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Overview

CrewForm supports the A2A (Agent-to-Agent) protocol, enabling your agents to communicate with external AI systems. This is the open standard for agent-to-agent interoperability.
A2A complements MCP (tools) and AG-UI (frontend) — together they form the three agentic protocols that CrewForm supports.

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How It Works

A2A provides two capabilities:

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A2A Server — Expose Your Agents

External platforms can discover and call your CrewForm agents via standard A2A endpoints:
EndpointMethodDescription
/.well-known/agent.jsonGETAgent Card discovery — returns agent capabilities, skills, and metadata
/a2a/:agentIdPOSTJSON-RPC endpoint — accepts message/send, tasks/get, tasks/cancel
Agent Card example: 
{
  "name": "Research Agent",
  "description": "Performs web research and summarization",
  "version": "1.0.0",
  "skills": [
    {
      "id": "web_research",
      "name": "Web Research",
      "description": "Search the web and compile findings"
    }
  ]
}

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A2A Client — Delegate to External Agents

CrewForm agents can delegate tasks to any external A2A-compliant agent using the built-in a2a_delegate tool. How to enable:
  1. Go to Settings → A2A Protocol
  2. Enter the base URL of the external agent (e.g. https://agent.example.com)
  3. Click Discover — CrewForm fetches the Agent Card and registers the agent
  4. Toggle the agent to Enabled
  5. Add a2a_delegate to any agent’s tool list
The agent can then call: 
a2a_delegate(agent_id: "remote-agent-uuid", message: "Research the latest AI trends")

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Authentication

A2A endpoints require a Bearer token matching an API key in your workspace: 
curl -X POST https://your-task-runner/a2a/AGENT_ID \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"message/send","params":{"message":{"role":"user","parts":[{"text":"Hello"}]}},"id":"1"}'

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Managing Remote Agents

Navigate to Settings → A2A Protocol to:
  • Discover — Register external agents by URL
  • Toggle — Enable/disable remote agents
  • Refresh — Update cached Agent Cards
  • Delete — Remove remote agent registrations

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Database

A2A uses two tables:
  • a2a_remote_agents — Registered external agents and cached Agent Cards
  • a2a_task_log — Inbound and outbound A2A interaction history