diff --git a/.github/workflows/v2.1-artifact-qualification.yml b/.github/workflows/v2.1-artifact-qualification.yml
index f5f41c6..877b7a0 100644
--- a/.github/workflows/v2.1-artifact-qualification.yml
+++ b/.github/workflows/v2.1-artifact-qualification.yml
@@ -2,10 +2,11 @@ name: v2.1 Artifact Qualification
 
 on:
   pull_request:
-    branches: [develop]
+    branches: [develop, main]
     paths:
       - .github/workflows/v2.1-artifact-qualification.yml
       - scripts/prepare-v2.1-npm-artifacts.mjs
+      - scripts/npm-provenance-identity.mjs
   workflow_dispatch:
     inputs:
       source_commit:
diff --git a/scripts/stable-publication-recovery.mjs b/scripts/stable-publication-recovery.mjs
new file mode 100644
index 0000000..4bdfb18
--- /dev/null
+++ b/scripts/stable-publication-recovery.mjs
@@ -0,0 +1,53 @@
+import assert from "node:assert/strict";
+import crypto from "node:crypto";
+
+// Offline, content-addressed verification of the additive Registry correction.
+// Historical releases without a correction retain their original checks.
+export function verifyPublicationRecovery(record, qualification, readBytes) {
+  if (record.version !== "2.1.0" && record.provenanceRecovery === undefined) return;
+  assert.equal(record.version, "2.1.0", "Unsupported provenance recovery version");
+  const reference = record.provenanceRecovery;
+  assert.ok(reference, "v2.1.0 publication requires its additive provenance recovery");
+  const expectedPath = "release/stable/v2.1.0/v2.1.0-provenance-recovery.json";
+  assert.equal(reference.path, expectedPath, "Recovery reference must use the versioned repository path");
+  assert.match(reference.sha256 ?? "", /^[a-f0-9]{64}$/);
+  const bytes = readBytes(expectedPath);
+  assert.equal(crypto.createHash("sha256").update(bytes).digest("hex"), reference.sha256, "Recovery file SHA-256 changed");
+  const recovery = JSON.parse(bytes.toString("utf8"));
+  assert.equal(recovery.schemaVersion, "scanly-v2.1-provenance-recovery-1");
+  assert.equal(recovery.version, record.version);
+  assert.equal(recovery.package, "@scanly/url-safety");
+  assert.equal(recovery.sourceCommit, qualification.identity.productSourceCommit);
+  assert.deepEqual(recovery.qualificationManifest, record.qualificationManifest);
+  assert.ok(Number.isSafeInteger(reference.runId) && reference.runId > 0, "Recovery run ID must be a positive integer");
+  assert.equal(recovery.runId, reference.runId, "Recovery run ID changed");
+  assert.ok(Number.isSafeInteger(recovery.runAttempt) && recovery.runAttempt > 0);
+  const publication = record.npm.find((entry) => entry.name === recovery.package);
+  assert.equal(publication?.provenanceIdentity?.invocationId, `https://github.com/Yangjunjie-Lin/Scanly/actions/runs/${reference.runId}/attempts/${recovery.runAttempt}`, "Published provenance does not identify the recovery run");
+  assert.equal(recovery.npmCredentialsUsedByCI, false);
+  // The original proof is outside the replacement evidence directory and is
+  // deliberately not replaced. Preserve both sides of the additive audit trail.
