feat: codex support

.agents/plugins/marketplace.json

@@ -0,0 +1,21 @@
+{
+  "name": "ponytail",
+  "interface": {
+    "displayName": "Ponytail"
+  },
+  "plugins": [
+    {
+      "name": "ponytail",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/DietrichGebert/ponytail.git",
+        "ref": "main"
+      },
+      "policy": {
+        "installation": "AVAILABLE",
+        "authentication": "ON_INSTALL"
+      },
+      "category": "Productivity"
+    }
+  ]
+}

.claude-plugin/plugin.json

@@ -1,6 +1,6 @@
 {
   "name": "ponytail",
-  "version": "4.0.0",
+  "version": "4.1.0",
   "description": "Lazy senior dev mode. Forces the simplest, shortest solution that actually works: YAGNI, stdlib first, no unrequested abstractions.",
   "author": {
     "name": "Dietrich Gebert",

.codex-plugin/plugin.json

@@ -0,0 +1,31 @@
+{
+  "name": "ponytail",
+  "version": "4.1.0",
+  "description": "Lazy senior dev mode. Forces the simplest, shortest solution that actually works: YAGNI, stdlib first, no unrequested abstractions.",
+  "author": {
+    "name": "Dietrich Gebert",
+    "url": "https://github.com/DietrichGebert"
+  },
+  "homepage": "https://github.com/DietrichGebert/ponytail",
+  "repository": "https://github.com/DietrichGebert/ponytail",
+  "license": "MIT",
+  "keywords": ["yagni", "minimalism", "code-review", "productivity"],
+  "skills": "./skills/",
+  "interface": {
+    "displayName": "Ponytail",
+    "shortDescription": "Lazy senior developer mode",
+    "longDescription": "Prefer YAGNI, the standard library, native platform features, and the smallest correct implementation.",
+    "developerName": "Dietrich Gebert",
+    "category": "Productivity",
+    "capabilities": ["Instructions", "Lifecycle hooks"],
+    "websiteURL": "https://github.com/DietrichGebert/ponytail",
+    "defaultPrompt": [
+      "Use Ponytail mode for this task.",
+      "Review this diff for over-engineering.",
+      "Find the smallest correct implementation."
+    ],
+    "brandColor": "#111111",
+    "composerIcon": "./assets/logo.png",
+    "logo": "./assets/logo.png"
+  }
+}

README.md

@@ -56,15 +56,30 @@ Lazy, not negligent: trust-boundary validation, data-loss handling, security, an
 
 The most effort ponytail will ever ask of you:
 
+### Claude Code
+
 ```
 /plugin marketplace add DietrichGebert/ponytail
 /plugin install ponytail@ponytail
 ```
 
+### Codex
+
+```bash
+codex plugin marketplace add DietrichGebert/ponytail
+codex
+```
+
+Open `/plugins`, select the Ponytail marketplace, and install Ponytail. Then
+open `/hooks`, review and trust its two lifecycle hooks, and start a new thread.
+
 That was it. He'd be proud. He won't say it.
 
 Active every session. `/ponytail-review` finds what to delete in your diff. `/ponytail ultra` exists for when the codebase has wronged you personally. `/ponytail-help` explains the rest.
 
+In Codex, invoke the skills as `@ponytail`, `@ponytail-review`, and
+`@ponytail-help`. Startup and mode-change text shows the current mode.
+
 Cursor, Windsurf, Cline, Copilot, Aider: copy the matching rules file from this repo ([`.cursor/rules/`](.cursor/rules/), [`.windsurf/rules/`](.windsurf/rules/), [`.clinerules/`](.clinerules/), [`.github/copilot-instructions.md`](.github/copilot-instructions.md), [`AGENTS.md`](AGENTS.md)).
 
 ## FAQ

hooks/hooks.json

@@ -0,0 +1,31 @@
+{
+  "hooks": {
+    "SessionStart": [
+      {
+        "matcher": "startup|resume|clear|compact",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "node \"${PLUGIN_ROOT}/hooks/ponytail-activate.js\"",
+            "commandWindows": "node \"%PLUGIN_ROOT%\\hooks\\ponytail-activate.js\"",
+            "timeout": 5,
+            "statusMessage": "Loading ponytail mode..."
+          }
+        ]
+      }
+    ],
+    "UserPromptSubmit": [
+      {
+        "hooks": [
+          {
+            "type": "command",
+            "command": "node \"${PLUGIN_ROOT}/hooks/ponytail-mode-tracker.js\"",
+            "commandWindows": "node \"%PLUGIN_ROOT%\\hooks\\ponytail-mode-tracker.js\"",
+            "timeout": 5,
+            "statusMessage": "Tracking ponytail mode..."
+          }
+        ]
+      }
+    ]
+  }
+}

hooks/ponytail-activate.js

@@ -10,24 +10,28 @@ const fs = require('fs');
 const path = require('path');
 const os = require('os');
 const { getDefaultMode } = require('./ponytail-config');
+const {
+  clearMode,
+  isCodex,
+  setMode,
+  writeHookOutput,
+} = require('./ponytail-runtime');
 
 const claudeDir = path.join(os.homedir(), '.claude');
-const flagPath = path.join(claudeDir, '.ponytail-active');
 const settingsPath = path.join(claudeDir, 'settings.json');
 
 const mode = getDefaultMode();
 
