Integrate workflows with the Hosted Responses API

[shibayan]

Priority

P1

Goal

Allow a workflow-backed agent to execute through the existing Hosted Responses endpoint.

Scope

• Detect or configure workflow-backed hosted agents.
• Convert response input into workflow input and workflow events into response output.
• Associate response, conversation, user, and workflow execution identifiers.
• Support foreground, streaming, and background execution where applicable.

Acceptance criteria

• A simple multi-step workflow executes through /responses.
• Streaming workflow events produce valid Responses events.
• previous_response_id or conversation context can identify resumable execution.
• Cancellation reaches the workflow runtime.
• Integration tests cover success, failure, cancellation, and invalid resume state.

Dependency

Blocked by the workflow execution and checkpoint contracts.