Function runBackgroundDaemonStart

apps/cli/src/main.ts:1300–1334

(input: {
  port: number;
  hostname: string;
  allowedHosts: ReadonlyArray<string>;
})

// command is idempotent: re-running while a daemon is already up should report success
// (matching the auto-start behaviour) rather than fail or spawn a duplicate.
const runBackgroundDaemonStart = (input: {
  port: number;
  hostname: string;
  allowedHosts: ReadonlyArray<string>;
}): Effect.Effect<void, Error, FileSystem.FileSystem | PlatformPath.Path> =>
  Effect.gen(function* () {
    const host = canonicalDaemonHost(input.hostname);
    const requestedUrl = daemonBaseUrl(host, input.port);
    const target = yield* resolveDaemonTarget(requestedUrl);

    if (yield* isServerReachable(target.baseUrl)) {
      console.log(`Daemon already running at ${target.baseUrl}.`);
      return;
    }

    if (!canAutoStartLocalDaemonForHost(host)) {
      return yield* Effect.fail(
        new Error(
          [
            `Cannot background a daemon for non-local host ${host}.`,
            `Use --foreground or bind to localhost / 127.0.0.1.`,
          ].join("\n"),
        ),
      );
    }

    const startBaseUrl = yield* spawnAndWaitForDaemon({
      host,
      scopeId: target.scopeId,
      preferredPort: input.port,
      allowedHosts: input.allowedHosts,
    });

    console.log(`Daemon ready on ${startBaseUrl}`);
  }).pipe(Effect.mapError(toError));

// ---------------------------------------------------------------------------
// Stdio MCP session: a pure stdio <-> HTTP bridge to the owning local daemon.