diff --git a/packages/gittensory-miner/lib/orb-export.d.ts b/packages/gittensory-miner/lib/orb-export.d.ts
new file mode 100644
index 0000000000..5595bc83af
--- /dev/null
+++ b/packages/gittensory-miner/lib/orb-export.d.ts
@@ -0,0 +1,42 @@
+import type { NormalizedPrOutcomePayload, PrOutcomeLedgerReader } from "./pr-outcome.js";
+
+/** OPT-IN default: a laptop miner exports nothing unless a contributor turns it on. */
+export const ORB_EXPORT_ENABLED_BY_DEFAULT: false;
+
+/** One anonymized outcome in an export batch — no raw repo name, PR number, or free-text reason. */
+export interface OrbExportRow {
+  repoHash: string;
+  prHash: string;
+  decision: string;
+  reasonBucket: string;
+  closedAt: string | null;
+}
+
+/** The local orb-export store: the per-instance anonymization secret + export cursor, in local SQLite. */
+export interface OrbExportStore {
+  dbPath: string;
+  getOrCreateAnonSecret(): string;
+  getCursor(): string | null;
+  setCursor(cursor: string): void;
+  close(): void;
+}
+
+/** A pr_outcome record as produced by `readPrOutcomes` (the local ledger's latest-per-PR reduction). */
+export type OrbExportOutcome = NormalizedPrOutcomePayload & { repoFullName: string };
+
+export function resolveOrbExportDbPath(env?: Record<string, string | undefined>): string;
+
+export function hmacAnonymize(value: string | number, secret: string): string;
+
+export function buildAnonymizedOrbBatch(
+  outcomes: Iterable<OrbExportOutcome> | Map<string, OrbExportOutcome>,
+  secret: string,
+): OrbExportRow[];
+
+export function openOrbExportStore(dbPath?: string): OrbExportStore;
+
+export function collectOrbExportBatch(options?: {
+  store: OrbExportStore;
+  eventLedger: PrOutcomeLedgerReader;
+  enabled?: boolean;
+}): OrbExportRow[] | null;
diff --git a/packages/gittensory-miner/lib/orb-export.js b/packages/gittensory-miner/lib/orb-export.js
new file mode 100644
index 0000000000..7d56b79f22
--- /dev/null
+++ b/packages/gittensory-miner/lib/orb-export.js
@@ -0,0 +1,133 @@
+import { chmodSync, mkdirSync } from "node:fs";
+import { homedir } from "node:os";
+import { dirname, join } from "node:path";
+import { DatabaseSync } from "node:sqlite";
+import { createHmac, randomBytes } from "node:crypto";
+import { readPrOutcomes } from "./pr-outcome.js";
+
+// Optional anonymized Orb telemetry export (#4277). The self-host Orb collector (src/selfhost/orb-collector.ts,
+// #1255) is ALWAYS-ON for a maintainer's own instance; a miner runs on a third-party contributor's laptop with a
+// much lower consent bar, so this export is OPT-IN (default OFF) — hence "optional". It mirrors the collector's
+// privacy posture: repo/PR identifiers are HMAC-anonymized with a per-instance DEDICATED secret (generated once,
+// persisted locally, single-purpose), and only a fixed low-cardinality reason bucket + the decision leave — never
+// raw repo names or free text. The data source is the local pr_outcome ledger (pr-outcome.js), not a hosted D1.
+// This module builds the anonymized batch and manages the local secret + cursor; performing the network POST is the
+// caller's job, so this stays pure over its inputs + local store and needs no network to test.
