diff --git a/package.json b/package.json
index 040eed5..c53d745 100644
--- a/package.json
+++ b/package.json
@@ -28,7 +28,7 @@
     "README.md"
   ],
   "scripts": {
-    "test": "npm run validate:scheduler && node --test test/*.test.mjs tests/*.test.js",
+    "test": "npm run validate:scheduler && npm run test:integration:e2e && node --test test/*.test.mjs tests/*.test.js",
     "test:unit:lock-backend": "node --test test/lock-ops.test.mjs test/lock-ops-publish-retry.test.mjs",
     "lock:check:daily": "node bin/torch-lock.mjs check --cadence daily",
     "lock:check:weekly": "node bin/torch-lock.mjs check --cadence weekly",
@@ -42,7 +42,8 @@
     "validate:scheduler": "node scripts/validate-scheduler-roster.mjs && node scripts/validate-prompt-contract.mjs && node scripts/validate-scheduler-flow-parity.mjs",
     "scheduler:daily": "node scripts/agent/run-scheduler-cycle.mjs daily",
     "scheduler:weekly": "node scripts/agent/run-scheduler-cycle.mjs weekly",
-    "report:lock-reliability": "node scripts/agent/summarize-lock-reliability.mjs --since-days 30"
+    "report:lock-reliability": "node scripts/agent/summarize-lock-reliability.mjs --since-days 30",
+    "test:integration:e2e": "node --test test/scheduler-preflight-lock.e2e.test.mjs"
   },
   "dependencies": {
     "nostr-tools": "2.19.4",
diff --git a/scripts/agent/run-scheduler-cycle.mjs b/scripts/agent/run-scheduler-cycle.mjs
index b12b71f..1f4b1ee 100644
--- a/scripts/agent/run-scheduler-cycle.mjs
+++ b/scripts/agent/run-scheduler-cycle.mjs
@@ -794,7 +794,7 @@ async function main() {
         status: 'failed',
         platform,
         reason: 'Lock backend error',
-        detail: `Lock backend error (${backendCategory}) after ${lockAttempt.attempts} attempt(s). ${buildLockBackendRemediation({ cadence, retryWindowMs: schedulerConfig.lockFailurePolicy.degradedLockRetryWindowMs, maxDeferrals: schedulerConfig.lockFailurePolicy.maxDeferrals })}`,
+        detail: `Lock backend error (${backendCategory}) after ${lockAttempt.attempts} attempt(s). Prompt not executed. ${buildLockBackendRemediation({ cadence, retryWindowMs: schedulerConfig.lockFailurePolicy.degradedLockRetryWindowMs, maxDeferrals: schedulerConfig.lockFailurePolicy.maxDeferrals })}`,
         metadata: {
           ...categorizeFailureMetadata(FAILURE_CATEGORY.LOCK_BACKEND, { failure_class: 'backend_unavailable' }),
           lock_attempts_total: lockAttempt.attempts,
diff --git a/test/scheduler-preflight-lock.e2e.test.mjs b/test/scheduler-preflight-lock.e2e.test.mjs
new file mode 100644
index 0000000..3ee5380
--- /dev/null
+++ b/test/scheduler-preflight-lock.e2e.test.mjs
@@ -0,0 +1,232 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import fs from 'node:fs/promises';
+import os from 'node:os';
+import path from 'node:path';
+import { spawn } from 'node:child_process';
+
+const SOURCE_SCRIPT = path.resolve('scripts/agent/run-scheduler-cycle.mjs');
+
+async function runNode(scriptPath, args, { cwd, env }) {
+  return new Promise((resolve) => {
+    const child = spawn(process.execPath, [scriptPath, ...args], {
+      cwd,
+      env,
+      stdio: ['ignore', 'pipe', 'pipe'],
+    });
+
+    let stdout = '';
+    let stderr = '';
+
+    child.stdout.on('data', (chunk) => {
+      stdout += chunk.toString();
+    });
+
