A2A Protocol

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.

How It Works

A2A provides two capabilities:

A2A Server — Expose Your Agents

External platforms can discover and call your CrewForm agents via standard A2A endpoints:

Endpoint	Method	Description
`/.well-known/agent.json`	GET	Agent Card discovery — returns agent capabilities, skills, and metadata
`/a2a/:agentId`	POST	JSON-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"
    }
  ]
}

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:

Go to Settings → A2A Protocol
Enter the base URL of the external agent (e.g. https://agent.example.com)
Click Discover — CrewForm fetches the Agent Card and registers the agent
Toggle the agent to Enabled
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")

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"}'

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

Database

A2A uses two tables:

a2a_remote_agents — Registered external agents and cached Agent Cards
a2a_task_log — Inbound and outbound A2A interaction history

Getting Started

Core Features

Integrations

Protocols

Tutorials

Resources

Overview

How It Works

A2A Server — Expose Your Agents

A2A Client — Delegate to External Agents

Authentication

Managing Remote Agents

Database

​Overview

​How It Works

​A2A Server — Expose Your Agents

​A2A Client — Delegate to External Agents

​Authentication

​Managing Remote Agents

​Database

Overview

How It Works

A2A Server — Expose Your Agents

A2A Client — Delegate to External Agents

Authentication

Managing Remote Agents

Database