feat: support deferred review posting

README.md

@@ -71,6 +71,9 @@ ecr review
 ecr review --pr 123
 # …and post it as the PR comment
 ecr review --pr 123 --post
+# Preview once, save the exact result, and post it later without another model run
+ecr review --repo owner/repo --pr 123 --save-review --json
+ecr post-review --artifact .expo-code-review/.runs/deferred/<artifact>.json --repo owner/repo --pr 123
 ```
 
 Options (most to least common):
@@ -79,6 +82,7 @@ Options (most to least common):
 | --- | --- |
 | `--pr <n>` | Review GitHub PR #n by number (diff fetched via `gh`, no checkout); not combinable with `--base`/`--head`/`--staged`. |
 | `--post` | With `--pr`, also post the result as the PR comment (needs `gh` auth). Omit to preview only; re-run with `--post` to publish. |
+| `--save-review` | With explicit `--repo` + `--pr`, save the exact preview as a private postable artifact. Mutually exclusive with `--post`. |
 | `--staged` | Review only staged changes (index vs HEAD; not combinable with `--base`/`--head`). |
 | `--base <ref>` | Base ref to diff against (default: merge-base with the default branch). |
 | `--head <ref>` | Head ref to diff (default: working tree, incl. uncommitted changes). |
@@ -111,6 +115,7 @@ is a ready example to adapt.
 | `ecr setup-auth [--yes]` | Walk through getting model credentials for local runs (ChatGPT/Claude sign-in and/or API keys), printing the `export` lines for your shell config. |
 | `ecr review [options]` | Review local changes and print an advisory review (default command). |
 | `ecr review --scope <name>` | Review only one routing scope over just that scope's changed files. |
+| `ecr post-review --artifact <path> --repo <owner/repo> --pr <n>` | Post an exact saved PR preview without re-running models; refuses target, head, config, or break-glass drift. |
 | `ecr ci` | Review the current GitHub PR and post/update a comment. For GitHub Actions. |
 | `ecr doctor [--list-scopes]` | Check environment, config, credentials, and (with a manifest) scopes. |
 | `ecr feedback [--repo <owner/repo>]` | Report which findings PR authors pushed back on, across history. See below. |
@@ -661,6 +666,12 @@ that the PR comment embeds for machine consumers. The same totals are printed as
 one-line summary to the terminal / CI job log at the end of each run, so cache reuse
 is visible even in CI (where the run log is ephemeral).
 
+`ecr review --save-review` additionally writes a versioned artifact under
+`.expo-code-review/.runs/deferred/` with owner-only permissions. It contains the
+verified final review and bounded feedback metadata, but no credential. `ecr
+post-review` schema-validates it and refuses to post if its explicit repo/PR, live
+head commit, or local comment-policy fingerprint no longer matches.
+
 </details>
 
 <a id="other-providers"></a>

llp/0007-cli-commands-and-ci.explainer.md

@@ -35,6 +35,36 @@ Flag exclusivity is rejected outright, never silently resolved, because silently
 
 `--scope --post` posts under the derived marker `<rootTag>:<scope>`, taken from the ROOT config's tag via `scopedCommentTag(rootConfig.commentTag, scope)` [observed: `src/commands/review.ts:230`]. This is not a local convenience — it must match `ecr ci`'s per-scope derivation exactly, so a standalone local scope post and CI's per-scope post/clear/reconcile paths always target the identical comment. The schema ban on scope-level `commentTag` overrides (LLP 0006) is the only thing keeping the two derivations from ever diverging; relaxing that schema rule would silently break marker consistency between local and CI posts.
 
+## Deferred Review Posting
+
+`ecr review --save-review --repo owner/repo --pr N` separates the expensive model
+run from the outward-facing GitHub write without changing the review between them.
+After terminal preview it writes the exact verified `CoordinatorOutput` plus bounded
+feedback records to an owner-only, versioned artifact under
+`.expo-code-review/.runs/deferred/`. The artifact contains no credential. Saving is
+PR-only, requires an explicit repo, and is mutually exclusive with immediate
+`--post`; scopes and alternate config directories are rejected in v1 rather than
+silently producing an artifact the post command cannot faithfully reconstruct
+[observed: `src/commands/review.ts` `validateReviewArgs`,
+`writeDeferredReviewArtifact`].
+
+`ecr post-review --artifact P --repo owner/repo --pr N` performs no model call. It
+loads config from the local checkout (the terminal user remains the trust principal),
+strictly schema-validates and byte-caps the artifact, and requires four independent
+bindings before any GitHub write: artifact target equals the explicit argv repo/PR;
+the live PR head equals the reviewed 40-hex OID; the current comment tag,
+break-glass marker, and feedback policy hash to the stored posting-policy
+fingerprint; and the live break-glass check returns false. A break-glass API error
+fails closed on this deferred path. Only then does it pass the stored review through
+the ordinary `GitHubReporter`, preserving the single-comment lifecycle, dismissal
+state, hidden review trace, links, pins, and feedback merge [observed:
+`src/commands/post-review.ts`, `src/core/deferred-review.ts`].
