Claude Platform Docs

Sessions

Create Session
client.beta.sessions.create(params, options?): BetaManagedAgentsSession
POST/v1/sessions
List Sessions
client.beta.sessions.list(params?, options?): BidirectionalPageCursor<BetaManagedAgentsSession>
GET/v1/sessions
Get Session
client.beta.sessions.retrieve(sessionID, params?, options?): BetaManagedAgentsSession
GET/v1/sessions/{session_id}
Update Session
client.beta.sessions.update(sessionID, params, options?): BetaManagedAgentsSession
POST/v1/sessions/{session_id}
Delete Session
client.beta.sessions.delete(sessionID, params?, options?): BetaManagedAgentsDeletedSession
DELETE/v1/sessions/{session_id}
Archive Session
client.beta.sessions.archive(sessionID, params?, options?): BetaManagedAgentsSession
POST/v1/sessions/{session_id}/archive
Models
interface BetaManagedAgentsAdvisorParams { 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
interface BetaManagedAgentsAgentMessagePreview { 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.

interface BetaManagedAgentsAgentParams { 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?: number

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

formatint32
interface BetaManagedAgentsAgentThinkingPreview { 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.

interface BetaManagedAgentsAgentWithOverridesParams { 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.

interface BetaManagedAgentsBranchCheckout { type: "branch"; name }
type: "branch"
name: string

Branch name to check out.

minLength1
maxLength255
interface BetaManagedAgentsBudgetLimit { 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: BetaMonetaryAmount { 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: BetaCurrency

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.

interface BetaManagedAgentsCacheCreationUsage { ephemeral_1h_input_tokens; ephemeral_5m_input_tokens }

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

ephemeral_1h_input_tokens?: number

Tokens used to create 1-hour ephemeral cache entries.

formatint32
ephemeral_5m_input_tokens?: number

Tokens used to create 5-minute ephemeral cache entries.

formatint32
interface BetaManagedAgentsCommitCheckout { type: "commit"; sha }
type: "commit"
sha: string

Full commit SHA to check out.

minLength7
maxLength64
interface BetaManagedAgentsDeletedSession { type: "session_deleted"; id }

Confirmation that a session has been permanently deleted.

type: "session_deleted"
id: string
interface BetaManagedAgentsDeltaContent { type: "content_delta"; content; index }
type: "content_delta"
content: BetaManagedAgentsTextBlock { 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?: 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.

interface BetaManagedAgentsDeltaEvent { 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.

type BetaManagedAgentsDeltaType = "agent.message" | "agent.thinking"
One of the following:
"agent.message"
"agent.thinking"
interface BetaManagedAgentsFileResourceParams { 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?: string | null

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

minLength1
maxLength4096
interface BetaManagedAgentsGitHubRepositoryResourceParams { type: "github_repository"; url; authorization_token; /* 2 more */ }

Mount a GitHub repository into the session's container.

interface BetaManagedAgentsMemoryStoreResourceParam { 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?: "read_write" | "read_only" | null

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?: string | null

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
type BetaManagedAgentsMultiagent = BetaManagedAgentsMultiagentCoordinator | BetaManagedAgentsMultiagent20261001

Resolved multiagent orchestration configuration as returned in API responses.

One of the following:
type BetaManagedAgentsMultiagentParams = BetaManagedAgentsMultiagentCoordinatorParams | BetaManagedAgentsMultiagent20261001Params

Multiagent orchestration configuration.

One of the following:
interface BetaManagedAgentsMultiagentCoordinatorParams { type: "coordinator"; agents }

A coordinator topology: the session's primary thread orchestrates work by spawning session threads, each running an agent drawn from the agents roster.

interface BetaManagedAgentsMultiagent20261001Params { type: "multiagent_20261001"; advisor; subagents; workflows }

Multiagent configuration with three members, each enabled or disabled on its own. On an update, if the agent's stored multiagent also has type multiagent_20261001, this configuration is merged into the stored one, level by level, instead of replacing it. A key that the update omits keeps its stored value. A key sent as null takes its default, on create as well, so "workflows": null enables workflows. An object sent with a type other than the stored one replaces the stored object, and the keys that it omits take their defaults. A predefined_agents list that is sent replaces the stored list. Every object that is sent needs its type, and an enabled advisor needs its model. Other validation applies to the merged result.

