fix: fail closed on invalid launch inputs

packages/mosaic/README.md

@@ -26,6 +26,15 @@ Set `MOSAIC_ASSUME_YES=1` (or ensure stdin is not a TTY) to skip all interactive
 | `MOSAIC_ANTHROPIC_API_KEY` | _(none)_                | No                 |
 | `MOSAIC_CORS_ORIGIN`       | `http://localhost:3000` | No                 |
 
+`MOSAIC_STORAGE_TIER` is a closed enum: `local`, `standalone`, or `federated`.
+Unset or empty input selects the documented local default. Any other non-empty
+value is a typed startup error and is rejected before a storage adapter is
+selected.
+
+The Gateway process also accepts `CHAT_HARNESS_RUNTIME=legacy|pi-rpc`. Unset or
+empty input retains the transitional `legacy` default. Any other non-empty value
+is a typed startup error and is rejected before either runtime is selected.
+
 ### Admin user bootstrap
 
 | Variable                | Default  | Required       |
@@ -55,6 +64,13 @@ mosaic yolo claude       # …with --dangerously-skip-permissions
 mosaic codex | opencode | pi
 ```
 
+Every runtime launch requires its immutable `session.launch` provenance record
+to be written before spawn. A provenance-write failure exits nonzero, starts no
+runtime, and propagates no `MOSAIC_LAUNCH_ID`. Likewise, a spawn error, signal,
+or missing numeric child status is reported with the fixed
+`runtime_launch_failed` code and exits nonzero rather than being interpreted as
+success.
+
 ### `mosaic claudex` (EXPERIMENTAL)
 
 Runs GPT models **inside the Claude Code harness** by pointing Claude Code at a

packages/mosaic/src/commands/launch-fail-closed.integration.spec.ts

@@ -0,0 +1,193 @@
+import { spawnSync, type SpawnSyncReturns } from 'node:child_process';
+import {
+  chmodSync,
+  existsSync,
+  mkdirSync,
+  mkdtempSync,
+  readFileSync,
+  rmSync,
+  writeFileSync,
+} from 'node:fs';
+import { createRequire } from 'node:module';
+import { delimiter, join } from 'node:path';
+import { pathToFileURL } from 'node:url';
+import { afterEach, beforeEach, describe, expect, it } from 'vitest';
+
+const require = createRequire(import.meta.url);
+const TSX_LOADER_URL = pathToFileURL(require.resolve('tsx')).href;
+const COMMANDER_MODULE_URL = pathToFileURL(require.resolve('commander')).href;
+const LAUNCH_MODULE_URL = pathToFileURL(join(import.meta.dirname, 'launch.ts')).href;
+const DRIVER = `
+  const launch = await import(${JSON.stringify(LAUNCH_MODULE_URL)});
+  if (process.env['TEST_CLAUDEX_PROVENANCE'] === '1') {
+    const execute = launch.execRecordedClaudexRuntime;
+    if (typeof execute !== 'function') {
+      process.stderr.write('[missing_recorded_claudex_runtime]\\n');
+      process.exit(70);
+    }
+    execute([], process.env, process.env['TEST_DANGEROUS'] === '1');
+  } else {
+    const { Command } = await import(${JSON.stringify(COMMANDER_MODULE_URL)});
+    const program = new Command();
+    program.exitOverride();
+    launch.registerLaunchCommands(program);
+    await program.parseAsync(['node', 'mosaic', 'opencode']);
+  }
+`;
+
+interface LaunchFixture {
+  readonly root: string;
+  readonly home: string;
+  readonly bin: string;
+  readonly runtimePath: string;
+}
+
+function createFixture(): LaunchFixture {
+  const root = mkdtempSync('/var/tmp/mosaic-launch-fail-closed-');
+  const home = join(root, 'mosaic-home');
+  const bin = join(root, 'bin');
+  const runtimePath = join(bin, 'opencode');
+  mkdirSync(join(home, 'runtime', 'opencode'), { recursive: true });
+  mkdirSync(bin, { recursive: true });
+  writeFileSync(join(home, 'AGENTS.md'), '# test agents\n');
+  writeFileSync(join(home, 'SOUL.md'), '# test soul\n');
+  writeFileSync(join(home, 'USER.md'), '# test user\n');
+  writeFileSync(join(home, 'TOOLS.md'), '# test tools\n');
+  writeFileSync(join(home, 'runtime', 'opencode', 'RUNTIME.md'), '# test runtime\n');
+  return { root, home, bin, runtimePath };