+
+The explicit repo/PR is deliberately repeated at post time. An artifact is data, not
+authority: even a locally replaced artifact cannot redirect a generic “post this”
+command to another PR. Head and policy drift require a fresh preview instead of
+publishing stale findings or rendering them under rules the model run never saw.
+
 ## ecr ci: The Trusted-Root Run
 
 `ecr ci` runs inside GitHub Actions with credentials, reading content authored by whoever opened the PR (including a fork PR reachable through the not-fork-restricted `issue_comment` `/review` workflow). Its structure is dictated by that threat model (LLP 0001).

src/__tests__/deferred-review.test.ts

@@ -0,0 +1,234 @@
+import { mkdtemp, readFile, rm, stat, writeFile } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import path from "node:path";
+
+import { afterEach, expect, test } from "bun:test";
+
+import { parsePostReviewArgs, publishDeferredReview } from "../commands/post-review.js";
+import { parseReviewArgs, validateReviewArgs } from "../commands/review.js";
+import type { LoadedConfig } from "../config/schema.js";
+import {
+  assertDeferredReviewCurrent,
+  DEFERRED_REVIEW_ARTIFACT_MAX_BYTES,
+  DeferredReviewArtifactSchema,
+  readDeferredReviewArtifact,
+  reviewPostingConfigFingerprint,
+  writeDeferredReviewArtifact,
+  type DeferredReviewArtifact,
+} from "../core/deferred-review.js";
+
+const roots: string[] = [];
+afterEach(async () => {
+  await Promise.all(roots.splice(0).map((root) => rm(root, { recursive: true, force: true })));
+});
+
+async function tempRoot(): Promise<string> {
+  const root = await mkdtemp(path.join(tmpdir(), "ecr-deferred-review-"));
+  roots.push(root);
+  return root;
+}
+
+function config(configDir: string, overrides: Partial<LoadedConfig> = {}): LoadedConfig {
+  return {
+    configDir,
+    commentTag: "expo-ai-code-reviewer",
+    breakGlassMarker: "/skip-review",
+    feedback: {
+      mode: "annotate",
+      dismiss: "never",
+      match: "both",
+      protectedCategories: ["security", "secrets"],
+      maxAdjudications: 10,
+    },
+    ...overrides,
+  } as LoadedConfig;
+}
+
+function artifact(overrides: Partial<DeferredReviewArtifact> = {}): DeferredReviewArtifact {
+  return DeferredReviewArtifactSchema.parse({
+    version: 1,
+    createdAt: "2026-08-06T00:00:00.000Z",
+    repo: "expo/expo",
+    pr: 48557,
+    headSha: "a".repeat(40),
+    configFingerprint: "b".repeat(64),
+    review: {
+      decision: "approve",
+      findings: [],
+      summary: "No findings.",
+      incomplete: [],
+      reviewTrace: {
+        version: 1,
+        trust: "unverified-model-diagnostics",
+        agents: { correctness: { checked: ["Traced the changed path."], uncertainties: [] } },
+      },
+    },
+    ...overrides,
+  });
+}
+
+test("writes and reads an owner-only exact review artifact", async () => {
+  const root = await tempRoot();
+  const loaded = config(path.join(root, ".expo-code-review"));
+  const saved = await writeDeferredReviewArtifact(loaded, {
+    repo: "expo/expo",
+    pr: 48557,
+    headSha: "a".repeat(40),
+    review: artifact().review,
+  });
+
+  expect(saved).toContain(path.join(".runs", "deferred", "expo-expo-pr-48557-"));
+  expect((await stat(saved)).mode & 0o777).toBe(0o600);
+  const parsed = await readDeferredReviewArtifact(saved);
+  expect(parsed.review).toEqual(artifact().review);
+  expect(parsed.configFingerprint).toBe(reviewPostingConfigFingerprint(loaded));
+  expect(JSON.parse(await readFile(saved, "utf8"))).toEqual(parsed);
+});
+
+test("strictly rejects malformed, oversized, and extended artifacts", async () => {
+  const root = await tempRoot();
+  const malformed = path.join(root, "malformed.json");
+  await writeFile(malformed, "{nope", "utf8");
+  await expect(readDeferredReviewArtifact(malformed)).rejects.toThrow("not valid JSON");
+
+  const oversized = path.join(root, "oversized.json");
+  await writeFile(oversized, "x".repeat(DEFERRED_REVIEW_ARTIFACT_MAX_BYTES + 1), "utf8");
+  await expect(readDeferredReviewArtifact(oversized)).rejects.toThrow("is over");
+
+  expect(() => DeferredReviewArtifactSchema.parse({ ...artifact(), injected: true })).toThrow();
+});
+
+test("refuses to create an artifact that its bounded reader could not reopen", async () => {
+  const root = await tempRoot();
+  const loaded = config(path.join(root, ".expo-code-review"));
+  await expect(
+    writeDeferredReviewArtifact(loaded, {
+      repo: "expo/expo",
+      pr: 48557,
+      headSha: "a".repeat(40),
+      review: artifact({ review: { ...artifact().review, summary: "x".repeat(1_000_000) } }).review,
+    }),
+  ).rejects.toThrow("would be");
+});
+
