feat(cli,core): add opt-in dev-only telnet log streaming

0ski · 0ski · commit 653556528a6d · 2026-07-02T17:43:17.000+02:00
Stream dev logs over a local telnet/TCP socket. `trigger dev` mirrors its terminal output on port 6700 by default (override with --telnet-logs-port or TRIGGER_DEV_TELNET_LOGS_PORT, 0 disables). webapp, supervisor, and coordinator each expose an opt-in stream gated on a per-service *_TELNET_LOGS_PORT env var. New @trigger.dev/core/v3/telnetLogServer module (localhost-only, backpressure-safe, plain-text) plus optional static Logger.onLog / SimpleStructuredLogger.onLog sinks.
diff --git a/.changeset/telnet-dev-logs.md b/.changeset/telnet-dev-logs.md
@@ -0,0 +1,5 @@
+---
+"@trigger.dev/core": patch
+---
+
+Add a `@trigger.dev/core/v3/telnetLogServer` module: the shared `TelnetLogServer` (localhost-only, backpressure-safe), `formatLogLine`, and `stripAnsi` helpers, plus an optional static `Logger.onLog` / `SimpleStructuredLogger.onLog` sink used to fan structured logs out to a local dev-only telnet/TCP stream.
diff --git a/.env.example b/.env.example
@@ -8,6 +8,8 @@ DATABASE_URL=postgresql://postgres:postgres@localhost:5432/postgres?schema=publi
 # See: https://www.prisma.io/docs/reference/api-reference/prisma-schema-reference#fields:~:text=the%20shadow%20database.-,directUrl,-No
 DIRECT_URL=${DATABASE_URL}
 REMIX_APP_PORT=3030
+# Dev-only: stream the webapp's logs over a local telnet/TCP socket (nc localhost 6767). Unset to disable.
+WEBAPP_TELNET_LOGS_PORT=6767
 APP_ENV=development
 APP_ORIGIN=http://localhost:3030
 ELECTRIC_ORIGIN=http://localhost:3060
diff --git a/.server-changes/coordinator-telnet-logs.md b/.server-changes/coordinator-telnet-logs.md
@@ -0,0 +1,6 @@
+---
+area: coordinator
+type: feature
+---
+
+Add an opt-in, dev-only telnet log stream: set `COORDINATOR_TELNET_LOGS_PORT` (e.g. 6770) to tail this process's logs as plain text over a local TCP socket (`nc localhost 6770`). Bound to localhost; off unless the port is set.
diff --git a/.server-changes/supervisor-telnet-logs.md b/.server-changes/supervisor-telnet-logs.md
@@ -0,0 +1,6 @@
+---
+area: supervisor
+type: feature
+---
+
+Add an opt-in, dev-only telnet log stream: set `SUPERVISOR_TELNET_LOGS_PORT` (e.g. 6769) to tail this process's logs as plain text over a local TCP socket (`nc localhost 6769`). Bound to localhost; off unless the port is set.
diff --git a/.server-changes/webapp-telnet-logs.md b/.server-changes/webapp-telnet-logs.md
@@ -0,0 +1,6 @@
+---
+area: webapp
+type: feature
+---
+
+Add an opt-in, dev-only telnet log stream: set `WEBAPP_TELNET_LOGS_PORT` (e.g. 6767) to tail this process's logs as plain text over a local TCP socket (`nc localhost 6767`). Bound to localhost; off unless the port is set.
diff --git a/apps/coordinator/.env.example b/apps/coordinator/.env.example
@@ -1,4 +1,6 @@
 HTTP_SERVER_PORT=8020
 PLATFORM_ENABLED=true
 PLATFORM_WS_PORT=3030
-SECURE_CONNECTION=false
+SECURE_CONNECTION=false
+# Dev-only: stream this process's logs over a local telnet/TCP socket (nc localhost 6770). Unset to disable.
+COORDINATOR_TELNET_LOGS_PORT=6770
diff --git a/apps/coordinator/src/index.ts b/apps/coordinator/src/index.ts
@@ -18,9 +18,13 @@ import { boolFromEnv, numFromEnv, safeJsonParse } from "./util";
 
