diff --git a/.github/scripts/pr-review/prepare.mjs b/.github/scripts/pr-review/prepare.mjs
index c283f1d..12c11cc 100644
--- a/.github/scripts/pr-review/prepare.mjs
+++ b/.github/scripts/pr-review/prepare.mjs
@@ -52,6 +52,7 @@ const maxDiffBytes = positiveInteger("MAX_DIFF_BYTES");
 const diffReadBufferBytes = maxDiffBytes + 64 * 1024;
 const automaticMaxDiffBytes = positiveInteger("AUTOMATIC_MAX_DIFF_BYTES");
 const largeDiffApproved = required("LARGE_DIFF_APPROVED") === "true";
+const privateRepository = required("PRIVATE_REPOSITORY") === "true";
 const chunkTargetBytes = positiveInteger("CHUNK_TARGET_BYTES");
 const ledgerPath = path.join(stateDir, "review-ledger.json");
 const generationsDir = path.join(stateDir, "generations");
@@ -97,7 +98,7 @@ if (fullDiff.length > maxDiffBytes) {
     `Pull-request diff is ${fullDiff.length} bytes; the configured total limit is ${maxDiffBytes} bytes.`,
   );
 }
-if (!largeDiffApproved && fullDiff.length > automaticMaxDiffBytes) {
+if (!privateRepository && !largeDiffApproved && fullDiff.length > automaticMaxDiffBytes) {
   throw new Error(
     `Pull-request diff is ${fullDiff.length} bytes; automatic reviews are limited to ${automaticMaxDiffBytes} bytes. A repository admin must comment @codex review approve ${headSha} on this PR to review this head.`,
   );
diff --git a/.github/scripts/pr-review/test.mjs b/.github/scripts/pr-review/test.mjs
index a69337c..705d2ff 100644
--- a/.github/scripts/pr-review/test.mjs
+++ b/.github/scripts/pr-review/test.mjs
@@ -154,6 +154,8 @@ assert.match(workflowSource, /^  review:\n(?:(?!^  \S)[\s\S])*?^      REVIEW_MAX
 assert.match(workflowSource, /^  review:\n(?:(?!^  \S)[\s\S])*?^      REVIEW_AUTOMATIC_MAX_DIFF_BYTES: '5000000'$/m);
 assert.match(workflowSource, /AUTOMATIC_MAX_DIFF_BYTES: \$\{\{ env\.REVIEW_AUTOMATIC_MAX_DIFF_BYTES \}\}/);
 assert.match(workflowSource, /LARGE_DIFF_APPROVED: \$\{\{ needs\.resolve\.outputs\.large_diff_approved \}\}/);
+assert.match(workflowSource, /PRIVATE_REPOSITORY: \$\{\{ needs\.resolve\.outputs\.private_repository \}\}/);
+assert.match(workflowSource, /private_repository', String\(pr\.base\.repo\?\.private === true\)/);
 assert.match(workflowSource, /getCollaboratorPermissionLevel/);
 assert.match(workflowSource, /^  publish:\n(?:(?!^  \S)[\s\S])*?^      REVIEW_MODEL: gpt-6-sol$/m);
 assert.match(workflowSource, /^  publish:\n(?:(?!^  \S)[\s\S])*?^      REVIEW_EFFORT: low$/m);
@@ -526,7 +528,7 @@ try {
   });
   assert.equal(plainPatch.status, 0);
   assert.ok(plainPatch.stdout.length < 1000);
-  const prepareBinary = (approved) => spawnSync(process.execPath, [
+  const prepareBinary = (approved, privateRepo = false, hardMax = "20000") => spawnSync(process.execPath, [
     path.join(path.dirname(new URL(import.meta.url).pathname), "prepare.mjs"),
   ], {
     cwd: binaryRepo,
@@ -538,9 +540,10 @@ try {
       PR_BASE_SHA: binaryBase,
       PR_HEAD_SHA: binaryHead,
       SESSION_KEY: "repo:1:pr:binary:v2",
-      MAX_DIFF_BYTES: "20000",
+      MAX_DIFF_BYTES: hardMax,
       AUTOMATIC_MAX_DIFF_BYTES: "4000",
       LARGE_DIFF_APPROVED: String(approved),
+      PRIVATE_REPOSITORY: String(privateRepo),
       CHUNK_TARGET_BYTES: "600",
       READINESS_CONTEXT_SHA256: "binary-context",
     },
@@ -549,6 +552,10 @@ try {
   assert.notEqual(blockedBinary.status, 0);
   assert.match(blockedBinary.stderr, /automatic reviews are limited to 4000 bytes/);
   assert.equal(prepareBinary(true).status, 0);
+  assert.equal(prepareBinary(false, true).status, 0);
+  const blockedPrivateHardCap = prepareBinary(false, true, "4000");
+  assert.notEqual(blockedPrivateHardCap.status, 0);
+  assert.match(blockedPrivateHardCap.stderr, /configured total limit is 4000 bytes/);
 
   const repo = path.join(temporary, "repo");