+test("refuses target, head, and posting-policy drift independently", () => {
+  const saved = artifact();
+  const expected = {
+    repo: saved.repo,
+    pr: saved.pr,
+    headSha: saved.headSha,
+    configFingerprint: saved.configFingerprint,
+  };
+  expect(() => assertDeferredReviewCurrent(saved, expected)).not.toThrow();
+  expect(() => assertDeferredReviewCurrent(saved, { ...expected, repo: "expo/eas-cli" })).toThrow(
+    "explicitly requested",
+  );
+  expect(() =>
+    assertDeferredReviewCurrent(saved, { ...expected, headSha: "c".repeat(40) }),
+  ).toThrow("head changed");
+  expect(() =>
+    assertDeferredReviewCurrent(saved, { ...expected, configFingerprint: "d".repeat(64) }),
+  ).toThrow("posting policy changed");
+});
+
+test("posting config fingerprint covers every comment-policy input", () => {
+  const root = "/repo/.expo-code-review";
+  const base = config(root);
+  const fingerprint = reviewPostingConfigFingerprint(base);
+  expect(reviewPostingConfigFingerprint(config(root, { commentTag: "other" }))).not.toBe(
+    fingerprint,
+  );
+  expect(reviewPostingConfigFingerprint(config(root, { breakGlassMarker: "/different" }))).not.toBe(
+    fingerprint,
+  );
+  expect(
+    reviewPostingConfigFingerprint(config(root, { feedback: { ...base.feedback, mode: "off" } })),
+  ).not.toBe(fingerprint);
+});
+
+test("post-review argv requires an explicit artifact, repo, and safe PR", () => {
+  expect(
+    parsePostReviewArgs(["--artifact", "/tmp/review.json", "--repo", "expo/expo", "--pr", "48557"]),
+  ).toEqual({
+    artifact: "/tmp/review.json",
+    repo: "expo/expo",
+    pr: 48557,
+    help: false,
+  });
+  expect(() => parsePostReviewArgs(["--pr", "9007199254740992"])).toThrow("safe integer");
+  expect(() => parsePostReviewArgs(["--wat"])).toThrow("Unknown argument");
+});
+
+test("save-review is PR-only, explicit-target, and mutually exclusive with immediate post", () => {
+  const valid = parseReviewArgs([
+    "--repo",
+    "expo/expo",
+    "--pr",
+    "48557",
+    "--save-review",
+    "--json",
+  ]);
+  expect(() => validateReviewArgs(valid)).not.toThrow();
+  expect(() => validateReviewArgs(parseReviewArgs(["--pr", "48557", "--save-review"]))).toThrow(
+    "requires explicit --repo",
+  );
+  expect(() =>
+    validateReviewArgs(
+      parseReviewArgs(["--repo", "expo/expo", "--pr", "48557", "--save-review", "--post"]),
+    ),
+  ).toThrow("mutually exclusive");
+  expect(() =>
+    validateReviewArgs(
+      parseReviewArgs(["--repo", "expo/expo", "--pr", "48557", "--save-review", "--scope", "api"]),
+    ),
+  ).toThrow("does not support --scope");
+});
+
+test("deferred publisher checks break-glass before posting the exact review", async () => {
+  const saved = artifact();
+  const calls: string[] = [];
+  let reportedArgs: unknown[] | undefined;
+  const poster = {
+    checkBreakGlass: async () => {
+      calls.push("break-glass");
+      return false;
+    },
+    report: async (...args: unknown[]) => {
+      calls.push("report");
+      reportedArgs = args;
+    },
+  };
+  expect(
+    await publishDeferredReview(poster, saved, async () => {
+      calls.push("final-gate");
+    }),
+  ).toBe("posted");
+  expect(calls).toEqual(["break-glass", "final-gate", "report"]);
+  expect(reportedArgs).toEqual([saved.review, saved.feedback]);
+
+  calls.length = 0;
+  expect(await publishDeferredReview({ ...poster, checkBreakGlass: async () => true }, saved)).toBe(
+    "break-glass",
+  );
+  expect(calls).toEqual([]);
+
+  await expect(
+    publishDeferredReview(
+      {
+        ...poster,
+        checkBreakGlass: async () => {
+          throw new Error("GitHub unavailable");
+        },
+      },
+      saved,
+    ),
+  ).rejects.toThrow("GitHub unavailable");
+  expect(calls).toEqual([]);
+
+  await expect(
+    publishDeferredReview(poster, saved, async () => {
+      throw new Error("head changed");
+    }),
+  ).rejects.toThrow("head changed");
+  expect(calls).toEqual(["break-glass"]);
+});

src/cli.ts

@@ -5,6 +5,7 @@ import { dismissCommand } from "./commands/dismiss.js";
 import { doctorCommand } from "./commands/doctor.js";
 import { feedbackCommand } from "./commands/feedback.js";
 import { initCommand } from "./commands/init.js";
+import { postReviewCommand } from "./commands/post-review.js";
 import { refCheckCommand } from "./commands/ref-check.js";
 import { reviewCommand } from "./commands/review.js";
 import { setupAuthCommand } from "./commands/setup-auth.js";
@@ -14,6 +15,7 @@ const USAGE = `expo-code-review (ecr) — config-driven AI code reviewer
 
 Usage:
   ecr review [options]   Review local changes (default). See \`ecr review --help\`.
