Stream a thread run

Start a run on a thread and stream output as server-sent events. The request must use agent_id; assistant_id is reserved for server-side forwarding and is rejected.

POST /threads/{threadID}/runs/stream

Stream a thread run

cURL

curl --request POST \
  --url https://api.smith.langchain.com/v1/deepagents/threads/{threadID}/runs/stream \
  --header 'Content-Type: application/json' \
  --header 'X-Api-Key: <api-key>' \
  --data '
{
  "agent_id": "11111111-1111-1111-1111-111111111111",
  "messages": [
    {
      "role": "user",
      "content": "Research recent approaches to agent memory and summarize the main tradeoffs."
    }
  ],
  "stream_mode": [
    "updates"
  ],
  "stream_subgraphs": true,
  "user_timezone": "America/Los_Angeles"
}
'

200

"<string>"

Authorizations

X-Api-Key · string · header · default: LANGSMITH_API_KEY · required

Path Parameters

threadID · string · required

Thread ID.

Body

application/json

agent_id · string<uuid> · required

Managed Deep Agent ID. The server forwards this upstream as assistant_id.

messages · object[] · required

Input messages for the run.

Minimum array length: 1

Show child attributes

stream_mode · enum<string>[]

Stream modes to return.

Available options: values, updates, messages-tuple

stream_subgraphs · boolean

Whether to stream subgraph events.

user_timezone · string

User timezone for runtime context.

Example:

"America/Los_Angeles"

Response

200

text/event-stream

Server-sent event stream.

The response is of type string.