Logger

Mastra sets the project's logger from a logger.ts file directly under src/mastra/. The file default-exports a logger, which replaces the built-in ConsoleLogger used across agents, workflows, and other components.

Use this page for the file-based convention. For log levels, transports, and provider details, see logging.

Quickstart

Create src/mastra/logger.ts and default-export a logger, such as PinoLogger:

src/mastra/logger.ts

import { PinoLogger } from '@mastra/loggers'

export default new PinoLogger({
  name: 'Mastra',
  level: 'info',
})

Mastra registers the logger before storage, observability, and file-based agents, so those primitives log through this logger as they are wired up.

Precedence with code

Code-registered logging wins over logger.ts. If you pass logger to new Mastra({ logger }) in src/mastra/index.ts (or set logger: false to disable logging), logger.ts is ignored with a warning. Use logger.ts when one project-wide logger is enough; use code registration when setup depends on runtime wiring.