Server transport

Use @anvia/server to convert an async event iterable into an HTTP Response with streaming headers and serialization.

Return JSONL

import type { UIStreamRequest } from '@anvia/core'
import { createEventStream } from '@anvia/server'

export async function POST(request: Request) {
  const body = (await request.json()) as UIStreamRequest
  const promptRequest = agent.prompt(body.messages)
  const events = promptRequest.stream()

  return createEventStream(events, { format: 'jsonl' })
}

JSONL is the default. Each event is serialized as one JSON object followed by a newline, with application/x-ndjson response content.

Use SSE when a client expects text/event-stream:

const promptRequest = agent.prompt(body.messages)
const events = promptRequest.stream()

return createEventStream(events, {
  format: 'sse',
})

Project client-safe events

Do not expose raw runtime events without reviewing their contents.

import type { PromptRequest } from '@anvia/core'

async function* clientEvents(request: PromptRequest) {
  for await (const event of request.stream()) {
    if (event.type === 'text_delta') {
      yield { type: 'text', delta: event.delta }
    }
    if (event.type === 'tool_call') {
      yield { type: 'status', label: 'Checking data' }
    }
    if (event.type === 'final') {
      yield { type: 'done', output: event.output }
    }
  }
}

const promptRequest = agent.prompt('Explain the latest invoice.')
return createEventStream(clientEvents(promptRequest))

Keep credentials and agent execution on the server. Tool arguments, results, reasoning, and provider metadata can contain private application data.

Use promptRequest.readableStream() directly only when a small custom route intentionally exposes its JSONL runtime-event shape.