 import { collectDefaultMetrics, register, Gauge } from "prom-client";
 import { SimpleStructuredLogger } from "@trigger.dev/core/v3/utils/structuredLogger";
+import { formatLogLine, startTelnetLogServer } from "@trigger.dev/core/v3/telnetLogServer";
 collectDefaultMetrics();
 
 const HTTP_SERVER_PORT = Number(process.env.HTTP_SERVER_PORT || 8020);
+const TELNET_LOGS_PORT = process.env.COORDINATOR_TELNET_LOGS_PORT
+  ? Number(process.env.COORDINATOR_TELNET_LOGS_PORT)
+  : undefined;
 const NODE_NAME = process.env.NODE_NAME || "coordinator";
 const DEFAULT_RETRY_DELAY_THRESHOLD_IN_MS = 30_000;
 
@@ -1777,5 +1781,11 @@ class TaskCoordinator {
   }
 }
 
+// Opt-in, dev-only: mirror this process's structured logs to a local telnet/TCP stream.
+if (TELNET_LOGS_PORT && Number.isFinite(TELNET_LOGS_PORT) && TELNET_LOGS_PORT > 0) {
+  const telnetLogServer = startTelnetLogServer({ port: TELNET_LOGS_PORT, name: "coordinator" });
+  SimpleStructuredLogger.onLog = (log) => telnetLogServer.broadcast(formatLogLine(log));
+}
+
 const coordinator = new TaskCoordinator(HTTP_SERVER_PORT);
 coordinator.listen();
diff --git a/apps/supervisor/.env.example b/apps/supervisor/.env.example
@@ -14,4 +14,7 @@ OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:3030/otel
 
 # Optional settings
 DEBUG=1
-TRIGGER_DEQUEUE_INTERVAL_MS=1000
+TRIGGER_DEQUEUE_INTERVAL_MS=1000
+
+# Dev-only: stream this process's logs over a local telnet/TCP socket (nc localhost 6769). Unset to disable.
+SUPERVISOR_TELNET_LOGS_PORT=6769
diff --git a/apps/supervisor/src/env.ts b/apps/supervisor/src/env.ts
@@ -9,6 +9,9 @@ export const Env = z
     TRIGGER_WORKER_INSTANCE_NAME: z.string().default(randomUUID()),
     TRIGGER_WORKER_HEARTBEAT_INTERVAL_SECONDS: z.coerce.number().default(30),
 
+    // Opt-in, dev-only: stream this process's logs over a local telnet/TCP socket on this port.
+    SUPERVISOR_TELNET_LOGS_PORT: z.coerce.number().optional(),
+
     // Required settings
     TRIGGER_API_URL: z.string().url(),
     TRIGGER_WORKER_TOKEN: z.string(), // accepts file:// path to read from a file
diff --git a/apps/supervisor/src/index.ts b/apps/supervisor/src/index.ts
@@ -1,5 +1,6 @@
 import { SupervisorSession } from "@trigger.dev/core/v3/workers";
 import { SimpleStructuredLogger } from "@trigger.dev/core/v3/utils/structuredLogger";
+import { formatLogLine, startTelnetLogServer } from "@trigger.dev/core/v3/telnetLogServer";
 import { env } from "./env.js";
 import { WorkloadServer } from "./workloadServer/index.js";
 import type { WorkloadManagerOptions, WorkloadManager } from "./workloadManager/types.js";
@@ -749,5 +750,14 @@ class ManagedSupervisor {
   }
 }
 
