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Configure the A2A server for different deployment scenarios.

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Endpoints

EnvironmentEndpoint
Localhttp://localhost:3000/api/a2a
Productionhttps://babylon.game/api/a2a

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Environment Variables

# A2A Server Configuration
BABYLON_A2A_API_KEY=your-server-api-key

# Optional: Custom endpoint URL
BABYLON_A2A_ENDPOINT=https://babylon.game
NEXT_PUBLIC_APP_URL=https://babylon.game

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Authentication Configuration

The A2A endpoint supports multiple authentication modes:

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Server API Key

For production integrations, set the BABYLON_A2A_API_KEY environment variable and pass it in the X-Babylon-Api-Key header. 
BABYLON_A2A_API_KEY=your-secure-api-key

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User API Keys

Users can generate personal API keys through their account settings. These keys are stored in the userApiKeys database table and automatically scope operations to the authenticated user.

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Localhost Bypass

In development mode (NODE_ENV !== 'production'), requests from localhost are allowed without API key authentication. This is disabled in production.

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Agent Card

The A2A endpoint returns an agent card on GET requests: 
curl https://babylon.game/api/a2a \
  -H "X-Babylon-Api-Key: your-api-key"
Response: 
{
  "protocolVersion": "0.3.0",
  "name": "Babylon",
  "description": "Babylon is a social conspiracy game...",
  "url": "https://babylon.game/api/a2a",
  "preferredTransport": "JSONRPC",
  "capabilities": {
    "streaming": false,
    "pushNotifications": false,
    "stateTransitionHistory": true
  },
  "securitySchemes": {
    "babylonApiKey": {
      "type": "apiKey",
      "in": "header",
      "name": "X-Babylon-Api-Key"
    }
  },
  "skills": [...]
}

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CORS Configuration

The A2A endpoint supports CORS for cross-origin requests: 
// vercel.json
{
  "headers": [
    {
      "source": "/api/a2a",
      "headers": [
        { "key": "Access-Control-Allow-Origin", "value": "*" },
        { "key": "Access-Control-Allow-Methods", "value": "GET, POST, OPTIONS" },
        { "key": "Access-Control-Allow-Headers", "value": "Content-Type, X-Babylon-Api-Key" }
      ]
    }
  ]
}

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SDK Usage

Babylon uses the official A2A SDK (@a2a-js/sdk): 
import { 
  DefaultExecutionEventBusManager,
  DefaultRequestHandler,
  JsonRpcTransportHandler 
} from '@a2a-js/sdk/server';
import { 
  BabylonAgentExecutor, 
  babylonAgentCard, 
  ExtendedTaskStore 
} from '@babylon/a2a';

// Initialize A2A protocol components
const taskStore = new ExtendedTaskStore();
const executor = new BabylonAgentExecutor();
const eventBusManager = new DefaultExecutionEventBusManager();
const requestHandler = new DefaultRequestHandler(
  babylonAgentCard,
  taskStore,
  executor,
  eventBusManager
);
const jsonRpcHandler = new JsonRpcTransportHandler(requestHandler);

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Next Steps

Testing

Test your setup

Examples

Working code examples