Routing

Routes are registered on an app with an HTTP method and a path. Methods are matched in registration order.

const app = new Jinatra()

app.get('/', () => 'home')
app.post('/users', () => 'create user')
app.put('/users/:id', (c) => `update ${c.param('id')}`)
app.delete('/users/:id', (c) => `delete ${c.param('id')}`)

Supported methods are get, post, put, patch, delete, options, head, and any. all is an alias for any.

Parameters

Use :name for a single path segment and * for a wildcard:

app.get('/posts/:id', (c) => ({ id: c.param('id') }))
app.get('/files/*', (c) => c.param('wildcard'))
app.get('/optional', (c) => c.param('name', 'anonymous'))

A missing named parameter returns null by default. Pass a second argument to provide a fallback:

c.param('name', 'anonymous')

The params helper provides the same values without passing a context around:

app.get('/users/:id', () => ({
  id: params('id', 'unknown'),
}))

Paths may end with an optional trailing slash. Parameters are URL-decoded and invalid encoded parameters return a 400 response.

Route hooks

Attach hooks to the route most recently registered:

app.get('/admin', requireAuth, () => 'dashboard')
  .beforeRoute((c) => {
    c.state.startedAt = performance.now()
  })
  .afterRoute((c, response) => {
    const headers = new Headers(response.headers)
    headers.set('x-route-time', String(performance.now() - c.state.startedAt))
    return new Response(response.body, { status: response.status, headers })
  })

You can also register application-wide before() and after() handlers. See Middleware & errors.

Mount subapps

Mount another Fetch-compatible Jinatra app below a path prefix. The subapp receives a rewritten URL, so its routes remain prefix-free:

const api = new Jinatra()
api.get('/users/:id', (c) => ({ id: c.param('id') }))

const app = new Jinatra()
app.mount('/api', api)

/api/users/42 is handled by the subapp as /users/42. The mount also handles the prefix root (/api → /) and preserves the request method, body, query string, environment, and execution context.

HEAD behavior

If a HEAD route is not registered, Jinatra uses the matching GET route and returns the response without a body in the runtime adapter.