   fs.mkdirSync(repo);
@@ -590,12 +597,13 @@ try {
       MAX_DIFF_BYTES: "1000000",
       AUTOMATIC_MAX_DIFF_BYTES: "1000000",
       LARGE_DIFF_APPROVED: "false",
+      PRIVATE_REPOSITORY: "false",
       CHUNK_TARGET_BYTES: "600",
       READINESS_CONTEXT_SHA256: "context-v1",
     },
   });
   assert.equal(result.status, 0, result.stderr);
-  const prepareWithPolicy = (automaticMax, approved, hardMax = "1000000") =>
+  const prepareWithPolicy = (automaticMax, approved, hardMax = "1000000", privateRepo = false) =>
     spawnSync(process.execPath, [
       path.join(path.dirname(new URL(import.meta.url).pathname), "prepare.mjs"),
     ], {
@@ -611,6 +619,7 @@ try {
         MAX_DIFF_BYTES: hardMax,
         AUTOMATIC_MAX_DIFF_BYTES: automaticMax,
         LARGE_DIFF_APPROVED: String(approved),
+        PRIVATE_REPOSITORY: String(privateRepo),
         CHUNK_TARGET_BYTES: "600",
         READINESS_CONTEXT_SHA256: "context-v1",
       },
@@ -619,6 +628,7 @@ try {
   assert.notEqual(blockedAutomatic.status, 0);
   assert.match(blockedAutomatic.stderr, /automatic reviews are limited to 1000 bytes/);
   assert.equal(prepareWithPolicy("1000", true).status, 0);
+  assert.equal(prepareWithPolicy("1000", false, "1000000", true).status, 0);
   const blockedHardCap = prepareWithPolicy("1000", true, "1000");
   assert.notEqual(blockedHardCap.status, 0);
   assert.match(blockedHardCap.stderr, /configured total limit is 1000 bytes/);
@@ -660,6 +670,7 @@ try {
       MAX_DIFF_BYTES: "1000000",
       AUTOMATIC_MAX_DIFF_BYTES: "1000000",
       LARGE_DIFF_APPROVED: "false",
+      PRIVATE_REPOSITORY: "false",
       CHUNK_TARGET_BYTES: "600",
       READINESS_CONTEXT_SHA256: "context-v1",
     },
@@ -697,6 +708,7 @@ try {
       MAX_DIFF_BYTES: "1000000",
       AUTOMATIC_MAX_DIFF_BYTES: "1000000",
       LARGE_DIFF_APPROVED: "false",
+      PRIVATE_REPOSITORY: "false",
       CHUNK_TARGET_BYTES: "600",
       READINESS_CONTEXT_SHA256: "context-v1",
     },
@@ -757,8 +769,9 @@ try {
     PR_HEAD_SHA: mergedHead,
     SESSION_KEY: "repo:1:pr:2:v2",
     MAX_DIFF_BYTES: "1000000",
-      AUTOMATIC_MAX_DIFF_BYTES: "1000000",
-      LARGE_DIFF_APPROVED: "false",
+    AUTOMATIC_MAX_DIFF_BYTES: "1000000",
+    LARGE_DIFF_APPROVED: "false",
+    PRIVATE_REPOSITORY: "false",
     CHUNK_TARGET_BYTES: "600",
     READINESS_CONTEXT_SHA256: "context-v1",
   };
@@ -1106,8 +1119,9 @@ fs.writeFileSync(outputFile, JSON.stringify(result));
       env: { ...process.env, REPOSITORY_DIR: repo, PR_REVIEW_STATE_DIR: legacyState,
         PR_BASE_SHA: base, PR_HEAD_SHA: nextHead, SESSION_KEY: "repo:1:pr:2:v2",
         MAX_DIFF_BYTES: "1000000",
-      AUTOMATIC_MAX_DIFF_BYTES: "1000000",
-      LARGE_DIFF_APPROVED: "false", CHUNK_TARGET_BYTES: "600",
+        AUTOMATIC_MAX_DIFF_BYTES: "1000000",
+        LARGE_DIFF_APPROVED: "false",
+        PRIVATE_REPOSITORY: "false", CHUNK_TARGET_BYTES: "600",
         READINESS_CONTEXT_SHA256: "context-v1", GITHUB_OUTPUT: output },
     });
     assert.equal(prepared.status, 0, prepared.stderr);
@@ -1459,6 +1473,7 @@ fs.writeFileSync(outputFile, JSON.stringify(result));
       MAX_DIFF_BYTES: "1000000",
       AUTOMATIC_MAX_DIFF_BYTES: "1000000",
       LARGE_DIFF_APPROVED: "false",
+      PRIVATE_REPOSITORY: "false",
       CHUNK_TARGET_BYTES: "600",
       READINESS_CONTEXT_SHA256: "context-v1",
     },
diff --git a/.github/workflows/codex-openai-review.yml b/.github/workflows/codex-openai-review.yml
index da9d584..c470dbb 100644
--- a/.github/workflows/codex-openai-review.yml
+++ b/.github/workflows/codex-openai-review.yml
@@ -98,6 +98,7 @@ jobs:
       head_sha: ${{ steps.pr.outputs.head_sha }}
       request_comment_id: ${{ steps.pr.outputs.request_comment_id }}
