A2A Server — Agent-to-Agent Protocol

A2A Server — Agent-to-Agent Protocol

Nefesh exposes an Agent-to-Agent (A2A) server that lets AI agents collaborate with the Nefesh Human State Agent using the open A2A v1.0 protocol. A2A is a JSON-RPC 2.0 based standard for peer-to-peer agent communication, designed by Google and adopted across the AI agent ecosystem. The Nefesh A2A server runs at mcp.nefesh.ai/a2a and exposes 4 skills that let any A2A-compatible agent read, ingest, and track human physiological state in real time.

Endpoint & Discovery

Skills

1. get-human-state

Get the current unified human state (stress score, behavioral recommendation) for a session or subject.

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "skill/invoke",
  "params": {
    "skill_id": "get-human-state",
    "input": {
      "session_id": "sess_demo"
    }
  }
}

2. ingest-signals

Send biometric signals and receive an updated unified state in real time.

{
  "jsonrpc": "2.0",
  "id": 2,
  "method": "skill/invoke",
  "params": {
    "skill_id": "ingest-signals",
    "input": {
      "session_id": "sess_demo",
      "heart_rate": 72,
      "rmssd": 45
    }
  }
}

3. get-trigger-memory

Get the trigger memory profile for a subject — which conversation topics have historically caused stress and which have been resolved.

{
  "jsonrpc": "2.0",
  "id": 3,
  "method": "skill/invoke",
  "params": {
    "skill_id": "get-trigger-memory",
    "input": {
      "subject_id": "usr_demo"
    }
  }
}

4. get-session-history

Get the timestamped state history for a session with trend information.

{
  "jsonrpc": "2.0",
  "id": 4,
  "method": "skill/invoke",
  "params": {
    "skill_id": "get-session-history",
    "input": {
      "session_id": "sess_demo",
      "minutes": 10
    }
  }
}

Agent Card

The public Agent Card describes the server's capabilities in the A2A v1.0 schema. Fetch it with:

curl https://mcp.nefesh.ai/.well-known/agent-card.json

A2A vs MCP — When to Use Which

Both protocols are supported in parallel. The underlying capabilities (get state, ingest, trigger memory, history) are the same.

Get Started

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