+// Opt-in, dev-only: mirror this process's structured logs to a local telnet/TCP stream.
+if (env.SUPERVISOR_TELNET_LOGS_PORT && env.SUPERVISOR_TELNET_LOGS_PORT > 0) {
+  const telnetLogServer = startTelnetLogServer({
+    port: env.SUPERVISOR_TELNET_LOGS_PORT,
+    name: "supervisor",
+  });
+  SimpleStructuredLogger.onLog = (log) => telnetLogServer.broadcast(formatLogLine(log));
+}
+
 const worker = new ManagedSupervisor();
 worker.start();
diff --git a/apps/webapp/app/env.server.ts b/apps/webapp/app/env.server.ts
@@ -139,6 +139,9 @@ const EnvironmentSchema = z
       .optional(),
     ADMIN_EMAILS: z.string().refine(isValidRegex, "ADMIN_EMAILS must be a valid regex.").optional(),
     REMIX_APP_PORT: z.string().optional(),
+    // Opt-in, dev-only: stream this process's logs over a local telnet/TCP socket on this port.
+    // Read directly from process.env in server.ts (before this schema loads); declared here for discoverability.
+    WEBAPP_TELNET_LOGS_PORT: z.coerce.number().optional(),
     LOGIN_ORIGIN: z.string().default("http://localhost:3030"),
     LOGIN_RATE_LIMITS_ENABLED: BoolEnv.default(true),
     APP_ORIGIN: z.string().default("http://localhost:3030"),
diff --git a/apps/webapp/app/services/logger.server.ts b/apps/webapp/app/services/logger.server.ts
@@ -1,5 +1,6 @@
 import type { LogLevel } from "@trigger.dev/core/logger";
 import { Logger } from "@trigger.dev/core/logger";
+import { patchConsoleToTelnet, startTelnetLogServer } from "@trigger.dev/core/v3/telnetLogServer";
 import { sensitiveDataReplacer } from "./sensitiveDataReplacer";
 import { AsyncLocalStorage } from "async_hooks";
 import { getHttpContext } from "./httpAsyncStorage.server";
@@ -79,3 +80,19 @@ export const socketLogger = new Logger(
     return fields ? { ...fields } : {};
   }
 );
+
+// Opt-in, dev-only: mirror this process's stdout to a local telnet/TCP stream.
+// We patch console (rather than the static Logger.onLog sink) so the stream also captures logs
+// from separate/bundled copies of the Logger — e.g. the enterprise SSO plugin, which bundles its
+// own @trigger.dev/core and logs via its own console.log, invisible to the webapp's onLog hook.
+const telnetLogsPort = process.env.WEBAPP_TELNET_LOGS_PORT
+  ? Number(process.env.WEBAPP_TELNET_LOGS_PORT)
+  : undefined;
+if (telnetLogsPort && Number.isFinite(telnetLogsPort) && telnetLogsPort > 0) {
+  const telnetGlobal = globalThis as typeof globalThis & { __webappTelnetLogs?: boolean };
+  if (!telnetGlobal.__webappTelnetLogs) {
+    telnetGlobal.__webappTelnetLogs = true;
+    const telnetLogServer = startTelnetLogServer({ port: telnetLogsPort, name: "webapp" });
+    patchConsoleToTelnet(telnetLogServer, { pretty: true });
+  }
+}
diff --git a/packages/core/package.json b/packages/core/package.json
@@ -43,6 +43,7 @@
       "./v3/utils/omit": "./src/v3/utils/omit.ts",
       "./v3/utils/retries": "./src/v3/utils/retries.ts",
       "./v3/utils/structuredLogger": "./src/v3/utils/structuredLogger.ts",
+      "./v3/telnetLogServer": "./src/v3/telnetLogServer.ts",
       "./v3/test": "./src/v3/test/index.ts",
       "./v3/zodfetch": "./src/v3/zodfetch.ts",
       "./v3/zodMessageHandler": "./src/v3/zodMessageHandler.ts",
@@ -124,6 +125,9 @@
       "v3/utils/structuredLogger": [
         "dist/commonjs/v3/utils/structuredLogger.d.ts"
       ],
+      "v3/telnetLogServer": [
+        "dist/commonjs/v3/telnetLogServer.d.ts"
+      ],
       "v3/zodfetch": [
         "dist/commonjs/v3/zodfetch.d.ts"
       ],
@@ -490,6 +494,17 @@
         "default": "./dist/commonjs/v3/utils/structuredLogger.js"
       }
     },
+    "./v3/telnetLogServer": {
+      "import": {
+        "@triggerdotdev/source": "./src/v3/telnetLogServer.ts",
+        "types": "./dist/esm/v3/telnetLogServer.d.ts",
+        "default": "./dist/esm/v3/telnetLogServer.js"
+      },
+      "require": {
+        "types": "./dist/commonjs/v3/telnetLogServer.d.ts",
+        "default": "./dist/commonjs/v3/telnetLogServer.js"
+      }
+    },
     "./v3/test": {
       "import": {
         "@triggerdotdev/source": "./src/v3/test/index.ts",
diff --git a/packages/core/src/logger.ts b/packages/core/src/logger.ts
@@ -26,6 +26,10 @@ export class Logger {
   // Add a static "onError" method that will be called when an error is logged
   static onError: (message: string, ...args: Array<Record<string, unknown> | undefined>) => void;
 