+
+/** OPT-IN: a laptop miner exports nothing unless a contributor explicitly turns it on. */
+export const ORB_EXPORT_ENABLED_BY_DEFAULT = false;
+
+const ANON_SECRET_KEY = "anon_secret";
+const CURSOR_KEY = "export_cursor";
+const defaultDbFileName = "orb-export.sqlite3";
+
+export function resolveOrbExportDbPath(env = process.env) {
+  const explicitPath =
+    typeof env.GITTENSORY_MINER_ORB_EXPORT_DB === "string" ? env.GITTENSORY_MINER_ORB_EXPORT_DB.trim() : "";
+  if (explicitPath) return explicitPath;
+
+  const explicitConfigDir =
+    typeof env.GITTENSORY_MINER_CONFIG_DIR === "string" ? env.GITTENSORY_MINER_CONFIG_DIR.trim() : "";
+  if (explicitConfigDir) return join(explicitConfigDir, defaultDbFileName);
+
+  const configHome =
+    typeof env.XDG_CONFIG_HOME === "string" && env.XDG_CONFIG_HOME.trim()
+      ? env.XDG_CONFIG_HOME.trim()
+      : join(homedir(), ".config");
+  return join(configHome, "gittensory-miner", defaultDbFileName);
+}
+
+function normalizeDbPath(dbPath) {
+  const path = (dbPath ?? resolveOrbExportDbPath()).trim();
+  if (!path) throw new Error("invalid_orb_export_db_path");
+  return path;
+}
+
+/** HMAC a value with the per-instance secret — mirrors orb-collector.ts's hmacField (sha256, first 24 hex). */
+export function hmacAnonymize(value, secret) {
+  if (typeof secret !== "string" || !secret) throw new Error("invalid_anon_secret");
+  return createHmac("sha256", secret).update(String(value)).digest("hex").slice(0, 24);
+}
+
+/**
+ * Turn the local pr_outcome map (pr-outcome.js `readPrOutcomes`) into an anonymized export batch: repo and PR
+ * identifiers are HMAC-hashed, and only the `decision` + a low-cardinality `reasonBucket` (already one of the
+ * miner's `REJECTION_REASONS`, else `"none"`) + `closedAt` leave. Pure and deterministic (rows sorted by prHash).
+ * Accepts either the Map `readPrOutcomes` returns or any iterable of outcome records.
+ */
+export function buildAnonymizedOrbBatch(outcomes, secret) {
+  const iterable = outcomes && typeof outcomes.values === "function" ? outcomes.values() : outcomes;
+  const rows = [];
+  for (const outcome of iterable ?? []) {
+    if (!outcome || typeof outcome.repoFullName !== "string" || !outcome.repoFullName.trim()) continue;
+    if (!Number.isInteger(outcome.prNumber) || outcome.prNumber <= 0) continue;
+    rows.push({
+      repoHash: hmacAnonymize(outcome.repoFullName, secret),
+      prHash: hmacAnonymize(`${outcome.repoFullName}:${outcome.prNumber}`, secret),
+      decision: outcome.decision,
+      reasonBucket: typeof outcome.reason === "string" && outcome.reason ? outcome.reason : "none",
+      closedAt: typeof outcome.closedAt === "string" && outcome.closedAt ? outcome.closedAt : null,
+    });
+  }
+  rows.sort((a, b) => a.prHash.localeCompare(b.prHash));
+  return rows;
+}
+
+/**
+ * Open/create the local orb-export store: a small key/value SQLite table holding the per-instance anonymization
+ * secret and the export cursor. Mirrors the other miner ledgers' node:sqlite pattern — a `0o700` config dir and a
+ * `0o600` file, since the secret must never leave this machine.
+ */
+export function openOrbExportStore(dbPath = resolveOrbExportDbPath()) {
+  const resolvedPath = normalizeDbPath(dbPath);
+  mkdirSync(dirname(resolvedPath), { recursive: true, mode: 0o700 });
+  const db = new DatabaseSync(resolvedPath);
+  chmodSync(resolvedPath, 0o600);
+  db.exec("PRAGMA busy_timeout = 5000");
+  db.exec(`CREATE TABLE IF NOT EXISTS orb_export_meta (key TEXT PRIMARY KEY, value TEXT NOT NULL)`);
+
+  const getStatement = db.prepare("SELECT value FROM orb_export_meta WHERE key = ?");
+  const setStatement = db.prepare(
+    "INSERT INTO orb_export_meta (key, value) VALUES (?, ?) ON CONFLICT(key) DO UPDATE SET value = excluded.value",
+  );
+  const readValue = (key) => {
+    const row = getStatement.get(key);
+    return row && typeof row.value === "string" ? row.value : null;
+  };
+
+  return {
+    dbPath: resolvedPath,
+    /** The per-instance DEDICATED anonymization secret — generated once (256-bit) and persisted, then reused
+     *  forever so a repo/PR always hashes the same way. Single-purpose: only this export uses it. */
+    getOrCreateAnonSecret() {
+      const existing = readValue(ANON_SECRET_KEY);
+      if (existing) return existing;
+      const generated = randomBytes(32).toString("hex");
+      setStatement.run(ANON_SECRET_KEY, generated);
+      return generated;
+    },
+    /** The export watermark (opaque string), or null before the first export. */
+    getCursor() {
+      return readValue(CURSOR_KEY);
+    },
+    setCursor(cursor) {
+      setStatement.run(CURSOR_KEY, String(cursor));
+    },
+    close() {
+      db.close();
+    },
+  };
+}
+
+/**
+ * Collect the anonymized Orb export batch from the local pr_outcome ledger. OPT-IN: returns null (exports nothing)
+ * unless `enabled` is true — a third-party contributor's laptop must explicitly turn this on. Never performs the
+ * network POST itself; the caller sends the returned batch to the Orb ingest endpoint and then advances the store
+ * cursor, so this function stays pure over its inputs and the local store.
