Hono + Pino

A pino logger plugin for hono.

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Features

• Fast, minimal overhead logging for Hono
• Full pino compatibility
• Works in Node.js and browser
• Custom transports, including a built-in pretty/debug transport
• TypeScript support

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Table of Contents

• Installation
• Usage
• Example
• Options & Types
• Contributing
• License

This repository is inspired by pino-http and nestjs-pino.

Runtime Support

[!IMPORTANT] This package uses pino. Pino is designed for Node.js and supports browser environments.
For edge environments (e.g. Cloudflare Workers), some advanced pino features may not work.
If fixing these issues is feasible, I will make an effort to implement it, but I cannot guarantee this.

Known issues:

• transports: Alternative -> browser.write

Installation

# npm
npm install hono-pino pino
# pnpm
pnpm add hono-pino pino
# bun
bun add hono-pino pino

Usage

import { Hono } from 'hono'
import { pinoLogger } from 'hono-pino'

const app = new Hono()
  .use(
    pinoLogger({
      pino: {level: "debug"}
    }),
  )
  .get((c) => {
    const { logger } = c.var;

    const token = c.req.header("Authorization") ?? "";
    logger.debug({ token });

    const user = getAuthorizedUser(token);
    logger.assign({ user });

    const posts = getPosts();
    logger.assign({ posts });


    logger.setResMessage("Get posts success"); // optional

    return c.text("");
  });

await app.request("/", {
  headers: {
    Authorization: "Bearer token",
  },
});

// output (formatted for easier reading)
{"level":20, "token":"Bearer token"}
{
  "level": 30,
  "msg": "Get posts success",
  "user": {
    "id": 1,
    "name": "john"
  },
  "posts": [
    {
      "id": 1,
      "title": "My first post"
    },
    {
      "id": 2,
      "title": "My second post"
    }
  ],
  "req": {
    "headers": {
      "authorization": "Bearer token"
    },
    "method": "GET",
    "url": "/"
  },
  "reqId": 1,
  "res": {
    "headers": {},
    "status": 200
  },
  "responseTime": 2
}

Example

See examples

hono-pino/debug-log Transport

hono-pino/debug-log is a lightweight pino transport designed for development and debugging. It makes logs more readable, similar to pino-pretty, but with a focus on simplicity and customization.

Options

• colorEnabled: Enable or disable color output (true | false | undefined for auto)
• messageKey: The key for the log message (default: msg)
• requestKey: The key for the request object (default: req)
• responseKey: The key for the response object (default: res)
• levelLabelMap: Map of log level numbers to their string labels
• normalLogFormat: Format string for normal logs (default: [{time}] {levelLabel} - {msg})
• httpLogFormat: Format string for HTTP logs (default: [{time}] {reqId} {req.method} {req.url} {res.status} ({responseTime}ms) - {msg} {bindings})
• timeFormatter: Function to format the time value (default: defaultTimeFormatter)
• bindingsFormatter: Function to format the context (bindings) (default: defaultBindingsFormat)
• levelFormatter: Function to format the log level label (default: defaultLevelFormatter)
• printer: Function to print the final log output (default: console.log)

See all options in src/debug-log/types.d.ts

Basic Usage (Node.js)

import { pino } from "pino";
import { Hono } from "hono";
import { pinoLogger } from "hono-pino";
import type { DebugLogOptions } from "hono-pino/debug-log";

const options: DebugLogOptions = {
  // options...
};

const app = new Hono().use(
  pinoLogger({
    pino: pino({
      base: null,
      level: "trace",
      transport: {
        target: "hono-pino/debug-log",
        options,
      },
      timestamp: pino.stdTimeFunctions.unixTime, // hh:mm:ss
      // or
      // timestamp: pino.stdTimeFunctions.epochTime, // hh:mm:ss.sss
    }),
  })
);

Basic Usage (Browser)

import { pino } from "pino";
import { Hono } from "hono";
import { pinoLogger } from "hono-pino";
import { createHandler as debugLog } from "hono-pino/debug-log";

const app = new Hono().use(
  pinoLogger({
    pino: pino({
      level: "trace",
      browser: {
        write: debugLog({
          ...options
        }),
      },
    }),
  })
);

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Options & Types

View the full options on GitHub or JSR

Logger Methods

class PinoLogger {
  // Same as pino[logger level]
  trace: pino.LogFn
  debug: pino.LogFn
  info: pino.LogFn
  warn: pino.LogFn
  error: pino.LogFn
  fatal: pino.LogFn

  // Get bindings (object)
  bindings(): pino.Bindings
  // Reset bindings
  resetBindings(): void
  // Assign bindings (default shallow merge)
  assign(
    bindings: pino.Bindings
    opts?: {
      /** deep merge */
      deep?: boolean;
    },
  ): void
}

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Contributing

Contributions, issues and feature requests are welcome! Feel free to check issues page or submit a pull request.

License

This project is MIT licensed.

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API Documentation

See the full API docs at jsr.io/@maou-shonen/hono-pino