Releases: honojs/hono
v4.8.0
Release Notes
Hono v4.8.0 is now available!
This release enhances existing features with new options and introduces powerful helpers for routing and static site generation. Additionally, we're introducing new third-party middleware packages.
- Route Helper
 - JWT Custom Header Location
 - JSX Streaming Nonce Support
 - CORS Dynamic allowedMethods
 - JWK Allow Anonymous Access
 - Cache Status Codes Option
 - Service Worker 
fire()Function - SSG Plugin System
 
Plus new third-party middleware:
- MCP Middleware
 - UA Blocker Middleware
 - Zod Validator v4 Support
 
Let's look at each of these.
Reduced the code size
First, this update reduces the code size! The smallest hono/tiny package has been reduced by about 800 bytes from v4.7.11, bringing it down to approximately 11 KB. When gzipped, it's only 4.5 KB. Very tiny!
Route Helper
New route helper functions provide easy access to route information and path utilities.
import { Hono } from 'hono'
import {
  matchedRoutes,
  routePath,
  baseRoutePath,
  basePath,
} from 'hono/route'
const api = new Hono()
api.get('/users/:id/posts/:postId', (c) => {
  const matched = matchedRoutes(c) // Array of matched route handlers
  const current = routePath(c) // '/api/users/:id/posts/:postId'
  const base = baseRoutePath(c) // '/api' Base route path
  const appBase = basePath(c) // '/api' Base path
  return c.json({ matched, current, base, appBase })
})
const app = new Hono()
app.route('/api', api)
export default appThese helpers make route introspection cleaner and more explicit.
Thanks @usualoma!
JWT Custom Header Location
JWT middleware now supports custom header locations beyond the standard Authorization header. You can specify any header name to retrieve JWT tokens from.
import { Hono } from 'hono'
import { jwt } from 'hono/jwt'
const app = new Hono()
app.use(
  '/api/*',
  jwt({
    secret: 'secret-key',
    headerName: 'X-Auth-Token', // Custom header name
  })
)
app.get('/api/protected', (c) => {
  return c.json({ message: 'Protected resource' })
})This is useful when working with APIs that use non-standard authentication headers.
Thanks @kunalbhagawati!
JSX Streaming Nonce Support
JSX streaming now supports nonce values for Content Security Policy (CSP) compliance. The streaming context can include a nonce that gets applied to inline scripts.
import { Hono } from 'hono'
import {
  renderToReadableStream,
  Suspense,
  StreamingContext,
} from 'hono/jsx/streaming'
const app = new Hono()
app.get('/', (c) => {
  const stream = renderToReadableStream(
    <html>
      <body>
        <StreamingContext
          value={{ scriptNonce: 'random-nonce-value' }}
        >
          <Suspense fallback={<div>Loading...</div>}>
            <AsyncComponent />
          </Suspense>
        </StreamingContext>
      </body>
    </html>
  )
  return c.body(stream, {
    headers: {
      'Content-Type': 'text/html; charset=UTF-8',
      'Transfer-Encoding': 'chunked',
      'Content-Security-Policy':
        "script-src 'nonce-random-nonce-value'",
    },
  })
})Thanks @usualoma!
CORS Dynamic allowedMethods
CORS middleware now supports dynamic allowedMethods based on the request origin. You can provide a function that returns different allowed methods depending on the origin.
import { Hono } from 'hono'
import { cors } from 'hono/cors'
const app = new Hono()
app.use(
  '*',
  cors({
    origin: ['https://example.com', 'https://api.example.com'],
    allowMethods: (origin) => {
      if (origin === 'https://api.example.com') {
        return ['GET', 'POST', 'PUT', 'DELETE']
      }
      return ['GET', 'POST'] // Default for other origins
    },
  })
)This enables fine-grained control over CORS policies per origin.
Thanks @Kanahiro!
JWK Allow Anonymous Access
JWK middleware now supports anonymous access with the allow_anon option. When enabled, requests without valid tokens can still proceed to your handlers.
import { Hono } from 'hono'
import { jwk } from 'hono/jwk'
const app = new Hono()
app.use(
  '/api/*',
  jwk({
    jwks_uri: 'https://example.com/.well-known/jwks.json',
    allow_anon: true,
  })
)
app.get('/api/data', (c) => {
  const payload = c.get('jwtPayload')
  if (payload) {
    return c.json({ message: 'Authenticated user', user: payload })
  }
  return c.json({ message: 'Anonymous access' })
})Additionally, keys and jwks_uri options now support functions that receive the context, enabling dynamic key resolution.
Thanks @Beyondo!
Cache Status Codes Option
Cache middleware now allows you to specify which status codes should be cached using the cacheableStatusCodes option.
import { Hono } from 'hono'
import { cache } from 'hono/cache'
const app = new Hono()
app.use(
  '*',
  cache({
    cacheName: 'my-cache',
