Streaming (v1)Legacy
Stream the result of executing a Run or resuming a Run after submitting tool outputs.
You can stream events from the Create Thread and Run,
Create Run, and Submit Tool Outputs
endpoints by passing "stream": true. The response will be a Server-Sent events stream.
Our Node and Python SDKs provide helpful utilities to make streaming easy. Reference the Assistants API quickstart to learn more.
The message delta object (v1)Legacy
Represents a message delta i.e. any changed fields on a message during streaming.
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{
"id": "msg_123",
"object": "thread.message.delta",
"delta": {
"content": [
{
"index": 0,
"type": "text",
"text": { "value": "Hello", "annotations": [] }
}
]
}
}The run step delta object (v1)Legacy
Represents a run step delta i.e. any changed fields on a run step during streaming.
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{
"id": "step_123",
"object": "thread.run.step.delta",
"delta": {
"step_details": {
"type": "tool_calls",
"tool_calls": [
{
"index": 0,
"id": "call_123",
"type": "code_interpreter",
"code_interpreter": { "input": "", "outputs": [] }
}
]
}
}
}Assistant stream events (v1)Legacy
Represents an event emitted when streaming a Run.
Each event in a server-sent events stream has an event and data property:
event: thread.created
data: {"id": "thread_123", "object": "thread", ...}We emit events whenever a new object is created, transitions to a new state, or is being
streamed in parts (deltas). For example, we emit thread.run.created when a new run
is created, thread.run.completed when a run completes, and so on. When an Assistant chooses
to create a message during a run, we emit a thread.message.created event, a
thread.message.in_progress event, many thread.message.delta events, and finally a
thread.message.completed event.
We may add additional events over time, so we recommend handling unknown events gracefully in your code. See the Assistants API quickstart to learn how to integrate the Assistants API with streaming.