Documentation Index

Fetch the complete documentation index at: https://agentclientprotocol.com/llms.txt Use this file to discover all available pages before exploring further.

Session Delete

Removing sessions from session history

The session/delete method allows Clients to remove sessions from an Agent’s session/list results. This gives users a standard way to manage session history across ACP Clients and Agents.

Before deleting sessions, Clients MUST first complete the initialization phase and verify the Agent supports this capability.

sequenceDiagram
    participant Client
    participant Agent

    Note over Agent,Client: Initialized

    Client->>Agent: session/list
    Agent-->>Client: session/list response (sessions)

    alt User deletes a session
        Client->>Agent: session/delete (sessionId)
        Agent-->>Client: session/delete response
    end

    Client->>Agent: session/list
    Agent-->>Client: session/list response (without deleted session)

Checking Support

Before attempting to delete a session, Clients MUST verify that the Agent supports this capability by checking the sessionCapabilities.delete field in the initialize response:

{
  "jsonrpc": "2.0",
  "id": 0,
  "result": {
    "protocolVersion": 1,
    "agentCapabilities": {
      "sessionCapabilities": {
        "delete": {}
      }
    }
  }
}

If sessionCapabilities.delete is omitted or null, the Agent does not support deleting sessions and Clients MUST NOT attempt to call session/delete. Supplying {} means the Agent supports the method.

Deleting a Session

Clients delete a session by calling session/delete with the session ID to remove from session history:

{
  "jsonrpc": "2.0",
  "id": 3,
  "method": "session/delete",
  "params": {
    "sessionId": "sess_abc123def456"
  }
}

On success, the Agent returns an empty result:

{
  "jsonrpc": "2.0",
  "id": 3,
  "result": {}
}

Semantics

• Deleted sessions no longer appear in future session/list results.
• Deleting an already-deleted session, or a session that never existed, SHOULD succeed silently.
• Agents may implement soft delete or hard delete. ACP only specifies the user-facing session-list behavior.
• Behavior for session/load on a deleted session is implementation-defined.
• Behavior for deleting an active session is implementation-defined.

Last updated Oct 08, 2026