type BetaManagedAgentsMultiagentRosterEntryParams = string | BetaManagedAgentsAgentParams | BetaManagedAgentsMultiagentSelfParams | BetaManagedAgentsAdvisorParams

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

One of the following:
interface BetaManagedAgentsOutcomeEvaluationResource { 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 | null

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

formatdate-time
description: string

What the agent should produce.

explanation: string | null

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.

interface BetaManagedAgentsServerToolUsage { web_fetch_requests; web_search_requests }

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

web_fetch_requests?: number

Number of server-executed web fetch requests.

formatint32
web_search_requests?: number

Number of server-executed web search requests.

formatint32
interface BetaManagedAgentsSession { type: "session"; id; agent; /* 14 more */ }

A Managed Agents session.

interface BetaManagedAgentsSessionAgent { type: "agent"; id; description; /* 8 more */ }

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

interface BetaManagedAgentsSessionAgentUpdate { 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.

type BetaManagedAgentsSessionMultiagent = BetaManagedAgentsSessionMultiagentCoordinator | BetaManagedAgentsSessionMultiagent20261001

Resolved multiagent orchestration configuration as returned on a session.

One of the following:
interface BetaManagedAgentsSessionMultiagentCoordinator { type: "coordinator"; agents }

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

type: "coordinator"
agents: Array<BetaManagedAgentsSessionThreadAgent | BetaManagedAgentsAdvisor>

Full agent definitions the coordinator may spawn as session threads.

One of the following:
interface BetaManagedAgentsSessionThreadAgent { type: "agent"; id; description; /* 7 more */ }

Resolved agent definition for a single session_thread. Snapshot of the agent at thread creation time. The multiagent roster is not repeated here; read it from Session.agent.

interface BetaManagedAgentsAdvisor { type: "advisor"; model }

Platform advisor roster entry: a model the session's primary thread may consult mid-turn.

type: "advisor"
model: string

The advisor model id.

type BetaManagedAgentsSessionMultiagentSubagents = BetaManagedAgentsSessionMultiagentSubagentsEnabled | BetaManagedAgentsMultiagentSubagentsDisabled

Whether the agent can spawn session threads.

One of the following:
interface BetaManagedAgentsSessionMultiagentSubagentsEnabled { type: "enabled"; inline_agents; predefined_agents }

The agent can spawn session threads.

interface BetaManagedAgentsMultiagentSubagentsDisabled { type: "disabled" }

The agent cannot spawn session threads.

type: "disabled"
interface BetaManagedAgentsSessionMultiagentSubagentsEnabled { type: "enabled"; inline_agents; predefined_agents }

The agent can spawn session threads.

type BetaManagedAgentsSessionMultiagentWorkflows = BetaManagedAgentsSessionMultiagentWorkflowsEnabled | BetaManagedAgentsMultiagentWorkflowsDisabled

Whether the agent can start workflow runs.

One of the following:
interface BetaManagedAgentsSessionMultiagentWorkflowsEnabled { type: "enabled"; inline_agents; predefined_agents }

The agent can start workflow runs.

interface BetaManagedAgentsMultiagentWorkflowsDisabled { type: "disabled" }

The agent cannot start workflow runs.

type: "disabled"
interface BetaManagedAgentsSessionMultiagentWorkflowsEnabled { type: "enabled"; inline_agents; predefined_agents }

The agent can start workflow runs.

interface BetaManagedAgentsSessionMultiagent20261001 { type: "multiagent_20261001"; advisor; subagents; workflows }

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

interface BetaManagedAgentsSessionStats { active_seconds; duration_seconds }

Timing statistics for a session.

active_seconds?: number

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

formatdouble
duration_seconds?: number

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

formatdouble
interface BetaManagedAgentsSessionUpdatedEvent { 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.

interface BetaManagedAgentsSessionUsage { active_seconds; cache_creation; cache_read_input_tokens; /* 4 more */ }

Cumulative token usage for a session across all turns.

interface BetaManagedAgentsSessionUsageEvent { type: "session.usage"; id; processed_at; /* 2 more */ }

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

interface BetaManagedAgentsStartEvent { 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.

type: "event_start"
event: BetaManagedAgentsStartEventPreview

The previewed event's type and id. The event type determines which delta types the preview's event_delta events carry: agent.message events stream content_delta fragments; agent.thinking previews are start-only — no deltas follow, and the buffered agent.thinking with the same id concludes them.