+    child.stderr.on('data', (chunk) => {
+      stderr += chunk.toString();
+    });
+
+    child.on('close', (code) => {
+      resolve({ code: code ?? 1, stdout, stderr });
+    });
+  });
+}
+
+async function setupFixture({ lockShellBody = ':', schedulerPolicy = {} }) {
+  const root = await fs.mkdtemp(path.join(os.tmpdir(), 'scheduler-lock-e2e-'));
+  const scriptsDir = path.join(root, 'scripts', 'agent');
+  const binDir = path.join(root, 'bin');
+
+  await fs.mkdir(path.join(root, 'src', 'prompts', 'daily'), { recursive: true });
+  await fs.mkdir(scriptsDir, { recursive: true });
+  await fs.mkdir(binDir, { recursive: true });
+
+  await fs.copyFile(SOURCE_SCRIPT, path.join(scriptsDir, 'run-scheduler-cycle.mjs'));
+  await fs.writeFile(
+    path.join(scriptsDir, 'verify-run-artifacts.mjs'),
+    '#!/usr/bin/env node\nprocess.exit(0);\n',
+    'utf8',
+  );
+  await fs.writeFile(path.join(root, 'src', 'prompts', 'roster.json'), JSON.stringify({ daily: ['agent-a'] }, null, 2));
+  await fs.writeFile(path.join(root, 'src', 'prompts', 'daily', 'agent-a.md'), '# agent-a\n', 'utf8');
+
+  await fs.writeFile(
+    path.join(root, 'torch-config.json'),
+    JSON.stringify({
+      scheduler: {
+        firstPromptByCadence: { daily: 'agent-a' },
+        handoffCommandByCadence: { daily: 'echo HANDOFF_OK' },
+        validationCommandsByCadence: { daily: ['true'] },
+        memoryPolicyByCadence: { daily: { mode: 'optional' } },
+        ...schedulerPolicy,
+      },
+    }, null, 2),
+    'utf8',
+  );
+
+  await fs.writeFile(
+    path.join(binDir, 'npm'),
+    `#!/usr/bin/env bash
+set -euo pipefail
+if [[ "$1" != "run" ]]; then
+  exit 1
+fi
+case "$2" in
+  lock:check:daily)
+    echo '{"excluded":[]}'
+    ;;
+  lock:lock)
+    ${lockShellBody}
+    ;;
+  lock:complete|lint)
+    ;;
+  *)
+    ;;
+esac
+`,
+    'utf8',
+  );
+  await fs.chmod(path.join(binDir, 'npm'), 0o755);
+
+  return {
+    root,
+    scriptPath: path.join(scriptsDir, 'run-scheduler-cycle.mjs'),
+    env: {
+      ...process.env,
+      PATH: `${binDir}:${process.env.PATH}`,
+    },
+  };
+}
+
+function parseFrontmatter(markdown) {
+  const lines = String(markdown).split(/\r?\n/);
+  if (lines[0] !== '---') return {};
+  const result = {};
+
+  for (let i = 1; i < lines.length; i += 1) {
+    const line = lines[i];
+    if (line === '---') break;
+    const sep = line.indexOf(':');
+    if (sep < 0) continue;
+    const key = line.slice(0, sep).trim();
+    const raw = line.slice(sep + 1).trim();
+    result[key] = raw.startsWith("'") && raw.endsWith("'")
+      ? raw.slice(1, -1).replace(/''/g, "'")
+      : raw;
+  }
+
+  return result;
+}
+
+async function readLogByStatus(root, status) {
+  const logDir = path.join(root, 'task-logs', 'daily');
+  const logs = await fs.readdir(logDir);
+  const file = logs.find((name) => name.endsWith(`__${status}.md`));
+  assert.ok(file, `expected ${status} log in ${logDir}; saw: ${logs.join(', ')}`);
+  const content = await fs.readFile(path.join(logDir, file), 'utf8');
+  return { file, content, frontmatter: parseFrontmatter(content) };
+}
+
+test('lock preflight e2e: successful lock writes completed status snapshot', { concurrency: false }, async () => {
+  const fixture = await setupFixture({ lockShellBody: ':' });
+  const result = await runNode(fixture.scriptPath, ['--cadence', 'daily'], {
