Merge branch 'jaime'

- Introduced StalkerResultItem and StalkerResultsResponse types for handling API responses.
- Implemented StalkerExplorer component for displaying Stalker results with search and filter options.
- Added sorting functionality for Stalker results table.
- Enhanced Dashboard to include a button for navigating to Stalker results.
- Updated routing to support Stalker results page.
- Improved styles for section headers and inventory columns in the results table.

package.json

@@ -7,6 +7,7 @@
     "bestsellers": "bun run src/bestsellers-by-category.ts",
     "monthly-sold": "bun run src/top-monthly-sold-by-category.ts",
     "mid-range": "bun run src/mid-range-sellers-by-category.ts",
+    "stalker": "bun run src/stalker.ts",
     "upc": "bun run src/upc-lookup.ts",
     "upc-file": "bun run src/upc-file-analysis.ts",
     "start": "bun run src/index.ts",

src/database.ts

@@ -333,4 +333,162 @@ export function initDb(dbPath: string): void {
   database.run(
     `CREATE INDEX IF NOT EXISTS idx_product_results_fetched_at ON product_analysis_results(fetched_at DESC);`,
   );
+  initStalkerDb(database);
+}
+
+export function initStalkerDb(database: Database): void {
+  resetLegacyStalkerSchema(database);
+
+  database.run(`
+    CREATE TABLE IF NOT EXISTS stalker_runs (
+      id INTEGER PRIMARY KEY AUTOINCREMENT,
+      input_file TEXT NOT NULL,
+      started_at TEXT NOT NULL,
+      completed_at TEXT,
+      requested_asins INTEGER NOT NULL DEFAULT 0,
+      skipped_asins INTEGER NOT NULL DEFAULT 0,
+      scanned_asins INTEGER NOT NULL DEFAULT 0,
+      source_asins_with_matches INTEGER NOT NULL DEFAULT 0,
+      candidate_sellers INTEGER NOT NULL DEFAULT 0,
+      qualifying_sellers INTEGER NOT NULL DEFAULT 0,
+      matched_sellers INTEGER NOT NULL DEFAULT 0,
+      seller_metadata_requests INTEGER NOT NULL DEFAULT 0,
+      seller_storefront_requests INTEGER NOT NULL DEFAULT 0,
+      inventory_sellability_checked_asins INTEGER NOT NULL DEFAULT 0,
+      inventory_sellability_available_asins INTEGER NOT NULL DEFAULT 0,
+      inventory_sellability_excluded_asins INTEGER NOT NULL DEFAULT 0,
+      persisted_inventory_asins INTEGER NOT NULL DEFAULT 0,
+      status TEXT NOT NULL,
+      error_message TEXT
+    );
+  `);
+
+  database.run(`
+    CREATE TABLE IF NOT EXISTS stalker_asin_scans (
+      id INTEGER PRIMARY KEY AUTOINCREMENT,
+      run_id INTEGER NOT NULL,
+      source_asin TEXT NOT NULL,
+      title TEXT,
+      offer_count INTEGER NOT NULL DEFAULT 0,
+      candidate_seller_count INTEGER NOT NULL DEFAULT 0,
+      matched_seller_count INTEGER NOT NULL DEFAULT 0,
+      fetched_at TEXT NOT NULL,
+      raw_product_json TEXT,
+      UNIQUE(run_id, source_asin),
+      FOREIGN KEY (run_id) REFERENCES stalker_runs(id) ON DELETE CASCADE
+    );
+  `);
+
+  database.run(`
+    CREATE TABLE IF NOT EXISTS stalker_sellers (
+      seller_id TEXT PRIMARY KEY,
+      seller_name TEXT,
+      rating REAL,
+      rating_count INTEGER,
+      storefront_asin_total INTEGER,
+      persisted_inventory_sample_count INTEGER,
+      last_updated_at TEXT NOT NULL,
+      raw_seller_json TEXT
+    );
+  `);
+
+  database.run(`
+    CREATE TABLE IF NOT EXISTS stalker_asin_sellers (
+      id INTEGER PRIMARY KEY AUTOINCREMENT,
+      scan_id INTEGER NOT NULL,
+      seller_id TEXT NOT NULL,
+      offer_price REAL,
+      condition TEXT,
+      is_fba INTEGER,
+      stock INTEGER,
+      seller_rating REAL,
+      seller_rating_count INTEGER,
+      raw_offer_json TEXT,
+      UNIQUE(scan_id, seller_id),
+      FOREIGN KEY (scan_id) REFERENCES stalker_asin_scans(id) ON DELETE CASCADE,
+      FOREIGN KEY (seller_id) REFERENCES stalker_sellers(seller_id)
+    );
+  `);
+
+  database.run(`
+    CREATE TABLE IF NOT EXISTS stalker_seller_inventory (
+      id INTEGER PRIMARY KEY AUTOINCREMENT,
+      run_id INTEGER NOT NULL,
+      seller_id TEXT NOT NULL,
+      asin TEXT NOT NULL,
+      can_sell INTEGER,
+      sellability_status TEXT,
+      sellability_reason TEXT,
+      product_title TEXT,
+      brand TEXT,
+      category_tree TEXT,
+      current_price REAL,
+      avg_price_90d REAL,
+      sales_rank INTEGER,
+      monthly_sold INTEGER,
+      seller_count INTEGER,
+      amazon_is_seller INTEGER,
+      raw_product_json TEXT,
+      last_seen_at TEXT NOT NULL,
+      raw_inventory_json TEXT,
+      UNIQUE(run_id, seller_id, asin),
+      FOREIGN KEY (run_id) REFERENCES stalker_runs(id) ON DELETE CASCADE,
+      FOREIGN KEY (seller_id) REFERENCES stalker_sellers(seller_id)
+    );
+  `);
+
+  database.run(
+    `CREATE INDEX IF NOT EXISTS idx_stalker_runs_started_at ON stalker_runs(started_at DESC);`,
+  );
+  database.run(
+    `CREATE INDEX IF NOT EXISTS idx_stalker_scans_run_id ON stalker_asin_scans(run_id);`,
+  );
+  database.run(
+    `CREATE INDEX IF NOT EXISTS idx_stalker_scans_source_asin ON stalker_asin_scans(source_asin);`,
+  );
+  database.run(
+    `CREATE INDEX IF NOT EXISTS idx_stalker_asin_sellers_seller_id ON stalker_asin_sellers(seller_id);`,
+  );
+  database.run(
+    `CREATE INDEX IF NOT EXISTS idx_stalker_inventory_seller_id ON stalker_seller_inventory(seller_id);`,
+  );
+  database.run(
+    `CREATE INDEX IF NOT EXISTS idx_stalker_inventory_asin ON stalker_seller_inventory(asin);`,
+  );
+  database.run(
+    `CREATE INDEX IF NOT EXISTS idx_stalker_inventory_product_title ON stalker_seller_inventory(product_title);`,
+  );
+}
+
+function resetLegacyStalkerSchema(database: Database): void {
+  const runColumns = database
+    .query("PRAGMA table_info(stalker_runs)")
+    .all() as Array<{ name: string }>;
+  if (runColumns.length === 0) return;
+
+  const columnNames = new Set(runColumns.map((column) => column.name));
+  if (
+    columnNames.has("scanned_asins") &&
+    columnNames.has("inventory_sellability_checked_asins") &&
+    inventoryColumnsHaveSellability(database)
+  ) {
+    return;
+  }
+
+  database.run("DROP TABLE IF EXISTS stalker_seller_inventory");
+  database.run("DROP TABLE IF EXISTS stalker_asin_sellers");
+  database.run("DROP TABLE IF EXISTS stalker_sellers");
+  database.run("DROP TABLE IF EXISTS stalker_asin_scans");
+  database.run("DROP TABLE IF EXISTS stalker_runs");
+}
+
+function inventoryColumnsHaveSellability(database: Database): boolean {
+  const inventoryColumns = database
+    .query("PRAGMA table_info(stalker_seller_inventory)")
+    .all() as Array<{ name: string }>;
+  const columnNames = new Set(inventoryColumns.map((column) => column.name));
+  return (
+    columnNames.has("sellability_status") &&
+    columnNames.has("product_title")
+  );
 }

src/index.ts

@@ -1,6 +1,10 @@
 import { readProducts } from "./reader.ts";
 import { connectCache, disconnectCache } from "./cache.ts";
-import { printResults, writeResultsToDb } from "./writer.ts";
+import {
+  printResults,
+  writeResultsToDb,
+  writeResultsWorkbook,
+} from "./writer.ts";
 import { initDb, closeDb } from "./database.ts";
 import {
   chunkArray,
@@ -40,14 +44,18 @@ function parseArgs(): {
   sellability: SellabilityFilter;
 } {
   const args = process.argv.slice(2);
-  const inputFile = args.find((a) => !a.startsWith("--"));
+  const outputFile = readFlagValue(args, "--out", "--output");
-  const outIdx = args.indexOf("--out");
+  const inputFile = readInputFileArg(
-  const outputFile = outIdx !== -1 ? args[outIdx + 1] : undefined;
+    args,
+    "--out",
+    "--output",
+    "--sellability",
+  );
   const sellability = parseSellabilityArg(args);
 
   if (!inputFile) {
     console.error(
-      "Usage: bun run src/index.ts <input.csv|xlsx> [--out results.csv] [--sellability available|all]",
+      "Usage: bun run src/index.ts <input.csv|xlsx> [--out results.xlsx|--output results.xlsx] [--sellability available|all]",
     );
     process.exit(1);
   }
@@ -55,6 +63,44 @@ function parseArgs(): {
   return { inputFile, outputFile, sellability };
 }
 
+function readFlagValue(args: string[], ...flags: string[]): string | undefined {
+  for (const flag of flags) {
+    const equalsArg = args.find((arg) => arg.startsWith(`${flag}=`));
+    if (equalsArg) {
+      const value = equalsArg.slice(flag.length + 1);
+      if (value) return value;
+    }
+
+    const flagIdx = args.indexOf(flag);
+    if (flagIdx !== -1) {
+      return args[flagIdx + 1];
+    }
+  }
+
+  return undefined;
+}
+
+function readInputFileArg(
+  args: string[],
+  ...flagsWithValues: string[]
+): string | undefined {
+  for (let i = 0; i < args.length; i++) {
+    const arg = args[i]!;
+    if (flagsWithValues.includes(arg)) {
+      i++;
+      continue;
+    }
+    if (flagsWithValues.some((flag) => arg.startsWith(`${flag}=`))) {
+      continue;
+    }
+    if (!arg.startsWith("--")) {
+      return arg;
+    }
+  }
+
+  return undefined;
+}
+
 function resolveBaseOutputPath(inputFile: string, outputFile?: string): string {
   if (outputFile) return outputFile;
 
@@ -103,7 +149,8 @@ async function main() {
     }
 
     printResults(allResults);
-    writeResultsToDb(allResults, DB_PATH, inputFile, outputFile);
+    writeResultsWorkbook(allResults, resolvedBaseOutputPath);
+    writeResultsToDb(allResults, DB_PATH, inputFile, resolvedBaseOutputPath);
   } finally {
     await disconnectCache();
     closeDb();

src/keepa.test.ts

@@ -48,7 +48,7 @@ test("lookupKeepaUpcs returns found, not_found, and multiple_asins outcomes", as
               current: [null, null, null, 1234],
               avg: [2500, null, null, 1400],
             },
-            csv: [[1, 2999]],
+            csv: [[5000000, 2999, 5000100]],
           },
           {
             asin: "B000MULTI01",
@@ -85,6 +85,7 @@ test("lookupKeepaUpcs returns found, not_found, and multiple_asins outcomes", as
   expect(details.get("012345678901")?.status).toBe("found");
   expect(details.get("012345678901")?.asin).toBe("B000FOUND01");
   expect(details.get("012345678901")?.keepaData?.currentPrice).toBe(29.99);
+  expect(details.get("012345678901")?.keepaData?.currentPrice).toBe(29.99);
 
   expect(details.get("098765432109")?.status).toBe("multiple_asins");
   expect(details.get("098765432109")?.candidateAsins).toEqual([

src/keepa.ts

@@ -531,11 +531,14 @@ function computeAmazonBuyBoxSharePctFromHistory(
 
 function extractLatestPositivePrice(series: unknown): number | null {
   if (!Array.isArray(series) || series.length < 2) return null;
-  const last = series[series.length - 1];
+  for (let i = series.length - 1; i >= 1; i--) {
-  if (typeof last !== "number" || !Number.isFinite(last) || last <= 0) {
+    if (i % 2 === 0) continue;
-    return null;
+    const value = series[i];
+    if (typeof value === "number" && Number.isFinite(value) && value > 0) {
+      return value / 100;
+    }
   }
-  return last / 100;
+  return null;
 }
 
 function pickKeepaNumber(...values: unknown[]): number | null {
@@ -552,12 +555,10 @@ function extractCurrentPrice(csv: number[][] | undefined): number | null {
   if (!csv) return null;
 
