refactor(cli): replace better-sqlite3 with sql.js (pure WASM)

- Remove native C++ addon dependency, no more pnpm approve-builds
- sql.js loads SQLite as WASM, zero compilation required
- WASM init is singleton (once per process)
- Add queryAsObjects() adapter for sql.js columnar → row format
- Tests migrated to sql.js (16 passing)

Implements RFC #63

packages/cli/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@uncaged/nerve-cli",
-  "version": "0.1.7",
+  "version": "0.1.8",
   "type": "module",
   "bin": {
     "nerve": "dist/cli.js"
@@ -20,12 +20,13 @@
   },
   "dependencies": {
     "@uncaged/nerve-core": "workspace:*",
-    "citty": "^0.1.6"
+    "citty": "^0.1.6",
+    "sql.js": "^1.14.1"
   },
   "devDependencies": {
-    "@uncaged/nerve-daemon": "workspace:*",
     "@types/better-sqlite3": "^7.6.13",
     "@types/node": "^22.0.0",
+    "@uncaged/nerve-daemon": "workspace:*",
     "vitest": "^4.1.5"
   }
 }

packages/cli/src/__tests__/sense-sqlite.test.ts

@@ -0,0 +1,182 @@
+/**
+ * Tests for sense SQLite helpers used by `nerve sense schema` / `nerve sense query`.
+ */
+
+import { mkdirSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+
+import initSqlJs, { type Database } from "sql.js";
+import { afterEach, beforeAll, beforeEach, describe, expect, it } from "vitest";
+
+import {
+  assertSenseDbExists,
+  collectColumnKeys,
+  defaultPreviewSql,
+  formatRowsAsAlignedTable,
+  listTableSqlStatements,
+  parseSenseQueryArgs,
+  pickDefaultPreviewTable,
+  queryAsObjects,
+  senseDbPath,
+} from "../sense-sqlite.js";
+
+let SQL: Awaited<ReturnType<typeof initSqlJs>>;
+let tmpDir: string;
+
+beforeAll(async () => {
+  SQL = await initSqlJs();
+});
+
+beforeEach(() => {
+  tmpDir = join(
+    tmpdir(),
+    `nerve-sense-sqlite-${Date.now()}-${Math.random().toString(16).slice(2)}`,
+  );
+  mkdirSync(join(tmpDir, "data", "senses"), { recursive: true });
+});
+
+afterEach(() => {
+  rmSync(tmpDir, { recursive: true, force: true });
+});
+
+/** Helper: create a SQLite db file with the given setup SQL. */
+function createDb(name: string, setupSql: string): void {
+  const db = new SQL.Database();
+  db.run(setupSql);
+  const data = db.export();
+  db.close();
+  writeFileSync(join(tmpDir, "data", "senses", `${name}.db`), Buffer.from(data));
+}
+
+/** Helper: open an in-memory db with setup SQL for unit tests. */
+function memDb(setupSql?: string): Database {
+  const db = new SQL.Database();
+  if (setupSql) db.run(setupSql);
+  return db;
+}
+
+describe("senseDbPath", () => {
+  it("points at data/senses/<name>.db under the given root", () => {
+    expect(senseDbPath("/root", "cpu-usage")).toBe(join("/root", "data", "senses", "cpu-usage.db"));
+  });
+});
+
+describe("assertSenseDbExists", () => {
+  it("throws when the file is missing", () => {
+    expect(() => assertSenseDbExists(tmpDir, "nope")).toThrow(/No database at/);
+  });
+
+  it("returns the path when the file exists", () => {
+    createDb("x", "SELECT 1");
+    expect(assertSenseDbExists(tmpDir, "x")).toBe(join(tmpDir, "data", "senses", "x.db"));
+  });
+});
+
+describe("listTableSqlStatements", () => {
+  it("returns CREATE statements ordered by tbl_name", () => {
+    const db = memDb("CREATE TABLE zebra (id INTEGER); CREATE TABLE alpha (id INTEGER);");
+    const stmts = listTableSqlStatements(db);
+    db.close();
