List Thread Events

Call Create session first and replace the example session ID with its returned ID.

GET /anthropic/v1/sessions/{session_id}/threads/{thread_id}/events◐ Partial

Request parameters

session_idstring必填
path: Session ID (path or query parameter).
thread_idstring必填
path: Path parameter: the thread ID.
session_idstring必填
query: Session ID (path or query parameter).
limitnumber可选
query: Maximum number of items per page.
pagestring可选
query: Pagination cursor taken from the previous response's next_page.

Returns

200

Reads the selected thread ledger: the primary session for the primary thread, or the child session for a child thread. Uses the session event query parameters, public event types and data + next_page envelope. Web tools return search_result blocks on both APIs; answer citations are an /agent/v1 extension, rendered as [n] on /anthropic.

Errors follow the Claude Managed Agents format — see error codes

Response

HTTP 200

Successful response

application/json

Name	Type	Description
data	array<object>
data[].id	string	Unique identifier for this event.
data[].content	array<object>	Array of content blocks comprising the user message. / The result content returned by the tool. / Array of text blocks comprising the agent response. / The result content returned by the tool. / The result content returned by the tool. / Message content blocks. / Message content blocks. / The result content returned by the tool. / System content blocks. Text-only.
data[].type	string
data[].processed_at	null \| string \| string \| string \| string \| string \| string \| string \| string \| string \| string \| string \| string \| string \| string \| string \| string \| string \| string \| string \| string \| string \| string \| string \| string \| string \| string \| string \| null \| string \| string \| string \| null \| string \| string	A timestamp in RFC 3339 format
data[].session_thread_id	null \| string \| string \| string \| string \| string \| null \| string \| string	If absent, interrupts every non-archived thread in a multiagent session (or the primary alone in a single-agent session). If present, interrupts only the named thread. / Set by the server to the subagent thread this confirmation was routed to. Omitted when it was routed to the primary thread. / Set by the server to the subagent thread this result was routed to. Omitted when it was routed to the primary thread. / When set, this event was cross-posted from a subagent's thread to surface its custom tool use on the primary thread's stream. Empty on the thread's own events. Informational only: the server routes the matching `user.custom_tool_result` by `custom_tool_use_id`, so clients do not send it back. / When set, this event was cross-posted from a subagent's thread to surface its permission request on the primary thread's stream. Empty on the thread's own events. Informational only: the server routes the matching `user.tool_confirmation` by `tool_use_id`, so clients do not send it back. / When set, this event was cross-posted from a subagent's thread to surface its permission request on the primary thread's stream. Empty on the thread's own events. Informational only: the server routes the matching `user.tool_confirmation` or `user.tool_result` by `tool_use_id`, so clients do not send it back. / Public `sthr_` ID of the newly created thread. / Public sthr_ ID of the thread that started running. / Public sthr_ ID of the thread that went idle. / Public sthr_ ID of the thread that terminated. / Set by the server to the subagent thread this result was routed to. Omitted when it was routed to the primary thread. / Public sthr_ ID of the thread that is retrying.
data[].result	string	UserToolConfirmationResult enum / Evaluation verdict. 'satisfied': criteria met, session goes idle. 'needs_revision': criteria not met, another revision cycle follows. 'max_iterations_reached': evaluation budget exhausted with criteria still unmet — one final acknowledgment turn follows before the session goes idle, but no further evaluation runs. 'failed': grader determined the rubric does not apply to the deliverables. 'interrupted': user sent an interrupt while evaluation was in progress.
data[].tool_use_id	string	The id of the `agent.tool_use` or `agent.mcp_tool_use` event this result corresponds to, which can be found in the last `session.status_idle` event's `stop_reason.event_ids` field. / The id of the `agent.tool_use` event this result corresponds to. / The id of the `agent.tool_use` event this result corresponds to, which can be found in the last `session.status_idle` event's `stop_reason.event_ids` field.
data[].deny_message	null \| string	Optional message providing context for a 'deny' decision. Only allowed when result is 'deny'.
data[].custom_tool_use_id	string	The id of the `agent.custom_tool_use` event this result corresponds to, which can be found in the last `session.status_idle` event's `stop_reason.event_ids` field.
data[].is_error	null \| boolean	Whether the tool execution resulted in an error. / Whether the model request resulted in an error. / Whether the tool execution resulted in an error.
data[].input	object	Input parameters for the tool call.
data[].name	string	Name of the custom tool being called. / Name of the MCP tool being used. / Name of the agent tool being used.
data[].mcp_server_name	string	Name of the MCP server providing the tool.
data[].evaluated_permission	string	AgentEvaluatedPermission enum
data[].evaluation	object	Names the resolved permission_policy that produced evaluated_permission, and under auto carries the judgement. Open union: clients must tolerate unknown variants.
data[].mcp_tool_use_id	string	The id of the `agent.mcp_tool_use` event this result corresponds to.
data[].from_session_thread_id	string	Public `sthr_` ID of the thread that sent the message.
data[].from_agent_name	null \| string	Name of the callable agent this message came from. Absent when received from the primary agent.
data[].to_session_thread_id	string	Public `sthr_` ID of the thread the message was sent to.
data[].to_agent_name	null \| string	Name of the callable agent this message was sent to. Absent when sent to the primary agent.
data[].error	object
data[].stop_reason	object
data[].agent_name	string	Name of the callable agent the thread runs. / Name of the agent the thread runs. / Name of the agent the thread runs. / Name of the agent the thread runs. / Name of the agent the thread runs.
data[].iteration	number	0-indexed revision cycle. 0 is the first evaluation; 1 is the re-evaluation after the first revision; etc. / 0-indexed revision cycle, matching the corresponding `span.outcome_evaluation_start`. / 0-indexed revision cycle, matching the corresponding `span.outcome_evaluation_start`.
data[].outcome_id	string	The `outc_` ID of the outcome being evaluated. / Server-generated `outc_` ID for this outcome. Referenced by `span.outcome_evaluation_*` events and the session's `outcome_evaluations` list.
data[].explanation	string	Human-readable explanation of the verdict. For `needs_revision`, describes which criteria failed and why.
data[].outcome_evaluation_start_id	string	The id of the corresponding `span.outcome_evaluation_start` event.
data[].usage	object	Token usage for a single model request. / Point-in-time snapshot of a session's cumulative usage.
data[].model_request_start_id	string	The id of the corresponding `span.model_request_start` event.
data[].model_usage	object	Token usage for a single model request.
data[].description	string	What the agent should produce. Copied from the input event.
data[].max_iterations	null \| number	Evaluate-then-revise cycles before giving up. Default 3, max 20.
data[].rubric	object	Rubric for grading the quality of an outcome.
data[].agent	null \| object	Resolved `agent` definition for a `session`. Snapshot of the `agent` at `session` creation time.
data[].budget	null \| object	A hard spend ceiling. The session stops issuing new model requests once the tracked list cost reaches `max_list_cost`.
data[].metadata	object	The session's full metadata bag after the update. Present when the update set non-empty metadata; absent when metadata was unchanged or cleared to empty.
data[].title	null \| string	The session's new title. Present only when the update changed it.
next_page	string \| null