   // csv[0] = Amazon price history, csv[1] = Marketplace new price history
-  // Each is [time, price, time, price, ...] — last value is most recent
+  // Each is [time, price, time, price, ...]. Only odd indexes are prices.
   for (const series of [csv[0], csv[1]]) {
-    if (series && series.length >= 2) {
+    const latestPrice = extractLatestPositivePrice(series);
-      const lastPrice = series[series.length - 1]!;
+    if (latestPrice != null) return latestPrice;
-      if (lastPrice > 0) return lastPrice / 100;
-    }
   }
   return null;
 }

src/server.ts

@@ -1,5 +1,6 @@
 import index from "./web/index.html";
 import path from "node:path";
+import * as XLSX from "xlsx";
 import { getDb, initDb } from "./database.ts";
 import {
   fetchKeepaDataBatch,
@@ -53,6 +54,50 @@ type ProductListRecord = {
   fetched_at: string;
 };
 
+type StalkerResultRecord = {
+  runId: number;
+  started_at: string;
+  status: string;
+  input_file: string;
+  seller_id: string;
+  seller_name: string | null;
+  rating: number | null;
+  rating_count: number | null;
+  storefront_asin_total: number | null;
+  persisted_inventory_sample_count: number | null;
+  discovered_from_count: number;
+  first_seen_at: string;
+  last_seen_at: string;
+  persisted_inventory_asin_count: number;
+  inventory_sample_asins: string | null;
+};
+
+type StalkerProductRecord = {
+  runId: number;
+  started_at: string;
+  seller_id: string;
+  seller_name: string | null;
+  rating: number | null;
+  rating_count: number | null;
+  asin: string;
+  can_sell: number;
+  sellability_status: string;
+  sellability_reason: string | null;
+  product_title: string | null;
+  brand: string | null;
+  category_tree: string | null;
+  current_price: number | null;
+  avg_price_90d: number | null;
+  sales_rank: number | null;
+  monthly_sold: number | null;
+  seller_count: number | null;
+  amazon_is_seller: number | null;
+  verdict: string | null;
+  confidence: number | null;
+  reasoning: string | null;
+  last_seen_at: string;
+};
+
 const DB_PATH = process.env.RESULTS_DB_PATH || path.join("db", "results.db");
 const DEFAULT_PAGE_SIZE = 25;
 const MAX_PAGE_SIZE = 200;
@@ -79,6 +124,16 @@ function csv(text: string, filename: string): Response {
   });
 }
 
+function xlsx(buffer: ArrayBuffer, filename: string): Response {
+  return new Response(buffer, {
+    status: 200,
+    headers: {
+      "content-type": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
+      "content-disposition": `attachment; filename="${filename}"`,
+    },
+  });
+}
+
 function parseIntParam(value: string | null, fallback: number): number {
   if (!value) return fallback;
   const parsed = Number.parseInt(value, 10);
@@ -629,6 +684,495 @@ function getProductList(filters: URLSearchParams) {
   };
 }
 
