fix(ci): block agent PR title prefixes

.changeset/block-agent-pr-title-prefixes.md

@@ -0,0 +1,7 @@
+---
+---
+
+ci: reject agent-prefixed PR titles such as `[codex]`.
+
+Empty changeset because this only affects repository automation and agent
+guidance, not the published Java SDK package.

.github/workflows/commitlint.yml

@@ -24,6 +24,11 @@ jobs:
       - name: Install dependencies
         run: npm ci
 
+      - name: Check for agent/tool PR title prefix
+        env:
+          PR_TITLE: ${{ github.event.pull_request.title }}
+        run: node scripts/check-pr-title.cjs "$PR_TITLE"
+
       - name: Validate PR title follows conventional commits
         env:
           PR_TITLE: ${{ github.event.pull_request.title }}

CLAUDE.md

@@ -55,6 +55,7 @@ Build infrastructure:
 - **`*Request` builds, `*Response` doesn't.** This naming invariant prevents IDE auto-complete from suggesting `.builder()` on response types.
 - **SLF4J for logging.** Not `java.util.logging`.
 - **Conventional Commits** for commit messages. Types: `feat fix docs style refactor perf test build ci chore revert`.
+- **Conventional PR titles** without agent/tool prefixes. Never start titles with `[codex]`, `[claude]`, `[cursor]`, or similar ownership tags.
 - **Changesets** for adopter-visible changes (`npx changeset`).
 
 ## Don't

scripts/check-pr-title.cjs

@@ -0,0 +1,18 @@
+#!/usr/bin/env node
+
+const title = (process.argv.slice(2).join(' ') || process.env.PR_TITLE || '').trim();
+
+if (!title) {
+  console.error('PR title is empty.');
+  process.exit(1);
+}
+
+const disallowedAgentPrefix =
+  /^\[(codex|claude|claude-code|openai|chatgpt|copilot|cursor|aider|devin|agent|ai)\](?:\s|:|-|$)/i;
+
+if (disallowedAgentPrefix.test(title)) {
+  console.error(`Invalid PR title: ${title}`);
+  console.error('Remove the leading agent/tool prefix. Use a concrete conventional-commits title instead, for example:');
+  console.error('  fix(ci): block agent PR title prefixes');
+  process.exit(1);
+}