diff --git a/.changeset/amber-foxes-leap.md b/.changeset/amber-foxes-leap.md
new file mode 100644
index 000000000..f27ee3d1e
--- /dev/null
+++ b/.changeset/amber-foxes-leap.md
@@ -0,0 +1,5 @@
+---
+type: Fixed
+pr: 2659
+---
+**`/gsd-profile-user` now writes the runtime-native instruction file on Codex and other AGENTS-native runtimes** — `generate-claude-profile` hardcoded `.claude/CLAUDE.md` for both project and global scope, ignoring the runtime-aware resolution that #3163 wired into the sibling `generate-claude-md` handler. The #3163 fix diverged when it didn't propagate here, so running `$gsd-profile-user --refresh` on a Codex install created/modified Claude configuration instead of producing a Codex `AGENTS.md` profile. The command now resolves its target through the shared runtime policy: project scope uses `getProjectInstructionFile(runtime)` and global scope derives `~/.<config-home>/<instruction-basename>`, so codex lands at `~/.codex/AGENTS.md`. Claude behaviour is preserved. A parity test guards against future re-divergence between the two handlers. (#2659)
diff --git a/src/profile-output.cts b/src/profile-output.cts
index daa2d4634..1a26c1e23 100644
--- a/src/profile-output.cts
+++ b/src/profile-output.cts
@@ -1028,20 +1028,52 @@ function cmdGenerateClaudeProfile(cwd: string, options: CmdGenerateClaudeProfile
 
   const sectionContent = sectionLines.join('\n');
 
+  // #2565: resolve target through effective runtime policy instead of
+  // hardcoded .claude/CLAUDE.md. Mirrors the #3163 fix applied to
+  // cmdGenerateClaudeMd above; that fix diverged when it didn't propagate
+  // here, leaving /gsd-profile-user writing Claude files on Codex installs.
+  // - Project scope: getProjectInstructionFile(runtime) is the single source
+  //   of truth (AGENTS.md for codex/opencode/kilo/kimi/unknown; GEMINI.md for
+  //   antigravity; .github/copilot-instructions.md for copilot).
+  // - Global scope: ~/.<config-home>/<instruction-basename>, derived from
+  //   getGlobalConfigDir + basename(getProjectInstructionFile), so codex lands
+  //   at ~/.codex/AGENTS.md. Claude global is preserved byte-for-byte (no
+  //   env-var drift beyond the prior hardcoded path).
+  // - GSD_RUNTIME env var takes precedence over config.runtime (mirrors the
+  //   #3163 env-precedence contract). Non-claude always wins over a stale
+  //   claude_md_path (#3163 rationale: an AGENTS-native project must never
+  //   write to CLAUDE.md even if a prior Claude setup left claude_md_path).
+  let config: Record<string, unknown> = {};
+  try {
+    config = loadConfig(cwd);
+  } catch { /* use defaults */ }
+  const effectiveRuntime = resolveRuntimeNameFromCandidates(
+    process.env['GSD_RUNTIME'],
+    config['runtime'],
+  );
+  const isClaudeRuntime = !effectiveRuntime || effectiveRuntime === 'claude';
+
   let targetPath: string;
   if (options.global) {
-    targetPath = path.join(os.homedir(), '.claude', 'CLAUDE.md');
+    if (isClaudeRuntime) {
+      targetPath = path.join(os.homedir(), '.claude', 'CLAUDE.md');
+    } else {
+      targetPath = path.join(
+        getGlobalConfigDir(effectiveRuntime),
+        path.basename(getProjectInstructionFile(effectiveRuntime)),
+      );
+    }
   } else if (options.output) {
     targetPath = path.isAbsolute(options.output) ? options.output : path.join(cwd, options.output);
   } else {
-    // Read claude_md_path from config; #1098 default is ./.claude/CLAUDE.md
+    // Read claude_md_path from config; #1098 default is .claude/CLAUDE.md
     // (kept consistent with cmdGenerateClaudeMd so the profile section and the
     // managed sections land in the same file on a config-less project).
-    let configClaudeMdPath = './.claude/CLAUDE.md';
-    try {
-      const config = loadConfig(cwd);
-      if (config['claude_md_path']) configClaudeMdPath = config['claude_md_path'] as string;
-    } catch { /* use default */ }
+    let configClaudeMdPath = '.claude/CLAUDE.md';
+    if (config['claude_md_path']) configClaudeMdPath = config['claude_md_path'] as string;
+    if (!isClaudeRuntime) {
+      configClaudeMdPath = getProjectInstructionFile(effectiveRuntime);
+    }
     targetPath = path.isAbsolute(configClaudeMdPath) ? configClaudeMdPath : path.join(cwd, configClaudeMdPath);
   }
 
diff --git a/tests/claude-md.test.cjs b/tests/claude-md.test.cjs
index c323d0bc5..3c0938f03 100644
--- a/tests/claude-md.test.cjs
+++ b/tests/claude-md.test.cjs
@@ -488,3 +488,202 @@ describe('bug #3163: generate-claude-md uses AGENTS.md for Codex runtime', () =>
 });
   });
 }
+
+// ─── Bug #2565: generate-claude-profile runtime-aware target ─────────────
+// #2565 is the same divergence class as #3163 above, but in the sibling
+// handler cmdGenerateClaudeProfile (the /gsd-profile-user surface) instead
+// of cmdGenerateClaudeMd. The #3163 fix did not propagate here, so
+// generate-claude-profile kept writing .claude/CLAUDE.md on Codex installs.