One of the following:
interface BetaManagedAgentsAgentMessagePreview { 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.

interface BetaManagedAgentsAgentThinkingPreview { 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.

type BetaManagedAgentsStartEventPreview = BetaManagedAgentsAgentMessagePreview | BetaManagedAgentsAgentThinkingPreview
One of the following:
interface BetaManagedAgentsAgentMessagePreview { 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.

interface BetaManagedAgentsAgentThinkingPreview { 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.

interface BetaManagedAgentsSystemContentBlock { type: "text"; text }

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

type: "text"
text: string

The text content.

minLength1
interface BetaManagedAgentsSystemMessageEvent { 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<BetaManagedAgentsSystemContentBlock { type: "text"; text }>

System content blocks. Text-only.

type: "text"
text: string

The text content.

minLength1
processed_at?: string | null

Timestamp when this system message was processed.

formatdate-time
interface BetaManagedAgentsUserToolResultEvent { 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
client.beta.sessions.events.list(sessionID, params?, options?): PageCursor<BetaManagedAgentsSessionEvent>
GET/v1/sessions/{session_id}/events
Send Events
client.beta.sessions.events.send(sessionID, params, options?): BetaManagedAgentsSendSessionEvents
POST/v1/sessions/{session_id}/events
Stream Events
client.beta.sessions.events.stream(sessionID, params?, options?): BetaManagedAgentsStreamSessionEvents | Stream<BetaManagedAgentsStreamSessionEvents>
GET/v1/sessions/{session_id}/events/stream

SessionsResources

Add Session Resource
client.beta.sessions.resources.add(sessionID, params, options?): BetaManagedAgentsFileResource
POST/v1/sessions/{session_id}/resources
List Session Resources
client.beta.sessions.resources.list(sessionID, params?, options?): PageCursor<BetaManagedAgentsSessionResource>
GET/v1/sessions/{session_id}/resources
Get Session Resource
client.beta.sessions.resources.retrieve(resourceID, params, options?): ResourceRetrieveResponse
GET/v1/sessions/{session_id}/resources/{resource_id}
Update Session Resource
client.beta.sessions.resources.update(resourceID, params, options?): ResourceUpdateResponse
POST/v1/sessions/{session_id}/resources/{resource_id}
Delete Session Resource
client.beta.sessions.resources.delete(resourceID, params, options?): BetaManagedAgentsDeleteSessionResource
DELETE/v1/sessions/{session_id}/resources/{resource_id}

SessionsThreads

List Session Threads
client.beta.sessions.threads.list(sessionID, params?, options?): PageCursor<BetaManagedAgentsSessionThread>
GET/v1/sessions/{session_id}/threads
Get Session Thread
client.beta.sessions.threads.retrieve(threadID, params, options?): BetaManagedAgentsSessionThread
GET/v1/sessions/{session_id}/threads/{thread_id}
Archive Session Thread
client.beta.sessions.threads.archive(threadID, params, options?): BetaManagedAgentsSessionThread
POST/v1/sessions/{session_id}/threads/{thread_id}/archive

SessionsThreadsEvents

List Session Thread Events
client.beta.sessions.threads.events.list(threadID, params, options?): PageCursor<BetaManagedAgentsSessionEvent>
GET/v1/sessions/{session_id}/threads/{thread_id}/events
Stream Session Thread Events
client.beta.sessions.threads.events.stream(threadID, params, options?): BetaManagedAgentsStreamSessionThreadEvents | Stream<BetaManagedAgentsStreamSessionThreadEvents>
GET/v1/sessions/{session_id}/threads/{thread_id}/stream