Claude Platform Docs

Sessions

Create Session
$ ant beta:sessions create
POST/v1/sessions
List Sessions
$ ant beta:sessions list
GET/v1/sessions
Get Session
$ ant beta:sessions retrieve
GET/v1/sessions/{session_id}
Update Session
$ ant beta:sessions update
POST/v1/sessions/{session_id}
Delete Session
$ ant beta:sessions delete
DELETE/v1/sessions/{session_id}
Archive Session
$ ant beta:sessions archive
POST/v1/sessions/{session_id}/archive
Models
beta_managed_agents_advisor_params: object{ type: "advisor", model }

Platform advisor roster entry: a model the session's primary thread may consult mid-turn. At most one per roster; the entry occupies the roster name anthropic.advisor.

type: "advisor"
model: string

A Claude model id. The model must be permitted as an advisor for this agent's model.

minLength1
maxLength256
beta_managed_agents_agent_message_preview: object{ type: "agent.message", id }
type: "agent.message"
id: string

The id the buffered agent.message will carry if it is emitted. Matches the event_id on this preview's event_delta events.

beta_managed_agents_agent_params: object{ type: "agent", id, version }

Specification for an Agent. Provide a specific version or use the short-form agent="agent_id" for the most recent version

type: "agent"
id: string

The agent ID.

minLength1
maxLength128
version: optional number

The specific agent version to use. Omit to use the latest version. Must be at least 1 if specified.

formatint32
beta_managed_agents_agent_thinking_preview: object{ type: "agent.thinking", id }
type: "agent.thinking"
id: string

The id the buffered agent.thinking will carry if it is emitted. Start-only — no event_delta events follow.

beta_managed_agents_agent_with_overrides_params: object{ type: "agent_with_overrides", id, mcp_servers, 5 more }

Reference to an agent plus optional configuration overrides. Each provided field replaces the agent's value for the caller's use; the agent resource is unchanged.

beta_managed_agents_branch_checkout: object{ type: "branch", name }
type: "branch"
name: string

Branch name to check out.

minLength1
maxLength255
beta_managed_agents_budget_limit: object{ type: "limit", max_list_cost }

A hard spend ceiling. The session stops issuing new model requests once the tracked list cost reaches max_list_cost.

type: "limit"
max_list_cost: object{ amount, currency }

Maximum list cost the session may accrue. List price is used regardless of any negotiated discount, so the cap fires at or before the actual charge.

amount: string

Amount in minor units of the currency, as an integer decimal string with no leading zeros: "2500" is $25.00 and "50" is fifty cents. A string rather than a number so no float rounding is ever applied.

currency: "USD"

Uppercase ISO-4217 currency code. USD is the only currency currently supported; the accepted set is closed and grows only when a new currency is priced.

beta_managed_agents_cache_creation_usage: object{ ephemeral_1h_input_tokens, ephemeral_5m_input_tokens }

Prompt-cache creation token usage broken down by cache lifetime.

ephemeral_1h_input_tokens: optional number

Tokens used to create 1-hour ephemeral cache entries.

formatint32
ephemeral_5m_input_tokens: optional number

Tokens used to create 5-minute ephemeral cache entries.

formatint32
beta_managed_agents_commit_checkout: object{ type: "commit", sha }
type: "commit"
sha: string

Full commit SHA to check out.

minLength7
maxLength64
beta_managed_agents_deleted_session: object{ type: "session_deleted", id }

Confirmation that a session has been permanently deleted.

type: "session_deleted"
id: string
beta_managed_agents_delta_content: object{ type: "content_delta", content, index }
type: "content_delta"
content: object{ type: "text", text }

A partial element of the content array at index, typed like the element itself — the same shape the buffered agent.message carries in content.

type: "text"
text: string

The text content.

minLength1
index: optional number

Which entry in the previewed event's content array this fragment lands in. Insert content as that entry when the index is new; append to the existing entry otherwise.

beta_managed_agents_delta_event: object{ type: "event_delta", delta, event_id }

An incremental update to an event that is still being streamed. Deltas are best-effort and may stop early; when the buffered event with id == event_id is produced it carries the complete content. A model request that ends early (an error or interrupt) produces no buffered event — its terminal span.model_request_end closes the preview. Only sent on stream connections that opt in via event_deltas; never appears in event history.

