requestId

Kind: Function

Source: src/middleware/request-id/request-id.ts

Part of: Middleware

Request ID Middleware for Hono.

requestId is Hono middleware that assigns an identifier to each incoming request. It makes the identifier available through the request context and returns it in the response header so logs, handlers, and clients can reference the same request.

Signature

ts
function requestId({
  limitLength = 255,
  headerName = 'X-Request-Id',
  generator = () => crypto.randomUUID(),
}: RequestIdOptions): MiddlewareHandler

Parameters

Returns: MiddlewareHandler

Diagram

mermaid
graph LR
  Client[Client Request] --> Middleware[requestId Middleware]
  Middleware --> Context[Hono Context: requestId]
  Middleware --> Handler[Route Handler]
  Handler --> Response[Response with Request ID Header]

Usage

ts
import { Hono } from 'hono'
import { requestId } from 'hono/request-id'

const app = new Hono()

app.use('*', requestId())

app.get('/status', (c) => {
  const id = c.get('requestId')

  return c.json({
    requestId: id,
    status: 'ok',
  })
})

export default app

AI Coding Instructions

• Register requestId() before route handlers that need access to c.get('requestId').
• Use the request ID when writing logs or reporting errors so related events can be correlated.
• Preserve the response request ID header when adding middleware that creates or replaces responses.
• Avoid generating separate request IDs inside handlers; read the value already stored on the Hono context.