 // "off" mode — skip activation entirely, don't write flag or emit rules
 if (mode === 'off') {
-  try { fs.unlinkSync(flagPath); } catch (e) {}
-  process.stdout.write('OK');
+  clearMode();
+  writeHookOutput('SessionStart', 'off', isCodex ? '' : 'OK');
   process.exit(0);
 }
 
 // 1. Write flag file
 try {
-  fs.mkdirSync(path.dirname(flagPath), { recursive: true });
-  fs.writeFileSync(flagPath, mode);
+  setMode(mode);
 } catch (e) {
   // Silent fail -- flag is best-effort, don't block the hook
 }
@@ -45,7 +49,11 @@ try {
 const INDEPENDENT_MODES = new Set(['review']);
 
 if (INDEPENDENT_MODES.has(mode)) {
-  process.stdout.write('PONYTAIL MODE ACTIVE — level: ' + mode + '. Behavior defined by /ponytail-' + mode + ' skill.');
+  writeHookOutput(
+    'SessionStart',
+    mode,
+    'PONYTAIL MODE ACTIVE — level: ' + mode + '. Behavior defined by /ponytail-' + mode + ' skill.',
+  );
   process.exit(0);
 }
 
@@ -124,7 +132,7 @@ if (skillContent) {
 }
 
 // 3. Detect missing statusline config — nudge Claude to help set it up
-try {
+if (!isCodex) try {
   let hasStatusline = false;
   if (fs.existsSync(settingsPath)) {
     const settings = JSON.parse(fs.readFileSync(settingsPath, 'utf8'));
@@ -153,4 +161,4 @@ try {
   // Silent fail — don't block session start over statusline detection
 }
 
-process.stdout.write(output);
+writeHookOutput('SessionStart', mode, output);

hooks/ponytail-mode-tracker.js

@@ -2,12 +2,8 @@
 // ponytail — UserPromptSubmit hook to track which ponytail mode is active
 // Inspects user input for /ponytail commands and writes mode to flag file
 
-const fs = require('fs');
-const path = require('path');
-const os = require('os');
 const { getDefaultMode } = require('./ponytail-config');
-
-const flagPath = path.join(os.homedir(), '.claude', '.ponytail-active');
+const { clearMode, setMode, writeHookOutput } = require('./ponytail-runtime');
 
 let input = '';
 process.stdin.on('data', chunk => { input += chunk; });
@@ -18,9 +14,9 @@ process.stdin.on('end', () => {
     const prompt = (data.prompt || '').trim().toLowerCase();
 
     // Match /ponytail commands
-    if (prompt.startsWith('/ponytail')) {
+    if (/^[/@$]ponytail/.test(prompt)) {
       const parts = prompt.split(/\s+/);
-      const cmd = parts[0]; // /ponytail, /ponytail-review, /ponytail:ponytail, etc.
+      const cmd = parts[0].replace(/^[@$]/, '/');
       const arg = parts[1] || '';
 
       let mode = null;
@@ -36,16 +32,22 @@ process.stdin.on('end', () => {
       }
 
       if (mode && mode !== 'off') {
-        fs.mkdirSync(path.dirname(flagPath), { recursive: true });
-        fs.writeFileSync(flagPath, mode);
+        setMode(mode);
+        writeHookOutput(
+          'UserPromptSubmit',
+          mode,
+          'PONYTAIL MODE CHANGED — level: ' + mode,
+        );
       } else if (mode === 'off') {
-        try { fs.unlinkSync(flagPath); } catch (e) {}
+        clearMode();
+        writeHookOutput('UserPromptSubmit', 'off', 'PONYTAIL MODE OFF');
       }
     }
 