+  ecr post-review --artifact <path> --repo <owner/repo> --pr <n>   Post an exact saved preview.
   ecr ci                 Review the current PR and post a comment (GitHub Actions).
   ecr dismiss --pr <n> <id...>     Hide a finding on a PR (see \`ecr dismiss --help\`).
   ecr undismiss --pr <n> <id...>   Restore a dismissed finding.
@@ -48,6 +50,9 @@ async function main(): Promise<void> {
     case "review":
       await reviewCommand(rest);
       break;
+    case "post-review":
+      await postReviewCommand(rest);
+      break;
     case "ci":
       await ciCommand(rest);
       break;

src/commands/post-review.ts

@@ -0,0 +1,182 @@
+// @ref LLP 0007#deferred-review-posting [implements] — no-model post of an exact, target-bound preview artifact
+import path from "node:path";
+
+import { loadReviewConfig } from "../config/load.js";
+import {
+  assertDeferredReviewCurrent,
+  readDeferredReviewArtifact,
+  reviewPostingConfigFingerprint,
+  type DeferredReviewArtifact,
+} from "../core/deferred-review.js";
+import { repoRoot } from "../core/exec.js";
+import { errorMessage } from "../core/util.js";
+import { GitHubReporter } from "../reporters/github.js";
+import { GitHubPRSource, isCommitOid } from "../sources/github-pr.js";
+
+const USAGE = `ecr post-review — post an exact saved PR review without re-running models
+
+Usage:
+  ecr post-review --artifact <path> --repo <owner/repo> --pr <n>
+
+The artifact must come from \`ecr review --save-review --repo <owner/repo> --pr <n>\`.
+Before writing to GitHub, this command verifies the explicit repo/PR, the live PR
+head commit, the local posting policy, and the PR's break-glass marker.
+`;
+
+export interface PostReviewArgs {
+  artifact?: string;
+  repo?: string;
+  pr?: number;
+  help: boolean;
+}
+
+function requireValue(flag: string, value: string | undefined): string {
+  if (value === undefined || value.startsWith("--")) {
+    throw new Error(`${flag} requires a value`);
+  }
+  return value;
+}
+
+export function parsePostReviewArgs(argv: string[]): PostReviewArgs {
+  const args: PostReviewArgs = { help: false };
+  for (let i = 0; i < argv.length; i++) {
+    const arg = argv[i];
+    switch (arg) {
+      case "--artifact":
+        args.artifact = requireValue(arg, argv[++i]);
+        break;
+      case "--repo":
+        args.repo = requireValue(arg, argv[++i]);
+        break;
+      case "--pr": {
+        const value = requireValue(arg, argv[++i]);
+        const number = Number(value);
+        if (!Number.isSafeInteger(number) || number <= 0) {
+          throw new Error(`--pr requires a positive safe integer (got "${value}")`);
+        }
+        args.pr = number;
+        break;
+      }
+      case "-h":
+      case "--help":
+        args.help = true;
+        break;
+      default:
+        throw new Error(`Unknown argument: ${arg}`);
+    }
+  }
+  return args;
+}
+
+function validatePostReviewArgs(
+  args: PostReviewArgs,
+): asserts args is PostReviewArgs & { artifact: string; repo: string; pr: number } {
+  if (!args.artifact || !args.repo || args.pr == null) {
+    throw new Error("--artifact, --repo, and --pr are all required");
+  }
+  if (!/^[A-Za-z0-9_.-]+\/[A-Za-z0-9_.-]+$/.test(args.repo)) {
+    throw new Error(`--repo requires owner/repo (got "${args.repo}")`);
+  }
+}
+
+interface DeferredReviewPoster {
+  checkBreakGlass(): Promise<boolean>;
+  report(
+    review: DeferredReviewArtifact["review"],
+    feedback?: DeferredReviewArtifact["feedback"],
+  ): Promise<void>;
+}
+
+/** Break-glass errors fail closed: no report call occurs unless the check says false. */
+export async function publishDeferredReview(
+  poster: DeferredReviewPoster,
+  artifact: DeferredReviewArtifact,
+  assertReadyToPost: () => Promise<void> = async () => {},
+): Promise<"posted" | "break-glass"> {
+  if (await poster.checkBreakGlass()) {
+    return "break-glass";
+  }
+  await assertReadyToPost();
+  await poster.report(artifact.review, artifact.feedback);
+  return "posted";
+}
+
+export async function postReviewCommand(argv: string[]): Promise<void> {
+  let args: PostReviewArgs;
+  try {
+    args = parsePostReviewArgs(argv);
+    if (args.help) {
+      process.stdout.write(USAGE);