+}
+
+function installRuntime(fixture: LaunchFixture, source: string): void {
+  writeFileSync(fixture.runtimePath, source);
+  chmodSync(fixture.runtimePath, 0o755);
+}
+
+function runLauncher(
+  fixture: LaunchFixture,
+  extraEnv: NodeJS.ProcessEnv = {},
+): SpawnSyncReturns<string> {
+  const env: NodeJS.ProcessEnv = {
+    ...process.env,
+    ...extraEnv,
+    MOSAIC_HOME: fixture.home,
+    PATH: `${fixture.bin}${delimiter}${process.env['PATH'] ?? ''}`,
+  };
+  delete env['MOSAIC_AGENT_NAME'];
+  delete env['MOSAIC_AGENT_CLASS'];
+  delete env['MOSAIC_AGENT_TOOL_POLICY'];
+
+  return spawnSync(
+    process.execPath,
+    ['--import', TSX_LOADER_URL, '--input-type=module', '--eval', DRIVER],
+    {
+      cwd: fixture.root,
+      encoding: 'utf8',
+      env,
+    },
+  );
+}
+
+describe('#1182 fail closed — a wrong answer must not be read as no answer', () => {
+  let fixture: LaunchFixture;
+
+  beforeEach(() => {
+    fixture = createFixture();
+  });
+
+  afterEach(() => {
+    rmSync(fixture.root, { recursive: true, force: true });
+  });
+
+  it.each([
+    {
+      condition: 'spawn error',
+      runtime: '#!/definitely/missing/interpreter\n',
+    },
+    {
+      condition: 'signal with null status',
+      runtime: '#!/usr/bin/env bash\nkill -TERM $$\n',
+    },
+  ])('FL-09 converts $condition into a sanitized nonzero launch failure', ({ runtime }) => {
+    installRuntime(fixture, runtime);
+
+    const result = runLauncher(fixture);
+
+    expect.soft(result.status, 'spawn failure must never be converted into exit 0').not.toBe(0);
+    expect
+      .soft(result.stderr, 'spawn failure must report the fixed typed runtime_launch_failed code')
+      .toContain('[runtime_launch_failed]');
+    expect(
+      result.stderr,
+      'spawn diagnostics must not disclose the runtime fixture path',
+    ).not.toContain(fixture.runtimePath);
+  });
+
+  it.each([
+    { launcher: 'opencode', extraEnv: {} },
+    {
+      launcher: 'claudex',
+      extraEnv: { TEST_CLAUDEX_PROVENANCE: '1' },
+    },
+    {
+      launcher: 'yolo claudex',
+      extraEnv: { TEST_CLAUDEX_PROVENANCE: '1', TEST_DANGEROUS: '1' },
+    },
+  ])(
+    'FL-10 refuses $launcher spawn when mandatory provenance cannot be recorded and fabricates no launch ID',
+    ({ extraEnv }) => {
+      const spawnMarker = join(fixture.root, 'runtime-spawned');
+      const launchIdMarker = join(fixture.root, 'runtime-saw-launch-id');
+      installRuntime(
+        fixture,
+        `#!/usr/bin/env bash\nprintf 'spawned' > "$TEST_SPAWN_MARKER"\nif [[ -n "\${MOSAIC_LAUNCH_ID:-}" ]]; then printf '%s' "$MOSAIC_LAUNCH_ID" > "$TEST_LAUNCH_ID_MARKER"; fi\n`,
+      );
+
+      const ledgerPath = join(fixture.home, 'fleet', 'run', 'sessions', 'events.ndjson');
+      mkdirSync(ledgerPath, { recursive: true });
+
+      const result = runLauncher(fixture, {
+        ...extraEnv,
+        TEST_SPAWN_MARKER: spawnMarker,
+        TEST_LAUNCH_ID_MARKER: launchIdMarker,
+      });
+
+      expect.soft(result.status, 'mandatory provenance failure must exit nonzero').not.toBe(0);
+      expect
+        .soft(existsSync(spawnMarker), 'mandatory provenance failure must prevent spawn')
+        .toBe(false);
+      expect
+        .soft(
+          existsSync(launchIdMarker),
+          'a failed provenance write must not fabricate or propagate a launch ID',
+        )
+        .toBe(false);
+      expect
+        .soft(
+          result.stderr,
+          'provenance refusal must report the fixed typed launch_provenance_failed code',
+        )
+        .toContain('[launch_provenance_failed]');
+      expect(
+        result.stderr,
+        'provenance diagnostics must not disclose filesystem details',
+      ).not.toContain(fixture.root);
+    },
+  );
+
+  it('anti-drift: launcher contains neither null-status success nor mandatory warn-and-run', () => {
