bodyLimit

Kind: Function

Source: src/middleware/body-limit/index.ts

Part of: Middleware

Body Limit Middleware for Hono.

bodyLimit creates Hono middleware that checks incoming request bodies against a configured maximum size. Requests that exceed the limit are handled by the middleware error path, while allowed requests continue to the next middleware or route handler.

Signature

ts
function bodyLimit(options: BodyLimitOptions): MiddlewareHandler

Parameters

Returns: MiddlewareHandler

Diagram

mermaid
graph LR
  Client[Client] --> Request[Incoming request]
  Request --> Limit[bodyLimit middleware]
  Limit -->|Within configured size| Next[Next middleware or route]
  Limit -->|Exceeds configured size| Error[Error handler]

Usage

ts
import { Hono } from 'hono'
import { bodyLimit } from 'hono/body-limit'

const app = new Hono()

const maxBodySize = Number(process.env.MAX_BODY_SIZE)

app.use(
  '/uploads/*',
  bodyLimit({
    maxSize: maxBodySize,
  })
)

app.post('/uploads', async (c) => {
  const body = await c.req.arrayBuffer()

  return c.json({
    receivedBytes: body.byteLength,
  })
})

AI Coding Instructions

• Register bodyLimit before routes or middleware that read the request body.
• Set maxSize from validated application configuration in bytes.
• Do not rely only on the Content-Length header; streamed request data is also checked.
• Use the onError option when the application needs a custom response for oversized bodies.