+ */
+export function collectOrbExportBatch({ store, eventLedger, enabled = ORB_EXPORT_ENABLED_BY_DEFAULT } = {}) {
+  if (!enabled) return null;
+  if (!store || typeof store.getOrCreateAnonSecret !== "function") throw new Error("invalid_orb_export_store");
+  const outcomes = readPrOutcomes(eventLedger);
+  return buildAnonymizedOrbBatch(outcomes, store.getOrCreateAnonSecret());
+}
diff --git a/test/unit/miner-orb-export.test.ts b/test/unit/miner-orb-export.test.ts
new file mode 100644
index 0000000000..6e6f5ab76c
--- /dev/null
+++ b/test/unit/miner-orb-export.test.ts
@@ -0,0 +1,142 @@
+import { mkdtempSync, rmSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+
+import {
+  ORB_EXPORT_ENABLED_BY_DEFAULT,
+  buildAnonymizedOrbBatch,
+  collectOrbExportBatch,
+  hmacAnonymize,
+  openOrbExportStore,
+} from "../../packages/gittensory-miner/lib/orb-export.js";
+import type { OrbExportOutcome } from "../../packages/gittensory-miner/lib/orb-export.js";
+
+let dir: string;
+function storePath() {
+  return join(dir, "orb-export.sqlite3");
+}
+
+/** A minimal in-memory event ledger of pr_outcome events, matching pr-outcome.js's readEvents contract. */
+function fakeLedger(events: Array<{ type: string; repoFullName: string; payload: unknown }>) {
+  return { readEvents: () => events };
+}
+function outcomeEvent(repoFullName: string, prNumber: number, decision: "merged" | "closed", reason: string | null) {
+  return { type: "pr_outcome", repoFullName, payload: { prNumber, decision, closedAt: "2026-01-01T00:00:00Z", reason } };
+}
+
+beforeEach(() => {
+  dir = mkdtempSync(join(tmpdir(), "orb-export-"));
+});
+afterEach(() => {
+  rmSync(dir, { recursive: true, force: true });
+});
+
+describe("orb-export store (#4277)", () => {
+  it("defaults to opt-OUT (export disabled unless explicitly enabled)", () => {
+    expect(ORB_EXPORT_ENABLED_BY_DEFAULT).toBe(false);
+  });
+
+  it("generates a stable 256-bit per-instance anon key and persists it across reopens", () => {
+    const store = openOrbExportStore(storePath());
+    const anonKey = store.getOrCreateAnonSecret();
+    expect(anonKey).toMatch(/^[0-9a-f]{64}$/);
+    expect(store.getOrCreateAnonSecret()).toBe(anonKey); // same within a session
+    store.close();
+
+    const reopened = openOrbExportStore(storePath());
+    expect(reopened.getOrCreateAnonSecret()).toBe(anonKey); // same across reopens
+    reopened.close();
+  });
+
+  it("tracks an export cursor (null until set)", () => {
+    const store = openOrbExportStore(storePath());
+    expect(store.getCursor()).toBeNull();
+    store.setCursor("2026-01-02T00:00:00Z");
+    expect(store.getCursor()).toBe("2026-01-02T00:00:00Z");
+    store.close();
+  });
+});
+
+describe("hmacAnonymize", () => {
+  const anonKey = "a".repeat(64);
+
+  it("is deterministic per (value, key), hides the raw value, and separates distinct values", () => {
+    const hashed = hmacAnonymize("owner/repo", anonKey);
+    expect(hashed).toBe(hmacAnonymize("owner/repo", anonKey));
+    expect(hashed).toMatch(/^[0-9a-f]{24}$/);
+    expect(hashed).not.toContain("owner");
+    expect(hmacAnonymize("owner/other", anonKey)).not.toBe(hashed);