    cacheControl: 'max-age=3600',
    cacheableStatusCodes: [200, 404], // Cache both success and not found responses
  })
)Thanks @miyamo2!
Service Worker fire() Function
A new fire() function is available from the Service Worker adapter, providing a cleaner alternative to app.fire().
import { Hono } from 'hono'
import { fire } from 'hono/service-worker'
const app = new Hono()
app.get('/', (c) => c.text('Hello from Service Worker!'))
// Use the standalone fire function
fire(app)The app.fire() method is now deprecated in favor of this approach. Goodbye app.fire().
SSG Plugin System
Static Site Generation (SSG) now supports a plugin system that allows you to extend the generation process with custom functionality.
For example, the following is easy implementation of a sitemap plugin:
// plugins.ts
import fs from 'node:fs/promises'
import path from 'node:path'
import type { SSGPlugin } from 'hono/ssg'
import { DEFAULT_OUTPUT_DIR } from 'hono/ssg'
export const sitemapPlugin = (baseURL: string): SSGPlugin => {
  return {
    afterGenerateHook: (result, fsModule, options) => {
      const outputDir = options?.dir ?? DEFAULT_OUTPUT_DIR
      const filePath = path.join(outputDir, 'sitemap.xml')
      const urls = result.files.map((file) =>
        new URL(file, baseURL).toString()
      )
      const siteMapText = `<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
${urls.map((url) => `<url><loc>${url}</loc></url>`).join('\n')}
</urlset>`
      fsModule.writeFile(filePath, siteMapText)
    },
  }
}Applying the plugin:
import { toSSG } from 'hono/ssg'
import { sitemapPlugin } from './plugins'
toSSG(app, fs, {
  plugins: [sitemapPlugin('https://example.com')],
})Plugins can hook into various stages of the generation process to perform custom actions.
Thanks @3w36zj6!
Third-party Middleware Updates
In addition to core Hono features, we're excited to introduce new third-party middleware packages that extend Hono's capabilities.
MCP Middleware
A new middleware package @hono/mcp enables creating remote MCP (Model Context Protocol) servers over Streamable HTTP Transport. This is the initial release with more features planned for the future.
import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js'
import { StreamableHTTPTransport } from '@hono/mcp'
import { Hono } from 'hono'
const app = new Hono()
// Your MCP server implementation
const mcpServer = new McpServer({
  name: 'my-mcp-server',
  version: '1.0.0',
})
app.all('/mcp', async (c) => {
  const transport = new StreamableHTTPTransport()
  await mcpServer.connect(transport)
  return transport.handleRequest(c)
})Currently, this is ideal for creating stateless and authentication-less remote MCP servers.
Thanks @MathurAditya724!
UA Blocker Middleware
The new @hono/ua-blocker middleware allows blocking requests based on user agent headers. It includes blocking AI bots functions.
import { uaBlocker } from '@hono/ua-blocker'
import { aiBots } from '@hono/ua-blocker/ai-bots'
import { Hono } from 'hono'
const app = new Hono()
// Block specific user agents
app.use(
  '*',
  uaBlocker({
    blocklist: ['ForbiddenBot', 'Not You'],
  })
)
// Block all AI bots
app.use(
  '*',
  uaBlocker({
    blocklist: aiBots,
  })
)
// Serve robots.txt to discourage AI bots
app.use('/robots.txt', useAiRobotsTxt())Thanks @finxol!
Zod Validator v4 Support
The @hono/zod-validator middleware now supports Zod v4!
All Changes
- fix(etag): fallback if 
res.clone()is not supported by @yusukebe in #4198 - Revert "fix(etag): fallback if 
res.clone()is not supported (#4198)" by @yusukebe in #4200 - chore(devcontainer): remove obsolete version field from docker-compose.yml by @kyodaj in #4208
 - docs(context): fix docstring link in the set header method by @Carlos-err406 in #4221
 - ci: consolidate perf-measures GitHub Actions comments by @yusukebe in #4222
 - chore(secure-headers): format by @yusukebe in #4224
 - ci: add HTTP speed check by @yusukebe in #4220
 - ci: simplify HTTP benchmark implementation by @yusukebe in #4226
 - feat(middleware/cache): add 
cacheableStatusCodesoptio... 
v4.7.11
What's Changed
- chore(benchmark): add 
URLSearchParamsto the query-params benchmark by @yusukebe in #4149 - ci: skip lib check in type check benchmark by @sushichan044 in #4162
 - CI: add type benchmark with typescript-go preview by @sushichan044 in #4161
 - chore: ignore CLAUDE.local.md in gitignore by @yusukebe in #4176
 - fix(middleware/etag): should return 304 when weak etag is passed in 'If-None-Match' by @techfish-11 in #4171
 - docs(readme): Added Deepwiki link in README by @MathurAditya724 in #4179
 - fix(base): use 
c.newResponse()for the response oferr.getResponse()by @yusukebe in #4181 
New Contributors
- @techfish-11 made their first contribution in #4171
 