beta_managed_agents_delta_type: "agent.message" or "agent.thinking"
"agent.message"
"agent.thinking"
beta_managed_agents_file_resource_params: object{ type: "file", file_id, mount_path }

Mount a file uploaded via the Files API into the session.

type: "file"
file_id: string

ID of a previously uploaded file.

minLength1
maxLength128
mount_path: optional string

Mount path in the container. Defaults to /mnt/session/uploads/<file_id>.

minLength1
maxLength4096
beta_managed_agents_github_repository_resource_params: object{ type: "github_repository", url, authorization_token, 2 more }

Mount a GitHub repository into the session's container.

beta_managed_agents_memory_store_resource_param: object{ type: "memory_store", memory_store_id, access, instructions }

Parameters for attaching a memory store to an agent session.

type: "memory_store"
memory_store_id: string

The memory store ID (memstore_...). Must belong to the caller's organization and workspace.

access: optional "read_write" or "read_only"

Access mode for the mounted store. Defaults to read_write. read_only mounts the store as a read-only filesystem.

One of the following:
"read_write"
"read_only"
instructions: optional string

Per-attachment guidance for the agent on how to use this store. Rendered into the memory section of the system prompt. Max 4096 chars.

maxLength4096

Resolved multiagent orchestration configuration as returned in API responses.

Multiagent orchestration configuration.

beta_managed_agents_multiagent_roster_entry_params: string or BetaManagedAgentsAgentParams or BetaManagedAgentsMultiagentSelfParams or BetaManagedAgentsAdvisorParams

An entry in a multiagent roster: an agent ID string, a versioned agent reference, or self.

beta_managed_agents_outcome_evaluation_resource: object{ type: "outcome_evaluation", completed_at, description, 4 more }

Evaluation state for a single outcome defined via a define_outcome event.

type: "outcome_evaluation"
completed_at: string

When the outcome reached a terminal result. Null while pending/running/evaluating.

formatdate-time
description: string

What the agent should produce.

explanation: string

Grader's verdict text from the most recent evaluation. For satisfied, explains why criteria are met; for needs_revision (intermediate), what's missing; for failed, why unrecoverable.

iteration: number

0-indexed revision cycle the outcome is currently on.

formatint32
outcome_id: string

Server-generated outc_ ID for this outcome.

result: string

Current evaluation state. pending before the agent begins work; running while producing or revising; evaluating while the grader scores; satisfied/max_iterations_reached/failed/interrupted are terminal.

beta_managed_agents_server_tool_usage: object{ web_fetch_requests, web_search_requests }

Cumulative count of server-executed tool invocations, broken down by tool.

web_fetch_requests: optional number

Number of server-executed web fetch requests.

formatint32
web_search_requests: optional number

Number of server-executed web search requests.

formatint32
beta_managed_agents_session: object{ type: "session", id, agent, 14 more }

A Managed Agents session.

beta_managed_agents_session_agent: object{ type: "agent", id, description, 8 more }

Resolved agent definition for a session. Snapshot of the agent at session creation time.

beta_managed_agents_session_agent_update: object{ mcp_servers, tools }

Mid-session agent configuration update. Only tools and mcp_servers are updatable. Full replacement: the provided array becomes the new value. To preserve existing entries, GET the session, modify the array, and POST it back.

Resolved multiagent orchestration configuration as returned on a session.

beta_managed_agents_session_multiagent_coordinator: object{ type: "coordinator", agents }

Resolved coordinator topology with full agent definitions for each roster member.

Whether the agent can spawn session threads.

beta_managed_agents_session_multiagent_subagents_enabled: object{ type: "enabled", inline_agents, predefined_agents }

The agent can spawn session threads.

