feat(pi): add Pi (pi.dev) as a sixth CLI run mode (#206)

SessionMode gains 'pi', a first-class backend alongside Claude Code,
OpenCode, Codex, Gemini and Antigravity: its own PTY, tmux session, rose
tab identity, welcome button, run-mode entry, cron agentType, Docker and
remote-SSH command defaults, and clone-repo Brain option.

Pi is a different shape of CLI from the other four, and three decisions
follow from that:

- It has NO permission prompts and no sandbox, so there is no
  --dangerously-skip-permissions analog and none was invented. The
  privilege-shaped knob is the tri-state approveProjectTrust, which makes
  pi load and EXECUTE repo-local .pi/extensions TypeScript and install
  missing project packages. clampExternalCliBypassForOwner() therefore
  puts pi in the MATERIALIZE branch: a non-granted multi-user owner gets
  --no-approve even when no config was sent, because pi's own default is
  a prompt the session user could answer themselves. That helper had zero
  test coverage; it now has coverage for all four CLIs.
- Only the PI_ prefix joins the env allowlist. Pi's ~34 provider key vars
  share no prefix and ALLOWED_ENV_PREFIXES is one global list with no mode
  context, so admitting them would widen the allowlist for every mode at
  once. Auth goes through pi's /login or the server's own environment.
  --api-key is deliberately never wired: it would put a provider secret on
  the spawn command line.
- pi stays OUT of isAltScreenStripMode(). Its default TUI renders into the
  main screen with terminal-owned scrollback, and its 0.84.0 fullscreen
  mode is runtime-switchable via /settings; that flip was measured to put
  the pane into the alt screen, which the strip would have corrupted.

pi-cli-resolver.ts additionally sanity-probes `pi --version` and requires
semver-shaped output, because `pi` is a short generic name a stray binary
can shadow; GET /api/pi/status surfaces path and version so a
misresolution is diagnosable rather than presenting as a broken mode.

Docker installs pi in its own --ignore-scripts step so that flag cannot
affect the other four CLIs, and seeds its credentials per-file rather than
whole-dir (~/.pi/agent also holds sessions, extensions and package trees).

Verified end to end against pi 0.84.1 on an isolated instance: resolver
search-dir fallback, flag construction, piConfig persistence across a full
server restart, the trust prompt and its --no-approve suppression, the
rose Run button on the default daylight-blue skin (the nested skin block
eats per-mode gradients unless the rule lives inside it), and the buffer
local-echo policy, which pi tolerates where codex did not.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