+function parseStalkerFilters(filters: URLSearchParams) {
+  const q = filters.get("q")?.trim() || "";
+  const sellerId = filters.get("sellerId")?.trim().toUpperCase() || "";
+  const runIdRaw = filters.get("runId")?.trim() || "";
+  const minRatingCountRaw = filters.get("minRatingCount")?.trim() || "";
+  const maxRatingCountRaw = filters.get("maxRatingCount")?.trim() || "";
+
+  const conditions: string[] = [];
+  const params: Array<string | number> = [];
+
+  if (runIdRaw) {
+    const runId = Number(runIdRaw);
+    if (Number.isInteger(runId) && runId > 0) {
+      conditions.push("r.id = ?");
+      params.push(runId);
+    }
+  }
+
+  if (sellerId) {
+    conditions.push("s.seller_id = ?");
+    params.push(sellerId);
+  }
+
+  if (minRatingCountRaw) {
+    conditions.push("s.rating_count >= ?");
+    params.push(Number(minRatingCountRaw));
+  }
+
+  if (maxRatingCountRaw) {
+    conditions.push("s.rating_count <= ?");
+    params.push(Number(maxRatingCountRaw));
+  }
+
+  if (q) {
+    const wildcard = `%${q}%`;
+    conditions.push(
+      `(s.seller_id LIKE ? OR s.seller_name LIKE ? OR EXISTS (
+        SELECT 1 FROM stalker_seller_inventory inv_q
+        WHERE inv_q.run_id = r.id
+          AND inv_q.seller_id = s.seller_id
+          AND inv_q.asin LIKE ?
+      ))`,
+    );
+    params.push(wildcard, wildcard, wildcard);
+  }
+
+  return {
+    where: conditions.length > 0 ? `WHERE ${conditions.join(" AND ")}` : "",
+    params,
+  };
+}
+
+function parseStalkerSort(sortParam: string | null): string {
+  const allowedSort = new Set([
+    "runId",
+    "started_at",
+    "seller_id",
+    "seller_name",
+    "rating",
+    "rating_count",
+    "discovered_from_count",
+    "persisted_inventory_asin_count",
+    "storefront_asin_total",
+    "last_seen_at",
+  ]);
+  const parsed = parseSort(
+    sortParam,
+    allowedSort,
+    "persisted_inventory_asin_count DESC, last_seen_at DESC, seller_id ASC",
+  );
+
+  return parsed
+    .replaceAll("runId", "runId")
+    .replaceAll("rating_count", "rating_count")
+    .replaceAll("persisted_inventory_asin_count", "persisted_inventory_asin_count")
+    .replaceAll("storefront_asin_total", "storefront_asin_total");
+}
+
+function getStalkerResults(filters: URLSearchParams) {
+  const page = parseIntParam(filters.get("page"), 1);
+  const pageSize = Math.min(
+    parseIntParam(filters.get("pageSize"), DEFAULT_PAGE_SIZE),
+    MAX_PAGE_SIZE,
+  );
+  const offset = (page - 1) * pageSize;
+  const { where, params } = parseStalkerFilters(filters);
+  const orderBy = parseStalkerSort(filters.get("sort"));
+
+  const baseSelect = `
+    SELECT
+      r.id AS runId,
+      r.started_at,
+      r.status,
+      r.input_file,
+      s.seller_id,
+      s.seller_name,
+      s.rating,
+      s.rating_count,
+      s.storefront_asin_total,
+      s.persisted_inventory_sample_count,
+      COUNT(DISTINCT sc.source_asin) AS discovered_from_count,
+      MIN(sc.fetched_at) AS first_seen_at,
+      MAX(sc.fetched_at) AS last_seen_at,
+      COUNT(DISTINCT inv.asin) AS persisted_inventory_asin_count,
+      GROUP_CONCAT(DISTINCT inv.asin) AS inventory_sample_asins
+    FROM stalker_asin_sellers sas
+    JOIN stalker_asin_scans sc ON sc.id = sas.scan_id
+    JOIN stalker_runs r ON r.id = sc.run_id
+    JOIN stalker_sellers s ON s.seller_id = sas.seller_id
+    LEFT JOIN stalker_seller_inventory inv
+      ON inv.run_id = r.id
+      AND inv.seller_id = s.seller_id
+    ${where}
+    GROUP BY r.id, s.seller_id
+  `;
+
+  const totalRow = db
+    .query(`SELECT COUNT(*) AS total FROM (${baseSelect}) stalker_rows`)
+    .get(...params) as { total: number };
+
+  const summary = db
+    .query(
+      `SELECT
+        COUNT(DISTINCT runId) AS runs,
+        COUNT(DISTINCT seller_id) AS sellers,
+        COALESCE(SUM(persisted_inventory_asin_count), 0) AS persistedInventoryAsins
+      FROM (${baseSelect}) stalker_rows`,
+    )
+    .get(...params) as {
+    runs: number;
+    sellers: number;
+    persistedInventoryAsins: number;
+  };
+
+  const items = db
+    .query(
+      `SELECT * FROM (${baseSelect}) stalker_rows
+       ORDER BY ${orderBy}
+       LIMIT ? OFFSET ?`,
+    )
+    .all(...params, pageSize, offset) as StalkerResultRecord[];
+
+  return {
+    items,
+    summary,
+    page,
+    pageSize,
+    total: totalRow.total,
+    totalPages: Math.max(1, Math.ceil(totalRow.total / pageSize)),
+  };
+}
+
+function parseStalkerProductFilters(filters: URLSearchParams) {
+  const q = filters.get("q")?.trim() || "";
+  const sellerId = filters.get("sellerId")?.trim().toUpperCase() || "";
+  const runIdRaw = filters.get("runId")?.trim() || "";
+  const verdict = filters.get("verdict")?.trim().toUpperCase() || "";
+  const amazonIsSeller = filters.get("amazonIsSeller")?.trim() || "";
+  const minPriceRaw = filters.get("minPrice")?.trim() || "";
+  const maxPriceRaw = filters.get("maxPrice")?.trim() || "";
+  const minMonthlySoldRaw = filters.get("minMonthlySold")?.trim() || "";
+  const maxMonthlySoldRaw = filters.get("maxMonthlySold")?.trim() || "";
+  const minSalesRankRaw = filters.get("minSalesRank")?.trim() || "";
+  const maxSalesRankRaw = filters.get("maxSalesRank")?.trim() || "";
+  const minSellerCountRaw = filters.get("minSellerCount")?.trim() || "";
+  const maxSellerCountRaw = filters.get("maxSellerCount")?.trim() || "";
+  const minRatingCountRaw = filters.get("minRatingCount")?.trim() || "";
+  const maxRatingCountRaw = filters.get("maxRatingCount")?.trim() || "";
+  const minConfidenceRaw = filters.get("minConfidence")?.trim() || "";
+  const maxConfidenceRaw = filters.get("maxConfidence")?.trim() || "";
+
+  const conditions = [
+    "inv.can_sell = 1",
+    "inv.sellability_status = 'available'",
+  ];
+  const params: Array<string | number> = [];
+
+  if (runIdRaw) {
+    const runId = Number(runIdRaw);
+    if (Number.isInteger(runId) && runId > 0) {
+      conditions.push("r.id = ?");
+      params.push(runId);
+    }
+  }
+
+  if (sellerId) {
+    conditions.push("s.seller_id = ?");
+    params.push(sellerId);
+  }
+
+  if (verdict === "FBA" || verdict === "FBM" || verdict === "SKIP") {
+    conditions.push("analysis.verdict = ?");
+    params.push(verdict);
+  } else if (verdict === "UNANALYZED") {
+    conditions.push("analysis.verdict IS NULL");
+  }
+
+  if (amazonIsSeller === "yes") {
+    conditions.push("inv.amazon_is_seller = 1");
+  } else if (amazonIsSeller === "no") {
+    conditions.push("inv.amazon_is_seller = 0");
+  } else if (amazonIsSeller === "unknown") {
+    conditions.push("inv.amazon_is_seller IS NULL");
+  }
+
+  const numericFilters: Array<[string, string, string]> = [
+    [minPriceRaw, "inv.current_price >= ?", "minPrice"],
+    [maxPriceRaw, "inv.current_price <= ?", "maxPrice"],
+    [minMonthlySoldRaw, "inv.monthly_sold >= ?", "minMonthlySold"],
+    [maxMonthlySoldRaw, "inv.monthly_sold <= ?", "maxMonthlySold"],
+    [minSalesRankRaw, "inv.sales_rank >= ?", "minSalesRank"],
+    [maxSalesRankRaw, "inv.sales_rank <= ?", "maxSalesRank"],
+    [minSellerCountRaw, "inv.seller_count >= ?", "minSellerCount"],
+    [maxSellerCountRaw, "inv.seller_count <= ?", "maxSellerCount"],
+    [minRatingCountRaw, "s.rating_count >= ?", "minRatingCount"],
+    [maxRatingCountRaw, "s.rating_count <= ?", "maxRatingCount"],
+    [minConfidenceRaw, "analysis.confidence >= ?", "minConfidence"],
+    [maxConfidenceRaw, "analysis.confidence <= ?", "maxConfidence"],
+  ];
+
+  for (const [raw, condition] of numericFilters) {
+    if (!raw) continue;
+    const value = Number(raw);
+    if (Number.isFinite(value)) {
+      conditions.push(condition);
+      params.push(value);
+    }
+  }
+
+  if (q) {
+    const wildcard = `%${q}%`;
+    conditions.push(
+      `(
+        inv.asin LIKE ?
+        OR inv.product_title LIKE ?
+        OR inv.brand LIKE ?
+        OR inv.category_tree LIKE ?
+        OR s.seller_id LIKE ?
+        OR s.seller_name LIKE ?
+      )`,
+    );
+    params.push(wildcard, wildcard, wildcard, wildcard, wildcard, wildcard);
+  }
+
+  return {
+    where: `WHERE ${conditions.join(" AND ")}`,
+    params,
+  };
+}
+
+function parseStalkerProductSort(sortParam: string | null): string {
+  const allowedSort = new Set([
+    "runId",
+    "started_at",
+    "seller_id",
+    "seller_name",
+    "rating",
+    "rating_count",
+    "asin",
+    "product_title",
+    "brand",
+    "current_price",
+    "avg_price_90d",
+    "sales_rank",
+    "monthly_sold",
+    "seller_count",
+    "amazon_is_seller",
+    "verdict",
+    "confidence",
+    "last_seen_at",
+  ]);
+  return parseSort(sortParam, allowedSort, "monthly_sold DESC, last_seen_at DESC, asin ASC");
+}
+
+function getStalkerProducts(filters: URLSearchParams) {
+  const page = parseIntParam(filters.get("page"), 1);
+  const pageSize = Math.min(
+    parseIntParam(filters.get("pageSize"), DEFAULT_PAGE_SIZE),
+    MAX_PAGE_SIZE,
+  );
+  const offset = (page - 1) * pageSize;
+  const { where, params } = parseStalkerProductFilters(filters);
+  const orderBy = parseStalkerProductSort(filters.get("sort"));
+
+  const baseSelect = `
+    SELECT
+      r.id AS runId,
+      r.started_at,
+      s.seller_id,
+      s.seller_name,
+      s.rating,
+      s.rating_count,
+      inv.asin,
+      inv.can_sell,
+      inv.sellability_status,
+      inv.sellability_reason,
+      inv.product_title,
+      inv.brand,
+      inv.category_tree,
+      inv.current_price,
+      inv.avg_price_90d,
+      inv.sales_rank,
+      inv.monthly_sold,
+      inv.seller_count,
+      inv.amazon_is_seller,
+      analysis.verdict,
+      analysis.confidence,
+      analysis.reasoning,
+      inv.last_seen_at
+    FROM stalker_seller_inventory inv
+    JOIN stalker_runs r ON r.id = inv.run_id
+    JOIN stalker_sellers s ON s.seller_id = inv.seller_id
+    LEFT JOIN product_analysis_results analysis ON analysis.asin = inv.asin
+    ${where}
+  `;
+
+  const totalRow = db
+    .query(`SELECT COUNT(*) AS total FROM (${baseSelect}) stalker_products`)
+    .get(...params) as { total: number };
+
+  const summary = db
+    .query(
+      `SELECT
+        COUNT(DISTINCT runId) AS runs,
+        COUNT(DISTINCT seller_id) AS sellers,
+        COUNT(DISTINCT asin) AS products
+      FROM (${baseSelect}) stalker_products`,
+    )
+    .get(...params) as {
+    runs: number;
+    sellers: number;
+    products: number;
+  };
+
+  const items = db
+    .query(
+      `SELECT * FROM (${baseSelect}) stalker_products
+       ORDER BY ${orderBy}
+       LIMIT ? OFFSET ?`,
+    )
+    .all(...params, pageSize, offset) as StalkerProductRecord[];
+
+  return {
+    items,
+    summary,
+    page,
+    pageSize,
+    total: totalRow.total,
+    totalPages: Math.max(1, Math.ceil(totalRow.total / pageSize)),
+  };
+}
+
+function getStalkerProductsForExport(filters: URLSearchParams): StalkerProductRecord[] {
+  const { where, params } = parseStalkerProductFilters(filters);
+  const orderBy = parseStalkerProductSort(filters.get("sort"));
+
+  return db
+    .query(
+      `SELECT * FROM (
+        SELECT
+          r.id AS runId,
+          r.started_at,
+          s.seller_id,
+          s.seller_name,
+          s.rating,
+          s.rating_count,
+          inv.asin,
+          inv.can_sell,
+          inv.sellability_status,
+          inv.sellability_reason,
+          inv.product_title,
+          inv.brand,
+          inv.category_tree,
+          inv.current_price,
+          inv.avg_price_90d,
+          inv.sales_rank,
+          inv.monthly_sold,
+          inv.seller_count,
+          inv.amazon_is_seller,
+          analysis.verdict,
+          analysis.confidence,
+          analysis.reasoning,
+          inv.last_seen_at
+        FROM stalker_seller_inventory inv
+        JOIN stalker_runs r ON r.id = inv.run_id
+        JOIN stalker_sellers s ON s.seller_id = inv.seller_id
+        LEFT JOIN product_analysis_results analysis ON analysis.asin = inv.asin
+        ${where}
+      ) stalker_products
+      ORDER BY ${orderBy}`,
+    )
+    .all(...params) as StalkerProductRecord[];
+}
+
+function parseCategoryTreeForExport(value: string | null): string {
+  if (!value) return "";
+  try {
+    const parsed = JSON.parse(value);
+    return Array.isArray(parsed)
+      ? parsed.filter((item) => typeof item === "string").join(" > ")
+      : "";
+  } catch {
+    return "";
+  }
+}
+
+function exportStalkerProductsXlsx(filters: URLSearchParams): Response {
+  const rows = getStalkerProductsForExport(filters);
+  const data = rows.map((row) => ({
+    ASIN: row.asin,
+    "Amazon URL": `https://amazon.com/dp/${row.asin}`,
+    Product: row.product_title ?? "",
+    Brand: row.brand ?? "",
+    Category: parseCategoryTreeForExport(row.category_tree),
+    "Monthly Sold": row.monthly_sold ?? null,
+    Sellers: row.seller_count ?? null,
+    "Amazon Seller": row.amazon_is_seller == null ? "" : row.amazon_is_seller === 1 ? "Yes" : "No",
+    "Sales Rank": row.sales_rank ?? null,
+    "Current Price": row.current_price ?? null,
+    "Avg 90d": row.avg_price_90d ?? null,
+    Verdict: row.verdict ?? "",
+    Confidence: row.confidence ?? null,
+    Reasoning: row.reasoning ?? "",
+    "Seller ID": row.seller_id,
+    Seller: row.seller_name ?? "",
+    "Seller Rating": row.rating ?? null,
+    "Seller Rating Count": row.rating_count ?? null,
+    "Sellability Status": row.sellability_status,
+    "Sellability Reason": row.sellability_reason ?? "",
+    "Run ID": row.runId,
+    "Last Seen": row.last_seen_at,
+  }));
+
+  const workbook = XLSX.utils.book_new();
+  const worksheet = XLSX.utils.json_to_sheet(data);
+  worksheet["!cols"] = [
+    { wch: 12 },
+    { wch: 32 },
+    { wch: 48 },
+    { wch: 20 },
+    { wch: 34 },
+    { wch: 14 },
+    { wch: 10 },
+    { wch: 14 },
+    { wch: 12 },
+    { wch: 12 },
+    { wch: 12 },
+    { wch: 10 },
+    { wch: 12 },
+    { wch: 60 },
+    { wch: 18 },
+    { wch: 24 },
+    { wch: 12 },
+    { wch: 20 },
+    { wch: 18 },
+    { wch: 40 },
+    { wch: 10 },
+    { wch: 24 },
+  ];
+  XLSX.utils.book_append_sheet(workbook, worksheet, "Sellable Products");
+
+  const buffer = XLSX.write(workbook, {
+    type: "array",
+    bookType: "xlsx",
+  }) as ArrayBuffer;
+
+  return xlsx(buffer, "stalker-sellable-products.xlsx");
+}
+
+function purgeStalkerData() {
+  const counts = {
+    inventory: (db.query("SELECT COUNT(*) AS count FROM stalker_seller_inventory").get() as { count: number }).count,
+    asinSellers: (db.query("SELECT COUNT(*) AS count FROM stalker_asin_sellers").get() as { count: number }).count,
+    sellers: (db.query("SELECT COUNT(*) AS count FROM stalker_sellers").get() as { count: number }).count,
+    scans: (db.query("SELECT COUNT(*) AS count FROM stalker_asin_scans").get() as { count: number }).count,
+    runs: (db.query("SELECT COUNT(*) AS count FROM stalker_runs").get() as { count: number }).count,
+  };
+
+  db.transaction(() => {
+    db.run("DELETE FROM stalker_seller_inventory");
+    db.run("DELETE FROM stalker_asin_sellers");
+    db.run("DELETE FROM stalker_sellers");
+    db.run("DELETE FROM stalker_asin_scans");
+    db.run("DELETE FROM stalker_runs");
+  })();
+
+  return { ok: true, deleted: counts };
+}
+
 function getRun(processType: ProcessType, runId: number) {
   if (processType === "lead_analysis") {
     const run = db
@@ -1259,6 +1803,8 @@ const server = Bun.serve({
   routes: {
     "/": index,
     "/products": index,
+    "/stalker": index,
+    "/stalker/products": index,
     "/runs/:processType/:runId": index,
     "/api/runs": (req) => {
       const url = new URL(req.url);
@@ -1268,6 +1814,24 @@ const server = Bun.serve({
       const url = new URL(req.url);
       return json(getProductList(url.searchParams));
     },
+    "/api/stalker/results": (req) => {
+      const url = new URL(req.url);
+      return json(getStalkerResults(url.searchParams));
+    },
+    "/api/stalker/products": (req) => {
+      const url = new URL(req.url);
+      return json(getStalkerProducts(url.searchParams));
+    },
+    "/api/stalker/products/export.xlsx": (req) => {
+      const url = new URL(req.url);
+      return exportStalkerProductsXlsx(url.searchParams);
+    },
+    "/api/stalker/purge": (req) => {
+      if (req.method !== "DELETE" && req.method !== "POST") {
+        return json({ error: "Method not allowed" }, 405);
+      }
+      return json(purgeStalkerData());
+    },
     "/api/upc/map": async (req) => {
       let upcs: string[];
       try {

src/sp-api.ts

@@ -123,7 +123,10 @@ function round2(value: number): number {
   return Math.round(value * 100) / 100;
 }
 
-const SELLABILITY_CONCURRENCY = 5;
+const LISTINGS_RESTRICTIONS_RATE_LIMIT_PER_SECOND = 5;
+const LISTINGS_RESTRICTIONS_BURST_REQUESTS = 10;
+const SELLABILITY_CONCURRENCY = LISTINGS_RESTRICTIONS_RATE_LIMIT_PER_SECOND;
+const SELLABILITY_PROGRESS_INTERVAL = LISTINGS_RESTRICTIONS_BURST_REQUESTS;
 const PRICING_CONCURRENCY = 5;
 const UPC_PATTERN = /^\d{12,14}$/;
 
