response-formatter

A zero-dependency Express middleware for consistent, standardized API JSON response formatting. Success, error, validation, pagination — all in one clean structure.

Installation

npm install response-formats

Quick Start

const express = require('express');
const { responseFormatter, errorHandler } = require('response-formats');

const app = express();
app.use(responseFormatter());

app.get('/api/users', (req, res) => {
  res.success([{ id: 1, name: 'John' }], 'Users fetched');
});

app.get('/api/users/:id', (req, res) => {
  res.notFound('User not found');
});

app.use(errorHandler());
app.listen(3000);

Response Helpers

| Method | Status | Description | |---|---|---| | res.success(data, msg, code) | 200 | Standard success | | res.created(data, msg) | 201 | Resource created | | res.paginated(data, pagination) | 200 | Paginated list | | res.error(msg, code, errors) | 500 | Error response | | res.validationError(errors) | 422 | Validation errors | | res.notFound(msg) | 404 | Not found | | res.unauthorized(msg) | 401 | Unauthorized | | res.forbidden(msg) | 403 | Forbidden |

License

MIT