JWT Auth Middleware

The JWT Auth Middleware provides authentication by verifying the token with JWT. Authorization header value or cookie value specified by the cookie option will be used as a token.

Import

import { Hono } from 'hono'
import { jwt } from 'hono/jwt'
import type { JwtVariables } from 'hono/jwt'

Usage

// Specify the variable types to infer the `c.get('jwtPayload')`:
type Variables = JwtVariables

const app = new Hono<{ Variables: Variables }>()

app.use(
  '/auth/*',
  jwt({
    secret: 'it-is-very-secret',
  })
)

app.get('/auth/page', (c) => {
  return c.text('You are authorized')
})

Get payload:

const app = new Hono()

app.use(
  '/auth/*',
  jwt({
    secret: 'it-is-very-secret',
  })
)

app.get('/auth/page', (c) => {
  const payload = c.get('jwtPayload')
  return c.json(payload) // eg: { "sub": "1234567890", "name": "John Doe", "iat": 1516239022 }
})

TIP

jwt() is just a middleware function. If you want to use an environment variable (eg: c.env.JWT_SECRET), you can use it as follows:

app.use('/auth/*', (c, next) => {
  const jwtMiddleware = jwt({
    secret: c.env.JWT_SECRET,
  })
  return jwtMiddleware(c, next)
})

Options

• secret: string - required
  • A value of your secret key.
• cookie: string
  • If this value is set, then the value is retrieved from the cookie header using that value as a key, which is then validated as a token.
• alg: string
  • An algorithm type that is used for verifying. Available types are HS256 | HS384 | HS512 | RS256 | RS384 | RS512 | PS256 | PS384 | PS512 | ES256 | ES384 | ES512 | EdDSA. Default is HS256.