Abort during streaming throws “ReadableStream is locked” in StreamedRunResult

[madavic]

Describe the bug

When running the JS Agents SDK in streaming mode with an AbortController, aborting while the consumer is iterating the stream throws a runtime error: “TypeError [ERR_INVALID_STATE]: Invalid state: ReadableStream is locked.” This happens because the SDK calls ReadableStream.cancel() while the stream is locked by an active async iterator.

Debug information

• Agents SDK version: v0.1.3
• Runtime environment: Node.js 22.10.0

Repro steps

Run the following script:

import { Agent, OpenAIProvider, Runner, setDefaultModelProvider, setTracingDisabled } from '@openai/agents'

setTracingDisabled(true)
setDefaultModelProvider(new OpenAIProvider())

function buildSimpleAgent() {
  return new Agent({
    name: 'Simple Chat Agent',
    instructions: 'You are a helpful assistant. Respond with enough text to stream.',
    model: 'openai/gpt-4o-mini',
    tools: [],
  })
}

async function main() {
  const controller = new AbortController()
  const agent = buildSimpleAgent()
  const runner = new Runner()
  const result = await runner.run(agent, 'Say something long to stream.', { stream: true, signal: controller.signal, maxTurns: 1 })
  ;(async () => { for await (const _ of result) {} })()
  setTimeout(() => { controller.abort() }, 10)
}

main().catch(err => { console.error(err); process.exit(1) })

Observed error:

TypeError [ERR_INVALID_STATE]: Invalid state: ReadableStream is locked
    at ReadableStream.cancel (node:internal/webstreams/readablestream:322:9)
    at AbortSignal.<anonymous> (.../node_modules/@openai/agents-core/dist/result.mjs:137:44)

Expected behavior

Aborting a streaming run should stop the stream cleanly without throwing, even while it is being iterated. The consumer’s for await loop should end gracefully and no unhandled exception should be raised.