CBOR

CBOR is a binary format for serializing objects defined in RFC 8949. It is JSON-compatible and suitable for network communications that require efficient data exchange, as well as for use in resource-constrained environments such as IoT devices.

Here's an example of using cbor2 package to respond with CBOR:

import { Hono } from 'hono'
import { createMiddleware } from 'hono/factory'
import { encode } from 'cbor2'

const app = new Hono()

declare module 'hono' {
  interface ContextRenderer {
    (content: any): Response | Promise<Response>
  }
}

const cborRenderer = createMiddleware(async (c, next) => {
  c.header('Content-Type', 'application/cbor')
  c.setRenderer((content) => {
    return c.body(encode(content))
  })
  await next()
})

app.use(cborRenderer)

app.get('/', (c) => {
  return c.render({ message: 'hello CBOR!' })
})

export default app

You can check the response using the following command.

plaintext

$ curl -s http://localhost:3000/ | hexdump -C
00000000  a1 67 6d 65 73 73 61 67  65 6b 68 65 6c 6c 6f 20  |.gmessagekhello |
00000010  43 42 4f 52 21                                    |CBOR!|
00000015

Additionally, you can verify that it decodes to a JSON object in the CBOR playground.

plaintext

A1                           # map(1)
   67                        # text(7)
      6D657373616765         # "message"
   6B                        # text(11)
      68656C6C6F2043424F5221 # "hello CBOR!"

json

{"message": "hello CBOR!"}

CBOR ​

See also ​

CBOR

See also