ctx.request

Read‑only property representing the original Web Standard Request, you typically don't need to access it directly; prefer using the convenience methods and properties on ctx.req to read request information.

app.use(async (ctx) => {
  ctx.req.method === ctx.request.method
  ctx.req.href === ctx.request.url
  ctx.req.get('user-agent') === ctx.request.headers.get('user-agent')
})

ctx.response

Read‑only property that returns a Web Standard Response built from the current context. You typically don't need to access it directly—use it when you want to construct and return a native Response yourself.

ctx.env

Read‑only environment bindings provided by the hosting platform. In Cloudflare Workers this corresponds to the Env object passed to the handler (KV namespaces, Durable Objects, secrets, R2 buckets, etc.). It may be undefined outside such environments.

app.use(async (ctx) => {
  // Access a bound KV namespace (Cloudflare Workers)
  const value = await ctx.env?.KV.get('key')

  // Access a secret
  const apiKey = ctx.env?.API_KEY
})

ctx.executionCtx

Platform execution context for the current request. In Cloudflare Workers this is the ExecutionContext, which exposes waitUntil() and passThroughOnException(). It may be undefined outside such environments.

app.use(async (ctx) => {
  // Schedule background work to complete after the response
  ctx.executionCtx?.waitUntil(logRequestAsync(ctx))

  // Optionally allow upstream to handle exceptions
  ctx.executionCtx?.passThroughOnException()
})

ctx.state

Per‑request mutable state object. Starts as an empty plain object and is intended for middleware and handlers to share data.

// Middleware A: attach data to ctx.state
app.use(async (ctx, next) => {
  ctx.state.startTime = Date.now()
  await next()
})

// Middleware B: read data from ctx.state
app.use(async (ctx) => {
  const ms = Date.now() - ctx.state.startTime
  ctx.res.body = { ok: true, elapsed: ms }
})

ctx.throw(status, [message], [options])

Throw an HttpError.

ctx.throw(400)
ctx.throw(400, 'Bad Request')
ctx.throw(400, 'Bad Request', {
  expose: true,
  cause: new Error('Another Error'),
  headers: { 'X-Foo': 'foo' }
})
ctx.throw(400, {
  message: 'Bad Request',
  expose: true,
  cause: new Error('Another Error'),
  headers: { 'X-Foo': 'foo' }
})

ctx.assert(value, status, [message], [options])

Assert condition or throw an HttpError.

ctx.assert(false, 400)
ctx.assert(false, 400, 'Bad Request')
ctx.assert(false, 400, 'Bad Request', {
  expose: true,
  cause: new Error('Another Error'),
  headers: { 'X-Foo': 'foo' }
})
ctx.assert(false, 400, {
  message: 'Bad Request',
  expose: true,
  cause: new Error('Another Error'),
  headers: { 'X-Foo': 'foo' }
})

ctx.toJSON()

Return JSON representation of the context.

ctx.toJSON() // { app, req, res }