+      return;
+    }
+    validatePostReviewArgs(args);
+  } catch (error) {
+    process.stderr.write(`${errorMessage(error)}\n\n${USAGE}`);
+    process.exitCode = 2;
+    return;
+  }
+
+  // Resolve before chdir so a relative artifact path keeps the caller's meaning.
+  const artifactPath = path.resolve(process.cwd(), args.artifact);
+  try {
+    const root = await repoRoot();
+    if (root && root !== process.cwd()) {
+      process.chdir(root);
+    }
+    const cwd = process.cwd();
+    const [artifact, config] = await Promise.all([
+      readDeferredReviewArtifact(artifactPath),
+      loadReviewConfig(cwd),
+    ]);
+    const source = new GitHubPRSource({ prNumber: args.pr, repo: args.repo, cwd });
+    const headSha = (await source.getMetadata()).headOid;
+    if (!isCommitOid(headSha)) {
+      throw new Error(`could not resolve a full head commit for ${args.repo}#${args.pr}`);
+    }
+    assertDeferredReviewCurrent(artifact, {
+      repo: args.repo,
+      pr: args.pr,
+      headSha,
+      configFingerprint: reviewPostingConfigFingerprint(config),
+    });
+
+    const reporter = new GitHubReporter({
+      prNumber: args.pr,
+      repo: args.repo,
+      commentTag: config.commentTag,
+      breakGlassMarker: config.breakGlassMarker,
+      cwd,
+      feedback: config.feedback,
+      headSha,
+    });
+    const result = await publishDeferredReview(reporter, artifact, async () => {
+      // Re-fetch rather than reusing GitHubPRSource's memoized metadata, and reload
+      // config after the break-glass API call. This narrows the unavoidable remote
+      // TOCTOU window and prevents a head/policy change during setup from reaching
+      // the reporter.
+      const [latestMetadata, latestConfig] = await Promise.all([
+        new GitHubPRSource({ prNumber: args.pr, repo: args.repo, cwd }).getMetadata(),
+        loadReviewConfig(cwd),
+      ]);
+      if (!isCommitOid(latestMetadata.headOid)) {
+        throw new Error(`could not re-resolve a full head commit for ${args.repo}#${args.pr}`);
+      }
+      assertDeferredReviewCurrent(artifact, {
+        repo: args.repo,
+        pr: args.pr,
+        headSha: latestMetadata.headOid,
+        configFingerprint: reviewPostingConfigFingerprint(latestConfig),
+      });
+    });
+    if (result === "break-glass") {
+      process.stderr.write(
+        `Not posting: ${config.breakGlassMarker} is set on ${args.repo}#${args.pr}.\n`,
+      );
+      return;
+    }
+    process.stderr.write(`Posted saved review to ${args.repo}#${args.pr}.\n`);
+  } catch (error) {
+    process.stderr.write(`Saved review was not posted: ${errorMessage(error)}\n`);
+    process.exitCode = 2;
+  }
+}

src/commands/review.ts

@@ -4,10 +4,11 @@ import { loadRoutingManifest, resolveScopes, scopedCommentTag } from "../config/
 import { repoRoot, resolveRepo } from "../core/exec.js";
 import { errorMessage } from "../core/util.js";
 import { readContextFile } from "../core/context-file.js";
+import { writeDeferredReviewArtifact } from "../core/deferred-review.js";
 import { feedbackNeedsRunSeam } from "../core/adjudicate.js";
 import { runReview } from "../core/review.js";
 import { LocalGitSource } from "../sources/local-git.js";
-import { GitHubPRSource } from "../sources/github-pr.js";
+import { GitHubPRSource, isCommitOid } from "../sources/github-pr.js";
 import type { ReviewSource } from "../sources/source.js";
 import { memoizeSource, stackConfirmFromConfig, stackWalkFromConfig } from "../sources/source.js";
 import { TerminalReporter } from "../reporters/terminal.js";
@@ -17,7 +18,8 @@ const USAGE = `ecr review — AI code review, printed to your terminal
 
 Usage:
   ecr review [options]                 review local changes
-  ecr review --pr <n> [--post]         review a GitHub PR by number
+  ecr review --pr <n> [--post | --save-review]
+                                       review a GitHub PR by number
 
 Source (pick one):
   (default)          diff the working tree against the merge-base
@@ -33,6 +35,8 @@ Options:
   --post               with --pr: also post the result as the PR comment (needs
                        \`gh\` auth). Omit to only preview here; re-run with --post
                        to publish.
