Skip to main content
Copy page
Version: Next

Deploy the A2A Notes Agent Sample

WSO2 Agent Manager includes a ready-to-deploy sample agent that speaks the A2A protocol, called the A2A Notes Agent. In this tutorial you deploy it as an A2A Agent, then call it through the gateway over both A2A transports. You do not need to write or change any code.

The sample lives in the platform's GitHub repository, at samples/a2a-agent. It is built on the official a2a-sdk Python package and FastAPI.

What You Will Build​

Give the A2A Notes Agent meeting notes and it does one of two things, both backed by OpenAI:

SkillWhat it doesResult
summarize-notesCondenses the notes into at most three sentences. This is the default skill.A text/plain artifact, streamed as it is written
extract-action-itemsPulls out who owes what, and whenAn application/json artifact

The sample shows the A2A protocol surface Agent Manager publishes:

  • An agent card at /.well-known/agent-card.json, declaring a JSON-RPC interface under /rpc, an HTTP+JSON interface under /rest, and the two skills.
  • Both transports from one process, over one task store, so a task sent over JSON-RPC can be read over HTTP+JSON.
  • Streaming through SendStreamingMessage, which returns the summary as a stream of artifact chunks.
  • The task lifecycle: submitted, working, then completed. A request with no notes is rejected, and a failed model call is failed.

For how Agent Manager exposes A2A agents in general, see Deploy an A2A Agent.

Prerequisites​

  • WSO2 Agent Manager installed. See the Quick Start Guide.
  • An OpenAI API key. Both skills call the model.
  • To use the CLI path: amctl installed and logged in. See CLI Installation.

Step 1: Create and Deploy the Agent​

  1. Open your project and click Add Agent.

  2. Choose Platform-Hosted Agent, then Source Code as the source type.

  3. Fill in the agent and repository details:

    FieldValue
    Namea2a-notes-agent
    Description (optional)Summarizes meeting notes and extracts action items over A2A
    GitHub Repositoryhttps://github.com/wso2/agent-manager
    Branchmain
    Project Path/samples/a2a-agent

  4. Choose Python as the build type, set Language Version to 3.11, and set Start Command to python main.py.

  5. Leave Enable auto instrumentation checked.

  6. Under Agent Type, choose A2A Agent, and set Port to 9099.

  7. Under Environment Variables (Optional), click Add, enter OPENAI_API_KEY as the Key and your OpenAI key as the Value, and turn on Mark as a Secret.

  8. Click Deploy.

The build takes a few minutes. When it finishes, the agent deploys to the first environment and the platform publishes it to the gateway.

Optional environment variables:

KeyDefaultPurpose
OPENAI_MODELgpt-4o-miniThe model both skills use
AGENT_PUBLIC_BASE_URLhttp://localhost:9099The address the agent advertises in its own card. Leave it unset for a deployed agent.
Why auto instrumentation works with this sample

The sample pins a2a-sdk to 1.1.5, the first release that accepts protobuf 7. The auto instrumentation init container puts protobuf 7 on the agent's PYTHONPATH, and a2a-sdk 1.1.2 through 1.1.4 fail every A2A message under it with JSON-RPC error -32603. If you adapt the sample with an older SDK, turn Enable auto instrumentation off.

Step 2: Get the Agent's URL and a Key​

  1. Open the agent's overview and copy the Invoke URL for the environment. The agent's transports sit under it:

    URLWhat it serves
    <invoke-url>/.well-known/agent-card.jsonThe agent card
    <invoke-url>/rpcThe JSON-RPC transport
    <invoke-url>/restThe HTTP+JSON transport

  2. If the agent's Endpoint Authentication is API key, create a key as described in Secure Agent Endpoints with API Keys.

The Try It page does not work for A2A agents, so the rest of this tutorial uses curl.

Step 3: Summarize Notes over JSON-RPC​

curl -X POST "<invoke-url>/rpc" \
  -H "Content-Type: application/json" \
  -H "A2A-Version: 1.0" \
  -H "X-API-Key: <agent-api-key>" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "SendMessage",
    "params": {
      "message": {
        "messageId": "msg-1",
        "role": "ROLE_USER",
        "parts": [{"text": "Standup: the gateway rollout is on track. Priya will cut the release branch on Thursday. Sam is blocked on the staging certificate."}]
      }
    }
  }'

Replace <invoke-url> and <agent-api-key> with the values from Step 2. If the agent uses No authentication, drop the X-API-Key header.

The reply is a Task in the completed state, carrying a summary.txt artifact with the summary.

Step 4: Extract Action Items over HTTP+JSON​

Choose the other skill by naming it in the message's metadata.skill, and send it over the HTTP+JSON transport:

curl -X POST "<invoke-url>/rest/message:send" \
  -H "Content-Type: application/json" \
  -H "A2A-Version: 1.0" \
  -H "X-API-Key: <agent-api-key>" \
  -d '{
    "message": {
      "messageId": "msg-2",
      "role": "ROLE_USER",
      "metadata": {"skill": "extract-action-items"},
      "parts": [{"text": "Standup: Priya cuts the release branch Thursday; Sam is blocked on the staging certificate."}]
    }
  }'

The task completes with an action-items.json artifact. You can also pick a skill by starting the text with Extract action items: or Summarize:. A metadata.skill the agent does not have is rejected rather than answered with a summary.

Step 5: Stream a Summary​

Call SendStreamingMessage with -N so curl prints events as they arrive:

curl -N -X POST "<invoke-url>/rpc" \
  -H "Content-Type: application/json" \
  -H "A2A-Version: 1.0" \
  -H "X-API-Key: <agent-api-key>" \
  -d '{
    "jsonrpc": "2.0",
    "id": 2,
    "method": "SendStreamingMessage",
    "params": {"message": {"messageId": "msg-3", "role": "ROLE_USER",
      "parts": [{"text": "Standup: Priya cuts the release branch Thursday."}]}}
  }'

Each server-sent event is one line: first the Task, then a working status update, then the summary as artifact chunks, then completed.

Call It from an A2A Client​

Any A2A client works. Point it at the agent's card through the gateway, <invoke-url>/.well-known/agent-card.json. That card lists the gateway URLs, so the client calls the agent through the gateway. The sample README includes an a2a-sdk client example.

Troubleshooting​

What you seeWhat to do
Every message fails with JSON-RPC error -32603, and the logs show 'FieldDescriptor' object has no attribute 'label'The agent runs an a2a-sdk release older than 1.1.5 with auto instrumentation on. Upgrade the SDK, or turn Enable auto instrumentation off.
The call returns 401Send a valid key in the X-API-Key header, or check the agent's Endpoint Authentication setting.
A GetExtendedAgentCard call always returns 401The sample publishes no extended card. The gateway serves an extended card only to a caller it has authenticated.
Push notification operations return FAILED_PRECONDITIONThe sample declares push notifications off in its card.
Task history disappears after a restartThe sample keeps tasks in memory. Swap in a database task store from a2a-sdk if tasks must survive restarts.

See Also​

GuideWhat it covers
Deploy an A2A AgentDeploying your own A2A agent, Agent Card CORS, and endpoint settings
Sample AgentsThe other samples in the repository
Create Your First AgentThe general agent creation flow