+    const source = readFileSync(new URL('./launch.ts', import.meta.url), 'utf8');
+
+    expect
+      .soft(
+        source.includes('result.status ?? 0'),
+        'spawnSync null status must never default to success',
+      )
+      .toBe(false);
+    expect
+      .soft(
+        source.includes('[mosaic] WARNING: launch record not written:'),
+        'mandatory provenance failures must never warn and continue',
+      )
+      .toBe(false);
+  });
+});

packages/mosaic/src/commands/launch.ts

@@ -162,13 +162,24 @@ function redactArgv(argv: string[]): string[] {
   );
 }
 
-function recordLaunch(runtime: RuntimeName, cliArgs: string[], yolo: boolean): void {
+interface LaunchRecordSuccess {
+  readonly ok: true;
+  readonly launchId: string;
+}
+
+interface LaunchRecordFailure {
+  readonly ok: false;
+  readonly code: 'launch_provenance_failed';
+}
+
+type LaunchRecordResult = LaunchRecordSuccess | LaunchRecordFailure;
+
+function recordLaunch(runtime: RuntimeName, cliArgs: string[], yolo: boolean): LaunchRecordResult {
+  // Never let a stale or caller-supplied correlation id masquerade as this launch.
+  delete process.env['MOSAIC_LAUNCH_ID'];
   try {
     mkdirSync(LAUNCH_LEDGER_DIR, { recursive: true, mode: 0o700 });
-    // Correlation id for the lease.register half. Set into process.env so it
-    // propagates through every `...process.env` / `...baseEnv` spread below.
     const launchId = `${Date.now().toString(36)}-${randomBytes(6).toString('hex')}`;
-    process.env['MOSAIC_LAUNCH_ID'] = launchId;
     const record = {
       seq: Date.now(),
       kind: 'session.launch',
@@ -193,14 +204,26 @@ function recordLaunch(runtime: RuntimeName, cliArgs: string[], yolo: boolean): v
     appendFileSync(join(LAUNCH_LEDGER_DIR, 'events.ndjson'), `${JSON.stringify(record)}\n`, {
       mode: 0o600,
     });
-  } catch (err) {
-    // Never block a launch on bookkeeping — but never fail silently either.
-    console.error(
-      `[mosaic] WARNING: launch record not written: ${err instanceof Error ? err.message : String(err)}`,
-    );
+    return { ok: true, launchId };
+  } catch {
+    return { ok: false, code: 'launch_provenance_failed' };
   }
 }
 
+function requireLaunchRecord(runtime: RuntimeName, cliArgs: string[], yolo: boolean): string {
+  const result = recordLaunch(runtime, cliArgs, yolo);
+  if (!result.ok) {
+    console.error(
+      `[mosaic] ERROR [${result.code}]: mandatory launch provenance could not be recorded; runtime was not started.`,
+    );
+    process.exit(1);
+  }
+
+  // Propagate correlation authority only after its immutable provenance exists.
+  process.env['MOSAIC_LAUNCH_ID'] = result.launchId;
+  return result.launchId;
+}
+
 // ─── Pre-flight checks ──────────────────────────────────────────────────────
 
 function checkMosaicHome(): void {
@@ -925,7 +948,7 @@ function launchRuntime(runtime: RuntimeName, args: string[], yolo: boolean): nev
         cliArgs.push(...args);
       }
       console.log(`[mosaic] Launching ${label}${modeStr}${missionStr}...`);
-      recordLaunch('claude', cliArgs, yolo);
+      requireLaunchRecord('claude', cliArgs, yolo);
       execLeaseGatedRuntime('claude', cliArgs, process.env, yolo);
       break;
     }
@@ -939,7 +962,7 @@ function launchRuntime(runtime: RuntimeName, args: string[], yolo: boolean): nev
         cliArgs.push(...args);
       }
       console.log(`[mosaic] Launching ${label}${modeStr}${missionStr}...`);
-      recordLaunch('codex', cliArgs, yolo);
+      requireLaunchRecord('codex', cliArgs, yolo);
       execRuntime('codex', cliArgs, { ...process.env, ...harnessEnv('codex') });
       break;
     }
@@ -948,7 +971,7 @@ function launchRuntime(runtime: RuntimeName, args: string[], yolo: boolean): nev
       // opencode follows XDG, so its config resolves to $XDG_CONFIG_HOME/opencode.