+  --save-review        with explicit --repo + --pr: save this exact preview as a
+                       postable artifact for a later \`ecr post-review\` command.
   --agents <a,b>       run only these agents (comma-separated ids); default: all
   --route              let the router pick relevant agents from the diff
   --scope <name>       review only this routing scope (needs a routing.jsonc);
@@ -57,13 +61,14 @@ principal here. In \`ecr ci\`, config loads from the PR's trusted base commit.
 Exit codes: 0 approve / approve-with-comments, 1 request-changes, 2 error.
 `;
 
-interface ReviewArgs {
+export interface ReviewArgs {
   base?: string;
   head?: string;
   staged: boolean;
   pr?: number;
   repo?: string;
   post: boolean;
+  saveReview: boolean;
   agents?: string[];
   route: boolean;
   scope?: string;
@@ -82,10 +87,11 @@ function requireValue(flag: string, value: string | undefined): string {
   return value;
 }
 
-function parseArgs(argv: string[]): ReviewArgs {
+export function parseReviewArgs(argv: string[]): ReviewArgs {
   const args: ReviewArgs = {
     staged: false,
     post: false,
+    saveReview: false,
     route: false,
     stackAware: false,
     json: false,
@@ -107,8 +113,8 @@ function parseArgs(argv: string[]): ReviewArgs {
       case "--pr": {
         const value = requireValue(arg, argv[++i]);
         const number = Number(value);
-        if (!Number.isInteger(number) || number <= 0) {
-          throw new Error(`--pr requires a positive PR number (got "${value}")`);
+        if (!Number.isSafeInteger(number) || number <= 0) {
+          throw new Error(`--pr requires a positive safe integer (got "${value}")`);
         }
         args.pr = number;
         break;
@@ -119,6 +125,9 @@ function parseArgs(argv: string[]): ReviewArgs {
       case "--post":
         args.post = true;
         break;
+      case "--save-review":
+        args.saveReview = true;
+        break;
       case "--agents":
         args.agents = requireValue(arg, argv[++i])
           .split(",")
@@ -160,7 +169,7 @@ function parseArgs(argv: string[]): ReviewArgs {
 export async function reviewCommand(argv: string[]): Promise<void> {
   let args: ReviewArgs;
   try {
-    args = parseArgs(argv);
+    args = parseReviewArgs(argv);
   } catch (error) {
     process.stderr.write(`${errorMessage(error)}\n\n${USAGE}`);
     process.exitCode = 2;
@@ -173,7 +182,7 @@ export async function reviewCommand(argv: string[]): Promise<void> {
   }
 
   try {
-    validateArgs(args);
+    validateReviewArgs(args);
   } catch (error) {
     process.stderr.write(`${errorMessage(error)}\n\n${USAGE}`);
     process.exitCode = 2;
@@ -333,11 +342,16 @@ export async function reviewCommand(argv: string[]): Promise<void> {
     const config = await loadReviewConfig(cwd, { configDir: args.configDir });
     const source = makeSource();
 
-    // Build the PR reporter up front when posting, so adjudicate mode can judge the
+    // Build the PR reporter up front when posting OR saving a postable preview, so
+    // adjudicate mode can judge the
     // PR's replies against the source before the result is rendered. Feedback only
     // has replies to match when reviewing a PR and posting (the terminal preview never
-    // renders annotations), so it is wired only on the --post --pr path.
-    const { repo: postRepo, error: postRepoError } = await resolvePostRepo(args, cwd);
+    // renders annotations), so it is wired only when a later/current post is possible.
