable Laptop Bundle</h3>
+                <span class="s-item__price">US$123.45</span>
+              </li>
+            </body></html>
+          `),
+      }),
+    ) as typeof fetch;
+
+    const results = await fetchEbayItems("laptop", 1000);
+
+    expect(results).toEqual([
+      expect.objectContaining({
+        listingPrice: expect.objectContaining({ currency: "USD", cents: 12345 }),
+      }),
+    ]);
+  });
+
+  test("maps pound prices to GBP", async () => {
+    global.fetch = mock(() =>
+      Promise.resolve({
+        ok: true,
+        text: () =>
+          Promise.resolve(`
+            <html><body>
+              <li class="s-item">
+                <a href="/itm/123"></a>
+                <h3>Stable Laptop Bundle</h3>
+                <span class="s-item__price">£123.45</span>
+              </li>
+            </body></html>
+          `),
+      }),
+    ) as typeof fetch;
+
+    const results = await fetchEbayItems("laptop", 1000);
+
+    expect(results).toEqual([
+      expect.objectContaining({
+        listingPrice: expect.objectContaining({ currency: "GBP", cents: 12345 }),
+      }),
+    ]);
+  });
+
+  test("maps euro and yen prices to the matching currency labels", async () => {
+    global.fetch = mock(() =>
+      Promise.resolve({
+        ok: true,
+        text: () =>
+          Promise.resolve(`
+            <html><body>
+              <li class="s-item">
+                <a href="/itm/123"></a>
+                <h3>Euro Bundle</h3>
+                <span class="s-item__price">€123.45</span>
+              </li>
+              <li class="s-item">
+                <a href="/itm/456"></a>
+                <h3>Yen Bundle</h3>
+                <span class="s-item__price">¥123</span>
+              </li>
+            </body></html>
+          `),
+      }),
+    ) as typeof fetch;
+
+    const results = await fetchEbayItems("bundle", 1000, {
+      keywords: ["bundle"],
+    });
+
+    expect(results).toEqual([
+      expect.objectContaining({
+        listingPrice: expect.objectContaining({ currency: "EUR", cents: 12345 }),
+      }),
+      expect.objectContaining({
+        listingPrice: expect.objectContaining({ currency: "JPY", cents: 12300 }),
+      }),
+    ]);
+  });
+
+  test("prefers the discounted Canadian-formatted price", async () => {
+    global.fetch = mock(() =>
+      Promise.resolve({
+        ok: true,
+        text: () =>
+          Promise.resolve(`
+            <html><body>
+              <li class="s-item">
+                <a href="/itm/123"></a>
+                <h3>Stable Laptop Bundle</h3>
+                <span class="s-item__price">
+                  <s>CA $150.00</s>
+                  <span>CA $100.00</span>
+                </span>
+              </li>
+            </body></html>
+          `),
+      }),
+    ) as typeof fetch;
+
+    const results = await fetchEbayItems("laptop", 1000);
+
+    expect(results).toEqual([
+      expect.objectContaining({
+        listingPrice: expect.objectContaining({
+          amountFormatted: "CA $100.00",
+          cents: 10000,
+        }),
+      }),
+    ]);
+  });
+
+  test("prefers discounted Canadian prices that contain four consecutive digits", async () => {
+    global.fetch = mock(() =>
+      Promise.resolve({
+        ok: true,
+        text: () =>
+          Promise.resolve(`
+            <html><body>
+              <li class="s-item">
+                <a href="/itm/123"></a>
+                <h3>Stable Laptop Bundle</h3>
+                <span class="s-item__price">
+                  <s>CA $1500.00</s>
+                  <span>CA $1000.00</span>
+                </span>
+              </li>
+            </body></html>
+          `),
+      }),
+    ) as typeof fetch;
+
+    const results = await fetchEbayItems("laptop", 1000);
+
+    expect(results).toEqual([
+      expect.objectContaining({
+        listingPrice: expect.objectContaining({
+          amountFormatted: "CA $1000.00",
+          cents: 100000,
+        }),
+      }),
+    ]);
+  });
+
+  test("prefers discounted US dollar prices over original prices", async () => {
+    global.fetch = mock(() =>
+      Promise.resolve({
+        ok: true,
+        text: () =>
+          Promise.resolve(`
+            <html><body>
+              <li class="s-item">
+                <a href="/itm/123"></a>
+                <h3>Stable Laptop Bundle</h3>
+                <span class="s-item__price">
+                  <s>US $150.00</s>
+                  <span>US $100.00</span>
+                </span>
+              </li>
+            </body></html>
+          `),
+      }),
+    ) as typeof fetch;
+
+    const results = await fetchEbayItems("laptop", 1000);
+
+    expect(results).toEqual([
+      expect.objectContaining({
+        listingPrice: expect.objectContaining({
+          amountFormatted: "US $100.00",
+          cents: 10000,
+          currency: "USD",
+        }),
+      }),
+    ]);
+  });
+
+  test("keeps short titles that were not shortened by UI cleaning", async () => {
+    global.fetch = mock(() =>
+      Promise.resolve({
+        ok: true,
+        text: () =>
+          Promise.resolve(`
+            <html><body>
+              <li class="s-item">
+                <a href="/itm/123"></a>
+                <h3>Free Bike</h3>
+                <span class="s-item__price">CA $0.00</span>
+              </li>
+            </body></html>
+          `),
+      }),
+    ) as typeof fetch;
+
+    const results = await fetchEbayItems("bike", 1000);
+
+    expect(results).toEqual([
+      expect.objectContaining({
+        title: "Free Bike",
+        listingPrice: expect.objectContaining({ cents: 0, currency: "CAD" }),
+      }),
+    ]);
+  });
+
+  test("accepts higher fallback prices without price classes", async () => {
+    global.fetch = mock(() =>
+      Promise.resolve({
+        ok: true,
+        text: () =>
+          Promise.resolve(`
+            <html><body>
+              <li class="s-item">
+                <a href="/itm/123"></a>
+                <h3>Studio Microphone Bundle</h3>
+                <div>CA $2500.00</div>
+              </li>
+            </body></html>
+          `),
+      }),
+    ) as typeof fetch;
+
+    const results = await fetchEbayItems("microphone", 1000, {
+      keywords: ["microphone"],
+    });
+
+    expect(results).toEqual([
+      expect.objectContaining({
+        title: "Studio Microphone Bundle",
+        listingPrice: expect.objectContaining({
+          amountFormatted: "CA $2500.00",
+          cents: 250000,
+        }),
+      }),
+    ]);
+  });
+
+  test("retains free items when the requested price range includes zero", async () => {
+    global.fetch = mock(() =>
+      Promise.resolve({
+        ok: true,
+        text: () =>
+          Promise.resolve(`
+            <html><body>
+              <li class="s-item">
+                <a href="/itm/123"></a>
+                <h3>Free Laptop Bundle</h3>
+                <span class="s-item__price">$0.00</span>
+              </li>
+            </body></html>
+          `),
+      }),
+    ) as typeof fetch;
+
+    const results = await fetchEbayItems("laptop", 1000, {
+      minPrice: 0,
+      maxPrice: 0,
+    });
+
+    expect(results).toEqual([
+      expect.objectContaining({
+        title: "Free Laptop Bundle",
+        listingPrice: expect.objectContaining({ cents: 0 }),
+      }),
+    ]);
+  });
+
+  test("returns results and unstableResults when unstable mode is enabled", async () => {
+    global.fetch = mock(() =>
+      Promise.resolve({
+        ok: true,
+        text: () =>
+          Promise.resolve(`
+            <html><body>
+              <li class="s-item">
+                <a href="https://www.ebay.ca/itm/1"></a>
+                <h3>Stable Laptop Bundle</h3>
+                <span class="s-item__price">CA $100.00</span>
+              </li>
+              <li class="s-item">
+                <a href="https://www.ebay.ca/itm/2"></a>
+                <h3>Another Laptop Bundle</h3>
+                <span class="s-item__price">CA $110.00</span>
+              </li>
+              <li class="s-item">
+                <a href="https://www.ebay.ca/itm/3"></a>
+                <h3>Cheap Laptop Bundle</h3>
+                <span class="s-item__price">CA $70.00</span>
+              </li>
+            </body></html>
+          `),
+      }),
+    ) as typeof fetch;
+
+    const results = await fetchEbayItems(
+      "laptop",
+      1000,
+      {},
+      { hideUnstableResults: true },
+    );
+
+    expect(results).toEqual({
+      results: [
+        expect.objectContaining({ title: "Stable Laptop Bundle" }),
+        expect.objectContaining({ title: "Another Laptop Bundle" }),
+      ],
+      unstableResults: [
+        expect.objectContaining({ title: "Cheap Laptop Bundle" }),
+      ],
+    });
+  });
+
+  test("respects maxItems in default mode", async () => {
+    global.fetch = mock(() =>
+      Promise.resolve({
+        ok: true,
+        text: () =>
+          Promise.resolve(`
+            <html><body>
+              <li class="s-item">
+                <a href="https://www.ebay.ca/itm/1"></a>
+                <h3>First Bundle</h3>
+                <span class="s-item__price">CA $100.00</span>
+              </li>
+              <li class="s-item">
+                <a href="https://www.ebay.ca/itm/2"></a>
+                <h3>Second Bundle</h3>
+                <span class="s-item__price">CA $110.00</span>
+              </li>
+              <li class="s-item">
+                <a href="https://www.ebay.ca/itm/3"></a>
+                <h3>Third Bundle</h3>
+                <span class="s-item__price">CA $70.00</span>
+              </li>
+            </body></html>
+          `),
+      }),
+    ) as typeof fetch;
+
+    const results = await fetchEbayItems("laptop", 1000, { maxItems: 2 });
+
+    expect(results).toHaveLength(2);
+    expect(results[0]).toEqual(
+      expect.objectContaining({ title: "First Bundle" }),
+    );
+    expect(results[1]).toEqual(
+      expect.objectContaining({ title: "Second Bundle" }),
+    );
+  });
+
+  test("respects maxItems in unstable mode", async () => {
+    global.fetch = mock(() =>
+      Promise.resolve({
+        ok: true,
+        text: () =>
+          Promise.resolve(`
+            <html><body>
+              <li class="s-item">
+                <a href="https://www.ebay.ca/itm/1"></a>
+                <h3>First Bundle</h3>
+                <span class="s-item__price">CA $100.00</span>
+              </li>
+              <li class="s-item">
+                <a href="https://www.ebay.ca/itm/2"></a>
+                <h3>Second Bundle</h3>
+                <span class="s-item__price">CA $110.00</span>
+              </li>
+              <li class="s-item">
+                <a href="https://www.ebay.ca/itm/3"></a>
+                <h3>Third Bundle</h3>
+                <span class="s-item__price">CA $70.00</span>
+              </li>
+            </body></html>
+          `),
+      }),
+    ) as typeof fetch;
+
+    const results = await fetchEbayItems(
+      "laptop",
+      1000,
+      { maxItems: 2 },
+      { hideUnstableResults: true },
+    );
+
+    expect(results.results).toHaveLength(2);
+    expect(results.unstableResults).toHaveLength(0);
+    expect(results.results[0]).toEqual(
+      expect.objectContaining({ title: "First Bundle" }),
+    );
+    expect(results.results[1]).toEqual(
+      expect.objectContaining({ title: "Second Bundle" }),
+    );
+  });
 });

