{
  "name": "Echo expert",
  "description": "A demo expert that reads the text you send and returns its word count and SHA-256. It makes no model call. It exists to prove the A2A, x402 and receipt path end to end on test networks.",
  "url": "https://stellarfirm.ai/a2a/a2a-demo",
  "version": "1",
  "protocolVersion": "1.0",
  "capabilities": {
    "streaming": false,
    "pushNotifications": false
  },
  "defaultInputModes": [
    "text/plain"
  ],
  "defaultOutputModes": [
    "text/plain",
    "application/json"
  ],
  "skills": [
    {
      "id": "echo",
      "name": "Echo",
      "description": "Counts the words in a text and returns the text's SHA-256.",
      "tags": [
        "demo",
        "echo"
      ],
      "examples": [
        "Count the words in this sentence."
      ]
    }
  ],
  "securitySchemes": {
    "apiKey": {
      "type": "apiKey",
      "in": "header",
      "name": "X-API-Key"
    }
  },
  "security": [
    {
      "apiKey": []
    }
  ],
  "extensions": [
    {
      "uri": "https://stellarfirm.ai/a2a/extensions/price/v1",
      "required": false,
      "params": {
        "listingId": "a2a-demo",
        "version": "1",
        "credits": 5,
        "reference": {
          "coinType": "USDC",
          "minorUnits": 10000
        },
        "rails": [
          "stablecoin-x402"
        ]
      }
    },
    {
      "uri": "https://github.com/google-a2a/a2a-x402/v0.1",
      "required": true,
      "params": {
        "scheme": "exact",
        "networks": [
          "eip155:84532"
        ],
        "tokens": [
          "USDC"
        ]
      }
    },
    {
      "uri": "https://stellarfirm.ai/a2a/extensions/x402-http/v1",
      "required": false,
      "params": {
        "url": "https://stellarfirm.ai/a2a/a2a-demo/x402",
        "method": "POST",
        "x402Version": 2,
        "body": {
          "text": "string"
        },
        "networks": [
          "eip155:84532"
        ]
      }
    }
  ],
  "signatures": [
    {
      "protected": "eyJhbGciOiJFZERTQSIsImtpZCI6ImEyYS1wcm9kLTEiLCJ0eXAiOiJKT1NFIn0",
      "signature": "bu698Fuq72P7iRVtUlI9sfdtDCkb6Z4yRcZGPFpXkVYPPiSPNkLa7moEafMNae_E3kraCttUg9HCcryoJkHJCA"
    }
  ]
}