+  for (const [key, expected] of [
+    ["originalProvenance", "release/stable/v2.1.0/artifacts/provenance/scanly-url-safety-2.1.0.tgz.sigstore.json"],
+    ["replacementProvenance", "release/stable/v2.1.0/publication-recovery/provenance-A/scanly-url-safety-2.1.0.tgz.sigstore.json"],
+  ]) {
+    assert.equal(recovery[key]?.path, expected, `${key} must retain its exact versioned path`);
+    assert.match(recovery[key].sha256 ?? "", /^[a-f0-9]{64}$/);
+    assert.equal(crypto.createHash("sha256").update(readBytes(expected)).digest("hex"), recovery[key].sha256, `${key} SHA-256 changed`);
+  }
+  assert.equal(recovery.originalProvenance.registryAccepted, false);
+  assert.equal(recovery.artifact?.path, "release/stable/v2.1.0/artifacts/npm/scanly-url-safety-2.1.0.tgz");
+  const artifactBytes = readBytes(recovery.artifact.path);
+  assert.equal(crypto.createHash("sha256").update(artifactBytes).digest("hex"), recovery.artifact.sha256, "Recovered artifact SHA-256 changed");
+  assert.equal(crypto.createHash("sha512").update(artifactBytes).digest("hex"), recovery.artifact.sha512, "Recovered artifact SHA-512 changed");
+  assert.equal(publication.integrity, `sha512-${Buffer.from(recovery.artifact.sha512, "hex").toString("base64")}`, "Recovered artifact does not match the published integrity");
+  assert.ok(Array.isArray(recovery.evidence) && recovery.evidence.length === 26, "Recovery must retain both build reports, 22 proofs, workflow evidence and reproducibility report");
+  const seen = new Set();
+  for (const evidence of recovery.evidence) {
+    assert.ok(typeof evidence.path === "string" && evidence.path.startsWith("release/stable/v2.1.0/publication-recovery/") && !evidence.path.includes("..") && !evidence.path.includes("\\"), "Unsafe recovery evidence path");
+    assert.ok(!seen.has(evidence.path), "Duplicate recovery evidence"); seen.add(evidence.path);
+    assert.match(evidence.sha256 ?? "", /^[a-f0-9]{64}$/);
+    assert.equal(crypto.createHash("sha256").update(readBytes(evidence.path)).digest("hex"), evidence.sha256, `Recovery evidence changed: ${evidence.path}`);
+  }
+  assert.ok(recovery.evidence.some((entry) => entry.path === recovery.replacementProvenance?.path && entry.sha256 === recovery.replacementProvenance.sha256), "Replacement provenance must be covered by the verified evidence set");
+}
diff --git a/scripts/verify-stable-publication-record.mjs b/scripts/verify-stable-publication-record.mjs
index ea43b34..141d4a5 100644
--- a/scripts/verify-stable-publication-record.mjs
+++ b/scripts/verify-stable-publication-record.mjs
@@ -2,6 +2,7 @@ import crypto from "node:crypto";
 import { execFileSync } from "node:child_process";
 import fs from "node:fs";
 import path from "node:path";
+import { verifyPublicationRecovery } from "./stable-publication-recovery.mjs";
 
 const root = path.resolve(import.meta.dirname, "..");
 const stableRoot = path.join(root, "release", "stable");
@@ -43,6 +44,7 @@ for (const recordPath of recordPaths) {
 
   if (sha256(qualificationPath) !== record.qualificationManifest.sha256) fail(`${version}: qualification manifest hash changed.`);
   if (qualification.version !== version || qualification.stable !== "V2_STABLE_RELEASE_GO") fail(`${version}: qualification identity is not the frozen Stable GO record.`);
+  verifyPublicationRecovery(record, qualification, (relative) => fs.readFileSync(path.join(root, relative)));
 
   const tagObject = git("rev-parse", record.gitTag.name);
   const tagTarget = git("rev-parse", `${record.gitTag.name}^{}`);
diff --git a/tests/unit/stable-publication-recovery.test.ts b/tests/unit/stable-publication-recovery.test.ts
new file mode 100644
index 0000000..90017c5
--- /dev/null
+++ b/tests/unit/stable-publication-recovery.test.ts
@@ -0,0 +1,75 @@
+import { describe, expect, it } from "vitest";
+import fs from "node:fs";
+import crypto from "node:crypto";
+// @ts-expect-error release-only MJS has no SDK declaration
+import { verifyPublicationRecovery } from "../../scripts/stable-publication-recovery.mjs";
+
+const root = "release/stable/v2.1.0";
+const publication = () => JSON.parse(fs.readFileSync(`${root}/v2.1.0-publication-record.json`, "utf8"));
+const qualification = JSON.parse(fs.readFileSync(`${root}/v2.1.0-manifest.json`, "utf8"));
+const readBytes = (file: string) => fs.readFileSync(file);
+
+describe("immutable publication provenance recovery reference", () => {
+  it("verifies the actual additive record without rewriting it", () => {
+    expect(() => verifyPublicationRecovery(publication(), qualification, readBytes)).not.toThrow();
+  });
+  it.each(["2.0.0", "2.0.1"])("retains historical %s verification without requiring a new record", (version) => {
+    expect(() => verifyPublicationRecovery({ version }, {}, () => { throw new Error("unexpected read"); })).not.toThrow();
+  });