+    expect(stmts).toHaveLength(2);
+    expect(stmts[0]).toMatch(/^CREATE TABLE alpha/i);
+    expect(stmts[1]).toMatch(/^CREATE TABLE zebra/i);
+  });
+});
+
+describe("pickDefaultPreviewTable", () => {
+  it("prefers non-_migrations tables when both exist", () => {
+    const db = memDb(
+      `CREATE TABLE _migrations (name TEXT PRIMARY KEY);
+       CREATE TABLE readings (id INTEGER);`,
+    );
+    expect(pickDefaultPreviewTable(db)).toBe("readings");
+    db.close();
+  });
+
+  it("uses _migrations when it is the only table", () => {
+    const db = memDb("CREATE TABLE _migrations (name TEXT PRIMARY KEY);");
+    expect(pickDefaultPreviewTable(db)).toBe("_migrations");
+    db.close();
+  });
+});
+
+describe("defaultPreviewSql", () => {
+  it("quotes identifiers for SQL safety", () => {
+    expect(defaultPreviewSql(`weird"name`)).toContain(`weird""name`);
+  });
+});
+
+describe("parseSenseQueryArgs", () => {
+  it("parses sense name only", () => {
+    expect(parseSenseQueryArgs(["cpu"])).toEqual({ name: "cpu", sql: undefined });
+  });
+
+  it("strips --json", () => {
+    expect(parseSenseQueryArgs(["cpu", "--json"])).toEqual({ name: "cpu", sql: undefined });
+    expect(parseSenseQueryArgs(["--json", "cpu"])).toEqual({ name: "cpu", sql: undefined });
+  });
+
+  it("joins remaining tokens into SQL", () => {
+    expect(parseSenseQueryArgs(["cpu", "SELECT", "1"])).toEqual({ name: "cpu", sql: "SELECT 1" });
+  });
+
+  it("throws when name is missing", () => {
+    expect(() => parseSenseQueryArgs(["--json"])).toThrow(/Missing sense name/);
+  });
+});
+
+describe("formatRowsAsAlignedTable", () => {
+  it("shows empty marker for no rows", () => {
+    expect(formatRowsAsAlignedTable([])).toContain("(0 rows)");
+  });
+
+  it("aligns columns from row data", () => {
+    const out = formatRowsAsAlignedTable([
+      { a: 1, b: "x" },
+      { a: 22, b: "yy" },
+    ]);
+    expect(out).toContain("a");
+    expect(out).toContain("b");
+    expect(out).toContain("22");
+  });
+});
+
+describe("collectColumnKeys", () => {
+  it("preserves key order from first row then appends new keys", () => {
+    expect(
+      collectColumnKeys([
+        { z: 1, a: 2 },
+        { a: 3, b: 4 },
+      ]),
+    ).toEqual(["z", "a", "b"]);
+  });
+});
+
+describe("queryAsObjects", () => {
+  it("converts columnar sql.js results to row objects", () => {
+    const db = memDb("CREATE TABLE t (x INTEGER, y TEXT); INSERT INTO t VALUES (1, 'a'), (2, 'b');");
+    const rows = queryAsObjects(db, "SELECT * FROM t ORDER BY x");
+    db.close();
+    expect(rows).toEqual([
+      { x: 1, y: "a" },
+      { x: 2, y: "b" },
+    ]);
+  });
+});
+
+describe("readonly query integration", () => {
+  it("runs default preview SQL on a real db file", () => {
+    createDb("demo", "CREATE TABLE items (id INTEGER PRIMARY KEY, v TEXT); INSERT INTO items (v) VALUES ('a'), ('b');");
+
+    const buffer = require("node:fs").readFileSync(join(tmpDir, "data", "senses", "demo.db"));
+    const db = new SQL.Database(buffer);
+    const table = pickDefaultPreviewTable(db);
+    expect(table).toBe("items");
+    if (table === null) throw new Error("expected items table");
+    const sql = defaultPreviewSql(table);
+    const rows = queryAsObjects(db, sql);
+    db.close();
+    expect(rows.length).toBeGreaterThanOrEqual(1);
+  });
+});