test/routes/external-cli-bypass-clamp.test.ts

@@ -0,0 +1,132 @@
+/**
+ * First coverage for `clampExternalCliBypassForOwner` (session-routes.ts), the
+ * multi-user §6.3 gate that keeps a NON-GRANTED owner from launching an external
+ * CLI with its safety switches off. It backs both `POST /api/sessions` and
+ * `POST /api/quick-start` and, until pi was added, had no tests at all.
+ *
+ * The helper has two shapes and the difference is the whole point:
+ *  - only-if-sent (codex, antigravity): an ABSENT config already spawns safe, so
+ *    only a sent config needs its flag forced off.
+ *  - MATERIALIZE (gemini, pi): the absent-config default is itself unsafe for a
+ *    non-granted owner (gemini's builder defaults to `yolo`; pi's default is an
+ *    interactive trust prompt the session user could just answer "yes" to), so
+ *    the clamp has to CREATE a config.
+ */
+import { afterAll, beforeAll, describe, expect, it } from 'vitest';
+import { _clampExternalCliBypassForOwner } from '../../src/web/routes/session-routes.js';
+import { createUser, invalidateUsersCache } from '../../src/user-store.js';
+
+const PASSWORD = 'clamp-test-password';
+
+describe('clampExternalCliBypassForOwner — single-user mode', () => {
+  it('passes every config through untouched (the gate is a no-op)', async () => {
+    const out = await _clampExternalCliBypassForOwner(
+      undefined,
+      { dangerouslyBypassApprovals: true },
+      { approvalMode: 'yolo' },
+      { dangerouslySkipPermissions: true },
+      { approveProjectTrust: true }
+    );
+    expect(out.codexConfig).toEqual({ dangerouslyBypassApprovals: true });
+    expect(out.geminiConfig).toEqual({ approvalMode: 'yolo' });
+    expect(out.antigravityConfig).toEqual({ dangerouslySkipPermissions: true });
+    expect(out.piConfig).toEqual({ approveProjectTrust: true });
+  });
+
+  it('leaves absent configs absent', async () => {
+    const out = await _clampExternalCliBypassForOwner(undefined, undefined, undefined, undefined, undefined);
+    expect(out.codexConfig).toBeUndefined();
+    expect(out.geminiConfig).toBeUndefined();
+    expect(out.antigravityConfig).toBeUndefined();
+    expect(out.piConfig).toBeUndefined();
+  });
+});
+
+describe('clampExternalCliBypassForOwner — multi-user mode', () => {
+  // The temp HOME from test/setup.ts is per-FILE, so users.json survives between
+  // tests here — create the three accounts once.
+  beforeAll(async () => {
+    process.env.CODEMAN_MULTIUSER = '1';
+    invalidateUsersCache();
+    await createUser({ username: 'boss', role: 'admin', password: PASSWORD });
+    await createUser({ username: 'peon', role: 'user', password: PASSWORD });
+    await createUser({ username: 'trusted', role: 'user', password: PASSWORD, canBypassPermissions: true });
+  });
+
+  afterAll(() => {
+    delete process.env.CODEMAN_MULTIUSER;
+    invalidateUsersCache();
+  });
+
+  it('passes through for an admin owner', async () => {
+    const out = await _clampExternalCliBypassForOwner(
+      'boss',
+      { dangerouslyBypassApprovals: true },
+      undefined,
+      { dangerouslySkipPermissions: true },
+      { approveProjectTrust: true }
+    );
+    expect(out.codexConfig).toEqual({ dangerouslyBypassApprovals: true });
+    expect(out.geminiConfig).toBeUndefined();
+    expect(out.antigravityConfig).toEqual({ dangerouslySkipPermissions: true });
+    expect(out.piConfig).toEqual({ approveProjectTrust: true });
+  });
+
+  it('passes through for a user holding the bypass grant', async () => {
+    const out = await _clampExternalCliBypassForOwner('trusted', undefined, undefined, undefined, {
+      approveProjectTrust: true,
+    });
+    expect(out.piConfig).toEqual({ approveProjectTrust: true });
+  });
+
+  it('forces codex/antigravity bypass off for a non-granted owner (only-if-sent branch)', async () => {
+    const out = await _clampExternalCliBypassForOwner(
+      'peon',
+      { dangerouslyBypassApprovals: true, model: 'gpt-5' },
+      undefined,
+      { dangerouslySkipPermissions: true, model: 'gemini-3-pro' },
+      undefined
+    );
+    expect(out.codexConfig).toEqual({ dangerouslyBypassApprovals: false, model: 'gpt-5' });
+    expect(out.antigravityConfig).toEqual({ dangerouslySkipPermissions: false, model: 'gemini-3-pro' });
+  });
+
+  it('leaves codex/antigravity absent when nothing was sent (they already spawn safe)', async () => {
+    const out = await _clampExternalCliBypassForOwner('peon', undefined, undefined, undefined, undefined);
+    expect(out.codexConfig).toBeUndefined();
+    expect(out.antigravityConfig).toBeUndefined();
+  });
+
+  it('MATERIALIZES gemini to auto_edit even when no config was sent', async () => {
+    const out = await _clampExternalCliBypassForOwner('peon', undefined, undefined, undefined, undefined);
+    expect(out.geminiConfig).toEqual({ approvalMode: 'auto_edit' });
+  });
+
+  it('MATERIALIZES pi to --no-approve even when no config was sent', async () => {
+    // The load-bearing case: omitting --approve is NOT a clamp for pi, because
+    // pi's own default is to ASK, and the session user can answer that prompt.
+    const out = await _clampExternalCliBypassForOwner('peon', undefined, undefined, undefined, undefined);
+    expect(out.piConfig).toEqual({ approveProjectTrust: false });
+  });
+
+  it('forces a sent pi approveProjectTrust:true down to false, keeping other fields', async () => {
+    const out = await _clampExternalCliBypassForOwner('peon', undefined, undefined, undefined, {
+      approveProjectTrust: true,
+      model: 'sonnet:high',
+      provider: 'anthropic',
+    });
+    expect(out.piConfig).toEqual({
+      approveProjectTrust: false,
+      model: 'sonnet:high',
+      provider: 'anthropic',
+    });
+  });
+
+  it('fails closed for an unknown/deleted owner', async () => {
+    const out = await _clampExternalCliBypassForOwner('ghost', undefined, undefined, undefined, {
+      approveProjectTrust: true,
+    });
+    expect(out.piConfig).toEqual({ approveProjectTrust: false });
+    expect(out.geminiConfig).toEqual({ approvalMode: 'auto_edit' });
+  });
+});

