Winston transport

@squasher-ai/winston is a Winston transport. It sends your Winston logs to Squasher, and log lines at error level become issues. This page is tested with version 0.4.2 and Winston 3.19 on Node.js 26.

Install the transport

npm install @squasher-ai/winston winston

Add your ingest key and project ID to the environment of your service:

.env

SQUASHER_API_KEY=sq_pk_...
SQUASHER_PROJECT_ID=...

To get both values, see Create an ingest key.

Add the transport to your logger

src/logger.ts

import winston from "winston";
import { SquasherTransport } from "@squasher-ai/winston";

export const logger = winston.createLogger({
  level: "info",
  format: winston.format.combine(winston.format.errors({ stack: true }), winston.format.json()),
  defaultMeta: { service: "checkout-api" },
  transports: [
    new winston.transports.Console(),
    new SquasherTransport({
      apiKey: process.env.SQUASHER_API_KEY!,
      projectId: process.env.SQUASHER_PROJECT_ID!,
      level: "info",
    }),
  ],
});

level sets the lowest level that goes to Squasher. The service field in defaultMeta sets the service name in Squasher. Other metadata goes into the event’s extra data.

Log errors

Pass the error as the first argument:

src/checkout.ts

import { logger } from "./logger";

try {
  await chargeCard(order);
} catch (error) {
  logger.error(error);
}

With format.errors({ stack: true }), the event gets the error message and a stack field in its extra data. Winston does not serialize an Error object inside metadata, so logger.error("checkout failed", { error }) sends {} for error.

Send a test error

Run this once with the same environment variables:

scripts/squasher-test.ts

import { logger } from "../src/logger";

logger.error(new Error("Squasher test error"));

The transport sends events in batches, every 5 seconds or when 25 events are queued. When the process exits, it sends the rest before the process ends, waiting up to 5 seconds. Then select Issues in the sidebar of your project. If the error does not appear, see Troubleshooting.

Options

Option	Default	Description
`apiKey`	Required	Your ingest key. An empty string turns the transport off.
`projectId`	Required	Your project ID.
`level`	The logger level	The lowest Winston level that the transport sends.
`endpoint`	`https://ingest.squasher.ai`	The ingest URL.

Winston warn becomes warning. verbose and silly become debug. Other levels, such as http, become info.

Limits

The transport has no environment or release option, so its events have no environment. Automatic AI triage runs only on production issues. To triage an issue from this transport, select Run triage in the Squasher triage card on the issue page.
The stack trace is an extra field, so the issue page does not show it as a stack trace.
The transport does not retry a failed send.
After an HTTP 401 response, the transport stops sending until the process restarts.
The batch size and the interval are fixed. You cannot change them.

Give the setup to a coding agent

Copy this prompt into your coding agent to install the transport the same way:

Install @squasher-ai/winston in this Node.js service. Add new SquasherTransport({ apiKey:
process.env.SQUASHER_API_KEY, projectId: process.env.SQUASHER_PROJECT_ID }) to the transports of the
existing Winston logger, next to the existing transports. Add winston.format.errors({ stack: true })
to the logger format. Log caught errors as logger.error(error), not inside metadata. Verify with
logger.error(new Error("Squasher test error")).

Next steps

Node.js SDK

Capture errors with an environment, a release, and stack traces.

Pino transport

Send Pino logs, with an environment option.

Design queryable logs

Choose log fields that are easy to search.

Read AI triage

Learn what the triage summary tells you.

Get started

Guides

Winston transport

Install the transport

Add the transport to your logger

Log errors

Send a test error

Options

Limits

Give the setup to a coding agent

Next steps

Node.js SDK

Pino transport

Design queryable logs

Read AI triage

​Install the transport

​Add the transport to your logger

​Log errors

​Send a test error

​Options

​Limits

​Give the setup to a coding agent

​Next steps

Node.js SDK

Pino transport

Design queryable logs

Read AI triage

Install the transport

Add the transport to your logger

Log errors

Send a test error

Options

Limits

Give the setup to a coding agent

Next steps