packages/core/test/facebook-core.test.ts

@@ -1,18 +1,46 @@
 import { afterEach, beforeEach, describe, expect, mock, test } from "bun:test";
+import cliProgress from "cli-progress";
 import {
   classifyFacebookResponse,
+  type FacebookListingDetails,
   ensureFacebookCookies,
   extractFacebookBootstrapCandidates,
   extractFacebookItemData,
   extractFacebookMarketplaceData,
+  default as fetchFacebookItems,
   fetchFacebookItem,
   parseFacebookAds,
   parseFacebookCookieString,
   parseFacebookItem,
 } from "../src/scrapers/facebook";
+import type { UnstableListingBuckets } from "../src/types/common";
 import { formatCookiesForHeader } from "../src/utils/cookies";
 import { formatCentsToCurrency } from "../src/utils/format";
 
+const originalStdoutIsTTY = process.stdout.isTTY;
+
+type Assert<T extends true> = T;
+type IsExact<T, U> =
+  (<G>() => G extends T ? 1 : 2) extends <G>() => G extends U ? 1 : 2
+    ? (<G>() => G extends U ? 1 : 2) extends <G>() => G extends T ? 1 : 2
+      ? true
+      : false
+    : false;
+
+const getDefaultFacebookItems = async () => fetchFacebookItems("chair");
+const getUnstableFacebookItems = async (): Promise<
+  UnstableListingBuckets<FacebookListingDetails>
+> => fetchFacebookItems("chair", 1, "toronto", 25, { hideUnstableResults: true });
+type _FacebookDefaultReturn = Assert<
+  IsExact<Awaited<ReturnType<typeof getDefaultFacebookItems>>, FacebookListingDetails[]>
+>;
+type _FacebookUnstableReturn = Assert<
+  IsExact<
+    Awaited<ReturnType<typeof getUnstableFacebookItems>>,
+    UnstableListingBuckets<FacebookListingDetails>
+  >
+>;
+
 // Mock fetch globally
 const originalFetch = global.fetch;
 
@@ -25,6 +53,7 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
 
   afterEach(() => {
     global.fetch = originalFetch;
+    process.stdout.isTTY = originalStdoutIsTTY;
   });
 
   describe("Cookie Parsing", () => {
@@ -162,6 +191,7 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
         try {
           const result = await fetchFacebookItem("123");
           expect(result).toBeNull();
+          expect(global.fetch).toHaveBeenCalledTimes(1);
           expect(warnMock).toHaveBeenCalledWith(
             "Authentication error: Invalid or expired cookies. Update FACEBOOK_COOKIE with a fresh raw Cookie header string.",
           );
@@ -247,6 +277,30 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
         // Should eventually succeed after retry
       });
 
+      test("should handle exhausted rate limiting retries as a 429", async () => {
+        let attempts = 0;
+
+        global.fetch = mock(() => {
+          attempts++;
+          return Promise.resolve({
+            ok: false,
+            status: 429,
+            headers: {
+              get: (header: string) => {
+                if (header === "X-RateLimit-Reset") return "0";
+                return null;
+              },
+            },
+            text: () => Promise.resolve("Rate limited"),
+          });
+        });
+
+        const result = await fetchFacebookItem("429-loop");
+
+        expect(result).toBeNull();
+        expect(attempts).toBe(4);
+      });
+
       test("should handle sold items", async () => {
         const mockData = {
           require: [
@@ -294,6 +348,101 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
         expect(result?.listingStatus).toBe("SOLD");
       });
 
+      test("should still parse sold items when structured data exists", async () => {
+        const soldStructuredHtml = `
+          <html><body>
+            <div>This item has been sold</div>
+            <script>"XCometMarketplacePermalinkController"</script>
+            <script>
+              ${JSON.stringify({
+                payload: {
+                  listing: {
+                    id: "457",
+                    __typename: "GroupCommerceProductItem",
+                    marketplace_listing_title: "Structured Sold Item",
+                    formatted_price: { text: "CA$90" },
+                    listing_price: {
+                      amount: "90.00",
+                      currency: "CAD",
+                      amount_with_offset: "90.00",
+                    },
+                    is_sold: true,
+                    is_live: false,
+                  },
+                },
+              })}
+            </script>
+          </body></html>
+        `;
+
+        global.fetch = mock(() =>
+          Promise.resolve({
+            ok: true,
+            text: () => Promise.resolve(soldStructuredHtml),
+            url: "https://www.facebook.com/marketplace/item/457/",
+            headers: {
+              get: () => null,
+            },
+          }),
+        );
+
+        const result = await fetchFacebookItem("457");
+
+        expect(result).toEqual(
+          expect.objectContaining({
+            title: "Structured Sold Item",
+            listingStatus: "SOLD",
+          }),
+        );
+      });
+
+      test("should parse structured data even when an unavailable banner is present", async () => {
+        const unavailableStructuredHtml = `
+          <html><body>
+            <div>This listing is no longer available.</div>
+            <script>"XCometMarketplacePermalinkController"</script>
+            <script>
+              ${JSON.stringify({
+                payload: {
+                  listing: {
+                    id: "458",
+                    __typename: "GroupCommerceProductItem",
+                    marketplace_listing_title: "Recovered Item",
+                    formatted_price: { text: "CA$120" },
+                    listing_price: {
+                      amount: "120.00",
+                      currency: "CAD",
+                      amount_with_offset: "120.00",
+                    },
+                    is_live: true,
+                  },
+                },
+              })}
+            </script>
+          </body></html>
+        `;
+
+        global.fetch = mock(() =>
+          Promise.resolve({
+            ok: true,
+            text: () => Promise.resolve(unavailableStructuredHtml),
+            url: "https://www.facebook.com/marketplace/item/458/",
+            headers: {
+              get: () => null,
+            },
+          }),
+        );
+
+        const result = await fetchFacebookItem("458");
+
+        expect(result).toEqual(
+          expect.objectContaining({
+            title: "Recovered Item",
+            listingStatus: "ACTIVE",
+          }),
+        );
+      });
+
       test("should handle successful item extraction", async () => {
         const mockData = {
           require: [
@@ -367,6 +516,338 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
     });
   });
 