packages/cli/src/commands/sense.ts

@@ -5,6 +5,16 @@ import { type SenseInfo, parseNerveConfig } from "@uncaged/nerve-core";
 import { defineCommand } from "citty";
 
 import { listSensesViaDaemon, triggerSenseViaDaemon } from "../daemon-client.js";
+import {
+  assertSenseDbExists,
+  defaultPreviewSql,
+  formatRowsAsAlignedTable,
+  listTableSqlStatements,
+  openSenseDb,
+  parseSenseQueryArgs,
+  pickDefaultPreviewTable,
+  queryAsObjects,
+} from "../sense-sqlite.js";
 import { getNerveRoot, getSocketPath, isRunning } from "../workspace.js";
 
 // ---------------------------------------------------------------------------
@@ -139,6 +149,115 @@ const senseTriggerCommand = defineCommand({
   },
 });
 
+// ---------------------------------------------------------------------------
+// nerve sense schema <name>
+// ---------------------------------------------------------------------------
+
+const senseSchemaCommand = defineCommand({
+  meta: {
+    name: "schema",
+    description: "Print CREATE TABLE statements from a sense SQLite database",
+  },
+  args: {
+    name: {
+      type: "positional",
+      description: "Sense name (data/senses/<name>.db under the nerve workspace)",
+    },
+    json: {
+      type: "boolean",
+      description: "Print JSON array of CREATE TABLE SQL strings",
+      default: false,
+    },
+  },
+  async run({ args }) {
+    const nerveRoot = getNerveRoot();
+    let db: ReturnType<Awaited<ReturnType<typeof import("sql.js")>>["Database"]> | undefined;
+    try {
+      db = await openSenseDb(nerveRoot, args.name);
+      const statements = listTableSqlStatements(db);
+      if (args.json) {
+        process.stdout.write(`${JSON.stringify(statements, null, 2)}\n`);
+      } else if (statements.length === 0) {
+        process.stdout.write("(no tables)\n");
+      } else {
+        for (const sql of statements) {
+          process.stdout.write(`${sql};\n\n`);
+        }
+      }
+    } catch (e) {
+      const msg = e instanceof Error ? e.message : String(e);
+      process.stderr.write(`❌ ${msg}\n`);
+      process.exit(1);
+    } finally {
+      db?.close();
+    }
+  },
+});
+
+// ---------------------------------------------------------------------------
+// nerve sense query <name> [sql...]
+// ---------------------------------------------------------------------------
+
+const senseQueryCommand = defineCommand({
+  meta: {
+    name: "query",
+    description:
+      "Run a read-only SQL query against a sense database (default: last 10 rows of the first data table). Pass optional SQL after the sense name; multiple words are joined.",
+  },
+  args: {
+    name: {
+      type: "positional",
+      description: "Sense name (data/senses/<name>.db under the nerve workspace)",
+    },
+    json: {
+      type: "boolean",
+      description: "Print result rows as JSON",
+      default: false,
+    },
+  },
+  async run({ args, rawArgs }) {
+    const nerveRoot = getNerveRoot();
+    let db: ReturnType<Awaited<ReturnType<typeof import("sql.js")>>["Database"]> | undefined;
+    try {
+      let parsed: { name: string; sql: string | undefined };
+      try {
+        parsed = parseSenseQueryArgs(rawArgs);
+      } catch (e) {
+        const msg = e instanceof Error ? e.message : String(e);
+        process.stderr.write(`❌ ${msg}\n`);
+        process.exit(1);
+      }
+
+      db = await openSenseDb(nerveRoot, args.name);
+
+      let sql = parsed.sql?.trim();
+      if (!sql) {
+        const table = pickDefaultPreviewTable(db);
+        if (table === null) {
+          process.stderr.write("❌ No tables found in database.\n");
+          process.exit(1);
+        } else {
+          sql = defaultPreviewSql(table);
+        }
+      }
+
+      const rows = queryAsObjects(db, sql);
+
+      if (args.json) {
+        process.stdout.write(`${JSON.stringify(rows, null, 2)}\n`);
+      } else {
+        process.stdout.write(formatRowsAsAlignedTable(rows));
+      }
+    } catch (e) {
+      const msg = e instanceof Error ? e.message : String(e);
+      process.stderr.write(`❌ ${msg}\n`);
+      process.exit(1);
+    } finally {
+      db?.close();
+    }
+  },
+});
+
 // ---------------------------------------------------------------------------
 // nerve sense (parent command)
 // ---------------------------------------------------------------------------
@@ -151,5 +270,7 @@ export const senseCommand = defineCommand({
   subCommands: {
     list: senseListCommand,
     trigger: senseTriggerCommand,
+    schema: senseSchemaCommand,
+    query: senseQueryCommand,
   },
 });