+  it("fails if the recovery reference or file is missing", () => {
+    const record = publication(); delete record.provenanceRecovery;
+    expect(() => verifyPublicationRecovery(record, qualification, readBytes)).toThrow();
+    expect(() => verifyPublicationRecovery(publication(), qualification, () => { throw new Error("ENOENT"); })).toThrow();
+  });
+  it.each(["path", "sha256", "runId"])("rejects a substituted reference %s", (field) => {
+    const record = publication(); record.provenanceRecovery[field] = field === "runId" ? 1 : "substituted";
+    expect(() => verifyPublicationRecovery(record, qualification, readBytes)).toThrow();
+  });
+  it("rejects changed bytes even if JSON remains valid", () => {
+    expect(() => verifyPublicationRecovery(publication(), qualification, (file: string) => Buffer.concat([readBytes(file), Buffer.from(" ")]))).toThrow(/SHA-256/);
+  });
+  it.each(["schemaVersion", "version", "package", "sourceCommit", "runId", "runAttempt"])("validates recovery %s independently of its digest", (field) => {
+    const record = publication(); const recovery = JSON.parse(readBytes(record.provenanceRecovery.path).toString());
+    recovery[field] = field.startsWith("run") ? -1 : "substituted";
+    const bytes = Buffer.from(JSON.stringify(recovery)); record.provenanceRecovery.sha256 = crypto.createHash("sha256").update(bytes).digest("hex");
+    expect(() => verifyPublicationRecovery(record, qualification, () => bytes)).toThrow();
+  });
+  it("binds the correction to the published URL Safety attestation", () => {
+    const record = publication(); record.npm.find((entry: { name: string }) => entry.name === "@scanly/url-safety").provenanceIdentity.invocationId = "substituted";
+    expect(() => verifyPublicationRecovery(record, qualification, readBytes)).toThrow();
+  });
+  it("rejects changes or deletion of any referenced proof", () => {
+    expect(() => verifyPublicationRecovery(publication(), qualification, (file: string) => file.includes("provenance-B/") ? Buffer.from("changed") : readBytes(file))).toThrow(/evidence changed/);
+    expect(() => verifyPublicationRecovery(publication(), qualification, (file: string) => { if (file.includes("provenance-A/")) throw new Error("ENOENT"); return readBytes(file); })).toThrow();
+  });
+  it.each(["changed", "missing"])("rejects a %s original proof outside the replacement directory", (mode) => {
+    const originalPath = `${root}/artifacts/provenance/scanly-url-safety-2.1.0.tgz.sigstore.json`;
+    expect(() => verifyPublicationRecovery(publication(), qualification, (file: string) => {
+      if (file !== originalPath) return readBytes(file);
+      if (mode === "missing") throw new Error("ENOENT");
+      return Buffer.from("changed");
+    })).toThrow();
+  });
+  it.each(["originalProvenance", "replacementProvenance", "artifact"])("rejects substituted %s paths even with an updated record digest", (key) => {
+    const record = publication(); const recovery = JSON.parse(readBytes(record.provenanceRecovery.path).toString());
+    recovery[key].path = "substituted";
+    const bytes = Buffer.from(JSON.stringify(recovery)); record.provenanceRecovery.sha256 = crypto.createHash("sha256").update(bytes).digest("hex");
+    expect(() => verifyPublicationRecovery(record, qualification, (file: string) => file === record.provenanceRecovery.path ? bytes : readBytes(file))).toThrow();
+  });
+  it("binds the recovery tarball to the published Registry integrity", () => {
+    const record = publication(); record.npm.find((entry: { name: string }) => entry.name === "@scanly/url-safety").integrity = "sha512-substituted";
+    expect(() => verifyPublicationRecovery(record, qualification, readBytes)).toThrow(/published integrity/);
+  });
+  it("rejects an evidence reference outside the versioned recovery directory", () => {
+    const record = publication(); const recovery = JSON.parse(readBytes(record.provenanceRecovery.path).toString());
+    recovery.evidence[0].path = "release/stable/v2.1.0/publication-recovery/../../outside.json";
+    const bytes = Buffer.from(JSON.stringify(recovery)); record.provenanceRecovery.sha256 = crypto.createHash("sha256").update(bytes).digest("hex");
+    expect(() => verifyPublicationRecovery(record, qualification, (file: string) => file === record.provenanceRecovery.path ? bytes : readBytes(file))).toThrow(/Unsafe/);
+  });
+  it("triggers real artifact qualification for helper-only changes on both maintained branches", () => {
+    const workflow = fs.readFileSync(".github/workflows/v2.1-artifact-qualification.yml", "utf8");
+    const pullRequest = workflow.split("  pull_request:")[1].split("  workflow_dispatch:")[0];
+    expect(pullRequest).toContain("branches: [develop, main]");
+    expect(pullRequest).toContain("- scripts/npm-provenance-identity.mjs");
+  });
+});