+  describe("fetchFacebookItems", () => {
+    let previousCookie: string | undefined;
+
+    beforeEach(() => {
+      previousCookie = process.env.FACEBOOK_COOKIE;
+      process.env.FACEBOOK_COOKIE = "c_user=12345; xs=abc123";
+    });
+
+    afterEach(() => {
+      if (previousCookie === undefined) {
+        delete process.env.FACEBOOK_COOKIE;
+      } else {
+        process.env.FACEBOOK_COOKIE = previousCookie;
+      }
+    });
+
+    test("returns an array by default", async () => {
+      const mockSearchHtml = `<html><body><script>"XCometMarketplaceSearchController"</script><script>${JSON.stringify({
+        payload: {
+          resultGroups: [
+            {
+              edges: [
+                {
+                  node: {
+                    listing: {
+                      id: "1",
+                      marketplace_listing_title: "Stable Chair Listing",
+                      listing_price: {
+                        amount: "120.00",
+                        formatted_amount: "CA$120",
+                        currency: "CAD",
+                      },
+                      is_live: true,
+                    },
+                  },
+                },
+              ],
+            },
+          ],
+        },
+      })}</script></body></html>`;
+
+      global.fetch = mock(() =>
+        Promise.resolve({
+          ok: true,
+          text: () => Promise.resolve(mockSearchHtml),
+          url: "https://www.facebook.com/marketplace/toronto/search?query=chair",
+          headers: {
+            get: () => null,
+          },
+        }),
+      );
+
+      const results = await fetchFacebookItems("chair", 1, "toronto", 25);
+
+      expect(Array.isArray(results)).toBe(true);
+      expect(results).toHaveLength(1);
+    });
+
+    test("preserves free listings through the public fetch entrypoint", async () => {
+      const mockSearchHtml = `<html><body><script>"XCometMarketplaceSearchController"</script><script>${JSON.stringify({
+        payload: {
+          resultGroups: [
+            {
+              edges: [
+                {
+                  node: {
+                    listing: {
+                      id: "free-1",
+                      marketplace_listing_title: "Free Chair",
+                      listing_price: {
+                        amount: "0.00",
+                        formatted_amount: "FREE",
+                        currency: "CAD",
+                      },
+                      is_live: true,
+                    },
+                  },
+                },
+              ],
+            },
+          ],
+        },
+      })}</script></body></html>`;
+
+      global.fetch = mock(() =>
+        Promise.resolve({
+          ok: true,
+          text: () => Promise.resolve(mockSearchHtml),
+          url: "https://www.facebook.com/marketplace/toronto/search?query=chair",
+          headers: {
+            get: () => null,
+          },
+        }),
+      );
+
+      const results = await fetchFacebookItems("chair", 1, "toronto", 25);
+
+      expect(results).toEqual([
+        expect.objectContaining({
+          title: "Free Chair",
+          listingPrice: expect.objectContaining({
+            cents: 0,
+            amountFormatted: "FREE",
+          }),
+        }),
+      ]);
+    });
+
+    test("does not start a progress bar when stdout is not a TTY", async () => {
+      const mockSearchHtml = `<html><body><script>"XCometMarketplaceSearchController"</script><script>${JSON.stringify({
+        payload: {
+          resultGroups: [
+            {
+              edges: [
+                {
+                  node: {
+                    listing: {
+                      id: "1",
+                      marketplace_listing_title: "Chair Listing",
+                      listing_price: {
+                        amount: "120.00",
+                        formatted_amount: "CA$120",
+                        currency: "CAD",
+                      },
+                      is_live: true,
+                    },
+                  },
+                },
+              ],
+            },
+          ],
+        },
+      })}</script></body></html>`;
+
+      process.stdout.isTTY = false;
+      const startSpy = mock(() => {});
+      const updateSpy = mock(() => {});
+      const stopSpy = mock(() => {});
+      const originalStart = cliProgress.SingleBar.prototype.start;
+      const originalUpdate = cliProgress.SingleBar.prototype.update;
+      const originalStop = cliProgress.SingleBar.prototype.stop;
+      try {
+        cliProgress.SingleBar.prototype.start = startSpy;
+        cliProgress.SingleBar.prototype.update = updateSpy;
+        cliProgress.SingleBar.prototype.stop = stopSpy;
+
+        global.fetch = mock(() =>
+          Promise.resolve({
+            ok: true,
+            text: () => Promise.resolve(mockSearchHtml),
+            url: "https://www.facebook.com/marketplace/toronto/search?query=chair",
+            headers: {
+              get: () => null,
+            },
+          }),
+        );
+
+        const results = await fetchFacebookItems("chair", 1, "toronto", 25);
+
+        expect(results).toHaveLength(1);
+        expect(startSpy).not.toHaveBeenCalled();
+        expect(updateSpy).not.toHaveBeenCalled();
+        expect(stopSpy).not.toHaveBeenCalled();
+      } finally {
+        cliProgress.SingleBar.prototype.start = originalStart;
+        cliProgress.SingleBar.prototype.update = originalUpdate;
+        cliProgress.SingleBar.prototype.stop = originalStop;
+      }
+    });
+
+    test("returns results and unstableResults when unstable mode is enabled", async () => {
+      const mockSearchHtml = `<html><body><script>"XCometMarketplaceSearchController"</script><script>${JSON.stringify({
+        payload: {
+          resultGroups: [
+            {
+              edges: [
+                {
+                  node: {
+                    listing: {
+                      id: "1",
+                      marketplace_listing_title: "Stable Chair Listing",
+                      listing_price: {
+                        amount: "100.00",
+                        formatted_amount: "CA$100",
+                        currency: "CAD",
+                      },
+                      is_live: true,
+                    },
+                  },
+                },
+                {
+                  node: {
+                    listing: {
+                      id: "2",
+                      marketplace_listing_title: "Another Stable Chair",
+                      listing_price: {
+                        amount: "110.00",
+                        formatted_amount: "CA$110",
+                        currency: "CAD",
+                      },
+                      is_live: true,
+                    },
+                  },
+                },
+                {
+                  node: {
+                    listing: {
+                      id: "3",
+                      marketplace_listing_title: "Suspiciously Cheap Chair",
+                      listing_price: {
+                        amount: "70.00",
+                        formatted_amount: "CA$70",
+                        currency: "CAD",
+                      },
+                      is_live: true,
+                    },
+                  },
+                },
+              ],
+            },
+          ],
+        },
+      })}</script></body></html>`;
+
+      global.fetch = mock(() =>
+        Promise.resolve({
+          ok: true,
+          text: () => Promise.resolve(mockSearchHtml),
+          url: "https://www.facebook.com/marketplace/toronto/search?query=chair",
+          headers: {
+            get: () => null,
+          },
+        }),
+      );
+
+      const results = await fetchFacebookItems("chair", 1, "toronto", 25, {
+        hideUnstableResults: true,
+      });
+
+      expect(results).toEqual({
+        results: [
+          expect.objectContaining({ title: "Stable Chair Listing" }),
+          expect.objectContaining({ title: "Another Stable Chair" }),
+        ],
+        unstableResults: [
+          expect.objectContaining({ title: "Suspiciously Cheap Chair" }),
+        ],
+      });
+    });
+
+    test("unstable mode classifies before the final MAX_ITEMS limit", async () => {
+      const mockSearchHtml = `<html><body><script>"XCometMarketplaceSearchController"</script><script>${JSON.stringify({
+        payload: {
+          resultGroups: [
+            {
+              edges: [
+                {
+                  node: {
+                    listing: {
+                      id: "1",
+                      marketplace_listing_title: "Boundary Stable Chair",
+                      listing_price: {
+                        amount: "100.00",
+                        formatted_amount: "CA$100",
+                        currency: "CAD",
+                      },
+                      is_live: true,
+                    },
+                  },
+                },
+                {
+                  node: {
+                    listing: {
+                      id: "2",
+                      marketplace_listing_title: "Second Boundary Stable Chair",
+                      listing_price: {
+                        amount: "110.00",
+                        formatted_amount: "CA$110",
+                        currency: "CAD",
+                      },
+                      is_live: true,
+                    },
+                  },
+                },
+                {
+                  node: {
+                    listing: {
+                      id: "3",
+                      marketplace_listing_title: "Past Boundary Cheap Chair",
+                      listing_price: {
+                        amount: "70.00",
+                        formatted_amount: "CA$70",
+                        currency: "CAD",
+                      },
+                      is_live: true,
+                    },
+                  },
+                },
+              ],
+            },
+          ],
+        },
+      })}</script></body></html>`;
+
+      global.fetch = mock(() =>
+        Promise.resolve({
+          ok: true,
+          text: () => Promise.resolve(mockSearchHtml),
+          url: "https://www.facebook.com/marketplace/toronto/search?query=chair",
+          headers: {
+            get: () => null,
+          },
+        }),
+      );
+
+      const results = await fetchFacebookItems("chair", 1, "toronto", 2, {
+        hideUnstableResults: true,
+      });
+
+      expect(results).toEqual({
+        results: [
+          expect.objectContaining({ title: "Boundary Stable Chair" }),
+          expect.objectContaining({ title: "Second Boundary Stable Chair" }),
+        ],
+        unstableResults: [
+          expect.objectContaining({ title: "Past Boundary Cheap Chair" }),
+        ],
+      });
+    });
+  });
+
   describe("Data Extraction", () => {
     describe("extractFacebookItemData", () => {
       test("extracts item details from Comet permalink bootstrap candidates", () => {
@@ -1051,10 +1532,21 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
         };
 