@@ -621,7 +624,6 @@ export async function fetchSellabilityBatch(
   }
 
   let completed = 0;
-  let running = 0;
   const queue = [...asins];
 
   async function next(): Promise<void> {
@@ -630,7 +632,10 @@ export async function fetchSellabilityBatch(
       const info = await fetchSellabilityInternal(spClient!, asin);
       results.set(asin, info);
       completed++;
-      if (completed % 10 === 0 || completed === asins.length) {
+      if (
+        completed % SELLABILITY_PROGRESS_INTERVAL === 0 ||
+        completed === asins.length
+      ) {
         console.log(`  [sellability] ${completed}/${asins.length} checked`);
       }
     }

src/stalker-analyze.ts

@@ -0,0 +1,374 @@
+import { type Database, closeDb, getDb, initDb } from "./database.ts";
+import { analyzeProducts } from "./llm.ts";
+import { fetchSpApiPricingAndFees } from "./sp-api.ts";
+import type {
+  AnalysisResult,
+  EnrichedProduct,
+  KeepaData,
+  ProductRecord,
+  SellabilityInfo,
+} from "./types.ts";
+
+const LLM_BATCH_SIZE = 5;
+const LLM_BATCH_DELAY_MS = 5_000;
+
+type Args = {
+  dbPath: string;
+  stalkerRunId: number;
+  analysisRunId: number;
+  asins: string[];
+};
+
+type InventoryRow = {
+  asin: string;
+  product_title: string | null;
+  brand: string | null;
+  category_tree: string | null;
+  current_price: number | null;
+  avg_price_90d: number | null;
+  sales_rank: number | null;
+  monthly_sold: number | null;
+  seller_count: number | null;
+  amazon_is_seller: number | null;
+  can_sell: number | null;
+  sellability_status: SellabilityInfo["sellabilityStatus"] | null;
+  sellability_reason: string | null;
+};
+
+function readFlagValue(args: string[], flag: string): string | undefined {
+  const index = args.indexOf(flag);
+  if (index === -1) return undefined;
+  return args[index + 1];
+}
+
+function parseArgs(argv = process.argv.slice(2)): Args {
+  const dbPath = readFlagValue(argv, "--db");
+  const stalkerRunId = Number(readFlagValue(argv, "--stalker-run-id"));
+  const analysisRunId = Number(readFlagValue(argv, "--analysis-run-id"));
+  const asins = (readFlagValue(argv, "--asins") ?? "")
+    .split(",")
+    .map((asin) => asin.trim().toUpperCase())
+    .filter(Boolean);
+
+  if (!dbPath) throw new Error("Missing --db");
+  if (!Number.isInteger(stalkerRunId) || stalkerRunId <= 0) {
+    throw new Error("--stalker-run-id must be a positive integer");
+  }
+  if (!Number.isInteger(analysisRunId) || analysisRunId <= 0) {
+    throw new Error("--analysis-run-id must be a positive integer");
+  }
+  if (asins.length === 0) throw new Error("Missing --asins");
+
+  return { dbPath, stalkerRunId, analysisRunId, asins };
+}
+
+function wait(ms: number): Promise<void> {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+function parseCategoryTree(value: string | null): string[] {
+  if (!value) return [];
+  try {
+    const parsed = JSON.parse(value);
+    return Array.isArray(parsed)
+      ? parsed.filter((item): item is string => typeof item === "string")
+      : [];
+  } catch {
+    return [];
+  }
+}
+
+function toProductRecord(row: InventoryRow): ProductRecord {
+  const categoryTree = parseCategoryTree(row.category_tree);
+  return {
+    asin: row.asin,
+    name: row.product_title ?? row.asin,
+    brand: row.brand ?? undefined,
+    category: categoryTree.join(" > ") || undefined,
+    unitCost: 0,
+    amazonRank: row.sales_rank ?? undefined,
+    sellingPriceFromSheet: row.current_price ?? undefined,
+    avgPrice90FromSheet: row.avg_price_90d ?? undefined,
+  };
+}
+
+function toKeepaData(row: InventoryRow): KeepaData {
+  return {
+    currentPrice: row.current_price,
+    avgPrice90: row.avg_price_90d,
+    minPrice90: null,
+    maxPrice90: null,
+    salesRank: row.sales_rank,
+    salesRankAvg90: null,
+    salesRankDrops30: null,
+    salesRankDrops90: null,
+    sellerCount: row.seller_count,
+    amazonIsSeller:
+      row.amazon_is_seller == null ? null : row.amazon_is_seller === 1,
+    amazonBuyboxSharePct90d: null,
+    buyBoxSeller: null,
+    buyBoxPrice: null,
+    buyBoxAvg90: null,
+    monthlySold: row.monthly_sold,
+    categoryTree: parseCategoryTree(row.category_tree),
+  };
+}
+
+function toSellability(row: InventoryRow): SellabilityInfo {
+  return {
+    canSell: row.can_sell == null ? null : row.can_sell === 1,
+    sellabilityStatus: row.sellability_status ?? "unknown",
+    sellabilityReason: row.sellability_reason ?? undefined,
+  };
+}
+
+function loadInventoryRows(
+  database: Database,
+  stalkerRunId: number,
+  asins: string[],
+): InventoryRow[] {
+  const placeholders = asins.map(() => "?").join(",");
+  return database
+    .query(
+      `SELECT
+        asin, product_title, brand, category_tree, current_price, avg_price_90d,
+        sales_rank, monthly_sold, seller_count, amazon_is_seller, can_sell,
+        sellability_status, sellability_reason
+       FROM stalker_seller_inventory
+       WHERE run_id = ?
+         AND can_sell = 1
+         AND sellability_status = 'available'
+         AND asin IN (${placeholders})
+       GROUP BY asin`,
+    )
+    .all(stalkerRunId, ...asins) as InventoryRow[];
+}
+
+async function buildEnrichedProducts(
+  rows: InventoryRow[],
+): Promise<EnrichedProduct[]> {
+  const enriched: EnrichedProduct[] = [];
+
+  for (const row of rows) {
+    const sellability = toSellability(row);
+    const spApi = await fetchSpApiPricingAndFees(
+      row.asin,
+      sellability,
+      row.current_price,
+    );
+
+    enriched.push({
+      record: toProductRecord(row),
+      keepa: toKeepaData(row),
+      spApi,
+      fetchedAt: new Date().toISOString(),
+    });
+  }
+
+  return enriched;
+}
+
+function insertProductAnalysisResults(
+  database: Database,
+  runId: number,
+  results: AnalysisResult[],
+): void {
+  if (results.length === 0) return;
+
+  const insert = database.prepare(`
+    INSERT INTO product_analysis_results (
+      asin, run_id, name, brand, category, unit_cost,
+      current_price, avg_price_90d, avg_price_90d_sheet,
+      selling_price_sheet, sales_rank, sales_rank_avg_90d,
+      seller_count, amazon_is_seller, amazon_buybox_share_pct_90d,
+      monthly_sold, rank_drops_30d, rank_drops_90d,
+      fba_fee, fbm_fee, referral_percent, can_sell,
+      sellability_status, sellability_reason,
+      verdict, confidence, reasoning, fetched_at
+    ) VALUES (
+      ?, ?, ?, ?, ?, ?, ?, ?, ?, ?,
+      ?, ?, ?, ?, ?, ?, ?, ?, ?, ?,
+      ?, ?, ?, ?, ?, ?, ?, ?
+    )
+    ON CONFLICT(asin) DO UPDATE SET
+      run_id = excluded.run_id,
+      name = excluded.name,
+      brand = excluded.brand,
+      category = excluded.category,
+      unit_cost = excluded.unit_cost,
+      current_price = excluded.current_price,
+      avg_price_90d = excluded.avg_price_90d,
+      avg_price_90d_sheet = excluded.avg_price_90d_sheet,
+      selling_price_sheet = excluded.selling_price_sheet,
+      sales_rank = excluded.sales_rank,
+      sales_rank_avg_90d = excluded.sales_rank_avg_90d,
+      seller_count = excluded.seller_count,
+      amazon_is_seller = excluded.amazon_is_seller,
+      amazon_buybox_share_pct_90d = excluded.amazon_buybox_share_pct_90d,
+      monthly_sold = excluded.monthly_sold,
+      rank_drops_30d = excluded.rank_drops_30d,
+      rank_drops_90d = excluded.rank_drops_90d,
+      fba_fee = excluded.fba_fee,
+      fbm_fee = excluded.fbm_fee,
+      referral_percent = excluded.referral_percent,
+      can_sell = excluded.can_sell,
+      sellability_status = excluded.sellability_status,
+      sellability_reason = excluded.sellability_reason,
+      verdict = excluded.verdict,
+      confidence = excluded.confidence,
+      reasoning = excluded.reasoning,
+      fetched_at = excluded.fetched_at
+  `);
+
+  database.transaction((batch: AnalysisResult[]) => {
+    for (const result of batch) {
+      const keepa = result.product.keepa;
+      const record = result.product.record;
+      const spApi = result.product.spApi;
+      insert.run(
+        record.asin,
+        runId,
+        record.name,
+        record.brand ?? null,
+        record.category ?? keepa?.categoryTree.join(" > ") ?? null,
+        record.unitCost ?? null,
+        keepa?.currentPrice ?? spApi.estimatedSalePrice ?? null,
+        keepa?.avgPrice90 ?? null,
+        record.avgPrice90FromSheet ?? null,
+        record.sellingPriceFromSheet ?? null,
+        keepa?.salesRank ?? record.amazonRank ?? null,
+        keepa?.salesRankAvg90 ?? null,
+        keepa?.sellerCount ?? null,
+        keepa?.amazonIsSeller == null ? null : keepa.amazonIsSeller ? 1 : 0,
+        keepa?.amazonBuyboxSharePct90d ?? null,
+        keepa?.monthlySold ?? null,
+        keepa?.salesRankDrops30 ?? null,
+        keepa?.salesRankDrops90 ?? null,
+        spApi.fbaFee ?? null,
+        spApi.fbmFee ?? null,
+        spApi.referralFeePercent ?? null,
+        spApi.canSell == null ? "unknown" : spApi.canSell ? "yes" : "no",
+        spApi.sellabilityStatus ?? null,
+        spApi.sellabilityReason ?? null,
+        result.verdict.verdict,
+        result.verdict.confidence,
+        result.verdict.reasoning ?? null,
+        result.product.fetchedAt,
+      );
+    }
+  })(results);
+}
+
+function refreshAnalysisRun(database: Database, runId: number): void {
+  const stats = database
+    .query(
+      `SELECT
+        COUNT(*) AS total,
+        SUM(CASE WHEN verdict = 'FBA' THEN 1 ELSE 0 END) AS fba,
+        SUM(CASE WHEN verdict = 'FBM' THEN 1 ELSE 0 END) AS fbm,
+        SUM(CASE WHEN verdict = 'SKIP' THEN 1 ELSE 0 END) AS skip
+      FROM product_analysis_results
+      WHERE run_id = ?`,
+    )
+    .get(runId) as {
+    total: number;
+    fba: number | null;
+    fbm: number | null;
+    skip: number | null;
+  };
+
+  database
+    .prepare(
+      `UPDATE category_analysis_runs
+       SET top_asins_checked = ?,
+           available_asins = ?,
+           fba_count = ?,
+           fbm_count = ?,
+           skip_count = ?
+       WHERE id = ?`,
+    )
+    .run(
+      stats.total ?? 0,
+      stats.total ?? 0,
+      stats.fba ?? 0,
+      stats.fbm ?? 0,
+      stats.skip ?? 0,
+      runId,
+    );
+}
+
+async function analyzeInBatches(
+  products: EnrichedProduct[],
+): Promise<AnalysisResult[]> {
+  const results: AnalysisResult[] = [];
+
+  for (let i = 0; i < products.length; i += LLM_BATCH_SIZE) {
+    const batch = products.slice(i, i + LLM_BATCH_SIZE);
+    const batchNumber = Math.floor(i / LLM_BATCH_SIZE) + 1;
+    const totalBatches = Math.ceil(products.length / LLM_BATCH_SIZE);
+    console.log(
+      `Stalker analysis: LLM batch ${batchNumber}/${totalBatches} (${batch.length} product(s)).`,
+    );
+
+    if (i > 0) {
+      await wait(LLM_BATCH_DELAY_MS);
+    }
+
+    let verdicts;
+    try {
+      verdicts = await analyzeProducts(batch);
+    } catch (error) {
+      console.warn(
+        `Stalker analysis: LLM batch ${batchNumber} failed: ${
+          error instanceof Error ? error.message : String(error)
+        }`,
+      );
+      verdicts = null;
+    }
+
+    for (let j = 0; j < batch.length; j++) {
+      const product = batch[j];
+      if (!product) continue;
+      results.push({
+        product,
+        verdict: verdicts?.[j] ?? {
+          asin: product.record.asin,
+          verdict: "SKIP",
+          confidence: 0,
+          reasoning: "LLM analysis failed or returned no verdict",
+        },
+      });
+    }
+  }
+
+  return results;
+}
+
+async function main(): Promise<void> {
+  const args = parseArgs();
+  initDb(args.dbPath);
+  const database = getDb(args.dbPath);
+
+  try {
+    const rows = loadInventoryRows(database, args.stalkerRunId, args.asins);
+    if (rows.length === 0) {
+      console.log("Stalker analysis: no sellable inventory rows to analyze.");
+      return;
+    }
+
+    console.log(`Stalker analysis: analyzing ${rows.length} sellable ASIN(s).`);
+    const enriched = await buildEnrichedProducts(rows);
+    const results = await analyzeInBatches(enriched);
+    insertProductAnalysisResults(database, args.analysisRunId, results);
+    refreshAnalysisRun(database, args.analysisRunId);
+  } finally {
+    closeDb();
+  }
+}
+
+if (import.meta.main) {
+  main().catch((error) => {
+    console.error(error instanceof Error ? error.message : String(error));
+    process.exit(1);
+  });
+}