+    expect(hmacAnonymize("owner/repo", "b".repeat(64))).not.toBe(hashed); // different key → different hash
+  });
+
+  it("throws on a missing key", () => {
+    expect(() => hmacAnonymize("owner/repo", "")).toThrow(/invalid_anon_secret/);
+  });
+});
+
+describe("buildAnonymizedOrbBatch", () => {
+  const anonKey = "c".repeat(64);
+
+  it("anonymizes a readPrOutcomes-shaped map, buckets a null reason to 'none', and sorts deterministically", () => {
+    const outcomes = new Map<string, OrbExportOutcome>([
+      ["owner/repo:2", { repoFullName: "owner/repo", prNumber: 2, decision: "closed", closedAt: "2026-01-02T00:00:00Z", reason: "gate_close" }],
+      ["owner/repo:1", { repoFullName: "owner/repo", prNumber: 1, decision: "merged", closedAt: null, reason: null }],
+    ]);
+    const batch = buildAnonymizedOrbBatch(outcomes, anonKey);
+    expect(batch).toHaveLength(2);
+    // no raw identifiers leak
+    const json = JSON.stringify(batch);
+    expect(json).not.toContain("owner/repo");
+    expect(json).not.toContain('"prNumber"');
+    const merged = batch.find((r) => r.decision === "merged");
+    expect(merged?.reasonBucket).toBe("none");
+    expect(merged?.closedAt).toBeNull();
+    expect(merged?.repoHash).toBe(hmacAnonymize("owner/repo", anonKey));
+    const closed = batch.find((r) => r.decision === "closed");
+    expect(closed?.reasonBucket).toBe("gate_close");
+    // deterministic prHash ordering
+    expect([...batch].sort((a, b) => a.prHash.localeCompare(b.prHash))).toEqual(batch);
+  });
+
+  it("skips malformed outcome records", () => {
+    const batch = buildAnonymizedOrbBatch(
+      [
+        null,
+        { repoFullName: "owner/repo", prNumber: 1.5, decision: "merged", reason: null, closedAt: null },
+        { repoFullName: "", prNumber: 1, decision: "merged", reason: null, closedAt: null },
+      ] as never,
+      anonKey,
+    );
+    expect(batch).toEqual([]);
+  });
+});
+
+describe("collectOrbExportBatch", () => {
+  it("returns null when export is not enabled (opt-in gate)", () => {
+    const store = openOrbExportStore(storePath());
+    expect(collectOrbExportBatch({ store, eventLedger: fakeLedger([]), enabled: false })).toBeNull();
+    // default (no `enabled`) is also opt-out
+    expect(collectOrbExportBatch({ store, eventLedger: fakeLedger([]) })).toBeNull();
+    store.close();
+  });
+
+  it("builds an anonymized batch from the local pr_outcome ledger when enabled", () => {
+    const store = openOrbExportStore(storePath());
+    const ledger = fakeLedger([
+      outcomeEvent("owner/a", 1, "merged", null),
+      outcomeEvent("owner/b", 2, "closed", "superseded_by_duplicate"),
+    ]);
+    const batch = collectOrbExportBatch({ store, eventLedger: ledger, enabled: true });
+    expect(batch).not.toBeNull();
+    expect(batch).toHaveLength(2);
+    expect(JSON.stringify(batch)).not.toContain("owner/");
+    store.close();
+  });
+
+  it("throws on an invalid store", () => {
+    expect(() =>
+      collectOrbExportBatch({ store: {} as never, eventLedger: fakeLedger([]), enabled: true }),
+    ).toThrow(/invalid_orb_export_store/);
+  });
+});