         const result = parseFacebookItem(item);
-        expect(result).not.toBeNull();
+        expect(result).toBeNull();
-        expect(result?.title).toBe("Minimal Item");
+      });
-        expect(result?.description).toBeUndefined();
+
-        expect(result?.seller).toBeUndefined();
+      test("returns null when item price data is present but unparseable", () => {
+        const item = {
+          id: "456b",
+          __typename: "GroupCommerceProductItem" as const,
+          marketplace_listing_title: "Broken Price Item",
+          formatted_price: { text: "price unavailable" },
+          listing_price: { amount: "not-a-number", currency: "CAD" },
+        };
+
+        const result = parseFacebookItem(item);
+
+        expect(result).toBeNull();
       });
 
       test("should identify vehicle listings", () => {
@@ -1198,6 +1690,10 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
       });
 
       test("should handle malformed ads gracefully", () => {
+        const originalWarn = console.warn;
+        const warnMock = mock(() => {});
+        console.warn = warnMock;
+
         const ads = [
           {
             node: {
@@ -1223,6 +1719,120 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
         const results = parseFacebookAds(ads);
         expect(results).toHaveLength(1);
         expect(results[0].title).toBe("Valid Ad");
+        expect(warnMock).toHaveBeenCalledTimes(1);
+
+        console.warn = originalWarn;
+      });
+
+      test("parses formatted fallback prices with multiple commas", () => {
+        const ads = [
+          {
+            node: {
+              listing: {
+                id: "big-price",
+                marketplace_listing_title: "Luxury Home",
+                listing_price: {
+                  amount_with_offset_in_currency: "123456789",
+                  formatted_amount: "$1,234,567.89",
+                  currency: "CAD",
+                },
+                is_live: true,
+              },
+            },
+          },
+        ];
+
+        const results = parseFacebookAds(ads);
+
+        expect(results).toEqual([
+          expect.objectContaining({
+            listingPrice: expect.objectContaining({ cents: 123456789 }),
+          }),
+        ]);
+      });
+
+      test("does not trust amount_with_offset_in_currency without a parseable formatted price", () => {
+        const ads = [
+          {
+            node: {
+              listing: {
+                id: "bad-offset",
+                marketplace_listing_title: "Broken Price Listing",
+                listing_price: {
+                  amount_with_offset_in_currency: "123456789",
+                  formatted_amount: "price unavailable",
+                  currency: "CAD",
+                },
+                is_live: true,
+              },
+            },
+          },
+        ];
+
+        const results = parseFacebookAds(ads);
+
+        expect(results).toEqual([]);
+      });
+
+      test("keeps valid free search listings", () => {
+        const ads = [
+          {
+            node: {
+              listing: {
+                id: "free-item",
+                marketplace_listing_title: "Free Chair",
+                listing_price: {
+                  amount: "0.00",
+                  formatted_amount: "FREE",
+                  currency: "CAD",
+                },
+                is_live: true,
+              },
+            },
+          },
+        ];
+
+        const results = parseFacebookAds(ads);
+
+        expect(results).toEqual([
+          expect.objectContaining({
+            title: "Free Chair",
+            listingPrice: expect.objectContaining({
+              cents: 0,
+              amountFormatted: "FREE",
+            }),
+          }),
+        ]);
+      });
+
+      test("keeps free search listings when amount is missing but formatted_amount is FREE", () => {
+        const ads = [
+          {
+            node: {
+              listing: {
+                id: "free-no-amount",
+                marketplace_listing_title: "Free Sofa",
+                listing_price: {
+                  formatted_amount: "FREE",
+                  currency: "CAD",
+                },
+                is_live: true,
+              },
+            },
+          },
+        ];
+
+        const results = parseFacebookAds(ads);
+
+        expect(results).toEqual([
+          expect.objectContaining({
+            title: "Free Sofa",
+            listingPrice: expect.objectContaining({
+              cents: 0,
+              amountFormatted: "FREE",
+            }),
+          }),
+        ]);
       });
     });
   });

packages/core/test/kijiji-core.test.ts

@@ -1,13 +1,60 @@
-import { describe, expect, test } from "bun:test";
+import { afterEach, beforeEach, describe, expect, mock, test } from "bun:test";
 import {
   buildSearchUrl,
+  default as fetchKijijiItems,
+  type DetailedListing,
   NetworkError,
+  parseSearch,
+  parseDetailedListing,
   ParseError,
   RateLimitError,
   resolveCategoryId,
   resolveLocationId,
   ValidationError,
 } from "../src/scrapers/kijiji";
+import type { UnstableListingBuckets } from "../src/types/common";
+
+type Assert<T extends true> = T;
+type IsExact<T, U> =
+  (<G>() => G extends T ? 1 : 2) extends <G>() => G extends U ? 1 : 2
+    ? (<G>() => G extends U ? 1 : 2) extends <G>() => G extends T ? 1 : 2
+      ? true
+      : false
+    : false;
+
+const getDefaultKijijiItems = async () => fetchKijijiItems("phone");
+const getUnstableKijijiItems = async (): Promise<
+  UnstableListingBuckets<DetailedListing>
+> =>
+  fetchKijijiItems(
+    "phone",
+    1000,
+    "https://www.kijiji.ca",
+    {},
+    {},
+    { hideUnstableResults: true },
+  );
+type _KijijiDefaultReturn = Assert<
+  IsExact<Awaited<ReturnType<typeof getDefaultKijijiItems>>, DetailedListing[]>
+>;
+type _KijijiUnstableReturn = Assert<
+  IsExact<
+    Awaited<ReturnType<typeof getUnstableKijijiItems>>,
+    UnstableListingBuckets<DetailedListing>
+  >
+>;
+
+const originalFetch = global.fetch;
+
+beforeEach(() => {
+  global.fetch = mock(() => {
+    throw new Error("fetch should be mocked in individual tests");
+  });
+});
+
+afterEach(() => {
+  global.fetch = originalFetch;
+});
 
 describe("Location and Category Resolution", () => {
   describe("resolveLocationId", () => {
@@ -21,6 +68,7 @@ describe("Location and Category Resolution", () => {
       expect(resolveLocationId("ontario")).toBe(9004);
       expect(resolveLocationId("toronto")).toBe(1700273);
       expect(resolveLocationId("gta")).toBe(1700272);
+      expect(resolveLocationId("Nova Scotia")).toBe(9002);
     });
 
     test("should handle case insensitive matching", () => {
@@ -77,7 +125,7 @@ describe("URL Construction", () => {
         sortOrder: "desc",
       });
 