Whether the agent can start workflow runs.

beta_managed_agents_session_multiagent_workflows_enabled: object{ type: "enabled", inline_agents, predefined_agents }

The agent can start workflow runs.

beta_managed_agents_session_multiagent20261001: object{ type: "multiagent_20261001", advisor, subagents, workflows }

Resolved multiagent configuration with three members, as copied to the session at creation.

beta_managed_agents_session_stats: object{ active_seconds, duration_seconds }

Timing statistics for a session.

active_seconds: optional number

Cumulative time in seconds the session spent in running status. Excludes idle time.

formatdouble
duration_seconds: optional number

Elapsed time since session creation in seconds. For terminated sessions, frozen at the final update.

formatdouble
beta_managed_agents_session_updated_event: object{ type: "session.updated", id, processed_at, 4 more }

Emitted when an UpdateSession request changed at least one field. Carries only the fields that changed; absent fields were not part of the update. The new configuration applies from the next turn.

beta_managed_agents_session_usage: object{ active_seconds, cache_creation, cache_read_input_tokens, 4 more }

Cumulative token usage for a session across all turns.

beta_managed_agents_session_usage_event: object{ type: "session.usage", id, processed_at, 2 more }

Periodic snapshot of the session's cumulative usage and tracked list cost.

beta_managed_agents_start_event: object{ type: "event_start", event }

Opens a preview of a buffered event. Carries the previewed event's type and id only. Followed by zero or more event_delta events with the same event id, normally concluded by the buffered event carrying that id. If the producing model request ends without that event (an error or interrupt mid-stream), its terminal span.model_request_end closes the preview. Only sent on stream connections that opt in via event_deltas; never appears in event history.

beta_managed_agents_agent_message_preview: object{ type: "agent.message", id }
type: "agent.message"
id: string

The id the buffered agent.message will carry if it is emitted. Matches the event_id on this preview's event_delta events.

beta_managed_agents_agent_thinking_preview: object{ type: "agent.thinking", id }
type: "agent.thinking"
id: string

The id the buffered agent.thinking will carry if it is emitted. Start-only — no event_delta events follow.

beta_managed_agents_system_content_block: object{ type: "text", text }

Content block in a mid-conversation system message. Text-only.

type: "text"
text: string

The text content.

minLength1
beta_managed_agents_system_message_event: object{ type: "system.message", id, content, processed_at }

A mid-conversation system message event. Carries system-role content that is appended to the session as a role: "system" turn.

type: "system.message"
id: string

Unique identifier for this event.

content: array of BetaManagedAgentsSystemContentBlock { type: "text", text }

System content blocks. Text-only.

type: "text"
text: string

The text content.

minLength1
processed_at: optional string

Timestamp when this system message was processed.

formatdate-time
beta_managed_agents_user_tool_result_event: object{ type: "user.tool_result", id, tool_use_id, 4 more }

Event sent by the client providing the result of an agent-toolset tool execution. Only valid on self_hosted environments, where sandbox-routed tools are executed by the client rather than the server.

SessionsEvents

List Events
$ ant beta:sessions:events list
GET/v1/sessions/{session_id}/events
Send Events
$ ant beta:sessions:events send
POST/v1/sessions/{session_id}/events
Stream Events
$ ant beta:sessions:events stream
GET/v1/sessions/{session_id}/events/stream

SessionsResources

Add Session Resource
$ ant beta:sessions:resources add
POST/v1/sessions/{session_id}/resources
List Session Resources
$ ant beta:sessions:resources list
GET/v1/sessions/{session_id}/resources
Get Session Resource
$ ant beta:sessions:resources retrieve
GET/v1/sessions/{session_id}/resources/{resource_id}
Update Session Resource
$ ant beta:sessions:resources update
POST/v1/sessions/{session_id}/resources/{resource_id}
Delete Session Resource
$ ant beta:sessions:resources delete
DELETE/v1/sessions/{session_id}/resources/{resource_id}

SessionsThreads

List Session Threads
$ ant beta:sessions:threads list
GET/v1/sessions/{session_id}/threads
Get Session Thread
$ ant beta:sessions:threads retrieve
GET/v1/sessions/{session_id}/threads/{thread_id}
Archive Session Thread
$ ant beta:sessions:threads archive
POST/v1/sessions/{session_id}/threads/{thread_id}/archive

SessionsThreadsEvents

List Session Thread Events
$ ant beta:sessions:threads:events list
GET/v1/sessions/{session_id}/threads/{thread_id}/events
Stream Session Thread Events
$ ant beta:sessions:threads:events stream
GET/v1/sessions/{session_id}/threads/{thread_id}/stream