A2A Integration - MemoryLake AI

MemoryLake implements the A2A (Agent-to-Agent) protocol by Google. If you are already familiar with A2A, you can use any A2A-compatible client to interact with MemoryLake agents. Refer to the A2A specification for the standard request and response schemas. Official SDKs are available at github.com/a2aproject.

Permission required: workspace:a2a

Base URL

https://app.memorylake.ai/openapi/memorylake/api/v3/workspaces/{workspaceId}/agents/{agentId}/a2a

Append standard A2A paths directly — for example POST {baseUrl}/message:send or GET {baseUrl}/tasks/{taskId}.

Protocol Versions

MemoryLake exposes two parallel sets of A2A routes, one per protocol version, and each version is reachable over two transports: REST and JSON-RPC 2.0.

Protocol version	REST routes	Message body	`role` value
A2A v1.0	`{baseUrl}/message:send`, `{baseUrl}/tasks/...`	`message.parts` (proto-JSON, no `kind` discriminator)	`ROLE_USER`
A2A v0.3	`{baseUrl}/v1/message:send`, `{baseUrl}/v1/tasks/...`	REST: `message.content` · JSON-RPC: `message.parts` with a `kind` discriminator	REST: `ROLE_USER` · JSON-RPC: `user`

The /v1/ path prefix refers to the older A2A v0.3 wire format, not to protocol version 1.0. The un-prefixed routes implement the current A2A v1.0 format. Make sure the request body shape matches the route you call — a v0.3-style REST body (message.content) is rejected by the v1.0 REST routes, and vice versa.

Over JSON-RPC, both versions post to the bare {baseUrl} and pick the operation with method: v1.0 uses SendMessage, SendStreamingMessage, GetTask, CancelTask, SubscribeToTask; v0.3 uses message/send, message/stream, tasks/get, tasks/cancel, tasks/resubscribe. The protocol version is negotiated from the method name, and v1.0 clients should also send A2A-Version: 1.0. All four route families accept the same configuration object and the same MemoryLake extension described below:

`configuration` field	Type	Description
`blocking`	boolean	Wait for the task to complete before responding. Applies to both v1.0 and v0.3.
`historyLength`	integer	Number of most recent messages from the task history to include in the response.
`acceptedOutputModes`	array	Output MIME types the client can handle.
`pushNotificationConfig`	object	Callback URL (plus optional auth) for task update notifications.

MemoryLake Extension

MemoryLake extends the standard A2A protocol through the metadata.memorylake namespace. Pass this object in the request metadata of message:send or message:stream to control how the agent interacts with MemoryLake’s memory layer. This is the key difference from a vanilla A2A server — these fields connect the agent to workspaces, projects, and actors in MemoryLake.

object

required

MemoryLake-specific configuration. Without this, the agent runs without any memory context.

Hide Fields

string

Actor identifier representing the end user. Facts extracted from the conversation are associated with this actor, enabling per-user memory.

string

Project the agent can both read from and write to. Extracted facts are persisted to this project; conversation history is stored at the workspace level, not in the project.

array

Additional projects the agent can search (documents and facts) but not modify. Use this to give the agent access to shared knowledge bases.

object

Maps subagent names (defined in the agent configuration) to concrete agent IDs. Allows dynamic routing of subagent calls at request time.

object

Runtime overrides for the agent’s configuration.

Show Override fields

string

Override the agent’s model (e.g. gpt-4o, claude-sonnet-4-20250514)

string

Replace the agent’s system prompt for this request

object

Override model parameters (e.g. temperature, max_tokens)

object

Reasoning configuration

Show Reasoning fields

string

Reasoning type

integer

Token budget for reasoning

array

Override the agent’s capabilities list

integer

Override the maximum number of turns

Examples

Sending a message spans three independent choices — protocol version (v1.0 / v0.3) × method (send / stream) × transport (REST / JSON-RPC) — so there are eight valid combinations. All eight are shown below. Paths below are relative to the base URL; JSON-RPC always posts to the bare base URL and selects the operation with method.