-      expect(url).toContain("b-buy-sell/canada/iphone/k0c132l1700272");
+      expect(url).toContain("b-phones/gta/iphone/k0c132l1700272");
       expect(url).toContain("sort=relevancyDesc");
       expect(url).toContain("order=DESC");
     });
@@ -97,6 +145,7 @@ describe("URL Construction", () => {
         sortBy: "date",
         sortOrder: "asc",
       });
+      expect(dateUrl.match(/sort=/g)?.length).toBe(1);
       expect(dateUrl).toContain("sort=DATE");
       expect(dateUrl).toContain("order=ASC");
 
@@ -108,12 +157,23 @@ describe("URL Construction", () => {
       expect(priceUrl).toContain("order=DESC");
     });
 
+    test("includes price filters in the generated search URL", () => {
+      const url = buildSearchUrl("iphone", {
+        priceMin: 8000,
+        priceMax: 10000,
+      });
+
+      expect(url).toContain("priceMin=80");
+      expect(url).toContain("priceMax=100");
+    });
+
     test("should handle string location/category inputs", () => {
       const url = buildSearchUrl("iphone", {
         location: "toronto",
         category: "phones",
       });
 
+      expect(url).toContain("/b-phones/toronto/");
       expect(url).toContain("k0c132l1700273"); // phones + toronto
     });
   });
@@ -155,3 +215,770 @@ describe("Error Classes", () => {
     expect(error.name).toBe("ValidationError");
   });
 });
+
+describe("fetchKijijiItems", () => {
+  test("filters fetched listings by priceMin and priceMax", async () => {
+    const searchHtml = `
+      <html>
+        <script id="__NEXT_DATA__" type="application/json">
+          ${JSON.stringify({
+            props: {
+              pageProps: {
+                __APOLLO_STATE__: {
+                  "Listing:1": {
+                    url: "/v-low/k0l0",
+                    title: "Low Listing",
+                  },
+                  "Listing:2": {
+                    url: "/v-mid/k0l0",
+                    title: "Mid Listing",
+                  },
+                  "Listing:3": {
+                    url: "/v-high/k0l0",
+                    title: "High Listing",
+                  },
+                },
+              },
+            },
+          })}
+        </script>
+      </html>
+    `;
+
+    const listingHtml = (title: string, amount: number, slug: string) => `
+      <html>
+        <script id="__NEXT_DATA__" type="application/json">
+          ${JSON.stringify({
+            props: {
+              pageProps: {
+                __APOLLO_STATE__: {
+                  "Listing:detail": {
+                    url: `/${slug}`,
+                    title,
+                    price: { amount, currency: "CAD", type: "FIXED" },
+                    type: "OFFER",
+                    status: "ACTIVE",
+                  },
+                },
+              },
+            },
+          })}
+        </script>
+      </html>
+    `;
+
+    global.fetch = mock((input: string | URL | Request) => {
+      const url = typeof input === "string" ? input : input.toString();
+
+      if (url.includes("/k0c0l1700272")) {
+        return Promise.resolve({
+          ok: true,
+          text: () => Promise.resolve(searchHtml),
+          headers: { get: () => null },
+          url,
+        });
+      }
+
+      if (url.endsWith("/v-low/k0l0")) {
+        return Promise.resolve({
+          ok: true,
+          text: () => Promise.resolve(listingHtml("Low Listing", 7000, "v-low/k0l0")),
+          headers: { get: () => null },
+          url,
+        });
+      }
+
+      if (url.endsWith("/v-mid/k0l0")) {
+        return Promise.resolve({
+          ok: true,
+          text: () => Promise.resolve(listingHtml("Mid Listing", 9000, "v-mid/k0l0")),
+          headers: { get: () => null },
+          url,
+        });
+      }
+
+      if (url.endsWith("/v-high/k0l0")) {
+        return Promise.resolve({
+          ok: true,
+          text: () => Promise.resolve(listingHtml("High Listing", 12000, "v-high/k0l0")),
+          headers: { get: () => null },
+          url,
+        });
+      }
+
+      throw new Error(`Unexpected URL: ${url}`);
+    }) as typeof fetch;
+
+    const results = await fetchKijijiItems(
+      "phone",
+      1000,
+      "https://www.kijiji.ca",
+      { maxPages: 1, priceMin: 8000, priceMax: 10000 },
+    );
+
+    expect(results).toEqual([
+      expect.objectContaining({ title: "Mid Listing" }),
+    ]);
+  });
+
+  test("respects REQUESTS_PER_SECOND without concurrent detail fetch bursts", async () => {
+    const searchHtml = `
+      <html>
+        <script id="__NEXT_DATA__" type="application/json">
+          ${JSON.stringify({
+            props: {
+              pageProps: {
+                __APOLLO_STATE__: {
+                  "Listing:1": { url: "/v-one/k0l0", title: "One" },
+                  "Listing:2": { url: "/v-two/k0l0", title: "Two" },
+                  "Listing:3": { url: "/v-three/k0l0", title: "Three" },
+                },
+              },
+            },
+          })}
+        </script>
+      </html>
+    `;
+
+    const listingHtml = (title: string, slug: string) => `
+      <html>
+        <script id="__NEXT_DATA__" type="application/json">
+          ${JSON.stringify({
+            props: {
+              pageProps: {
+                __APOLLO_STATE__: {
+                  "Listing:detail": {
+                    url: `/${slug}`,
+                    title,
+                    price: { amount: 10000, currency: "CAD", type: "FIXED" },
+                    type: "OFFER",
+                    status: "ACTIVE",
+                  },
+                },
+              },
+            },
+          })}
+        </script>
+      </html>
+    `;
+
+    let activeDetailRequests = 0;
+    let maxActiveDetailRequests = 0;
+
+    global.fetch = mock(async (input: string | URL | Request) => {
+      const url = typeof input === "string" ? input : input.toString();
+
+      if (url.includes("/k0c0l1700272")) {
+        return {
+          ok: true,
+          text: () => Promise.resolve(searchHtml),
+          headers: { get: () => null },
+          url,
+        };
+      }
+
+      activeDetailRequests++;
+      maxActiveDetailRequests = Math.max(
+        maxActiveDetailRequests,
+        activeDetailRequests,
+      );
+
+      await new Promise((resolve) => setTimeout(resolve, 5));
+
+      activeDetailRequests--;
+
+      if (url.endsWith("/v-one/k0l0")) {
+        return {
+          ok: true,
+          text: () => Promise.resolve(listingHtml("One", "v-one/k0l0")),
+          headers: { get: () => null },
+          url,
+        };
+      }
+
+      if (url.endsWith("/v-two/k0l0")) {
+        return {
+          ok: true,
+          text: () => Promise.resolve(listingHtml("Two", "v-two/k0l0")),
+          headers: { get: () => null },
+          url,
+        };
+      }
+
+      if (url.endsWith("/v-three/k0l0")) {
+        return {
+          ok: true,
+          text: () => Promise.resolve(listingHtml("Three", "v-three/k0l0")),
+          headers: { get: () => null },
+          url,
+        };
+      }
+
+      throw new Error(`Unexpected URL: ${url}`);
+    }) as typeof fetch;
+
+    const results = await fetchKijijiItems(
+      "phone",
+      1,
+      "https://www.kijiji.ca",
+      { maxPages: 1 },
+    );
+
+    expect(results).toHaveLength(3);
+    expect(maxActiveDetailRequests).toBe(1);
+  });
+
+  test("allows bounded concurrency to scale with REQUESTS_PER_SECOND", async () => {
+    const searchHtml = `
+      <html>
+        <script id="__NEXT_DATA__" type="application/json">
+          ${JSON.stringify({
+            props: {
+              pageProps: {
+                __APOLLO_STATE__: {
+                  "Listing:1": { url: "/v-one/k0l0", title: "One" },
+                  "Listing:2": { url: "/v-two/k0l0", title: "Two" },
+                },
+              },
+            },
+          })}
+        </script>
+      </html>
+    `;
+
+    const listingHtml = (title: string, slug: string) => `