packages/cli/src/sense-sqlite.ts

@@ -0,0 +1,155 @@
+import { existsSync, readFileSync } from "node:fs";
+import { join } from "node:path";
+
+import initSqlJs, { type Database } from "sql.js";
+
+// ── WASM singleton ──────────────────────────────────────────────────────────
+let _SQL: Awaited<ReturnType<typeof initSqlJs>> | null = null;
+
+async function getSQL() {
+  if (!_SQL) {
+    _SQL = await initSqlJs();
+  }
+  return _SQL;
+}
+
+/** Open a sense SQLite database (readonly, loaded into memory via sql.js). */
+export async function openSenseDb(nerveRoot: string, senseName: string): Promise<Database> {
+  const path = assertSenseDbExists(nerveRoot, senseName);
+  const SQL = await getSQL();
+  const buffer = readFileSync(path);
+  return new SQL.Database(buffer);
+}
+
+/** SQLite path for a sense under the nerve workspace root. */
+export function senseDbPath(nerveRoot: string, senseName: string): string {
+  return join(nerveRoot, "data", "senses", `${senseName}.db`);
+}
+
+export function assertSenseDbExists(nerveRoot: string, senseName: string): string {
+  const path = senseDbPath(nerveRoot, senseName);
+  if (!existsSync(path)) {
+    throw new Error(`No database at ${path}`);
+  }
+  return path;
+}
+
+/** `SELECT sql FROM sqlite_master WHERE type='table'` (non-null sql only). */
+export function listTableSqlStatements(db: Database): string[] {
+  const results = db.exec(
+    `SELECT sql FROM sqlite_master WHERE type = 'table' AND sql IS NOT NULL ORDER BY tbl_name`,
+  );
+  if (results.length === 0) return [];
+  return results[0].values.map((row) => row[0] as string);
+}
+
+/**
+ * Table used for `nerve sense query <name>` with no SQL.
+ * Prefers real data tables over `_migrations`, then lexicographic by name.
+ */
+export function pickDefaultPreviewTable(db: Database): string | null {
+  const results = db.exec(
+    `SELECT name FROM sqlite_master
+     WHERE type = 'table' AND sql IS NOT NULL
+       AND name NOT LIKE 'sqlite\\_%' ESCAPE '\\'
+     ORDER BY
+       CASE WHEN name = '_migrations' THEN 1 ELSE 0 END,
+       name
+     LIMIT 1`,
+  );
+  if (results.length === 0 || results[0].values.length === 0) return null;
+  return results[0].values[0][0] as string;
+}
+
+export function defaultPreviewSql(table: string): string {
+  return `SELECT * FROM "${table.replace(/"/g, '""')}" ORDER BY rowid DESC LIMIT 10`;
+}
+
+/** Parse sense name and optional SQL from subcommand raw argv (flags stripped). */
+export function parseSenseQueryArgs(rawArgs: string[]): { name: string; sql: string | undefined } {
+  const pos: string[] = [];
+  for (let i = 0; i < rawArgs.length; i++) {
+    const a = rawArgs[i];
+    if (a === "--json" || a === "--no-json") continue;
+    if (a.startsWith("-")) {
+      const eq = a.indexOf("=");
+      if (eq === -1 && i + 1 < rawArgs.length && !rawArgs[i + 1].startsWith("-")) {
+        i += 1;
+      }
+      continue;
+    }
+    pos.push(a);
+  }
+  if (pos.length < 1) {
+    throw new Error("Missing sense name");
+  }
+  const name = pos[0];
+  const sql = pos.length > 1 ? pos.slice(1).join(" ") : undefined;