+// These tests pin the parity contract: both handlers MUST resolve the
+// project instruction file through getProjectInstructionFile for non-claude
+// runtimes, and the final test asserts the two never diverge again
+// (the "generative fix divergence" guard from CLAUDE.md).
+describe('bug #2565: generate-claude-profile uses AGENTS.md for Codex runtime', () => {
+  let tmpDir;
+
+  beforeEach(() => {
+    tmpDir = createTempProject();
+    fs.writeFileSync(
+      path.join(tmpDir, '.planning', 'PROJECT.md'),
+      '# Test Project\n\nA Codex-hosted project.\n',
+      'utf-8'
+    );
+  });
+
+  afterEach(() => {
+    cleanup(tmpDir);
+  });
+
+  function writeAnalysis() {
+    const analysisPath = path.join(tmpDir, '.planning', 'analysis.json');
+    fs.writeFileSync(
+      analysisPath,
+      JSON.stringify({
+        dimensions: { communication_style: { rating: 'terse-direct', confidence: 'HIGH' } },
+        data_source: 'test',
+      }),
+      'utf-8'
+    );
+    return analysisPath;
+  }
+
+  function writeConfig(obj) {
+    fs.writeFileSync(
+      path.join(tmpDir, '.planning', 'config.json'),
+      JSON.stringify(obj),
+      'utf-8'
+    );
+  }
+
+  test('project scope writes AGENTS.md when config.runtime is codex (stale claude_md_path overridden)', () => {
+    writeConfig({ runtime: 'codex', claude_md_path: './CLAUDE.md' });
+    const analysisPath = writeAnalysis();
+
+    const result = runGsdTools(
+      ['generate-claude-profile', '--analysis', analysisPath],
+      tmpDir,
+      { HOME: tmpDir }
+    );
+    assert.ok(result.success, `Command failed: ${result.error}`);
+
+    const parsed = JSON.parse(result.output);
+    const realTmpDir = fs.realpathSync(tmpDir);
+    const expectedAgentsPath = path.join(realTmpDir, 'AGENTS.md');
+
+    assert.strictEqual(parsed.claude_md_path, expectedAgentsPath,
+      `Expected output path to be AGENTS.md but got: ${parsed.claude_md_path}`);
+    assert.ok(fs.existsSync(expectedAgentsPath), 'AGENTS.md must exist after generation');
+    assert.ok(!fs.existsSync(path.join(realTmpDir, 'CLAUDE.md')),
+      'CLAUDE.md must not be created for Codex runtime');
+  });
+
+  test('project scope: GSD_RUNTIME=codex env var overrides config.runtime=claude', () => {
+    writeConfig({ runtime: 'claude', claude_md_path: './CLAUDE.md' });
+    const analysisPath = writeAnalysis();
+
+    const result = runGsdTools(
+      ['generate-claude-profile', '--analysis', analysisPath],
+      tmpDir,
+      { HOME: tmpDir, GSD_RUNTIME: 'codex' }
+    );
+    assert.ok(result.success, `Command failed: ${result.error}`);
+
+    const parsed = JSON.parse(result.output);
+    const realTmpDir = fs.realpathSync(tmpDir);
+    assert.strictEqual(parsed.claude_md_path, path.join(realTmpDir, 'AGENTS.md'),
+      `Expected AGENTS.md under GSD_RUNTIME=codex but got: ${parsed.claude_md_path}`);
+    assert.ok(!fs.existsSync(path.join(realTmpDir, 'CLAUDE.md')),
+      'CLAUDE.md must not be created when GSD_RUNTIME=codex');
+  });
+
+  test('project scope: --output flag overrides runtime detection when explicitly provided', () => {
+    writeConfig({ runtime: 'codex', claude_md_path: './CLAUDE.md' });
+    const analysisPath = writeAnalysis();
+
+    const result = runGsdTools(
+      ['generate-claude-profile', '--analysis', analysisPath, '--output', 'EXPLICIT-OUTPUT.md'],
+      tmpDir,
+      { HOME: tmpDir }
+    );
+    assert.ok(result.success, `Command failed: ${result.error}`);
+
+    const parsed = JSON.parse(result.output);
+    const realTmpDir = fs.realpathSync(tmpDir);
+    assert.strictEqual(parsed.claude_md_path, path.join(realTmpDir, 'EXPLICIT-OUTPUT.md'),
+      `Expected explicit --output honoured but got: ${parsed.claude_md_path}`);
+  });
+
+  test('project scope: claude runtime still writes .claude/CLAUDE.md', () => {
+    writeConfig({ runtime: 'claude', claude_md_path: './.claude/CLAUDE.md' });
+    const analysisPath = writeAnalysis();
+
+    const result = runGsdTools(
+      ['generate-claude-profile', '--analysis', analysisPath],
+      tmpDir,
+      { HOME: tmpDir }
+    );
+    assert.ok(result.success, `Command failed: ${result.error}`);
+