#	Combination	Request	Headers
1	v1.0 · send · REST	`POST /message:send`	—
2	v1.0 · stream · REST	`POST /message:stream`	SSE
3	v0.3 · send · REST	`POST /v1/message:send`	—
4	v0.3 · stream · REST	`POST /v1/message:stream`	SSE
5	v1.0 · send · JSON-RPC	`SendMessage`	v1.0
6	v1.0 · stream · JSON-RPC	`SendStreamingMessage`	v1.0 + SSE
7	v0.3 · send · JSON-RPC	`message/send`	—
8	v0.3 · stream · JSON-RPC	`message/stream`	SSE

In the Headers column, SSE means Accept: text/event-stream and v1.0 means A2A-Version: 1.0. All eight take the same configuration object and the same metadata.memorylake extension. The four streaming variants respond with text/event-stream; the four send variants respond with a single JSON body.

Watch the three shape differences between versions and transports: v1.0 uses parts with role: "ROLE_USER"; v0.3 REST uses content with role: "ROLE_USER"; v0.3 JSON-RPC uses parts where every part carries a kind discriminator, with role: "user" in lowercase.

REST transport

curl -X POST 'https://app.memorylake.ai/openapi/memorylake/api/v3/workspaces/ws_abc123/agents/agt_r8k2m1n3/a2a/message:send' \
  -H 'Authorization: Bearer sk_xxxxxx' \
  -H 'Content-Type: application/json' \
  -d '{
    "message": {
      "role": "ROLE_USER",
      "parts": [
        { "text": "How do I configure two-factor authentication?" }
      ],
      "contextId": "ctx_m4n7p2q9"
    },
    "configuration": {
      "blocking": true,
      "historyLength": 10
    },
    "metadata": {
      "memorylake": {
        "actorId": "act_user_jane",
        "readWriteProjectId": "proj_def456",
        "readOnlyProjectIds": ["proj_shared_kb"],
        "overrides": {
          "model": "gpt-4o",
          "maxTurns": 5
        }
      }
    }
  }'

curl -X POST 'https://app.memorylake.ai/openapi/memorylake/api/v3/workspaces/ws_abc123/agents/agt_r8k2m1n3/a2a/message:stream' \
  -H 'Authorization: Bearer sk_xxxxxx' \
  -H 'Content-Type: application/json' \
  -H 'Accept: text/event-stream' \
  -d '{
    "message": {
      "role": "ROLE_USER",
      "parts": [
        { "text": "Summarize our last meeting notes" }
      ]
    },
    "metadata": {
      "memorylake": {
        "actorId": "act_user_jane",
        "readOnlyProjectIds": ["proj_meetings"]
      }
    }
  }'

curl -X POST 'https://app.memorylake.ai/openapi/memorylake/api/v3/workspaces/ws_abc123/agents/agt_r8k2m1n3/a2a/v1/message:send' \
  -H 'Authorization: Bearer sk_xxxxxx' \
  -H 'Content-Type: application/json' \
  -d '{
    "message": {
      "role": "ROLE_USER",
      "content": [
        { "text": "How do I configure two-factor authentication?" }
      ]
    },
    "configuration": {
      "blocking": true,
      "historyLength": 10
    },
    "metadata": {
      "memorylake": {
        "actorId": "act_user_jane",
        "readWriteProjectId": "proj_def456"
      }
    }
  }'

curl -X POST 'https://app.memorylake.ai/openapi/memorylake/api/v3/workspaces/ws_abc123/agents/agt_r8k2m1n3/a2a/v1/message:stream' \
  -H 'Authorization: Bearer sk_xxxxxx' \
  -H 'Content-Type: application/json' \
  -H 'Accept: text/event-stream' \
  -d '{
    "message": {
      "role": "ROLE_USER",
      "content": [
        { "text": "Summarize our last meeting notes" }
      ]
    },
    "metadata": {
      "memorylake": {
        "actorId": "act_user_jane",
        "readOnlyProjectIds": ["proj_meetings"]
      }
    }
  }'