src/stalker-sellability.test.ts

@@ -0,0 +1,207 @@
+import { afterAll, beforeEach, expect, mock, test } from "bun:test";
+import { mkdirSync, rmSync } from "node:fs";
+import path from "node:path";
+import * as XLSX from "xlsx";
+import { closeDb, getDb } from "./database.ts";
+
+const TEST_DIR = path.join(process.cwd(), "test_output", "stalker-sellability");
+const originalFetch = globalThis.fetch;
+const originalKeepaKey = Bun.env.KEEPA_API_KEY;
+
+const fetchSellabilityBatchMock = mock(async (asins: string[]) => {
+  return new Map(
+    asins.map((asin) => [
+      asin,
+      asin === "B111111111"
+        ? {
+            canSell: true,
+            sellabilityStatus: "available" as const,
+            sellabilityReason: "No listing restrictions reported",
+          }
+        : {
+            canSell: false,
+            sellabilityStatus: "restricted" as const,
+            sellabilityReason: "approval required",
+          },
+    ]),
+  );
+});
+
+mock.module("./sp-api.ts", () => ({
+  fetchSellabilityBatch: fetchSellabilityBatchMock,
+}));
+
+const modulePromise = import("./stalker.ts");
+
+beforeEach(() => {
+  closeDb();
+  rmSync(TEST_DIR, { recursive: true, force: true });
+  mkdirSync(TEST_DIR, { recursive: true });
+  globalThis.fetch = originalFetch;
+  Bun.env.KEEPA_API_KEY = "test-keepa-key";
+  fetchSellabilityBatchMock.mockClear();
+});
+
+afterAll(() => {
+  globalThis.fetch = originalFetch;
+  if (originalKeepaKey == null) {
+    delete Bun.env.KEEPA_API_KEY;
+  } else {
+    Bun.env.KEEPA_API_KEY = originalKeepaKey;
+  }
+  closeDb();
+  rmSync(TEST_DIR, { recursive: true, force: true });
+});
+
+test("sellability checks matched seller inventory, not the source ASIN", async () => {
+  const { runStalker } = await modulePromise;
+  const inputPath = path.join(TEST_DIR, "input.xlsx");
+  const dbPath = path.join(TEST_DIR, "stalker.sqlite");
+  const workbook = XLSX.utils.book_new();
+  XLSX.utils.book_append_sheet(
+    workbook,
+    XLSX.utils.json_to_sheet([{ asin: "B000000001" }]),
+    "Input",
+  );
+  XLSX.writeFile(workbook, inputPath);
+
+  globalThis.fetch = mock(async (input: string | URL | Request) => {
+    const rawUrl =
+      typeof input === "string"
+        ? input
+        : input instanceof URL
+          ? input.toString()
+          : input.url;
+    const url = new URL(rawUrl);
+
+    if (url.pathname === "/product") {
+      if (url.searchParams.get("asin") === "B111111111") {
+        return new Response(
+          JSON.stringify({
+            products: [
+              {
+                asin: "B111111111",
+                title: "Sellable Storefront Product",
+                brand: "Good Brand",
+                categoryTree: [{ name: "Kitchen" }, { name: "Storage" }],
+                monthlySold: 42,
+                stats: {
+                  current: [null, null, null, 12345, null, null, null, null, null, null, null, 7],
+                  avg: [2500],
+                },
+                csv: [[5000000, 1999, 5000100]],
+              },
+            ],
+            tokensLeft: 10,
+            refillRate: 10,
+          }),
+          { status: 200 },
+        );
+      }
+
+      return new Response(
+        JSON.stringify({
+          products: [
+            {
+              asin: "B000000001",
+              title: "Source Product",
+              offers: [{ sellerId: "AQUALIFIED", price: 1999 }],
+            },
+          ],
+          tokensLeft: 10,
+          refillRate: 10,
+        }),
+        { status: 200 },
+      );
+    }
+
+    if (url.pathname === "/seller") {
+      const wantsStorefront = url.searchParams.get("storefront") === "1";
+      return new Response(
+        JSON.stringify({
+          sellers: {
+            AQUALIFIED: {
+              sellerName: "New Seller",
+              currentRatingCount: 12,
+              asinList: wantsStorefront ? ["B111111111", "B222222222"] : [],
+            },
+          },
+          tokensLeft: 10,
+          refillRate: 10,
+        }),
+        { status: 200 },
+      );
+    }
+
+    return new Response("not found", { status: 404 });
+  }) as unknown as typeof globalThis.fetch;
+
+  const stats = await runStalker({
+    input: inputPath,
+    dbPath,
+    maxAsins: null,
+    storefrontUpdateHours: 168,
+    offerLimit: 20,
+    sellerLimit: 30,
+    inventoryLimit: 200,
+    sellerCacheHours: 168,
+    includeStock: false,
+    dryRun: false,
+    resume: true,
+    maxSellerRequests: null,
+    sellability: true,
+    analyzeSellable: false,
+  });
+
+  expect(fetchSellabilityBatchMock.mock.calls.length).toBe(1);
+  expect(fetchSellabilityBatchMock.mock.calls[0]?.[0]).toEqual([
+    "B111111111",
+    "B222222222",
+  ]);
+  expect(stats.inventorySellabilityCheckedAsins).toBe(2);
+  expect(stats.inventorySellabilityAvailableAsins).toBe(1);
+  expect(stats.inventorySellabilityExcludedAsins).toBe(1);
+  expect(stats.persistedInventoryAsins).toBe(1);
+
+  const db = getDb(dbPath);
+  const scan = db.query("SELECT source_asin FROM stalker_asin_scans").get() as {
+    source_asin: string;
+  };
+  expect(scan.source_asin).toBe("B000000001");
+
+  const inventory = db
+    .query(
+      `SELECT asin, can_sell, sellability_status, product_title, brand,
+        category_tree, current_price, avg_price_90d, sales_rank, monthly_sold,
+        seller_count
+       FROM stalker_seller_inventory ORDER BY asin`,
+    )
+    .all() as Array<{
+    asin: string;
+    can_sell: number | null;
+    sellability_status: string | null;
+    product_title: string | null;
+    brand: string | null;
+    category_tree: string | null;
+    current_price: number | null;
+    avg_price_90d: number | null;
+    sales_rank: number | null;
+    monthly_sold: number | null;
+    seller_count: number | null;
+  }>;
+  expect(inventory).toEqual([
+    {
+      asin: "B111111111",
+      can_sell: 1,
+      sellability_status: "available",
+      product_title: "Sellable Storefront Product",
+      brand: "Good Brand",
+      category_tree: JSON.stringify(["Kitchen", "Storage"]),
+      current_price: 19.99,
+      avg_price_90d: 25,
+      sales_rank: 12345,
+      monthly_sold: 42,
+      seller_count: 7,
+    },
+  ]);
+});