+    const { repo: postRepo, error: postRepoError } = await resolvePostRepo(
+      { ...args, post: args.post || args.saveReview },
+      cwd,
+    );
+    const headSha = postRepo != null && args.pr != null ? await reviewedHeadSha(source) : undefined;
     const reporter =
       postRepo != null && args.pr != null
         ? new GitHubReporter({
@@ -347,7 +361,7 @@ export async function reviewCommand(argv: string[]): Promise<void> {
             breakGlassMarker: config.breakGlassMarker,
             cwd,
             feedback: config.feedback,
-            headSha: await reviewedHeadSha(source),
+            headSha,
           })
         : null;
 
@@ -372,6 +386,22 @@ export async function reviewCommand(argv: string[]): Promise<void> {
     // Always print the result here first.
     await new TerminalReporter({ json: args.json, noFail: args.noFail }).report(review);
 
+    if (args.saveReview) {
+      if (postRepo == null || args.pr == null || !isCommitOid(headSha)) {
+        throw new Error(
+          `could not save a postable review: ${postRepoError ? errorMessage(postRepoError) : "the PR head commit could not be resolved"}`,
+        );
+      }
+      const artifactPath = await writeDeferredReviewArtifact(config, {
+        repo: postRepo,
+        pr: args.pr,
+        headSha,
+        review,
+        feedback: review.feedback,
+      });
+      process.stderr.write(`\nSaved postable review artifact: ${artifactPath}\n`);
+    }
+
     // Then, only if asked, publish the same result to the PR.
     if (args.pr != null && args.post) {
       if (reporter) {
@@ -460,14 +490,23 @@ export async function resolvePostRepo(
 
 // @ref LLP 0007#ecr-review-local-trust-and-flag-rules [implements] — mutually exclusive flags rejected outright, never silently ignored
 /** Reject flag combinations that don't make sense together. */
-function validateArgs(args: ReviewArgs): void {
+export function validateReviewArgs(args: ReviewArgs): void {
   if (args.pr != null && (args.base || args.head || args.staged)) {
     throw new Error(
       "--pr reviews a PR by its diff and cannot be combined with --base/--head/--staged.",
     );
   }
-  if (args.pr == null && (args.repo || args.post)) {
-    throw new Error("--repo/--post only apply together with --pr.");
+  if (args.pr == null && (args.repo || args.post || args.saveReview)) {
+    throw new Error("--repo/--post/--save-review only apply together with --pr.");
+  }
+  if (args.saveReview && !args.repo) {
+    throw new Error("--save-review requires explicit --repo owner/repo.");
+  }
+  if (args.saveReview && args.post) {
+    throw new Error("--save-review and --post are mutually exclusive.");
+  }
+  if (args.saveReview && (args.scope || args.configDir)) {
+    throw new Error("--save-review does not support --scope or --config-dir.");
   }
   // Same rule as --repo/--post: the stack walk needs a PR to walk from, so a bare
   // --stack-aware would be silently ignored — reject it instead.

src/core/deferred-review.ts

@@ -0,0 +1,163 @@
+// @ref LLP 0007#deferred-review-posting [implements] — exact preview artifact, explicit target binding, and stale-head/config refusal
+import { createHash, randomUUID } from "node:crypto";
+import { mkdir, open, writeFile } from "node:fs/promises";
+import path from "node:path";
+
+import { z } from "zod";
+
+import type { LoadedConfig } from "../config/schema.js";
+import {
+  CoordinatorOutputSchema,
+  FeedbackRecordSchema,
+  type CoordinatorOutput,
+  type FeedbackRecord,
+} from "./schema.js";
+
+export const DEFERRED_REVIEW_ARTIFACT_VERSION = 1;
+export const DEFERRED_REVIEW_ARTIFACT_MAX_BYTES = 1_000_000;
+const READ_CHUNK_BYTES = 65_536;
+
+const RepoSchema = z.string().regex(/^[A-Za-z0-9_.-]+\/[A-Za-z0-9_.-]+$/, "expected owner/repo");
+const CommitOidSchema = z.string().regex(/^[0-9a-f]{40}$/i, "expected a full commit OID");
+
+/**
+ * A postable review produced by one completed local PR review. The review and
+ * feedback are the exact verified values that terminal preview rendered; target,
+ * head and posting-policy bindings are checked again before any GitHub write.