JSON-RPC transport

Both versions share the same path — POST {baseUrl} with no suffix. The version comes from the method name; v1.0 clients should also send A2A-Version: 1.0.

curl -X POST 'https://app.memorylake.ai/openapi/memorylake/api/v3/workspaces/ws_abc123/agents/agt_r8k2m1n3/a2a' \
  -H 'Authorization: Bearer sk_xxxxxx' \
  -H 'Content-Type: application/json' \
  -H 'A2A-Version: 1.0' \
  -d '{
    "jsonrpc": "2.0",
    "id": "req-1",
    "method": "SendMessage",
    "params": {
      "message": {
        "messageId": "msg-1",
        "role": "ROLE_USER",
        "parts": [
          { "text": "How do I configure two-factor authentication?" }
        ],
        "contextId": "ctx_m4n7p2q9"
      },
      "configuration": {
        "blocking": true,
        "historyLength": 10
      },
      "metadata": {
        "memorylake": {
          "actorId": "act_user_jane",
          "readWriteProjectId": "proj_def456",
          "readOnlyProjectIds": ["proj_shared_kb"],
          "overrides": {
            "model": "gpt-4o",
            "maxTurns": 5
          }
        }
      }
    }
  }'

curl -X POST 'https://app.memorylake.ai/openapi/memorylake/api/v3/workspaces/ws_abc123/agents/agt_r8k2m1n3/a2a' \
  -H 'Authorization: Bearer sk_xxxxxx' \
  -H 'Content-Type: application/json' \
  -H 'A2A-Version: 1.0' \
  -H 'Accept: text/event-stream' \
  -d '{
    "jsonrpc": "2.0",
    "id": "req-2",
    "method": "SendStreamingMessage",
    "params": {
      "message": {
        "messageId": "msg-2",
        "role": "ROLE_USER",
        "parts": [
          { "text": "Summarize our last meeting notes" }
        ]
      },
      "metadata": {
        "memorylake": {
          "actorId": "act_user_jane",
          "readOnlyProjectIds": ["proj_meetings"]
        }
      }
    }
  }'

curl -X POST 'https://app.memorylake.ai/openapi/memorylake/api/v3/workspaces/ws_abc123/agents/agt_r8k2m1n3/a2a' \
  -H 'Authorization: Bearer sk_xxxxxx' \
  -H 'Content-Type: application/json' \
  -d '{
    "jsonrpc": "2.0",
    "id": "req-3",
    "method": "message/send",
    "params": {
      "message": {
        "messageId": "msg-3",
        "role": "user",
        "parts": [
          { "kind": "text", "text": "How do I configure two-factor authentication?" }
        ],
        "contextId": "ctx_m4n7p2q9"
      },
      "configuration": {
        "blocking": true,
        "historyLength": 10
      },
      "metadata": {
        "memorylake": {
          "actorId": "act_user_jane",
          "readWriteProjectId": "proj_def456"
        }
      }
    }
  }'

curl -X POST 'https://app.memorylake.ai/openapi/memorylake/api/v3/workspaces/ws_abc123/agents/agt_r8k2m1n3/a2a' \
  -H 'Authorization: Bearer sk_xxxxxx' \
  -H 'Content-Type: application/json' \
  -H 'Accept: text/event-stream' \
  -d '{
    "jsonrpc": "2.0",
    "id": "req-4",
    "method": "message/stream",
    "params": {
      "message": {
        "messageId": "msg-4",
        "role": "user",
        "parts": [
          { "kind": "text", "text": "Summarize our last meeting notes" }
        ]
      },
      "metadata": {
        "memorylake": {
          "actorId": "act_user_jane",
          "readOnlyProjectIds": ["proj_meetings"]
        }
      }
    }
  }'

​Base URL

​Protocol Versions

​MemoryLake Extension

​Examples

​REST transport

​JSON-RPC transport

Base URL

Protocol Versions

MemoryLake Extension

Examples

REST transport

JSON-RPC transport