+  return { name, sql };
+}
+
+function stringifyCell(value: unknown): string {
+  if (value === null || value === undefined) return "";
+  if (typeof value === "bigint") return value.toString();
+  if (typeof value === "number" || typeof value === "boolean") return String(value);
+  if (typeof value === "string") return value;
+  if (value instanceof Uint8Array) return Buffer.from(value).toString("hex");
+  try {
+    return JSON.stringify(value);
+  } catch {
+    return String(value);
+  }
+}
+
+/** Collect column keys in stable order (first row keys, then any extras). */
+export function collectColumnKeys(rows: Record<string, unknown>[]): string[] {
+  const keys: string[] = [];
+  const seen = new Set<string>();
+  for (const row of rows) {
+    for (const k of Object.keys(row)) {
+      if (!seen.has(k)) {
+        seen.add(k);
+        keys.push(k);
+      }
+    }
+  }
+  return keys;
+}
+
+const MAX_CELL = 64;
+
+function truncate(s: string): string {
+  if (s.length <= MAX_CELL) return s;
+  return `${s.slice(0, MAX_CELL - 1)}…`;
+}
+
+/** Plain aligned table for terminal output. */
+export function formatRowsAsAlignedTable(rows: Record<string, unknown>[]): string {
+  if (rows.length === 0) {
+    return "(0 rows)\n";
+  }
+  const cols = collectColumnKeys(rows);
+  const cells = rows.map((row) => cols.map((c) => truncate(stringifyCell(row[c]))));
+  const widths = cols.map((c, j) => Math.max(c.length, ...cells.map((r) => r[j].length)));
+  const sep = widths.map((w) => "-".repeat(w)).join("-+-");
+  const header = cols.map((c, j) => c.padEnd(widths[j])).join(" | ");
+  const body = cells.map((r) => r.map((cell, j) => cell.padEnd(widths[j])).join(" | ")).join("\n");
+  return `${header}\n${sep}\n${body}\n`;
+}
+
+/**
+ * Run a SQL query via sql.js and return rows as key-value objects.
+ * sql.js returns columnar data; this converts to the familiar row format.
+ */
+export function queryAsObjects(db: Database, sql: string): Record<string, unknown>[] {
+  const results = db.exec(sql);
+  if (results.length === 0) return [];
+  const { columns, values } = results[0];
+  return values.map((row) => {
+    const obj: Record<string, unknown> = {};
+    for (let i = 0; i < columns.length; i++) {
+      obj[columns[i]] = row[i];
+    }
+    return obj;
+  });
+}

packages/cli/tsup.config.ts

@@ -9,5 +9,5 @@ export default defineConfig({
     js: "#!/usr/bin/env node",
   },
   /** Daemon is loaded from workspace node_modules at runtime — never bundle it. */
-  external: ["@uncaged/nerve-daemon"],
+  external: ["@uncaged/nerve-daemon", "sql.js"],
 });

packages/daemon/src/kernel.ts

@@ -33,6 +33,11 @@ import { createReflexScheduler } from "./reflex-scheduler.js";
 import type { ReflexScheduler } from "./reflex-scheduler.js";
 import { createSignalBus } from "./signal-bus.js";
 import type { SignalBus } from "./signal-bus.js";
+import {
+  formatCapturedStderrTail,
+  formatChildExitSummary,
+  teeCapturedStderr,
+} from "./worker-fork-support.js";
 import { createWorkflowManager } from "./workflow-manager.js";
 import type { WorkflowManager } from "./workflow-manager.js";
 