+      <html>
+        <script id="__NEXT_DATA__" type="application/json">
+          ${JSON.stringify({
+            props: {
+              pageProps: {
+                __APOLLO_STATE__: {
+                  "Listing:detail": {
+                    url: `/${slug}`,
+                    title,
+                    price: { amount: 10000, currency: "CAD", type: "FIXED" },
+                    type: "OFFER",
+                    status: "ACTIVE",
+                  },
+                },
+              },
+            },
+          })}
+        </script>
+      </html>
+    `;
+
+    let activeDetailRequests = 0;
+    let maxActiveDetailRequests = 0;
+
+    global.fetch = mock(async (input: string | URL | Request) => {
+      const url = typeof input === "string" ? input : input.toString();
+
+      if (url.includes("/k0c0l1700272")) {
+        return {
+          ok: true,
+          text: () => Promise.resolve(searchHtml),
+          headers: { get: () => null },
+          url,
+        };
+      }
+
+      activeDetailRequests++;
+      maxActiveDetailRequests = Math.max(
+        maxActiveDetailRequests,
+        activeDetailRequests,
+      );
+
+      await new Promise((resolve) => setTimeout(resolve, 300));
+
+      activeDetailRequests--;
+
+      if (url.endsWith("/v-one/k0l0")) {
+        return {
+          ok: true,
+          text: () => Promise.resolve(listingHtml("One", "v-one/k0l0")),
+          headers: { get: () => null },
+          url,
+        };
+      }
+
+      if (url.endsWith("/v-two/k0l0")) {
+        return {
+          ok: true,
+          text: () => Promise.resolve(listingHtml("Two", "v-two/k0l0")),
+          headers: { get: () => null },
+          url,
+        };
+      }
+
+      throw new Error(`Unexpected URL: ${url}`);
+    }) as typeof fetch;
+
+    const results = await fetchKijijiItems(
+      "phone",
+      4,
+      "https://www.kijiji.ca",
+      { maxPages: 1 },
+    );
+
+    expect(results).toHaveLength(2);
+    expect(maxActiveDetailRequests).toBeGreaterThan(1);
+    expect(maxActiveDetailRequests).toBeLessThanOrEqual(4);
+  });
+
+  test("classifies the filtered Kijiji result set in unstable mode", async () => {
+    const searchHtml = `
+      <html>
+        <script id="__NEXT_DATA__" type="application/json">
+          ${JSON.stringify({
+            props: {
+              pageProps: {
+                __APOLLO_STATE__: {
+                  "Listing:1": { url: "/v-stable-one/k0l0", title: "Stable Listing One" },
+                  "Listing:2": { url: "/v-stable-two/k0l0", title: "Stable Listing Two" },
+                  "Listing:3": { url: "/v-unstable/k0l0", title: "Unstable Listing" },
+                },
+              },
+            },
+          })}
+        </script>
+      </html>
+    `;
+
+    const listingHtml = (title: string, amount: number, slug: string) => `
+      <html>
+        <script id="__NEXT_DATA__" type="application/json">
+          ${JSON.stringify({
+            props: {
+              pageProps: {
+                __APOLLO_STATE__: {
+                  "Listing:detail": {
+                    url: `/${slug}`,
+                    title,
+                    price: { amount, currency: "CAD", type: "FIXED" },
+                    type: "OFFER",
+                    status: "ACTIVE",
+                  },
+                },
+              },
+            },
+          })}
+        </script>
+      </html>
+    `;
+
+    global.fetch = mock((input: string | URL | Request) => {
+      const url = typeof input === "string" ? input : input.toString();
+
+      if (url.includes("/k0c0l1700272") && url.includes("priceMin=80")) {
+        return Promise.resolve({
+          ok: true,
+          text: () => Promise.resolve(searchHtml),
+          headers: { get: () => null },
+          url,
+        });
+      }
+
+      if (url.endsWith("/v-stable-one/k0l0")) {
+        return Promise.resolve({
+          ok: true,
+          text: () => Promise.resolve(listingHtml("Stable Listing One", 10000, "v-stable-one/k0l0")),
+          headers: { get: () => null },
+          url,
+        });
+      }
+
+      if (url.endsWith("/v-stable-two/k0l0")) {
+        return Promise.resolve({
+          ok: true,
+          text: () => Promise.resolve(listingHtml("Stable Listing Two", 11000, "v-stable-two/k0l0")),
+          headers: { get: () => null },
+          url,
+        });
+      }
+
+      if (url.endsWith("/v-unstable/k0l0")) {
+        return Promise.resolve({
+          ok: true,
+          text: () => Promise.resolve(listingHtml("Unstable Listing", 7000, "v-unstable/k0l0")),
+          headers: { get: () => null },
+          url,
+        });
+      }
+
+      throw new Error(`Unexpected URL: ${url}`);
+    }) as typeof fetch;
+
+    const results = await fetchKijijiItems(
+      "phone",
+      1000,
+      "https://www.kijiji.ca",
+      { maxPages: 1, priceMin: 8000 },
+      {},
+      { hideUnstableResults: true },
+    );
+
+    expect(results).toEqual({
+      results: [
+        expect.objectContaining({ title: "Stable Listing One" }),
+        expect.objectContaining({ title: "Stable Listing Two" }),
+      ],
+      unstableResults: [],
+    });
+  });
+
+  test("keeps out-of-range Kijiji listings out of both buckets and median input", async () => {
+    const searchHtml = `
+      <html>
+        <script id="__NEXT_DATA__" type="application/json">
+          ${JSON.stringify({
+            props: {
+              pageProps: {
+                __APOLLO_STATE__: {
+                  "Listing:1": { url: "/v-stable-one/k0l0", title: "Stable Listing One" },
+                  "Listing:2": { url: "/v-stable-two/k0l0", title: "Stable Listing Two" },
+                  "Listing:3": { url: "/v-out-of-range-high/k0l0", title: "Out Of Range High" },
+                  "Listing:4": { url: "/v-out-of-range-low/k0l0", title: "Out Of Range Low" },
+                },
+              },
+            },
+          })}
+        </script>
+      </html>
+    `;
+
+    const listingHtml = (title: string, amount: number, slug: string) => `
+      <html>
+        <script id="__NEXT_DATA__" type="application/json">
+          ${JSON.stringify({
+            props: {
+              pageProps: {
+                __APOLLO_STATE__: {
+                  "Listing:detail": {
+                    url: `/${slug}`,
+                    title,
+                    price: { amount, currency: "CAD", type: "FIXED" },
+                    type: "OFFER",
+                    status: "ACTIVE",
+                  },
+                },
+              },
+            },
+          })}
+        </script>
+      </html>
+    `;
+
+    global.fetch = mock((input: string | URL | Request) => {
+      const url = typeof input === "string" ? input : input.toString();
+
+      if (url.includes("/k0c0l1700272") && url.includes("priceMin=80") && url.includes("priceMax=150")) {
+        return Promise.resolve({
+          ok: true,
+          text: () => Promise.resolve(searchHtml),
+          headers: { get: () => null },
+          url,
+        });
+      }
+
+      if (url.endsWith("/v-stable-one/k0l0")) {
+        return Promise.resolve({
+          ok: true,
+          text: () => Promise.resolve(listingHtml("Stable Listing One", 10000, "v-stable-one/k0l0")),
+          headers: { get: () => null },
+          url,
+        });
+      }
+
+      if (url.endsWith("/v-stable-two/k0l0")) {
+        return Promise.resolve({
+          ok: true,
+          text: () => Promise.resolve(listingHtml("Stable Listing Two", 11000, "v-stable-two/k0l0")),
+          headers: { get: () => null },
+          url,
+        });
+      }
+
+      if (url.endsWith("/v-out-of-range-high/k0l0")) {
+        return Promise.resolve({
+          ok: true,
+          text: () => Promise.resolve(listingHtml("Out Of Range High", 20000, "v-out-of-range-high/k0l0")),
+          headers: { get: () => null },
+          url,
+        });
+      }
+