+    cwd: fixture.root,
+    env: fixture.env,
+  });
+
+  assert.equal(result.code, 0, `stdout: ${result.stdout}\nstderr: ${result.stderr}`);
+
+  const { frontmatter } = await readLogByStatus(fixture.root, 'completed');
+  assert.deepEqual(
+    {
+      cadence: frontmatter.cadence,
+      agent: frontmatter.agent,
+      status: frontmatter.status,
+      platform: frontmatter.platform,
+    },
+    {
+      cadence: 'daily',
+      agent: 'agent-a',
+      status: 'completed',
+      platform: 'codex',
+    },
+  );
+});
+
+test('lock preflight e2e: exit code 2 quorum failure persists failed backend status and prompt-not-started marker', { concurrency: false }, async () => {
+  const fixture = await setupFixture({
+    schedulerPolicy: {
+      strict_lock: true,
+    },
+    lockShellBody: "echo 'lock_publish_quorum_failed error_category=relay_publish_quorum_failure publish failed to all relays' >&2\n    exit 2",
+  });
+
+  const result = await runNode(fixture.scriptPath, ['--cadence', 'daily'], {
+    cwd: fixture.root,
+    env: {
+      ...fixture.env,
+      SCHEDULER_LOCK_MAX_RETRIES: '0',
+      SCHEDULER_LOCK_BACKOFF_MS: '0',
+      SCHEDULER_LOCK_JITTER_MS: '0',
+    },
+  });
+
+  assert.equal(result.code, 2, `stdout: ${result.stdout}\nstderr: ${result.stderr}`);
+
+  const { content, frontmatter } = await readLogByStatus(fixture.root, 'failed');
+  assert.deepEqual(
+    {
+      status: frontmatter.status,
+      failure_category: frontmatter.failure_category,
+      failure_class: frontmatter.failure_class,
+      backend_category: frontmatter.backend_category,
+    },
+    {
+      status: 'failed',
+      failure_category: 'lock_backend_error',
+      failure_class: 'backend_unavailable',
+      backend_category: 'publish failed to all relays',
+    },
+  );
+
+  assert.match(content, /Prompt not executed\./i);
+  assert.doesNotMatch(content, /prompt_parse_error|prompt_schema_error/i);
+
+  const stateRaw = JSON.parse(await fs.readFile(path.join(fixture.root, 'task-logs', 'daily', '.scheduler-run-state.json'), 'utf8'));
+  assert.deepEqual(
+    {
+      has_run_date: typeof stateRaw.run_date === 'string' && stateRaw.run_date.length > 0,
+      lock_deferral: stateRaw.lock_deferral,
+    },
+    {
+      has_run_date: true,
+      lock_deferral: null,
+    },
+  );
+});
+
+test('lock preflight e2e: non-lock failure exits failed without prompt parse/schema classification', { concurrency: false }, async () => {
+  const fixture = await setupFixture({ lockShellBody: "echo 'unexpected lock command crash' >&2\n    exit 9" });
+
+  const result = await runNode(fixture.scriptPath, ['--cadence', 'daily'], {
+    cwd: fixture.root,
+    env: fixture.env,
+  });
+
+  assert.equal(result.code, 9, `stdout: ${result.stdout}\nstderr: ${result.stderr}`);
+
+  const { content, frontmatter } = await readLogByStatus(fixture.root, 'failed');
+  assert.deepEqual(
+    {
+      status: frontmatter.status,
+      reason_line: /- reason: (.+)/.exec(content)?.[1] ?? null,
+      failure_category: frontmatter.failure_category ?? null,
+    },
+    {
+      status: 'failed',
+      reason_line: 'Failed to acquire lock',
+      failure_category: null,
+    },
+  );
+  assert.doesNotMatch(content, /prompt_parse_error|prompt_schema_error/i);
+});