+ */
+export const DeferredReviewArtifactSchema = z
+  .object({
+    version: z.literal(DEFERRED_REVIEW_ARTIFACT_VERSION),
+    createdAt: z.string().datetime(),
+    repo: RepoSchema,
+    pr: z.number().int().positive().safe(),
+    headSha: CommitOidSchema,
+    configFingerprint: z.string().regex(/^[0-9a-f]{64}$/i),
+    review: CoordinatorOutputSchema,
+    feedback: z.array(FeedbackRecordSchema).optional(),
+  })
+  .strict();
+
+export type DeferredReviewArtifact = z.infer<typeof DeferredReviewArtifactSchema>;
+
+export interface DeferredReviewInput {
+  repo: string;
+  pr: number;
+  headSha: string;
+  review: CoordinatorOutput;
+  feedback?: FeedbackRecord[];
+}
+
+/** Bind the artifact to the local config fields that affect the posted comment. */
+export function reviewPostingConfigFingerprint(config: LoadedConfig): string {
+  return createHash("sha256")
+    .update(
+      JSON.stringify({
+        commentTag: config.commentTag,
+        breakGlassMarker: config.breakGlassMarker,
+        feedback: config.feedback,
+      }),
+    )
+    .digest("hex");
+}
+
+function artifactFilename(repo: string, pr: number): string {
+  const safeRepo = repo.replace(/[^A-Za-z0-9_.-]+/g, "-");
+  return `${safeRepo}-pr-${pr}-${randomUUID()}.json`;
+}
+
+/**
+ * Persist with owner-only permissions and exclusive creation. The random filename
+ * avoids overwriting another session's pending review; no credential is stored.
+ */
+export async function writeDeferredReviewArtifact(
+  config: LoadedConfig,
+  input: DeferredReviewInput,
+): Promise<string> {
+  const artifact = DeferredReviewArtifactSchema.parse({
+    version: DEFERRED_REVIEW_ARTIFACT_VERSION,
+    createdAt: new Date().toISOString(),
+    repo: input.repo,
+    pr: input.pr,
+    headSha: input.headSha,
+    configFingerprint: reviewPostingConfigFingerprint(config),
+    review: input.review,
+    ...(input.feedback ? { feedback: input.feedback } : {}),
+  });
+  const serialized = `${JSON.stringify(artifact, null, 2)}\n`;
+  const serializedBytes = Buffer.byteLength(serialized);
+  if (serializedBytes > DEFERRED_REVIEW_ARTIFACT_MAX_BYTES) {
+    throw new Error(
+      `deferred review artifact would be ${serializedBytes} bytes; maximum is ${DEFERRED_REVIEW_ARTIFACT_MAX_BYTES}`,
+    );
+  }
+  const dir = path.join(config.configDir, ".runs", "deferred");
+  await mkdir(dir, { recursive: true });
+  const artifactPath = path.join(dir, artifactFilename(input.repo, input.pr));
+  await writeFile(artifactPath, serialized, {
+    encoding: "utf8",
+    flag: "wx",
+    mode: 0o600,
+  });
+  return artifactPath;
+}
+
+/** Read once, byte-cap before parsing, then cross the strict schema boundary. */
+export async function readDeferredReviewArtifact(
+  artifactPath: string,
+): Promise<DeferredReviewArtifact> {
+  const handle = await open(artifactPath, "r");
+  const chunks: Buffer[] = [];
+  let total = 0;
+  try {
+    for (;;) {
+      const chunk = Buffer.alloc(READ_CHUNK_BYTES);
+      const { bytesRead } = await handle.read(chunk, 0, READ_CHUNK_BYTES);
+      if (bytesRead === 0) {
+        break;
+      }
+      total += bytesRead;
+      if (total > DEFERRED_REVIEW_ARTIFACT_MAX_BYTES) {
+        throw new Error(
+          `deferred review artifact is over ${DEFERRED_REVIEW_ARTIFACT_MAX_BYTES} bytes`,
+        );
+      }
+      chunks.push(chunk.subarray(0, bytesRead));
+    }
+  } finally {
+    await handle.close();
+  }
+  const raw = Buffer.concat(chunks);
+  let parsed: unknown;
+  try {
+    parsed = JSON.parse(raw.toString("utf8"));
+  } catch (error) {
+    throw new Error(`deferred review artifact is not valid JSON: ${String(error)}`);
+  }
+  return DeferredReviewArtifactSchema.parse(parsed);
+}
+
+/**
+ * Final no-write gate. Every value comes from a separate authority: repo/PR from
+ * explicit argv, head from live GitHub, config from the local trusted checkout.
+ */
+export function assertDeferredReviewCurrent(
+  artifact: DeferredReviewArtifact,
+  expected: { repo: string; pr: number; headSha: string; configFingerprint: string },
+): void {
+  if (artifact.repo !== expected.repo || artifact.pr !== expected.pr) {
+    throw new Error(
+      `artifact targets ${artifact.repo}#${artifact.pr}, not explicitly requested ${expected.repo}#${expected.pr}`,
+    );
+  }
+  if (artifact.headSha !== expected.headSha) {
+    throw new Error(
+      `PR head changed after preview (${artifact.headSha} → ${expected.headSha}); run a fresh review instead of posting stale findings`,
+    );
+  }
+  if (artifact.configFingerprint !== expected.configFingerprint) {
+    throw new Error(
+      "local review posting policy changed after preview; run a fresh review before posting",
+    );
+  }
+}