       large_diff_approved: ${{ steps.pr.outputs.large_diff_approved }}
+      private_repository: ${{ steps.pr.outputs.private_repository }}
     steps:
       - name: Check out the exact comment-trigger implementation
         if: github.event_name == 'issue_comment'
@@ -193,6 +194,7 @@ jobs:
             }
             core.setOutput('eligible', String(eligible));
             core.setOutput('large_diff_approved', String(largeDiffApproved));
+            core.setOutput('private_repository', String(pr.base.repo?.private === true));
             core.setOutput('number', String(pr.number));
             core.setOutput('base_sha', pr.base.sha);
             core.setOutput('base_ref', pr.base.ref);
@@ -881,6 +883,7 @@ jobs:
           MAX_DIFF_BYTES: ${{ env.REVIEW_MAX_DIFF_BYTES }}
           AUTOMATIC_MAX_DIFF_BYTES: ${{ env.REVIEW_AUTOMATIC_MAX_DIFF_BYTES }}
           LARGE_DIFF_APPROVED: ${{ needs.resolve.outputs.large_diff_approved }}
+          PRIVATE_REPOSITORY: ${{ needs.resolve.outputs.private_repository }}
           CHUNK_TARGET_BYTES: ${{ inputs.chunk-target-bytes }}
           READINESS_CONTEXT_SHA256: ${{ steps.prepare_readiness.outputs.context_sha256 }}
         run: node "$REVIEWER_SOURCE_DIR/.github/scripts/pr-review/prepare.mjs"
diff --git a/README.md b/README.md
index 20212d9..d579748 100644
--- a/README.md
+++ b/README.md
@@ -32,11 +32,12 @@ and `actions: write` so the reviewer can restore the latest per-PR Codex
 session artifact and delete superseded snapshots only after a replacement
 upload succeeds.
 
-Complete binary-aware Git patches up to 5,000,000 bytes are reviewed
-automatically. Binary models, images, and other changed binary payloads count
-toward this limit even though their contents are not sent to the model. For a larger
-diff, an admin of the **calling repository** must post this line as a PR comment
-with the current full head commit SHA:
+In public caller repositories, complete binary-aware Git patches up to
+5,000,000 bytes are reviewed automatically. Binary models, images, and other
+changed binary payloads count toward this limit even though their contents are
+not sent to the model. For a larger public-repository diff, an admin of the
+**calling repository** must post this line as a PR comment with the current
+full head commit SHA:
 
 ```text
 @codex review approve <40-character-head-sha>
@@ -45,8 +46,11 @@ with the current full head commit SHA:
 The shared reviewer checks the comment author's admin permission in the caller
 repository and the live head SHA before model work. A push requires a new
 approval. This uses the existing `issue_comment` trigger and works for public
-and private callers without a GitHub Environment or per-repository approver
-configuration. Diffs above 100,000,000 bytes remain rejected.
+callers without a GitHub Environment or per-repository approver configuration.
+Private caller repositories skip the 5,000,000-byte approval gate and review
+automatically. The caller's base repository privacy comes from GitHub's PR API;
+unknown privacy is treated as public. Diffs above 100,000,000 bytes remain
+rejected in every repository.
 
 ## Behavior
 
@@ -155,7 +159,7 @@ configuration. Diffs above 100,000,000 bytes remain rejected.
   `pull_request_target` workflow and use the caller's explicitly forwarded
   secret. Secrets from the contributor's fork are not imported or used.
 - Automatic PR events permit an external contributor to consume review
-  requests up to the 5,000,000-byte automatic limit. Use a
+  requests up to the 5,000,000-byte automatic limit in public callers. Use a
   dedicated API project with appropriate usage limits and restrict the
   organization secret to selected repositories.
 - Complete diffs larger than 100,000,000 bytes fail before Codex runs. The