src/stalker.test.ts

@@ -0,0 +1,283 @@
+import { afterAll, beforeEach, expect, mock, test } from "bun:test";
+import { mkdirSync, rmSync } from "node:fs";
+import path from "node:path";
+import * as XLSX from "xlsx";
+import { closeDb, getDb, initDb } from "./database.ts";
+import {
+  extractLiveOfferSellerCandidates,
+  isQualifyingSeller,
+  readAsinsFromXlsx,
+  runStalker,
+} from "./stalker.ts";
+
+const TEST_DIR = path.join(process.cwd(), "test_output", "stalker");
+const originalFetch = globalThis.fetch;
+const originalKeepaKey = Bun.env.KEEPA_API_KEY;
+
+beforeEach(() => {
+  closeDb();
+  rmSync(TEST_DIR, { recursive: true, force: true });
+  mkdirSync(TEST_DIR, { recursive: true });
+  globalThis.fetch = originalFetch;
+  Bun.env.KEEPA_API_KEY = "test-keepa-key";
+});
+
+afterAll(() => {
+  globalThis.fetch = originalFetch;
+  if (originalKeepaKey == null) {
+    delete Bun.env.KEEPA_API_KEY;
+  } else {
+    Bun.env.KEEPA_API_KEY = originalKeepaKey;
+  }
+  closeDb();
+  rmSync(TEST_DIR, { recursive: true, force: true });
+});
+
+test("readAsinsFromXlsx extracts valid ASINs and deduplicates in order", () => {
+  const filePath = path.join(TEST_DIR, "asins.xlsx");
+  const workbook = XLSX.utils.book_new();
+  const sheet = XLSX.utils.json_to_sheet([
+    { ASIN: "b000000001" },
+    { ASIN: "invalid" },
+    { ASIN: "B000000002" },
+    { ASIN: "B000000001" },
+    { ASIN: "" },
+  ]);
+  XLSX.utils.book_append_sheet(workbook, sheet, "Input");
+  XLSX.writeFile(workbook, filePath);
+
+  expect(readAsinsFromXlsx(filePath)).toEqual(["B000000001", "B000000002"]);
+});
+
+test("isQualifyingSeller accepts rating counts from 1 to 30 only", () => {
+  expect(isQualifyingSeller({ ratingCount: null })).toBe(false);
+  expect(isQualifyingSeller({ ratingCount: 0 })).toBe(false);
+  expect(isQualifyingSeller({ ratingCount: 1 })).toBe(true);
+  expect(isQualifyingSeller({ ratingCount: 30 })).toBe(true);
+  expect(isQualifyingSeller({ ratingCount: 31 })).toBe(false);
+});
+
+test("extractLiveOfferSellerCandidates ignores Amazon, missing seller IDs, and duplicates", () => {
+  const offers = extractLiveOfferSellerCandidates({
+    offers: [
+      { sellerId: "ATVPDKIKX0DER", price: 1999 },
+      { price: 1899 },
+      { sellerId: "A1SELLER", price: 1599, isFBA: true, stock: 4 },
+      { sellerId: "A1SELLER", price: 1499 },
+      { sellerID: "A2SELLER", currentPrice: 2499, isFba: false },
+    ],
+  });
+
+  expect(offers.map((offer) => offer.sellerId)).toEqual([
+    "A1SELLER",
+    "A2SELLER",
+  ]);
+  expect(offers[0]?.offerPrice).toBe(15.99);
+  expect(offers[0]?.isFba).toBe(true);
+  expect(offers[0]?.stock).toBe(4);
+});
+
+test("initDb creates stalker tables and indexes", () => {
+  const dbPath = path.join(TEST_DIR, "schema.sqlite");
+  initDb(dbPath);
+  const db = getDb(dbPath);
+
+  const tables = db
+    .query(
+      `SELECT name FROM sqlite_master WHERE type = 'table' AND name LIKE 'stalker_%' ORDER BY name`,
+    )
+    .all() as Array<{ name: string }>;
+  expect(tables.map((row) => row.name)).toEqual([
+    "stalker_asin_scans",
+    "stalker_asin_sellers",
+    "stalker_runs",
+    "stalker_seller_inventory",
+    "stalker_sellers",
+  ]);
+
+  const indexes = db
+    .query(
+      `SELECT name FROM sqlite_master WHERE type = 'index' AND name LIKE 'idx_stalker_%' ORDER BY name`,
+    )
+    .all() as Array<{ name: string }>;
+  expect(indexes.length).toBeGreaterThanOrEqual(6);
+});
+
+test("runStalker fetches product offers, filters sellers, and persists storefront inventory", async () => {
+  const inputPath = path.join(TEST_DIR, "input.xlsx");
+  const dbPath = path.join(TEST_DIR, "stalker.sqlite");
+  const workbook = XLSX.utils.book_new();
+  XLSX.utils.book_append_sheet(
+    workbook,
+    XLSX.utils.json_to_sheet([{ asin: "B000000001" }]),
+    "Input",
+  );
+  XLSX.writeFile(workbook, inputPath);
+
+  const fetchMock = mock(async (input: string | URL | Request) => {
+    const rawUrl =
+      typeof input === "string"
+        ? input
+        : input instanceof URL
+          ? input.toString()
+          : input.url;
+    const url = new URL(rawUrl);
+
+    if (url.pathname === "/product") {
+      expect(url.searchParams.get("asin")).toBe("B000000001");
+      expect(url.searchParams.get("offers")).toBe("20");
+      expect(url.searchParams.get("only-live-offers")).toBe("1");
+      expect(url.searchParams.has("stock")).toBe(false);
+
+      return new Response(
+        JSON.stringify({
+          products: [
+            {
+              asin: "B000000001",
+              title: "Tracked Product",
+              offers: [
+                {
+                  sellerId: "AQUALIFIED",
+                  price: 1999,
+                  condition: "New",
+                  isFBA: true,
+                  stock: 3,
+                },
+                {
+                  sellerId: "AOLDSELLER",
+                  price: 2099,
+                },
+              ],
+            },
+          ],
+          tokensLeft: 10,
+          refillRate: 10,
+        }),
+        { status: 200 },
+      );
+    }
+
+    if (url.pathname === "/seller") {
+      const wantsStorefront = url.searchParams.get("storefront") === "1";
+      if (wantsStorefront) {
+        expect(url.searchParams.get("update")).toBe("168");
+      }
+      const sellerId = url.searchParams.get("seller");
+
+      return new Response(
+        JSON.stringify({
+          sellers: {
+            ...(!wantsStorefront && sellerId === "AQUALIFIED,AOLDSELLER"
+              ? {
+                  AQUALIFIED: {
+                    sellerName: "New Seller",
+                    currentRating: 96,
+                    currentRatingCount: 12,
+                  },
+                  AOLDSELLER: {
+                    sellerName: "Old Seller",
+                    currentRating: 99,
+                    currentRatingCount: 120,
+                  },
+                }
+              : {}),
+            ...(wantsStorefront && sellerId === "AQUALIFIED"
+              ? {
+                  AQUALIFIED: {
+                    sellerName: "New Seller",
+                    currentRating: 96,
+                    currentRatingCount: 12,
+                    asinList: ["B111111111", "B222222222"],
+                  },
+                }
+              : {}),
+          },
+          tokensLeft: 10,
+          refillRate: 10,
+        }),
+        { status: 200 },
+      );
+    }
+
+    return new Response("not found", { status: 404 });
+  });
+  globalThis.fetch = fetchMock as unknown as typeof globalThis.fetch;
+
+  const stats = await runStalker({
+    input: inputPath,
+    dbPath,
+    maxAsins: null,
+    storefrontUpdateHours: 168,
+    offerLimit: 20,
+    sellerLimit: 30,
+    inventoryLimit: 200,
+    sellerCacheHours: 168,
+    includeStock: false,
+    dryRun: false,
+    resume: true,
+    maxSellerRequests: null,
+    sellability: false,
+    analyzeSellable: false,
+  });
+
+  expect(stats.scannedAsins).toBe(1);
+  expect(stats.sourceAsinsWithMatches).toBe(1);
+  expect(stats.matchedSellers).toBe(1);
+  expect(stats.persistedInventoryAsins).toBe(0);
+  expect(stats.failedAsins).toBe(0);
+  expect(stats.candidateSellers).toBe(2);
+  expect(stats.qualifyingSellers).toBe(1);
+  expect(stats.sellerMetadataRequests).toBe(1);
+  expect(stats.sellerStorefrontRequests).toBe(1);
+  const sellerCalls = fetchMock.mock.calls.filter((call) => {
+    const rawUrl =
+      typeof call[0] === "string"
+        ? call[0]
+        : call[0] instanceof URL
+          ? call[0].toString()
+          : (call[0] as Request).url;
+    return new URL(rawUrl).pathname === "/seller";
+  });
+  expect(sellerCalls.length).toBe(2);
+
+  const db = getDb(dbPath);
+  const run = db.query("SELECT * FROM stalker_runs").get() as any;
+  expect(run.status).toBe("completed");
+  expect(run.requested_asins).toBe(1);
+  expect(run.scanned_asins).toBe(1);
+  expect(run.source_asins_with_matches).toBe(1);
+  expect(run.candidate_sellers).toBe(2);
+  expect(run.qualifying_sellers).toBe(1);
+  expect(run.matched_sellers).toBe(1);
+  expect(run.seller_metadata_requests).toBe(1);
+  expect(run.seller_storefront_requests).toBe(1);
+  expect(run.inventory_sellability_checked_asins).toBe(0);
+  expect(run.inventory_sellability_available_asins).toBe(0);
+  expect(run.inventory_sellability_excluded_asins).toBe(0);
+  expect(run.persisted_inventory_asins).toBe(0);
+
+  const scan = db.query("SELECT * FROM stalker_asin_scans").get() as any;
+  expect(scan.source_asin).toBe("B000000001");
+  expect(scan.title).toBe("Tracked Product");
+  expect(scan.offer_count).toBe(2);
+  expect(scan.candidate_seller_count).toBe(2);
+  expect(scan.matched_seller_count).toBe(1);
+
+  const sellers = db.query("SELECT * FROM stalker_sellers").all() as any[];
+  expect(sellers.length).toBe(1);
+  expect(sellers[0].seller_id).toBe("AQUALIFIED");
+  expect(sellers[0].rating_count).toBe(12);
+  expect(sellers[0].storefront_asin_total).toBe(2);
+  expect(sellers[0].persisted_inventory_sample_count).toBe(0);
+
+  const asinSellers = db.query("SELECT * FROM stalker_asin_sellers").all() as any[];
+  expect(asinSellers.length).toBe(1);
+  expect(asinSellers[0].offer_price).toBe(19.99);
+  expect(asinSellers[0].is_fba).toBe(1);
+  expect(asinSellers[0].stock).toBe(3);
+
+  const inventory = db
+    .query("SELECT asin FROM stalker_seller_inventory ORDER BY asin")
+    .all() as Array<{ asin: string }>;
+  expect(inventory.map((row) => row.asin)).toEqual([]);
+});

src/web/frontend.tsx

@@ -109,6 +109,76 @@ type ProductListResponse = {
   totalPages: number;
 };
 
+type StalkerResultItem = {
+  runId: number;
+  started_at: string;
+  status: string;
+  input_file: string;
+  seller_id: string;
+  seller_name: string | null;
+  rating: number | null;
+  rating_count: number | null;
+  storefront_asin_total: number | null;
+  persisted_inventory_sample_count: number | null;
+  discovered_from_count: number;
+  first_seen_at: string;
+  last_seen_at: string;
+  persisted_inventory_asin_count: number;
+  inventory_sample_asins: string | null;
+};
+
+type StalkerResultsResponse = {
+  items: StalkerResultItem[];
+  summary: {
+    runs: number;
+    sellers: number;
+    persistedInventoryAsins: number;
+  };
+  page: number;
+  pageSize: number;
+  total: number;
+  totalPages: number;
+};
+
+type StalkerProductItem = {
+  runId: number;
+  started_at: string;
+  seller_id: string;
+  seller_name: string | null;
+  rating: number | null;
+  rating_count: number | null;
+  asin: string;
+  can_sell: number;
+  sellability_status: string;
+  sellability_reason: string | null;
+  product_title: string | null;
+  brand: string | null;
+  category_tree: string | null;
+  current_price: number | null;
+  avg_price_90d: number | null;
+  sales_rank: number | null;
+  monthly_sold: number | null;
+  seller_count: number | null;
+  amazon_is_seller: number | null;
+  verdict: "FBA" | "FBM" | "SKIP" | null;
+  confidence: number | null;
+  reasoning: string | null;
+  last_seen_at: string;
+};
+
+type StalkerProductsResponse = {
+  items: StalkerProductItem[];
+  summary: {
+    runs: number;
+    sellers: number;
+    products: number;
+  };
+  page: number;
+  pageSize: number;
+  total: number;
+  totalPages: number;
+};
+
 type SortState = {
   field: string;
   direction: SortDirection;
@@ -139,6 +209,23 @@ function formatAmazonSeller(value: number | null | undefined): string {
   return value === 1 ? "Yes" : "No";
 }
 
+function formatBoolean(value: number | null | undefined): string {
+  if (value === null || value === undefined) return "-";
+  return value === 1 ? "Yes" : "No";
+}
+
+function parseStringArrayJson(value: string | null | undefined): string[] {
+  if (!value) return [];
+  try {
+    const parsed = JSON.parse(value);
+    return Array.isArray(parsed)
+      ? parsed.filter((item): item is string => typeof item === "string")
+      : [];
+  } catch {
+    return [];
+  }
+}
+
 function buildSortValue(sort: SortState): string {
   return `${sort.field}:${sort.direction}`;
 }
@@ -197,9 +284,13 @@ function detectAnomaly(item: ResultItem): string {
 function Dashboard({
   onOpenRun,
   onOpenProducts,
+  onOpenStalker,
+  onOpenStalkerProducts,
 }: {
   onOpenRun: (run: Run) => void;
   onOpenProducts: (verdict: VerdictFilter) => void;
+  onOpenStalker: () => void;
+  onOpenStalkerProducts: () => void;
 }) {
   const [runs, setRuns] = useState<RunsResponse | null>(null);
   const [loading, setLoading] = useState(false);
@@ -288,7 +379,13 @@ function Dashboard({
   return (
     <div className="page">
       <div className="card">
-        <h2>Runs Dashboard</h2>
+        <div className="section-header">
+          <h2>Runs Dashboard</h2>
+          <div className="button-row">
+            <button onClick={onOpenStalker}>Stalker sellers</button>
+            <button onClick={onOpenStalkerProducts}>Sellable products</button>
+          </div>
+        </div>
       </div>
 
       <div className="metrics">
@@ -848,10 +945,451 @@ function ProductList({ verdict, onBack }: { verdict: VerdictFilter; onBack: () =
   );
 }
 