+      if (url.endsWith("/v-out-of-range-low/k0l0")) {
+        return Promise.resolve({
+          ok: true,
+          text: () => Promise.resolve(listingHtml("Out Of Range Low", 7000, "v-out-of-range-low/k0l0")),
+          headers: { get: () => null },
+          url,
+        });
+      }
+
+      throw new Error(`Unexpected URL: ${url}`);
+    }) as typeof fetch;
+
+    const results = await fetchKijijiItems(
+      "phone",
+      1000,
+      "https://www.kijiji.ca",
+      { maxPages: 1, priceMin: 8000, priceMax: 15000 },
+      {},
+      { hideUnstableResults: true },
+    );
+
+    expect(results).toEqual({
+      results: [
+        expect.objectContaining({ title: "Stable Listing One" }),
+        expect.objectContaining({ title: "Stable Listing Two" }),
+      ],
+      unstableResults: [],
+    });
+  });
+
+  test("parseDetailedListing ignores non-root listing-like entities", async () => {
+    const html = `
+      <html>
+        <script id="__NEXT_DATA__" type="application/json">
+          ${JSON.stringify({
+            props: {
+              pageProps: {
+                __APOLLO_STATE__: {
+                  "SearchListingCard:1": {
+                    url: "/v-card/k0l0",
+                    title: "Card Listing",
+                  },
+                  "Listing:detail": {
+                    url: "/v-detailed/k0l0",
+                    title: "Detailed Listing",
+                    price: { amount: 10000, currency: "CAD", type: "FIXED" },
+                    type: "OFFER",
+                    status: "ACTIVE",
+                  },
+                },
+              },
+            },
+          })}
+        </script>
+      </html>
+    `;
+
+    const result = await parseDetailedListing(html, "https://www.kijiji.ca");
+
+    expect(result).toEqual(
+      expect.objectContaining({ title: "Detailed Listing" }),
+    );
+  });
+
+  test("fetchSellerDetails does not fire concurrent GraphQL requests", async () => {
+    const html = `
+      <html>
+        <script id="__NEXT_DATA__" type="application/json">
+          ${JSON.stringify({
+            props: {
+              pageProps: {
+                __APOLLO_STATE__: {
+                  "Listing:detail": {
+                    url: "/v-test/k0l0",
+                    title: "Test Listing",
+                    price: { amount: 10000, currency: "CAD", type: "FIXED" },
+                    type: "OFFER",
+                    status: "ACTIVE",
+                    posterInfo: { posterId: "123" },
+                  },
+                },
+              },
+            },
+          })}
+        </script>
+      </html>
+    `;
+
+    let activeAnvilRequests = 0;
+    let maxActiveAnvilRequests = 0;
+
+    global.fetch = mock(async (input: string | URL | Request) => {
+      const url = typeof input === "string" ? input : input.toString();
+
+      if (url.includes("/anvil/api")) {
+        activeAnvilRequests++;
+        maxActiveAnvilRequests = Math.max(
+          maxActiveAnvilRequests,
+          activeAnvilRequests,
+        );
+        await new Promise((resolve) => setTimeout(resolve, 50));
+        activeAnvilRequests--;
+        return {
+          ok: true,
+          json: () => Promise.resolve({ data: { user: {} } }),
+          headers: { get: () => null },
+          url,
+        };
+      }
+
+      throw new Error(`Unexpected URL: ${url}`);
+    }) as typeof fetch;
+
+    await parseDetailedListing(html, "https://www.kijiji.ca", {
+      includeClientSideData: true,
+      sellerDataDepth: "detailed",
+    });
+
+    expect(maxActiveAnvilRequests).toBe(1);
+  });
+
+  test("returns results and unstableResults when unstable mode is enabled", async () => {
+    const searchHtml = `
+      <html>
+        <script id="__NEXT_DATA__" type="application/json">
+          ${JSON.stringify({
+            props: {
+              pageProps: {
+                __APOLLO_STATE__: {
+                  "Listing:1": {
+                    url: "/v-stable-one/k0l0",
+                    title: "Stable Listing One",
+                  },
+                  "Listing:2": {
+                    url: "/v-stable-two/k0l0",
+                    title: "Stable Listing Two",
+                  },
+                  "Listing:3": {
+                    url: "/v-unstable/k0l0",
+                    title: "Unstable Listing",
+                  },
+                },
+              },
+            },
+          })}
+        </script>
+      </html>
+    `;
+
+    const listingHtml = (title: string, amount: number, slug: string) => `
+      <html>
+        <script id="__NEXT_DATA__" type="application/json">
+          ${JSON.stringify({
+            props: {
+              pageProps: {
+                __APOLLO_STATE__: {
+                  "Listing:detail": {
+                    url: `/${slug}`,
+                    title,
+                    price: { amount, currency: "CAD", type: "FIXED" },
+                    type: "OFFER",
+                    status: "ACTIVE",
+                  },
+                },
+              },
+            },
+          })}
+        </script>
+      </html>
+    `;
+
+    global.fetch = mock((input: string | URL | Request) => {
+      const url = typeof input === "string" ? input : input.toString();
+
+      if (url.includes("/k0c0l1700272")) {
+        return Promise.resolve({
+          ok: true,
+          text: () => Promise.resolve(searchHtml),
+          headers: { get: () => null },
+          url,
+        });
+      }
+
+      if (url.endsWith("/v-stable-one/k0l0")) {
+        return Promise.resolve({
+          ok: true,
+          text: () =>
+            Promise.resolve(
+              listingHtml("Stable Listing One", 10000, "v-stable-one/k0l0"),
+            ),
+          headers: { get: () => null },
+          url,
+        });
+      }
+
+      if (url.endsWith("/v-stable-two/k0l0")) {
+        return Promise.resolve({
+          ok: true,
+          text: () =>
+            Promise.resolve(
+              listingHtml("Stable Listing Two", 11000, "v-stable-two/k0l0"),
+            ),
+          headers: { get: () => null },
+          url,
+        });
+      }
+
+      if (url.endsWith("/v-unstable/k0l0")) {
+        return Promise.resolve({
+          ok: true,
+          text: () =>
+            Promise.resolve(
+              listingHtml("Unstable Listing", 7000, "v-unstable/k0l0"),
+            ),
+          headers: { get: () => null },
+          url,
+        });
+      }
+
+      throw new Error(`Unexpected URL: ${url}`);
+    }) as typeof fetch;
+
+    const results = await fetchKijijiItems(
+      "phone",
+      1000,
+      "https://www.kijiji.ca",
+      { maxPages: 1 },
+      {},
+      { hideUnstableResults: true },
+    );
+
+    expect(results).toEqual({
+      results: [
+        expect.objectContaining({ title: "Stable Listing One" }),
+        expect.objectContaining({ title: "Stable Listing Two" }),
+      ],
+      unstableResults: [expect.objectContaining({ title: "Unstable Listing" })],
+    });
+  });
+});
+
+describe("parseSearch", () => {
+  test("ignores SearchListingCard noise keys", () => {
+    const html = `
+      <html>
+        <script id="__NEXT_DATA__" type="application/json">
+          ${JSON.stringify({
+            props: {
+              pageProps: {
+                __APOLLO_STATE__: {
+                  "SearchListingCard:1": {
+                    url: "/v-card-noise/k0l0",
+                    title: "Card Noise",
+                  },
+                  "Listing:1": {
+                    url: "/v-real-result/k0l0",
+                    title: "Real Result",
+                  },
+                },
+              },
+            },
+          })}
+        </script>
+      </html>
+    `;
+
+    expect(parseSearch(html, "https://www.kijiji.ca")).toEqual([
+      {
+        listingLink: "https://www.kijiji.ca/v-real-result/k0l0",
+        name: "Real Result",
+      },
+    ]);
+  });
+});