       ensureRuntimeConfig('opencode', join(harnessHome('opencode'), 'opencode', 'AGENTS.md'));
       console.log(`[mosaic] Launching ${label}${modeStr}...`);
-      recordLaunch('opencode', args, yolo);
+      requireLaunchRecord('opencode', args, yolo);
       execRuntime('opencode', args, { ...process.env, ...harnessEnv('opencode') });
       break;
     }
@@ -964,7 +987,7 @@ function launchRuntime(runtime: RuntimeName, args: string[], yolo: boolean): nev
         cliArgs.push(...args);
       }
       console.log(`[mosaic] Launching ${label}${modeStr}${missionStr}...`);
-      recordLaunch('pi', cliArgs, yolo);
+      requireLaunchRecord('pi', cliArgs, yolo);
       execLeaseGatedRuntime('pi', cliArgs);
       break;
     }
@@ -1008,19 +1031,31 @@ function execLeaseGatedRuntime(
   );
 }
 
-/** exec into the runtime, replacing the current process. */
+type RuntimeLaunchFailureReason = 'spawn_error' | 'signal' | 'missing_status';
+
+interface RuntimeLaunchFailure {
+  readonly code: 'runtime_launch_failed';
+  readonly reason: RuntimeLaunchFailureReason;
+}
+
+function refuseRuntimeLaunch(reason: RuntimeLaunchFailureReason): never {
+  const failure: RuntimeLaunchFailure = { code: 'runtime_launch_failed', reason };
+  console.error(
+    `[mosaic] ERROR [${failure.code}]: runtime process did not produce a successful exit result (${failure.reason}).`,
+  );
+  process.exit(1);
+}
+
+/** Spawn the runtime and preserve only a real numeric exit status as success. */
 function execRuntime(cmd: string, args: string[], env: NodeJS.ProcessEnv = process.env): void {
-  try {
-    // Use execFileSync with inherited stdio to replace the process
-    const result = spawnSync(cmd, args, {
-      stdio: 'inherit',
-      env,
-    });
-    process.exit(result.status ?? 0);
-  } catch (err) {
-    console.error(`[mosaic] Failed to launch ${cmd}:`, err instanceof Error ? err.message : err);
-    process.exit(1);
-  }
+  const result = spawnSync(cmd, args, {
+    stdio: 'inherit',
+    env,
+  });
+  if (result.error !== undefined) refuseRuntimeLaunch('spawn_error');
+  if (result.signal !== null) refuseRuntimeLaunch('signal');
+  if (result.status === null) refuseRuntimeLaunch('missing_status');
+  process.exit(result.status);
 }
 
 /**
@@ -1030,6 +1065,15 @@ function execRuntime(cmd: string, args: string[], env: NodeJS.ProcessEnv = proce
  * orchestration to `launchClaudex` in `claudex.ts`. Kept thin so the tested
  * logic lives in the DI module, not here.
  */
+export function execRecordedClaudexRuntime(
+  args: string[],
+  env: NodeJS.ProcessEnv,
+  dangerous: boolean,
+): void {
+  const launchId = requireLaunchRecord('claude', args, dangerous);
+  execLeaseGatedRuntime('claude', args, { ...env, MOSAIC_LAUNCH_ID: launchId }, dangerous);
+}
+
 function launchClaudexProduction(args: string[], yolo: boolean): void {
   writeSessionLock('claude');
   const adapter: ClaudexHarnessAdapter = {
@@ -1041,8 +1085,7 @@ function launchClaudexProduction(args: string[], yolo: boolean): void {
       checkSequentialThinking('claude');
     },
     composePrompt: () => buildRuntimePrompt('claude'),
-    execLeaseGated: (cmdArgs, env, dangerous) =>
-      execLeaseGatedRuntime('claude', cmdArgs, env, dangerous),
+    execLeaseGated: execRecordedClaudexRuntime,
   };
   void launchClaudex(args, yolo, adapter);
 }