Last Updated: 3/11/2026

AWS Lambda

AWS Lambda is a serverless platform by Amazon Web Services. Hono works on AWS Lambda with Node.js 18+ using the AWS Lambda adapter.

Setup

Use AWS CDK to set up functions, IAM roles, and API Gateway:


mkdir my-app
cd my-app
cdk init app -l typescript
npm install hono
npm install -D esbuild
mkdir lambda
touch lambda/index.ts

Hello World

Edit lambda/index.ts:


import { Hono } from 'hono'
import { handle } from 'hono/aws-lambda'
 
const app = new Hono()
 
app.get('/', (c) => c.text('Hello Hono!'))
 
export const handler = handle(app)

Deploy

Edit lib/my-app-stack.ts:


import * as cdk from 'aws-cdk-lib'
import { Construct } from 'constructs'
import * as lambda from 'aws-cdk-lib/aws-lambda'
import { NodejsFunction } from 'aws-cdk-lib/aws-lambda-nodejs'
 
export class MyAppStack extends cdk.Stack {
  constructor(scope: Construct, id: string, props?: cdk.StackProps) {
    super(scope, id, props)
 
    const fn = new NodejsFunction(this, 'lambda', {
      entry: 'lambda/index.ts',
      handler: 'handler',
      runtime: lambda.Runtime.NODEJS_22_X,
    })
    
    const fnUrl = fn.addFunctionUrl({
      authType: lambda.FunctionUrlAuthType.NONE,
    })
    
    new cdk.CfnOutput(this, 'lambdaUrl', {
      value: fnUrl.url!,
    })
  }
}

Deploy:


cdk deploy

Binary Data

Hono automatically encodes binary responses to base64:


app.get('/image', async (c) => {
  const buffer = await getImageBuffer()
  c.header('Content-Type', 'image/png')
  return c.body(buffer) // Automatically base64 encoded
})

Access Lambda Context

Access AWS Lambda events and context:


import { Hono } from 'hono'
import type { LambdaEvent, LambdaContext } from 'hono/aws-lambda'
import { handle } from 'hono/aws-lambda'
 
type Bindings = {
  event: LambdaEvent
  lambdaContext: LambdaContext
}
 
const app = new Hono<{ Bindings: Bindings }>()
 
app.get('/info', (c) => {
  return c.json({
    isBase64Encoded: c.env.event.isBase64Encoded,
    awsRequestId: c.env.lambdaContext.awsRequestId,
  })
})
 
export const handler = handle(app)

Request Context

Access API Gateway request context:


import type { LambdaEvent } from 'hono/aws-lambda'
 
type Bindings = {
  event: LambdaEvent
}
 
const app = new Hono<{ Bindings: Bindings }>()
 
app.get('/context', (c) => {
  const context = c.env.event.requestContext
  return c.json(context)
})

Response Streaming

Enable Lambda response streaming :


// In CDK stack
fn.addFunctionUrl({
  authType: lambda.FunctionUrlAuthType.NONE,
  invokeMode: lambda.InvokeMode.RESPONSE_STREAM,
})

Use streamHandle:


import { streamHandle } from 'hono/aws-lambda'
import { streamText } from 'hono/streaming'
 
const app = new Hono()
 
app.get('/stream', async (c) => {
  return streamText(c, async (stream) => {
    for (let i = 0; i < 3; i++) {
      await stream.writeln(`Chunk ${i}`)
      await stream.sleep(1000)
    }
  })
})
 
export const handler = streamHandle(app)