+    const parsed = JSON.parse(result.output);
+    const realTmpDir = fs.realpathSync(tmpDir);
+    assert.strictEqual(parsed.claude_md_path, path.join(realTmpDir, '.claude', 'CLAUDE.md'),
+      `Expected .claude/CLAUDE.md for claude runtime but got: ${parsed.claude_md_path}`);
+    assert.ok(fs.existsSync(path.join(realTmpDir, '.claude', 'CLAUDE.md')),
+      '.claude/CLAUDE.md must exist for claude runtime');
+    assert.ok(!fs.existsSync(path.join(realTmpDir, 'AGENTS.md')),
+      'AGENTS.md must not be created for claude runtime');
+  });
+
+  test('global scope: codex runtime writes to <CODEX_HOME>/AGENTS.md', () => {
+    writeConfig({ runtime: 'codex' });
+    const analysisPath = writeAnalysis();
+    const codexHome = path.join(tmpDir, 'codex-config');
+
+    const result = runGsdTools(
+      ['generate-claude-profile', '--analysis', analysisPath, '--global'],
+      tmpDir,
+      { HOME: tmpDir, CODEX_HOME: codexHome }
+    );
+    assert.ok(result.success, `Command failed: ${result.error}`);
+
+    const parsed = JSON.parse(result.output);
+    const expected = path.join(codexHome, 'AGENTS.md');
+    assert.strictEqual(parsed.claude_md_path, expected,
+      `Expected <CODEX_HOME>/AGENTS.md but got: ${parsed.claude_md_path}`);
+    assert.ok(fs.existsSync(expected), '<CODEX_HOME>/AGENTS.md must exist after generation');
+    assert.ok(!fs.existsSync(path.join(tmpDir, '.claude', 'CLAUDE.md')),
+      '~/.claude/CLAUDE.md must not be created for Codex global profile');
+  });
+
+  test('global scope: claude runtime writes to ~/.claude/CLAUDE.md (preserved, no env drift)', () => {
+    writeConfig({ runtime: 'claude' });
+    const analysisPath = writeAnalysis();
+
+    // #2659: set USERPROFILE alongside HOME so os.homedir() resolves to tmpDir
+    // on Windows too — Node's os.homedir() reads USERPROFILE on Windows and
+    // HOME on POSIX, so HOME alone leaves the real user profile in place on
+    // Windows and the path assertion fails cross-platform.
+    const result = runGsdTools(
+      ['generate-claude-profile', '--analysis', analysisPath, '--global'],
+      tmpDir,
+      { HOME: tmpDir, USERPROFILE: tmpDir }
+    );
+    assert.ok(result.success, `Command failed: ${result.error}`);
+
+    const parsed = JSON.parse(result.output);
+    assert.strictEqual(parsed.claude_md_path, path.join(tmpDir, '.claude', 'CLAUDE.md'),
+      `Expected ~/.claude/CLAUDE.md for claude global but got: ${parsed.claude_md_path}`);
+    assert.ok(fs.existsSync(path.join(tmpDir, '.claude', 'CLAUDE.md')),
+      '~/.claude/CLAUDE.md must exist for claude global profile');
+  });
+
+  // Parity guard (CLAUDE.md "Generative Fix Divergence"): both
+  // generate-claude-md and generate-claude-profile MUST resolve the SAME
+  // project instruction path for the same runtime. Fails loudly if either
+  // handler re-diverges (the original #3163 -> #2565 drift).
+  test('parity: generate-claude-md and generate-claude-profile agree on project instruction path for codex', () => {
+    writeConfig({ runtime: 'codex' });
+    const analysisPath = writeAnalysis();
+
+    const mdResult = runGsdTools('generate-claude-md', tmpDir, { HOME: tmpDir });
+    assert.ok(mdResult.success, `generate-claude-md failed: ${mdResult.error}`);
+    const mdParsed = JSON.parse(mdResult.output);
+
+    // generate-claude-md created AGENTS.md; remove it so generate-claude-profile
+    // starts from the same empty-project state (independent parity read).
+    try { fs.unlinkSync(mdParsed.claude_md_path); } catch { /* already gone */ }
+
+    const profileResult = runGsdTools(
+      ['generate-claude-profile', '--analysis', analysisPath],
+      tmpDir,
+      { HOME: tmpDir }
+    );
+    assert.ok(profileResult.success, `generate-claude-profile failed: ${profileResult.error}`);
+    const profileParsed = JSON.parse(profileResult.output);
+
+    assert.strictEqual(profileParsed.claude_md_path, mdParsed.claude_md_path,
+      `Divergence: generate-claude-md targeted ${mdParsed.claude_md_path} but ` +
+      `generate-claude-profile targeted ${profileParsed.claude_md_path}. ` +
+      `Both handlers must share the runtime-aware instruction-file policy.`);
+  });
+});