LoadAgentSession-阿里云帮助中心

Loads the message history of an existing session and returns it as an SSE stream. If the session does not exist, the server sends a JSONRPCResponse.error with a code of 400 through the SSE stream. The Content-Type is text/event-stream. Use this operation to restore session context.

Operation description

Request

This operation retrieves session details and streams the Agent response using Server-Sent Events (SSE).
If the target session does not exist, the operation returns an error frame with an error code of 400.
The response includes information about the Agent's request processing, such as message chunks, thought processes, and tool call status updates.
The stopReason field indicates why the Agent stops the current turn. Possible values include reaching the maximum turn limit or being canceled.
The returned content conforms to the Agent Client Protocol (ACP). For more information, see https://agentclientprotocol.com.

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Test

RAM authorization

No authorization for this operation. If you encounter issues with this operation, contact technical support.

Request syntax

POST  HTTP/1.1

Request parameters

Parameter	Type	Required	Description	Example
Jsonrpc	string	No	The JSON-RPC version. The value must be `2.0`.	2.0
Id	string	No	The client-generated request ID, which is returned in the response.	4as3dasf654a
Params	object	No	Business parameters.
SessionId	string	No	The ID of the target session. If the session does not exist, an SSE error frame is returned.	sess_0f12abc34
Meta	object	No	DataWorks-specific extended parameters for ACP.
IsReload	boolean	No	Specifies whether to use resumable transfer. If the SSE stream is interrupted due to issues like an unstable network connection, you can set this parameter to `true` to re-fetch the stream data from the point of failure.	true or false
BeginLogOffset	integer	No	In a resumable transfer scenario, this specifies the offset from which to resume fetching the SSE output.	10000

Response elements

Element	Type	Description	Example
	object
RequestId	string	The unique request ID generated for this request.	0D41C608-0C60-5EB0-B986-1460909CF642
Timestamp	integer	The timestamp.	1769479322828
Jsonrpc	string	The JSON-RPC version. The value is `2.0`.	2.0
Id	string	The client-generated request ID, returned from the request.	676303114031776
Result	any	The result object of the SSE frame. This field is present when the operation is successful.	{"stopReason":"end_turn"}
Error	any	The error object of the SSE frame. This field is present when an error occurs.	{"code": 400, "errorCode": "0x50000000001", "message": "not exist session", "data": null}
Method	string	The method of the SSE frame.	session/update
Params	any	The parameters of the SSE frame.	{"sessionId":"af4f5ef8-e8f5-481c-ad1f-94886c6c0aed","update":{"sessionUpdate":"agent_message_chunk","content":{"type":"text","text":"hello world"}}}

Examples

Success response

JSON format

{
  "RequestId": "0D41C608-0C60-5EB0-B986-1460909CF642",
  "Timestamp": 1769479322828,
  "Jsonrpc": "2.0",
  "Id": "676303114031776",
  "Result": "{\"stopReason\":\"end_turn\"}",
  "Error": "{\"code\": 400, \"errorCode\": \"0x50000000001\", \"message\": \"not exist session\", \"data\": null}",
  "Method": "session/update",
  "Params": "{\"sessionId\":\"af4f5ef8-e8f5-481c-ad1f-94886c6c0aed\",\"update\":{\"sessionUpdate\":\"agent_message_chunk\",\"content\":{\"type\":\"text\",\"text\":\"hello world\"}}}"
}

Error codes

See Error Codes for a complete list.

Release notes

See Release Notes for a complete list.