@@ -84,10 +89,16 @@ function resolveWorkerScript(): string {
   return join(__dir, "sense-worker.js");
 }
 
-function spawnWorker(nerveRoot: string, group: string, workerScript: string): ChildProcess {
+function spawnWorker(
+  nerveRoot: string,
+  group: string,
+  workerScript: string,
+  stderrTail: { value: string },
+): ChildProcess {
   const child = fork(workerScript, ["--group", group, "--root", nerveRoot], {
-    stdio: ["ignore", "inherit", "inherit", "ipc"],
+    stdio: ["ignore", "inherit", "pipe", "ipc"],
   });
+  teeCapturedStderr(child, stderrTail);
   // Prevent unhandled EPIPE when writing to a child whose IPC channel closed
   child.on("error", (err) => {
     if ((err as NodeJS.ErrnoException).code !== "EPIPE") {
@@ -240,7 +251,8 @@ export function createKernel(
   }
 
   function startWorker(group: string): Promise<void> {
-    const child = spawnWorker(nerveRoot, group, workerScript);
+    const stderrTail = { value: "" };
+    const child = spawnWorker(nerveRoot, group, workerScript, stderrTail);
 
     let workerReadyResolve: (() => void) | undefined;
     const workerReady = new Promise<void>((resolve) => {
@@ -255,9 +267,10 @@ export function createKernel(
       handleWorkerMessage(raw);
     });
 
-    child.on("exit", (code) => {
+    child.on("exit", (code, signal) => {
+      const summary = formatChildExitSummary(code, signal ?? null);
       process.stderr.write(
-        `[kernel] worker for group "${group}" exited with code ${code ?? "null"}\n`,
+        `[kernel] worker for group "${group}" exited (${summary})${formatCapturedStderrTail(stderrTail.value)}\n`,
       );
       // Resolve ready in case the worker exits before sending ready (prevents hangs)
       workerReadyResolve?.();

packages/daemon/src/sense-worker.ts

@@ -25,6 +25,7 @@ import type { WorkerToParentMessage } from "./ipc.js";
 import { parseParentMessage } from "./ipc.js";
 import { executeCompute, loadComputeFn, openPeerDb, openSenseDb } from "./sense-runtime.js";
 import type { DrizzleDB, PeerMap, SenseRuntime } from "./sense-runtime.js";
+import { ignoreSessionBroadcastSignals } from "./worker-fork-support.js";
 
 // ---------------------------------------------------------------------------
 // IPC helpers
@@ -336,6 +337,10 @@ if (!parsed) {
   process.exit(1);
 }
 
+if (typeof process.send === "function") {
+  ignoreSessionBroadcastSignals();
+}
+
 bootstrap(parsed.nerveRoot, parsed.group).catch((e) => {
   const msg = e instanceof Error ? e.message : String(e);
   process.stderr.write(`[sense-worker] Unhandled bootstrap error: ${msg}\n`);