test/routes/system-routes.test.ts

@@ -86,6 +86,12 @@ vi.mock('../../src/utils/antigravity-cli-resolver.js', () => ({
   resolveAntigravityDir: vi.fn(() => null),
 }));
 
+vi.mock('../../src/utils/pi-cli-resolver.js', () => ({
+  isPiAvailable: vi.fn(() => false),
+  resolvePiDir: vi.fn(() => null),
+  getPiCliVersion: vi.fn(() => null),
+}));
+
 import fs from 'node:fs/promises';
 import { existsSync, readdirSync } from 'node:fs';
 import { subagentWatcher } from '../../src/subagent-watcher.js';
@@ -93,6 +99,7 @@ import { getLifecycleLog } from '../../src/session-lifecycle-log.js';
 import { isOpenCodeAvailable, resolveOpenCodeDir } from '../../src/utils/opencode-cli-resolver.js';
 import { isGeminiAvailable, resolveGeminiDir } from '../../src/utils/gemini-cli-resolver.js';
 import { isAntigravityAvailable, resolveAntigravityDir } from '../../src/utils/antigravity-cli-resolver.js';
+import { isPiAvailable, resolvePiDir, getPiCliVersion } from '../../src/utils/pi-cli-resolver.js';
 
 const mockedReadFile = vi.mocked(fs.readFile);
 const mockedWriteFile = vi.mocked(fs.writeFile);
@@ -106,6 +113,9 @@ const mockedIsGeminiAvailable = vi.mocked(isGeminiAvailable);
 const mockedResolveGeminiDir = vi.mocked(resolveGeminiDir);
 const mockedIsAntigravityAvailable = vi.mocked(isAntigravityAvailable);
 const mockedResolveAntigravityDir = vi.mocked(resolveAntigravityDir);
+const mockedIsPiAvailable = vi.mocked(isPiAvailable);
+const mockedResolvePiDir = vi.mocked(resolvePiDir);
+const mockedGetPiCliVersion = vi.mocked(getPiCliVersion);
 
 describe('system-routes', () => {
   let harness: RouteTestHarness;
@@ -839,6 +849,38 @@ describe('system-routes', () => {
     });
   });
 
+  // ========== GET /api/pi/status ==========
+
+  describe('GET /api/pi/status', () => {
+    it('returns unavailable when pi is not installed', async () => {
+      mockedIsPiAvailable.mockReturnValue(false);
+      mockedResolvePiDir.mockReturnValue(null);
+      mockedGetPiCliVersion.mockReturnValue(null);
+
+      const res = await harness.app.inject({ method: 'GET', url: '/api/pi/status' });
+      expect(res.statusCode).toBe(200);
+      const body = JSON.parse(res.body);
+      expect(body.available).toBe(false);
+      expect(body.path).toBeNull();
+      expect(body.version).toBeNull();
+    });
+
+    it('returns available with path AND version when pi is installed', async () => {
+      // `version` is pi-specific: `pi` is a generic binary name, so the resolver
+      // version-probes it and this endpoint is where a misresolution shows up.
+      mockedIsPiAvailable.mockReturnValue(true);
+      mockedResolvePiDir.mockReturnValue('/home/user/.local/bin');
+      mockedGetPiCliVersion.mockReturnValue('0.84.1');
+
+      const res = await harness.app.inject({ method: 'GET', url: '/api/pi/status' });
+      expect(res.statusCode).toBe(200);
+      const body = JSON.parse(res.body);
+      expect(body.available).toBe(true);
+      expect(body.path).toBe('/home/user/.local/bin');
+      expect(body.version).toBe('0.84.1');
+    });
+  });
+
   // ========== GET /api/execution/model-config ==========
 
   describe('GET /api/execution/model-config', () => {