     // Detect deactivation
     if (/\b(stop ponytail|normal mode)\b/i.test(prompt)) {
-      try { fs.unlinkSync(flagPath); } catch (e) {}
+      clearMode();
+      writeHookOutput('UserPromptSubmit', 'off', 'PONYTAIL MODE OFF');
     }
   } catch (e) {
     // Silent fail

hooks/ponytail-runtime.js

@@ -0,0 +1,39 @@
+const fs = require('fs');
+const path = require('path');
+const os = require('os');
+
+const isCodex = Boolean(process.env.PLUGIN_DATA);
+const statePath = isCodex
+  ? path.join(process.env.PLUGIN_DATA, '.ponytail-active')
+  : path.join(os.homedir(), '.claude', '.ponytail-active');
+
+function setMode(mode) {
+  fs.mkdirSync(path.dirname(statePath), { recursive: true });
+  fs.writeFileSync(statePath, mode);
+}
+
+function clearMode() {
+  try { fs.unlinkSync(statePath); } catch (e) {}
+}
+
+function writeHookOutput(event, mode, context = '') {
+  if (!isCodex) {
+    process.stdout.write(context);
+    return;
+  }
+  const output = { systemMessage: `PONYTAIL:${mode.toUpperCase()}` };
+  if (context) {
+    output.hookSpecificOutput = {
+      hookEventName: event,
+      additionalContext: context,
+    };
+  }
+  process.stdout.write(JSON.stringify(output));
+}
+
+module.exports = {
+  clearMode,
+  isCodex,
+  setMode,
+  writeHookOutput,
+};

skills/ponytail-help/SKILL.md

@@ -29,6 +29,9 @@ Level sticks until changed or session end.
 | **ponytail-review** | `/ponytail-review` | Over-engineering review: `L42: yagni: factory, one product. Inline.` |
 | **ponytail-help** | `/ponytail-help` | This card. |
 
+Codex uses `@ponytail`, `@ponytail-review`, and `@ponytail-help`; Claude Code
+uses the slash-command forms above.
+
 ## Deactivate
 
 Say "stop ponytail" or "normal mode". Resume anytime with `/ponytail`.

tests/hooks.test.js

@@ -0,0 +1,75 @@
+#!/usr/bin/env node
+
+const assert = require('assert');
+const fs = require('fs');
+const os = require('os');
+const path = require('path');
+const { spawnSync } = require('child_process');
+
+const root = path.join(__dirname, '..');
+
+function run(script, env, input = '') {
+  return spawnSync(process.execPath, [path.join(root, 'hooks', script)], {
+    env: { ...process.env, ...env },
+    input,
+    encoding: 'utf8',
+  });
+}
+
+const temp = fs.mkdtempSync(path.join(os.tmpdir(), 'ponytail-hooks-'));
+const home = path.join(temp, 'home');
+const pluginData = path.join(temp, 'plugin-data');
+fs.mkdirSync(home, { recursive: true });
+
+const codexEnv = {
+  HOME: home,
+  PLUGIN_DATA: pluginData,
+  PONYTAIL_DEFAULT_MODE: 'ultra',
+};
+const codexState = path.join(pluginData, '.ponytail-active');
+
+let result = run('ponytail-activate.js', codexEnv);
+assert.equal(result.status, 0, result.stderr);
+assert.equal(fs.readFileSync(codexState, 'utf8'), 'ultra');
+let output = JSON.parse(result.stdout);
+assert.equal(output.systemMessage, 'PONYTAIL:ULTRA');
+assert.match(
+  output.hookSpecificOutput.additionalContext,
+  /PONYTAIL MODE ACTIVE — level: ultra/,
+);
+
+result = run(
+  'ponytail-mode-tracker.js',
+  codexEnv,
+  JSON.stringify({ prompt: '@ponytail lite' }),
+);
+assert.equal(result.status, 0, result.stderr);
+assert.equal(fs.readFileSync(codexState, 'utf8'), 'lite');
+output = JSON.parse(result.stdout);
+assert.equal(output.systemMessage, 'PONYTAIL:LITE');
+
+result = run(
+  'ponytail-mode-tracker.js',
+  codexEnv,
+  JSON.stringify({ prompt: 'normal mode' }),
+);
+assert.equal(result.status, 0, result.stderr);
+assert.equal(fs.existsSync(codexState), false);
+output = JSON.parse(result.stdout);
+assert.equal(output.systemMessage, 'PONYTAIL:OFF');
+
+const claudeEnv = {
+  HOME: home,
+  PONYTAIL_DEFAULT_MODE: 'full',
+};
+delete claudeEnv.PLUGIN_DATA;
+
+result = run('ponytail-activate.js', claudeEnv);
+assert.equal(result.status, 0, result.stderr);
+assert.equal(
+  fs.readFileSync(path.join(home, '.claude', '.ponytail-active'), 'utf8'),
+  'full',
+);
+
+fs.rmSync(temp, { recursive: true, force: true });
+console.log('hook compatibility checks passed');