+function StalkerExplorer({
+  onBack,
+  onOpenProducts,
+}: {
+  onBack: () => void;
+  onOpenProducts: () => void;
+}) {
+  const [results, setResults] = useState<StalkerResultsResponse | null>(null);
+  const [loading, setLoading] = useState(false);
+  const [purging, setPurging] = useState(false);
+  const [search, setSearch] = useState("");
+  const [sellerId, setSellerId] = useState("");
+  const [runId, setRunId] = useState("");
+  const [minRatingCount, setMinRatingCount] = useState("1");
+  const [maxRatingCount, setMaxRatingCount] = useState("30");
+  const [page, setPage] = useState(1);
+  const [pageSize, setPageSize] = useState(25);
+  const [sort, setSort] = useState<SortState>({ field: "persisted_inventory_asin_count", direction: "DESC" });
+  const [refreshTick, setRefreshTick] = useState(0);
+
+  useEffect(() => {
+    let cancelled = false;
+    async function load() {
+      setLoading(true);
+      const params = new URLSearchParams({
+        page: String(page),
+        pageSize: String(pageSize),
+        sort: buildSortValue(sort),
+      });
+      if (search) params.set("q", search);
+      if (sellerId) params.set("sellerId", sellerId);
+      if (runId) params.set("runId", runId);
+      if (minRatingCount) params.set("minRatingCount", minRatingCount);
+      if (maxRatingCount) params.set("maxRatingCount", maxRatingCount);
+
+      const res = await fetch(`/api/stalker/results?${params.toString()}`);
+      const payload = (await res.json()) as StalkerResultsResponse;
+      if (!cancelled) {
+        setResults(payload);
+        setLoading(false);
+      }
+    }
+
+    load();
+    return () => {
+      cancelled = true;
+    };
+  }, [search, sellerId, runId, minRatingCount, maxRatingCount, page, pageSize, sort, refreshTick]);
+
+  async function purgeStalkerData() {
+    const confirmed = window.confirm("Permanently delete all Stalker runs, sellers, and sellable products from the database?");
+    if (!confirmed) return;
+
+    setPurging(true);
+    try {
+      const res = await fetch("/api/stalker/purge", { method: "DELETE" });
+      if (!res.ok) {
+        const payload = await res.json().catch(() => null) as { error?: string } | null;
+        window.alert(payload?.error ?? "Failed to purge Stalker data");
+        return;
+      }
+      setPage(1);
+      setRefreshTick((tick) => tick + 1);
+    } finally {
+      setPurging(false);
+    }
+  }
+
+  return (
+    <div className="page">
+      <button className="back" onClick={onBack}>Back</button>
+
+      <div className="card">
+        <div className="section-header">
+          <h2>Seller Storefronts</h2>
+          <div className="button-row">
+            <button onClick={onOpenProducts}>Sellable products</button>
+            <button className="danger" disabled={purging} onClick={purgeStalkerData}>
+              {purging ? "Purging..." : "Purge Stalker data"}
+            </button>
+          </div>
+        </div>
+      </div>
+
+      <div className="metrics">
+        <div className="metric">
+          <div className="label">Runs</div>
+          <div className="value">{formatNumber(results?.summary.runs)}</div>
+        </div>
+        <div className="metric">
+          <div className="label">Matched sellers</div>
+          <div className="value">{formatNumber(results?.summary.sellers)}</div>
+        </div>
+        <div className="metric">
+          <div className="label">Sellable inventory ASINs</div>
+          <div className="value">{formatNumber(results?.summary.persistedInventoryAsins)}</div>
+        </div>
+      </div>
+
+      <div className="card">
+        <div className="toolbar">
+          <input value={search} onChange={(e) => { setPage(1); setSearch(e.target.value); }} placeholder="Search seller or sellable ASIN" />
+          <input value={sellerId} onChange={(e) => { setPage(1); setSellerId(e.target.value.toUpperCase()); }} placeholder="Seller ID" />
+          <input value={runId} onChange={(e) => { setPage(1); setRunId(e.target.value); }} placeholder="Run ID" />
+          <input value={minRatingCount} onChange={(e) => { setPage(1); setMinRatingCount(e.target.value); }} placeholder="Min rating count" />
+          <input value={maxRatingCount} onChange={(e) => { setPage(1); setMaxRatingCount(e.target.value); }} placeholder="Max rating count" />
+          <select value={String(pageSize)} onChange={(e) => { setPage(1); setPageSize(Number(e.target.value)); }}>
+            <option value="25">25 / page</option>
+            <option value="50">50 / page</option>
+            <option value="100">100 / page</option>
+          </select>
+        </div>
+      </div>
+
+      <div className="card">
+        <div className="table-wrap">
+          <table className="stalker-table">
+            <thead>
+              <tr>
+                <th><button onClick={() => setSort(nextSort(sort, "runId"))}>Run</button></th>
+                <th><button onClick={() => setSort(nextSort(sort, "seller_id"))}>Seller ID</button></th>
+                <th><button onClick={() => setSort(nextSort(sort, "seller_name"))}>Seller</button></th>
+                <th><button onClick={() => setSort(nextSort(sort, "rating"))}>Rating</button></th>
+                <th><button onClick={() => setSort(nextSort(sort, "rating_count"))}>Rating Count</button></th>
+                <th><button onClick={() => setSort(nextSort(sort, "discovered_from_count"))}>Hits</button></th>
+                <th><button onClick={() => setSort(nextSort(sort, "storefront_asin_total"))}>Storefront total</button></th>
+                <th><button onClick={() => setSort(nextSort(sort, "persisted_inventory_asin_count"))}>Sellable sample</button></th>
+                <th><button onClick={() => setSort(nextSort(sort, "last_seen_at"))}>Last Seen</button></th>
+                <th className="inventory-col">Sellable inventory ASIN sample</th>
+              </tr>
+            </thead>
+            <tbody>
+              {loading ? (
+                <tr><td colSpan={10}>Loading...</td></tr>
+              ) : results?.items.length ? (
+                results.items.map((item) => {
+                  const inventorySample = (item.inventory_sample_asins ?? "")
+                    .split(",")
+                    .filter(Boolean)
+                    .slice(0, 20);
+                  return (
+                    <tr key={`${item.runId}-${item.seller_id}`}>
+                      <td>{item.runId}</td>
+                      <td>{item.seller_id}</td>
+                      <td>{item.seller_name || "-"}</td>
+                      <td>{formatNumber(item.rating)}</td>
+                      <td>{formatNumber(item.rating_count)}</td>
+                      <td>{formatNumber(item.discovered_from_count)}</td>
+                      <td>{formatNumber(item.storefront_asin_total)}</td>
+                      <td>{formatNumber(item.persisted_inventory_asin_count)}</td>
+                      <td>{formatDate(item.last_seen_at)}</td>
+                      <td className="inventory-col">
+                        {inventorySample.length === 0 ? "-" : inventorySample.map((asin) => (
+                          <a key={asin} href={`http://amazon.com/dp/${asin}`} target="_blank" rel="noreferrer">{asin}</a>
+                        ))}
+                      </td>
+                    </tr>
+                  );
+                })
+              ) : (
+                <tr><td colSpan={10}>No seller storefronts found</td></tr>
+              )}
+            </tbody>
+          </table>
+        </div>
+        <div className="pager">
+          <div>Showing {results?.items.length ?? 0} of {results?.total ?? 0}</div>
+          <div>
+            <button disabled={page <= 1} onClick={() => setPage((p) => Math.max(1, p - 1))}>Previous</button>
+            <span style={{ padding: "0 8px" }}>Page {results?.page ?? page} / {results?.totalPages ?? 1}</span>
+            <button disabled={Boolean(results && page >= results.totalPages)} onClick={() => setPage((p) => p + 1)}>Next</button>
+          </div>
+        </div>
+      </div>
+    </div>
+  );
+}
+
+function StalkerProductsExplorer({
+  onBack,
+  onOpenSellers,
+}: {
+  onBack: () => void;
+  onOpenSellers: () => void;
+}) {
+  const [results, setResults] = useState<StalkerProductsResponse | null>(null);
+  const [loading, setLoading] = useState(false);
+  const [search, setSearch] = useState("");
+  const [sellerId, setSellerId] = useState("");
+  const [runId, setRunId] = useState("");
+  const [verdict, setVerdict] = useState("");
+  const [amazonIsSeller, setAmazonIsSeller] = useState("");
+  const [minPrice, setMinPrice] = useState("");
+  const [maxPrice, setMaxPrice] = useState("");
+  const [minMonthlySold, setMinMonthlySold] = useState("");
+  const [maxMonthlySold, setMaxMonthlySold] = useState("");
+  const [minSalesRank, setMinSalesRank] = useState("");
+  const [maxSalesRank, setMaxSalesRank] = useState("");
+  const [minSellerCount, setMinSellerCount] = useState("");
+  const [maxSellerCount, setMaxSellerCount] = useState("");
+  const [minRatingCount, setMinRatingCount] = useState("");
+  const [maxRatingCount, setMaxRatingCount] = useState("");
+  const [minConfidence, setMinConfidence] = useState("");
+  const [maxConfidence, setMaxConfidence] = useState("");
+  const [page, setPage] = useState(1);
+  const [pageSize, setPageSize] = useState(50);
+  const [sort, setSort] = useState<SortState>({ field: "monthly_sold", direction: "DESC" });
+
+  function buildStalkerProductParams(includePaging: boolean): URLSearchParams {
+    const params = new URLSearchParams({
+      sort: buildSortValue(sort),
+    });
+    if (includePaging) {
+      params.set("page", String(page));
+      params.set("pageSize", String(pageSize));
+    }
+    if (search) params.set("q", search);
+    if (sellerId) params.set("sellerId", sellerId);
+    if (runId) params.set("runId", runId);
+    if (verdict) params.set("verdict", verdict);
+    if (amazonIsSeller) params.set("amazonIsSeller", amazonIsSeller);
+    if (minPrice) params.set("minPrice", minPrice);
+    if (maxPrice) params.set("maxPrice", maxPrice);
+    if (minMonthlySold) params.set("minMonthlySold", minMonthlySold);
+    if (maxMonthlySold) params.set("maxMonthlySold", maxMonthlySold);
+    if (minSalesRank) params.set("minSalesRank", minSalesRank);
+    if (maxSalesRank) params.set("maxSalesRank", maxSalesRank);
+    if (minSellerCount) params.set("minSellerCount", minSellerCount);
+    if (maxSellerCount) params.set("maxSellerCount", maxSellerCount);
+    if (minRatingCount) params.set("minRatingCount", minRatingCount);
+    if (maxRatingCount) params.set("maxRatingCount", maxRatingCount);
+    if (minConfidence) params.set("minConfidence", minConfidence);
+    if (maxConfidence) params.set("maxConfidence", maxConfidence);
+    return params;
+  }
+
+  useEffect(() => {
+    let cancelled = false;
+    async function load() {
+      setLoading(true);
+      const params = buildStalkerProductParams(true);
+
+      const res = await fetch(`/api/stalker/products?${params.toString()}`);
+      const payload = (await res.json()) as StalkerProductsResponse;
+      if (!cancelled) {
+        setResults(payload);
+        setLoading(false);
+      }
+    }
+
+    load();
+    return () => {
+      cancelled = true;
+    };
+  }, [
+    search,
+    sellerId,
+    runId,
+    verdict,
+    amazonIsSeller,
+    minPrice,
+    maxPrice,
+    minMonthlySold,
+    maxMonthlySold,
+    minSalesRank,
+    maxSalesRank,
+    minSellerCount,
+    maxSellerCount,
+    minRatingCount,
+    maxRatingCount,
+    minConfidence,
+    maxConfidence,
+    page,
+    pageSize,
+    sort,
+  ]);
+
+  function resetFilters() {
+    setSearch("");
+    setSellerId("");
+    setRunId("");
+    setVerdict("");
+    setAmazonIsSeller("");
+    setMinPrice("");
+    setMaxPrice("");
+    setMinMonthlySold("");
+    setMaxMonthlySold("");
+    setMinSalesRank("");
+    setMaxSalesRank("");
+    setMinSellerCount("");
+    setMaxSellerCount("");
+    setMinRatingCount("");
+    setMaxRatingCount("");
+    setMinConfidence("");
+    setMaxConfidence("");
+    setPage(1);
+  }
+
+  const exportHref = `/api/stalker/products/export.xlsx?${buildStalkerProductParams(false).toString()}`;
+
+  return (
+    <div className="page">
+      <button className="back" onClick={onBack}>Back</button>
+
+      <div className="card">
+        <div className="section-header">
+          <h2>Sellable Stalker Products</h2>
+          <button onClick={onOpenSellers}>Seller storefronts</button>
+        </div>
+      </div>
+
+      <div className="metrics">
+        <div className="metric">
+          <div className="label">Runs</div>
+          <div className="value">{formatNumber(results?.summary.runs)}</div>
+        </div>
+        <div className="metric">
+          <div className="label">Sellers</div>
+          <div className="value">{formatNumber(results?.summary.sellers)}</div>
+        </div>
+        <div className="metric">
+          <div className="label">Sellable products</div>
+          <div className="value">{formatNumber(results?.summary.products)}</div>
+        </div>
+      </div>
+
+      <div className="card">
+        <div className="toolbar">
+          <input value={search} onChange={(e) => { setPage(1); setSearch(e.target.value); }} placeholder="Search ASIN, product, brand, category, or seller" />
+          <input value={sellerId} onChange={(e) => { setPage(1); setSellerId(e.target.value.toUpperCase()); }} placeholder="Seller ID" />
+          <input value={runId} onChange={(e) => { setPage(1); setRunId(e.target.value); }} placeholder="Run ID" />
+          <select value={verdict} onChange={(e) => { setPage(1); setVerdict(e.target.value); }}>
+            <option value="">All verdicts</option>
+            <option value="FBA">FBA</option>
+            <option value="FBM">FBM</option>
+            <option value="SKIP">SKIP</option>
+            <option value="UNANALYZED">Unanalyzed</option>
+          </select>
+          <select value={amazonIsSeller} onChange={(e) => { setPage(1); setAmazonIsSeller(e.target.value); }}>
+            <option value="">Amazon seller: all</option>
+            <option value="yes">Amazon seller: yes</option>
+            <option value="no">Amazon seller: no</option>
+            <option value="unknown">Amazon seller: unknown</option>
+          </select>
+          <input value={minPrice} onChange={(e) => { setPage(1); setMinPrice(e.target.value); }} placeholder="Min price" />
+          <input value={maxPrice} onChange={(e) => { setPage(1); setMaxPrice(e.target.value); }} placeholder="Max price" />
+          <input value={minMonthlySold} onChange={(e) => { setPage(1); setMinMonthlySold(e.target.value); }} placeholder="Min monthly sold" />
+          <input value={maxMonthlySold} onChange={(e) => { setPage(1); setMaxMonthlySold(e.target.value); }} placeholder="Max monthly sold" />
+          <input value={minSalesRank} onChange={(e) => { setPage(1); setMinSalesRank(e.target.value); }} placeholder="Min rank" />
+          <input value={maxSalesRank} onChange={(e) => { setPage(1); setMaxSalesRank(e.target.value); }} placeholder="Max rank" />
+          <input value={minSellerCount} onChange={(e) => { setPage(1); setMinSellerCount(e.target.value); }} placeholder="Min sellers" />
+          <input value={maxSellerCount} onChange={(e) => { setPage(1); setMaxSellerCount(e.target.value); }} placeholder="Max sellers" />
+          <input value={minRatingCount} onChange={(e) => { setPage(1); setMinRatingCount(e.target.value); }} placeholder="Min seller rating count" />
+          <input value={maxRatingCount} onChange={(e) => { setPage(1); setMaxRatingCount(e.target.value); }} placeholder="Max seller rating count" />
+          <input value={minConfidence} onChange={(e) => { setPage(1); setMinConfidence(e.target.value); }} placeholder="Min confidence" />
+          <input value={maxConfidence} onChange={(e) => { setPage(1); setMaxConfidence(e.target.value); }} placeholder="Max confidence" />
+          <select value={String(pageSize)} onChange={(e) => { setPage(1); setPageSize(Number(e.target.value)); }}>
+            <option value="25">25 / page</option>
+            <option value="50">50 / page</option>
+            <option value="100">100 / page</option>
+          </select>
+          <button onClick={resetFilters}>Reset filters</button>
+          <a className="button-link" href={exportHref}>Export XLSX</a>
+        </div>
+      </div>
+
+      <div className="card">
+        <div className="table-wrap">
+          <table className="stalker-table">
+            <thead>
+              <tr>
+                <th><button onClick={() => setSort(nextSort(sort, "asin"))}>ASIN</button></th>
+                <th className="product-col"><button onClick={() => setSort(nextSort(sort, "product_title"))}>Product</button></th>
+                <th><button onClick={() => setSort(nextSort(sort, "brand"))}>Brand</button></th>
+                <th>Category</th>
+                <th><button onClick={() => setSort(nextSort(sort, "monthly_sold"))}>Monthly Sold</button></th>
+                <th><button onClick={() => setSort(nextSort(sort, "seller_count"))}>Sellers</button></th>
+                <th><button onClick={() => setSort(nextSort(sort, "amazon_is_seller"))}>Amazon Seller</button></th>
+                <th><button onClick={() => setSort(nextSort(sort, "sales_rank"))}>Sales Rank</button></th>
+                <th><button onClick={() => setSort(nextSort(sort, "current_price"))}>Current Price</button></th>
+                <th><button onClick={() => setSort(nextSort(sort, "avg_price_90d"))}>Avg 90d</button></th>
+                <th><button onClick={() => setSort(nextSort(sort, "verdict"))}>Verdict</button></th>
+                <th><button onClick={() => setSort(nextSort(sort, "confidence"))}>Confidence</button></th>
+                <th><button onClick={() => setSort(nextSort(sort, "seller_id"))}>Seller ID</button></th>
+                <th><button onClick={() => setSort(nextSort(sort, "seller_name"))}>Seller</button></th>
+                <th><button onClick={() => setSort(nextSort(sort, "rating_count"))}>Rating Count</button></th>
+                <th>Status</th>
+                <th><button onClick={() => setSort(nextSort(sort, "runId"))}>Run</button></th>
+                <th><button onClick={() => setSort(nextSort(sort, "last_seen_at"))}>Last Seen</button></th>
+              </tr>
+            </thead>
+            <tbody>
+              {loading ? (
+                <tr><td colSpan={18}>Loading...</td></tr>
+              ) : results?.items.length ? (
+                results.items.map((item) => {
+                  const categories = parseStringArrayJson(item.category_tree);
+                  return (
+                    <tr key={`${item.runId}-${item.seller_id}-${item.asin}`}>
+                      <td><a href={`http://amazon.com/dp/${item.asin}`} target="_blank" rel="noreferrer">{item.asin}</a></td>
+                      <td className="product-col" title={item.product_title || undefined}>{item.product_title || "-"}</td>
+                      <td>{item.brand || "-"}</td>
+                      <td>{categories.at(-1) || "-"}</td>
+                      <td>{formatNumber(item.monthly_sold)}</td>
+                      <td>{formatNumber(item.seller_count)}</td>
+                      <td>{formatAmazonSeller(item.amazon_is_seller)}</td>
+                      <td>{formatNumber(item.sales_rank)}</td>
+                      <td>{formatCurrency(item.current_price)}</td>
+                      <td>{formatCurrency(item.avg_price_90d)}</td>
+                      <td>{item.verdict ? <span className={verdictBadgeClass(item.verdict)}>{item.verdict}</span> : "-"}</td>
+                      <td title={item.reasoning || undefined}>{formatNumber(item.confidence)}</td>
+                      <td>{item.seller_id}</td>
+                      <td>{item.seller_name || "-"}</td>
+                      <td>{formatNumber(item.rating_count)}</td>
+                      <td><span className="badge badge-ok">{item.sellability_status}</span></td>
+                      <td>{item.runId}</td>
+                      <td>{formatDate(item.last_seen_at)}</td>
+                    </tr>
+                  );
+                })
+              ) : (
+                <tr><td colSpan={18}>No sellable Stalker products found</td></tr>
+              )}
+            </tbody>
+          </table>
+        </div>
+        <div className="pager">
+          <div>Showing {results?.items.length ?? 0} of {results?.total ?? 0}</div>
+          <div>
+            <button disabled={page <= 1} onClick={() => setPage((p) => Math.max(1, p - 1))}>Previous</button>
+            <span style={{ padding: "0 8px" }}>Page {results?.page ?? page} / {results?.totalPages ?? 1}</span>
+            <button disabled={Boolean(results && page >= results.totalPages)} onClick={() => setPage((p) => p + 1)}>Next</button>
+          </div>
+        </div>
+      </div>
+    </div>
+  );
+}
+
 type AppRoute =
   | { kind: "dashboard" }
   | { kind: "run"; processType: ProcessType; runId: number }
-  | { kind: "products"; verdict: VerdictFilter };
+  | { kind: "products"; verdict: VerdictFilter }
+  | { kind: "stalker" }
+  | { kind: "stalker-products" };
 