Full Changelog: v4.7.10...v4.7.11
v4.7.10
v4.7.9
What's Changed
- fix(helper/cookie): correct 
getSignedCookieparameters type by @Hill-98 in #4123 - fix(ssg): Fix SSG Extension Map by @pspeter3 in #4130
 - fix(cookie): get deleted value with prefix by @BarryThePenguin in #4133
 
New Contributors
Full Changelog: v4.7.8...v4.7.9
v4.7.8
v4.7.7
What's Changed
- fix(trailing-slash): handle HEAD request in trailing slash middleware by @sushichan044 in #4049
 - fix(proxy): accept a Request object as proxyInit by @usualoma in #4067
 - test(deno): wait for stream to start before aborting request by @yusukebe in #4068
 - ci: Add Bundle Analysis by @katia-sentry in #4072
 - chore: Revert "ci: Add Bundle Analysis (#4072)" by @yusukebe in #4076
 - fix(context): don't throw the error with 
c.header()when it's finalized by @yusukebe in #4078 
New Contributors
- @katia-sentry made their first contribution in #4072
 
Full Changelog: v4.7.6...v4.7.7
v4.7.6
What's Changed
- fix(compress): avoid compressing if transfer-encoding is set by @usualoma in #4027
 - chore(lint): patch warnings by @EdamAme-x in #4034
 - chore(april-fool): change 
hono is cooltohono is hotby @EdamAme-x in #4035 - fix(client): Support browsers without Array.prototype.at by @isnifer in #4057
 
New Contributors
Full Changelog: v4.7.5...v4.7.6
v4.7.5
What's Changed
- docs(MIGRATION): Fix typo by @movahhedi in #3999
 - fix(bun): export 
BunWebSocketDataandBunWebSocketHandlerby @yusukebe in #4002 - types(compose): follow up #3932 by @EdamAme-x in #3934
 - fix(adapter/aws-lambda): APIGWProxyResult should contain either of headers or multiValueHeaders, not both by @exoego in #3883
 
New Contributors
- @movahhedi made their first contribution in #3999
 
Full Changelog: v4.7.4...v4.7.5
v4.7.4
v4.7.3
What's Changed
- refactor: support TypeScript 5.7 for Deno 2.2 by @yusukebe in #3939
 - refactor(pattern-router): reduce bundle size and fix comments by @EdamAme-x in #3936
 - fix(bun): export 
BunWebSocketHandlerby @yusukebe in #3964 - fix(hono-base): prevent options object mutation by @yusukebe in #3975
 - perf(utils/url): Short circuit the regex in checkOptionalParameter by @csainty in #3974
 
New Contributors
Full Changelog: v4.7.2...v4.7.3