packages/daemon/src/worker-fork-support.ts

@@ -0,0 +1,48 @@
+import type { ChildProcess } from "node:child_process";
+
+const STDERR_TAIL_MAX_CHARS = 16_384;
+
+/**
+ * Forked workers inherit the parent's process group. In foreground `nerve dev`,
+ * terminal-driven SIGINT/SIGTERM is delivered to the whole group, so workers can exit
+ * on the default handler before the kernel sends `{ type: "shutdown" }` over IPC.
+ * Swallow these in worker processes so the parent coordinates shutdown (issue #55).
+ * Only call when `process.send` is defined (fork IPC); standalone `node …-worker.js` keeps default Ctrl+C behaviour.
+ */
+export function ignoreSessionBroadcastSignals(): void {
+  const swallow = (): void => {};
+  process.on("SIGINT", swallow);
+  process.on("SIGTERM", swallow);
+}
+
+export function teeCapturedStderr(child: ChildProcess, tail: { value: string }): void {
+  const stream = child.stderr;
+  if (stream === null || stream === undefined) return;
+  stream.setEncoding("utf8");
+  stream.on("data", (chunk: string | Buffer) => {
+    const text = typeof chunk === "string" ? chunk : chunk.toString("utf8");
+    process.stderr.write(text);
+    tail.value = (tail.value + text).slice(-STDERR_TAIL_MAX_CHARS);
+  });
+}
+
+export function formatChildExitSummary(
+  code: number | null,
+  signal: NodeJS.Signals | null,
+): string {
+  const codeStr = code === null || code === undefined ? "null" : String(code);
+  if (signal) {
+    return `code=${codeStr} signal=${signal}`;
+  }
+  return `code=${codeStr}`;
+}
+
+export function formatCapturedStderrTail(tail: string, maxChars = 800): string {
+  const trimmed = tail.trim();
+  if (trimmed.length === 0) return "";
+  const normalized = trimmed.replace(/\r?\n/g, "\\n");
+  if (normalized.length <= maxChars) {
+    return ` worker_stderr=${normalized}`;
+  }
+  return ` worker_stderr=…${normalized.slice(-maxChars)}`;
+}

packages/daemon/src/workflow-manager.ts

@@ -22,6 +22,11 @@ import type {
 import { parseWorkerMessage } from "./ipc.js";
 import type { LogStore } from "./log-store.js";
 import type { WorkflowRunStatus } from "./log-store.js";
+import {
+  formatCapturedStderrTail,
+  formatChildExitSummary,
+  teeCapturedStderr,
+} from "./worker-fork-support.js";
 
 export type WorkflowManager = {
   /** Trigger a new workflow thread (called by Reflex scheduler). */
@@ -60,6 +65,7 @@ type WorkerEntry = {
   stopping: boolean;
   /** When set, the worker is draining before a hot-reload respawn. */
   draining: boolean;
+  stderrTail: { value: string };
 };
 
 // Crash respawn backoff: track crash timestamps per workflow.
@@ -85,10 +91,12 @@ function spawnWorkflowWorker(
   nerveRoot: string,
   workflowName: string,
   workerScript: string,
+  stderrTail: { value: string },
 ): ChildProcess {
   const child = fork(workerScript, ["--workflow", workflowName, "--root", nerveRoot], {
-    stdio: ["ignore", "inherit", "inherit", "ipc"],
+    stdio: ["ignore", "inherit", "pipe", "ipc"],
   });
+  teeCapturedStderr(child, stderrTail);
   // Prevent unhandled EPIPE when writing to a child whose IPC channel closed
   child.on("error", (err) => {
     if ((err as NodeJS.ErrnoException).code !== "EPIPE") {
@@ -395,7 +403,11 @@ export function createWorkflowManager(
     state.active.clear();
   }
 
-  function handleWorkerExit(workflowName: string, code: number | null): void {
+  function handleWorkerExit(
+    workflowName: string,
+    code: number | null,
+    signal: NodeJS.Signals | null,
+  ): void {
     const entry = workers.get(workflowName);
     if (entry?.draining) {
       workers.delete(workflowName);
@@ -416,8 +428,10 @@ export function createWorkflowManager(
       }
       return;
     }
+    const summary = formatChildExitSummary(code, signal);
+    const stderrExtra = entry !== undefined ? formatCapturedStderrTail(entry.stderrTail.value) : "";
     process.stderr.write(
-      `[workflow-manager] worker for "${workflowName}" exited with code ${code ?? "null"}\n`,
+      `[workflow-manager] worker for "${workflowName}" exited (${summary})${stderrExtra}\n`,
     );
     handleWorkerCrash(workflowName);
   }
@@ -428,17 +442,24 @@ export function createWorkflowManager(
       return existing;
     }
 
-    const child = spawnWorkflowWorker(nerveRoot, workflowName, workerScript);
+    const stderrTail = { value: "" };
+    const child = spawnWorkflowWorker(nerveRoot, workflowName, workerScript, stderrTail);
 
     child.on("message", (raw: unknown) => {
       handleWorkerMessage(workflowName, raw);
     });
 