 function parseRoute(pathname: string, search: string): AppRoute {
   const runMatch = pathname.match(/^\/runs\/(lead_analysis|category_analysis)\/(\d+)$/);
@@ -866,6 +1404,14 @@ function parseRoute(pathname: string, search: string): AppRoute {
     return { kind: "products", verdict };
   }
 
+  if (pathname === "/stalker") {
+    return { kind: "stalker" };
+  }
+
+  if (pathname === "/stalker/products") {
+    return { kind: "stalker-products" };
+  }
+
   return { kind: "dashboard" };
 }
 
@@ -890,6 +1436,16 @@ function App() {
     setRoute({ kind: "products", verdict });
   }
 
+  function openStalker() {
+    history.pushState({}, "", "/stalker");
+    setRoute({ kind: "stalker" });
+  }
+
+  function openStalkerProducts() {
+    history.pushState({}, "", "/stalker/products");
+    setRoute({ kind: "stalker-products" });
+  }
+
   function backToDashboard() {
     history.pushState({}, "", "/");
     setRoute({ kind: "dashboard" });
@@ -903,7 +1459,22 @@ function App() {
     return <ProductList verdict={route.verdict} onBack={backToDashboard} />;
   }
 
-  return <Dashboard onOpenRun={openRun} onOpenProducts={openProducts} />;
+  if (route.kind === "stalker") {
+    return <StalkerExplorer onBack={backToDashboard} onOpenProducts={openStalkerProducts} />;
+  }
+
+  if (route.kind === "stalker-products") {
+    return <StalkerProductsExplorer onBack={backToDashboard} onOpenSellers={openStalker} />;
+  }
+
+  return (
+    <Dashboard
+      onOpenRun={openRun}
+      onOpenProducts={openProducts}
+      onOpenStalker={openStalker}
+      onOpenStalkerProducts={openStalkerProducts}
+    />
+  );
 }
 
 const root = document.getElementById("root");

src/web/styles.css

@@ -41,9 +41,24 @@ p {
   gap: 10px;
 }
 
+.section-header {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 12px;
+}
+
+.button-row {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  flex-wrap: wrap;
+}
+
 .toolbar input,
 .toolbar select,
-button {
+button,
+.button-link {
   height: 36px;
   border-radius: 8px;
   border: 1px solid #d8dce0;
@@ -52,10 +67,29 @@ button {
   font-size: 14px;
 }
 
+.button-link {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  color: inherit;
+  text-decoration: none;
+}
+
 button {
   cursor: pointer;
 }
 
+button.danger {
+  border-color: #efb8b8;
+  color: #9f1c1c;
+  background: #fff6f6;
+}
+
+button:disabled {
+  cursor: not-allowed;
+  opacity: 0.58;
+}
+
 .table-wrap {
   overflow: auto;
   border: 1px solid #eceef0;
@@ -91,6 +125,23 @@ td {
   overflow-wrap: anywhere;
 }
 
+.inventory-col {
+  min-width: 360px;
+  max-width: 520px;
+  white-space: normal;
+  overflow-wrap: anywhere;
+}
+
+.inventory-col a {
+  display: inline-block;
+  margin-right: 8px;
+  margin-bottom: 4px;
+}
+
+.stalker-table {
+  min-width: 1320px;
+}
+
 th {
   background: #fafafb;
   font-weight: 600;
@@ -262,4 +313,9 @@ th button {
   .spark-grid {
     grid-template-columns: repeat(2, minmax(0, 1fr));
   }
+
+  .section-header {
+    align-items: flex-start;
+    flex-direction: column;
+  }
 }

src/writer.ts

@@ -1,5 +1,8 @@
 import { getDb } from "./database.ts";
 import type { AnalysisResult, SupplierAnalysisResult } from "./types.ts";
+import { mkdirSync } from "node:fs";
+import path from "node:path";
+import * as XLSX from "xlsx";
 
 export type RunCounts = {
   totalProducts: number;
@@ -93,6 +96,22 @@ export function writeResultsToDb(
   console.log(`Results written to SQLite database for run_id: ${runId}`);
 }
 
+export function writeResultsWorkbook(
+  results: AnalysisResult[],
+  outputFile: string,
+): void {
+  const outputDir = path.dirname(outputFile);
+  if (outputDir && outputDir !== ".") {
+    mkdirSync(outputDir, { recursive: true });
+  }
+
+  const workbook = XLSX.utils.book_new();
+  const worksheet = XLSX.utils.json_to_sheet(results.map(buildRow));
+  XLSX.utils.book_append_sheet(workbook, worksheet, "Results");
+  XLSX.writeFile(workbook, outputFile);
+  console.log(`Results workbook written: ${outputFile}`);
+}
+
 export function startRunInDb(
   dbPath: string,
   inputFile: string,