+  // Optional static sink called with the fully-structured log for every emitted line.
+  // Used (e.g.) to fan logs out to a dev-only telnet stream. Must not re-enter the Logger.
+  static onLog?: (structuredLog: Record<string, unknown>) => void;
+
   constructor(
     name: string,
     level: LogLevel = "info",
@@ -134,6 +138,14 @@ export class Logger {
       structuredLog.skipForwarding = true;
     }
 
+    if (Logger.onLog) {
+      try {
+        Logger.onLog(structuredLog);
+      } catch {
+        // A sink must never break logging — and must never re-enter the Logger.
+      }
+    }
+
     loggerFunction(JSON.stringify(structuredLog, this.#jsonReplacer));
   }
 }
diff --git a/packages/core/src/v3/telnetLogServer.test.ts b/packages/core/src/v3/telnetLogServer.test.ts
@@ -0,0 +1,162 @@
+import net from "node:net";
+import { afterEach, describe, expect, test } from "vitest";
+import { formatConsoleLine, formatLogLine, stripAnsi, TelnetLogServer } from "./telnetLogServer.js";
+
+const servers: TelnetLogServer[] = [];
+
+afterEach(() => {
+  while (servers.length) {
+    servers.pop()?.close();
+  }
+});
+
+/** Grab a port the OS just told us is free, then hand it to a TelnetLogServer. */
+async function startServerOnFreePort(
+  name = "test"
+): Promise<{ server: TelnetLogServer; port: number }> {
+  const probe = net.createServer();
+  const port = await listening(probe, 0);
+  await new Promise<void>((resolve) => probe.close(() => resolve()));
+
+  // A banner lets clients deterministically wait until the server has registered them
+  // (it's written in the connection handler), removing the connect/register race.
+  const server = new TelnetLogServer({ port, name, banner: "ready" });
+  servers.push(server);
+  server.start();
+  await delay(30);
+  return { server, port };
+}
+
+/** Connects and resolves only once the first bytes (the banner) arrive — server-side socket is registered by then. */
+function connectAndCollect(port: number): Promise<{ socket: net.Socket; lines: () => string }> {
+  return new Promise((resolve, reject) => {
+    let buffer = "";
+    const socket = net.connect(port, "127.0.0.1");
+    socket.setEncoding("utf8");
+    socket.on("data", (chunk) => {
+      const first = buffer === "";
+      buffer += chunk;
+      if (first) {
+        resolve({ socket, lines: () => buffer });
+      }
+    });
+    socket.on("error", reject);
+  });
+}
+
+function listening(server: net.Server, port: number, host = "127.0.0.1"): Promise<number> {
+  return new Promise((resolve) => {
+    server.listen(port, host, () => {
+      const address = server.address();
+      resolve(typeof address === "object" && address ? address.port : port);
+    });
+  });
+}
+
+describe("stripAnsi", () => {
+  test("removes color escape codes", () => {
+    const colored = "[90m2026-06-11[39m [31mERROR[39m boom";
+    expect(stripAnsi(colored)).toBe("2026-06-11 ERROR boom");
+  });
+});
+
+describe("formatLogLine", () => {
+  test("formats a core Logger-shaped object (level/name)", () => {
+    const line = formatLogLine({
+      timestamp: new Date("2026-06-11T12:00:00.000Z"),
+      name: "webapp",
+      level: "info",
+      message: "queue drained",
+      count: 3,
+    });
+    expect(line).toBe("2026-06-11T12:00:00.000Z INFO  [webapp] queue drained {count=3}");
+  });
+
+  test("formats a SimpleStructuredLogger-shaped object ($level/$name)", () => {