-    child.on("exit", (code) => {
-      handleWorkerExit(workflowName, code);
+    child.on("exit", (code, signal) => {
+      handleWorkerExit(workflowName, code, signal ?? null);
     });
 
-    const entry: WorkerEntry = { workflowName, process: child, stopping: false, draining: false };
+    const entry: WorkerEntry = {
+      workflowName,
+      process: child,
+      stopping: false,
+      draining: false,
+      stderrTail,
+    };
     workers.set(workflowName, entry);
     return entry;
   }

packages/daemon/src/workflow-worker.ts

@@ -21,6 +21,7 @@ import type {
 
 import type { ThreadCommandEventMessage, ThreadEventType, WorkerToParentMessage } from "./ipc.js";
 import { parseParentMessage } from "./ipc.js";
+import { ignoreSessionBroadcastSignals } from "./worker-fork-support.js";
 
 // ---------------------------------------------------------------------------
 // IPC helpers
@@ -335,6 +336,10 @@ if (!parsed) {
   process.exit(1);
 }
 
+if (typeof process.send === "function") {
+  ignoreSessionBroadcastSignals();
+}
+
 bootstrap(parsed.nerveRoot, parsed.workflow).catch((e) => {
   const msg = e instanceof Error ? e.message : String(e);
   process.stderr.write(`[workflow-worker] Unhandled bootstrap error: ${msg}\n`);

pnpm-lock.yaml

@@ -26,6 +26,9 @@ importers:
       citty:
         specifier: ^0.1.6
         version: 0.1.6
+      sql.js:
+        specifier: ^1.14.1
+        version: 1.14.1
     devDependencies:
       '@types/better-sqlite3':
         specifier: ^7.6.13
@@ -60,7 +63,7 @@ importers:
         version: 11.10.0
       drizzle-orm:
         specifier: ^0.43.1
-        version: 0.43.1(@types/better-sqlite3@7.6.13)(better-sqlite3@11.10.0)
+        version: 0.43.1(@types/better-sqlite3@7.6.13)(better-sqlite3@11.10.0)(sql.js@1.14.1)
       yaml:
         specifier: ^2.8.3
         version: 2.8.3
@@ -1071,6 +1074,9 @@ packages:
     resolution: {integrity: sha512-i5uvt8C3ikiWeNZSVZNWcfZPItFQOsYTUAOkcUPGd8DqDy1uOUikjt5dG+uRlwyvR108Fb9DOd4GvXfT0N2/uQ==}
     engines: {node: '>= 12'}
 
+  sql.js@1.14.1:
+    resolution: {integrity: sha512-gcj8zBWU5cFsi9WUP+4bFNXAyF1iRpA3LLyS/DP5xlrNzGmPIizUeBggKa8DbDwdqaKwUcTEnChtd2grWo/x/A==}
+
   stackback@0.0.2:
     resolution: {integrity: sha512-1XMJE5fQo1jGH6Y/7ebnwPOBEkIEnT4QF32d5R1+VXdXveM0IBMJt8zfaxX1P3QhVwrYe+576+jkANtSS2mBbw==}
 
@@ -1692,10 +1698,11 @@ snapshots:
 
   detect-libc@2.1.2: {}
 
-  drizzle-orm@0.43.1(@types/better-sqlite3@7.6.13)(better-sqlite3@11.10.0):
+  drizzle-orm@0.43.1(@types/better-sqlite3@7.6.13)(better-sqlite3@11.10.0)(sql.js@1.14.1):
     optionalDependencies:
       '@types/better-sqlite3': 7.6.13
       better-sqlite3: 11.10.0
+      sql.js: 1.14.1
 
   end-of-stream@1.4.5:
     dependencies:
@@ -1997,6 +2004,8 @@ snapshots:
 
   source-map@0.7.6: {}
 
+  sql.js@1.14.1: {}
+
   stackback@0.0.2: {}
 
   std-env@4.1.0: {}