packages/core/test/unstable-listing-mode.test.ts

@@ -0,0 +1,84 @@
+import { describe, expect, test } from "bun:test";
+import type { ListingDetails } from "../src/types/common";
+import { classifyUnstableListings } from "../src/utils/unstable";
+
+interface TestListing extends ListingDetails {
+  id: string;
+}
+
+function makeListing(id: string, cents: number): TestListing {
+  return {
+    id,
+    url: `https://example.com/${id}`,
+    title: id,
+    listingPrice: {
+      amountFormatted: `$${(cents / 100).toFixed(2)}`,
+      cents,
+      currency: "CAD",
+    },
+    listingType: "test",
+    listingStatus: "active",
+  };
+}
+
+describe("classifyUnstableListings", () => {
+  test("moves listings below 80% of median into unstableResults", () => {
+    const listings = [
+      makeListing("stable-1", 100_00),
+      makeListing("stable-2", 110_00),
+      makeListing("unstable", 70_00),
+    ];
+
+    const buckets = classifyUnstableListings(listings);
+
+    expect(buckets.results.map((listing) => listing.id)).toEqual(["stable-1", "stable-2"]);
+    expect(buckets.unstableResults.map((listing) => listing.id)).toEqual(["unstable"]);
+  });
+
+  test("uses the midpoint median for even-sized priced inputs", () => {
+    const listings = [
+      makeListing("low", 79_00),
+      makeListing("mid-low", 100_00),
+      makeListing("mid-high", 120_00),
+      makeListing("high", 140_00),
+    ];
+
+    const buckets = classifyUnstableListings(listings);
+
+    expect(buckets.results.map((listing) => listing.id)).toEqual(["mid-low", "mid-high", "high"]);
+    expect(buckets.unstableResults.map((listing) => listing.id)).toEqual(["low"]);
+  });
+
+  test("keeps non-positive prices in results and excludes them from the median input", () => {
+    const listings = [
+      makeListing("zero", 0),
+      makeListing("negative", -500),
+      makeListing("stable-1", 100_00),
+      makeListing("stable-2", 120_00),
+      makeListing("unstable", 70_00),
+    ];
+
+    const buckets = classifyUnstableListings(listings);
+
+    expect(buckets.results.map((listing) => listing.id)).toEqual([
+      "zero",
+      "negative",
+      "stable-1",
+      "stable-2",
+    ]);
+    expect(buckets.unstableResults.map((listing) => listing.id)).toEqual(["unstable"]);
+  });
+
+  test("returns all listings in results when fewer than two valid prices are present", () => {
+    const listings = [
+      makeListing("zero", 0),
+      makeListing("negative", -100),
+      makeListing("only-valid", 150_00),
+    ];
+
+    const buckets = classifyUnstableListings(listings);
+
+    expect(buckets.results.map((listing) => listing.id)).toEqual(["zero", "negative", "only-valid"]);
+    expect(buckets.unstableResults).toEqual([]);
+  });
+});

packages/mcp-server/src/protocol/handler.ts

@@ -116,6 +116,8 @@ export async function handleMcpRequest(req: Request): Promise<Response> {
           if (args.priceMax)
             params.append("priceMax", args.priceMax.toString());
           if (args.cookies) params.append("cookies", args.cookies);
+          if (args.unstableFilter !== undefined)
+            params.append("unstableFilter", args.unstableFilter.toString());
 
           console.log(
             `[MCP] Calling Kijiji API: ${API_BASE_URL}/kijiji?${params.toString()}`,
@@ -155,6 +157,8 @@ export async function handleMcpRequest(req: Request): Promise<Response> {
           if (args.location) params.append("location", args.location);
           if (args.maxItems)
             params.append("maxItems", args.maxItems.toString());
+          if (args.unstableFilter !== undefined)
+            params.append("unstableFilter", args.unstableFilter.toString());
 
           console.log(
             `[MCP] Calling Facebook API: ${API_BASE_URL}/facebook?${params.toString()}`,
@@ -207,6 +211,8 @@ export async function handleMcpRequest(req: Request): Promise<Response> {
             params.append("canadaOnly", args.canadaOnly.toString());
           if (args.maxItems)
             params.append("maxItems", args.maxItems.toString());
+          if (args.unstableFilter !== undefined)
+            params.append("unstableFilter", args.unstableFilter.toString());
 
           console.log(
             `[MCP] Calling eBay API: ${API_BASE_URL}/ebay?${params.toString()}`,

packages/mcp-server/src/protocol/tools.ts

@@ -57,6 +57,11 @@ export const tools = [
           description:
             "Optional: Kijiji session cookies to bypass bot detection (JSON array or 'name1=value1; name2=value2')",
         },
+        unstableFilter: {
+          type: "boolean",
+          description:
+            "optional: when enabled, listings priced more than 20% below the median are moved into an `unstableResults` bucket. Changes the response shape from a plain list to an object with `results` and `unstableResults`.",
+        },
       },
       required: ["query"],
     },
@@ -81,6 +86,11 @@ export const tools = [
           description: "Maximum number of items to return",
           default: 5,
         },
+        unstableFilter: {
+          type: "boolean",
+          description:
+            "optional: when enabled, listings priced more than 20% below the median are moved into an `unstableResults` bucket. Changes the response shape from a plain list to an object with `results` and `unstableResults`.",
+        },
       },
       required: ["query"],
     },
@@ -134,6 +144,11 @@ export const tools = [
           description: "Maximum number of items to return",
           default: 5,
         },
+        unstableFilter: {
+          type: "boolean",
+          description:
+            "optional: when enabled, listings priced more than 20% below the median are moved into an `unstableResults` bucket. Changes the response shape from a plain list to an object with `results` and `unstableResults`.",
+        },
       },
       required: ["query"],
     },

packages/mcp-server/test/protocol.test.ts

@@ -54,3 +54,102 @@ describe("MCP protocol cookie inputs", () => {
     expect(String(calledUrl)).not.toContain("cookies=");
   });
 });
+
+describe("MCP protocol unstableFilter", () => {
+  beforeEach(() => {
+    global.fetch = mock(() =>
+      Promise.resolve(new Response(JSON.stringify([]), { status: 200 })),
+    ) as typeof fetch;
+  });
+
+  afterEach(() => {
+    global.fetch = originalFetch;
+  });
+
+  test("all search tools should document the unstableFilter property", () => {
+    const toolNames = ["search_kijiji", "search_facebook", "search_ebay"];
+    for (const toolName of toolNames) {
+      const tool = tools.find((t) => t.name === toolName);
+      expect(tool).toBeDefined();
+      expect(tool?.inputSchema.properties).toHaveProperty("unstableFilter");
+      const prop = tool?.inputSchema.properties.unstableFilter as any;
+      expect(prop.type).toBe("boolean");
+      expect(prop.description).toContain("optional");
+      expect(prop.description).toContain("20%");
+      expect(prop.description).toContain("median");
+      expect(prop.description).toContain("unstableResults");
+    }
+  });
+
+  test("handler should forward unstableFilter=true for search_kijiji", async () => {
+    await handleMcpRequest(
+      new Request("http://localhost", {
+        method: "POST",
+        body: JSON.stringify({
+          jsonrpc: "2.0",
+          id: 1,
+          method: "tools/call",
+          params: {
+            name: "search_kijiji",
+            arguments: {
+              query: "laptop",
+              unstableFilter: true,
+            },
+          },
+        }),
+      }),
+    );
+
+    const calledUrl = (global.fetch as ReturnType<typeof mock>).mock
+      .calls[0]?.[0];
+    expect(String(calledUrl)).toContain("unstableFilter=true");
+  });
+
+  test("handler should forward unstableFilter=true for search_facebook", async () => {
+    await handleMcpRequest(
+      new Request("http://localhost", {
+        method: "POST",
+        body: JSON.stringify({
+          jsonrpc: "2.0",
+          id: 1,
+          method: "tools/call",
+          params: {
+            name: "search_facebook",
+            arguments: {
+              query: "laptop",
+              unstableFilter: true,
+            },
+          },
+        }),
+      }),
+    );
+
+    const calledUrl = (global.fetch as ReturnType<typeof mock>).mock
+      .calls[0]?.[0];
+    expect(String(calledUrl)).toContain("unstableFilter=true");
+  });
+
+  test("handler should forward unstableFilter=true for search_ebay", async () => {
+    await handleMcpRequest(
+      new Request("http://localhost", {
+        method: "POST",
+        body: JSON.stringify({
+          jsonrpc: "2.0",
+          id: 1,
+          method: "tools/call",
+          params: {
+            name: "search_ebay",
+            arguments: {
+              query: "laptop",
+              unstableFilter: true,
+            },
+          },
+        }),
+      }),
+    );
+
+    const calledUrl = (global.fetch as ReturnType<typeof mock>).mock
+      .calls[0]?.[0];
+    expect(String(calledUrl)).toContain("unstableFilter=true");
+  });
+});