+    const line = formatLogLine({
+      timestamp: new Date("2026-06-11T12:00:00.000Z"),
+      $name: "supervisor",
+      $level: "warn",
+      message: "retrying",
+      attempt: 2,
+    });
+    expect(line).toBe("2026-06-11T12:00:00.000Z WARN  [supervisor] retrying {attempt=2}");
+  });
+
+  test("omits empty name and extras", () => {
+    const line = formatLogLine({
+      timestamp: "2026-06-11T12:00:00.000Z",
+      level: "log",
+      message: "hello",
+    });
+    expect(line).toBe("2026-06-11T12:00:00.000Z LOG   hello");
+  });
+});
+
+describe("formatConsoleLine", () => {
+  test("pretty-formats a JSON structured-log line", () => {
+    const raw = JSON.stringify({
+      timestamp: "2026-06-11T12:00:00.000Z",
+      name: "sso-plugin",
+      level: "info",
+      message: "sso.webhook.connection.activated: connection marked active",
+      connId: "conn_123",
+    });
+    expect(formatConsoleLine(raw)).toBe(
+      "2026-06-11T12:00:00.000Z INFO  [sso-plugin] sso.webhook.connection.activated: connection marked active {connId=conn_123}"
+    );
+  });
+
+  test("passes non-JSON console output through unchanged", () => {
+    expect(formatConsoleLine("GET /healthcheck 200 1.2 ms")).toBe("GET /healthcheck 200 1.2 ms");
+  });
+
+  test("passes JSON that isn't a structured log through unchanged", () => {
+    const raw = JSON.stringify({ foo: "bar" });
+    expect(formatConsoleLine(raw)).toBe(raw);
+  });
+});
+
+describe("TelnetLogServer", () => {
+  test("broadcasts a line to a connected client", async () => {
+    const { server, port } = await startServerOnFreePort();
+    const client = await connectAndCollect(port);
+    server.broadcast("first line");
+    await delay(50);
+    expect(client.lines()).toContain("first line\r\n");
+    client.socket.destroy();
+  });
+
+  test("close() ends connected sockets", async () => {
+    const { server, port } = await startServerOnFreePort();
+    const client = await connectAndCollect(port);
+    server.broadcast("alive");
+    await delay(30);
+    expect(client.lines()).toContain("alive\r\n");
+
+    let closed = false;
+    client.socket.on("close", () => {
+      closed = true;
+    });
+    server.close();
+    await delay(30);
+    expect(closed).toBe(true);
+  });
+
+  test("EADDRINUSE does not throw", async () => {
+    const blocker = net.createServer();
+    const port = await listening(blocker, 0);
+
+    const server = new TelnetLogServer({ port, name: "test" });
+    servers.push(server);
+    // Must not throw even though the port is taken.
+    expect(() => server.start()).not.toThrow();
+    await delay(30);
+
+    blocker.close();
+  });
+});
+
+function delay(ms: number): Promise<void> {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
diff --git a/packages/core/src/v3/telnetLogServer.ts b/packages/core/src/v3/telnetLogServer.ts
diff --git a/packages/core/src/v3/utils/structuredLogger.ts b/packages/core/src/v3/utils/structuredLogger.ts

-Original file line number
+Diff line change
@@ @@ -0,0 +1,5 @@ @@
 +---
 +"@trigger.dev/core": patch
 +---
++
 +Add a `@trigger.dev/core/v3/telnetLogServer` module: the shared `TelnetLogServer` (localhost-only, backpressure-safe), `formatLogLine`, and `stripAnsi` helpers, plus an optional static `Logger.onLog` / `SimpleStructuredLogger.onLog` sink used to fan structured logs out to a local dev-only telnet/TCP stream.