{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://pactspec.dev/schema/v1.json",
  "title": "PactSpec v1",
  "description": "Machine-readable capability declaration for AI agents. Defines what an agent does, how to call it, what it costs, and how to test it. See https://pactspec.dev/spec for documentation.",
  "type": "object",
  "required": [
    "specVersion",
    "id",
    "name",
    "version",
    "provider",
    "endpoint",
    "skills"
  ],
  "properties": {
    "specVersion": {
      "type": "string",
      "const": "1.0.0",
      "description": "PactSpec schema version. Always \"1.0.0\" for v1 specs."
    },
    "id": {
      "type": "string",
      "pattern": "^urn:pactspec:[a-z0-9-]+:[a-z0-9-]+$",
      "description": "Unique URN identifier, e.g. urn:pactspec:acme:invoice-processor"
    },
    "name": {
      "type": "string",
      "minLength": 1,
      "maxLength": 100,
      "description": "Human-readable agent name."
    },
    "version": {
      "type": "string",
      "pattern": "^\\d+\\.\\d+\\.\\d+$",
      "description": "Semantic version of this agent, e.g. \"1.2.0\"."
    },
    "description": {
      "type": "string",
      "maxLength": 500,
      "description": "What this agent does."
    },
    "provider": {
      "type": "object",
      "description": "Who operates this agent.",
      "required": ["name"],
      "properties": {
        "name": {
          "type": "string",
          "description": "Organization or individual name."
        },
        "url": {
          "type": "string",
          "format": "uri",
          "description": "Provider's website."
        },
        "contact": {
          "type": "string",
          "format": "email",
          "description": "Contact email."
        }
      }
    },
    "endpoint": {
      "type": "object",
      "description": "Where to call this agent.",
      "required": ["url"],
      "properties": {
        "url": {
          "type": "string",
          "format": "uri",
          "description": "Agent endpoint URL."
        },
        "auth": {
          "type": "object",
          "description": "Authentication configuration.",
          "properties": {
            "type": {
              "type": "string",
              "enum": ["none", "bearer", "x-agent-id", "header"],
              "description": "Authentication method."
            },
            "header": {
              "type": "string",
              "description": "Custom header name when type is \"header\"."
            }
          }
        }
      }
    },
    "skills": {
      "type": "array",
      "minItems": 1,
      "description": "Capabilities this agent provides. Each skill has typed input/output schemas.",
      "items": {
        "type": "object",
        "required": [
          "id",
          "name",
          "description",
          "inputSchema",
          "outputSchema"
        ],
        "properties": {
          "id": {
            "type": "string",
            "pattern": "^[a-z0-9-]+$",
            "description": "Skill identifier (lowercase, hyphens allowed)."
          },
          "name": {
            "type": "string",
            "description": "Human-readable skill name."
          },
          "description": {
            "type": "string",
            "description": "What this skill does."
          },
          "tags": {
            "type": "array",
            "items": { "type": "string" },
            "description": "Searchable tags."
          },
          "inputSchema": {
            "type": "object",
            "description": "JSON Schema for the skill's input."
          },
          "outputSchema": {
            "type": "object",
            "description": "JSON Schema for the skill's output."
          },
          "examples": {
            "type": "array",
            "description": "Example input/output pairs.",
            "items": {
              "type": "object",
              "required": ["input", "expectedOutput"],
              "properties": {
                "description": { "type": "string" },
                "input": { "description": "Example input value." },
                "expectedOutput": {
                  "description": "Expected output for the example input."
                }
              }
            }
          },
          "pricing": {
            "type": "object",
            "description": "What this skill costs per invocation.",
            "required": ["model", "amount", "currency"],
            "properties": {
              "model": {
                "type": "string",
                "enum": ["per-invocation", "per-token", "per-second", "free"],
                "description": "Billing model."
              },
              "amount": {
                "type": "number",
                "minimum": 0,
                "description": "Price per unit."
              },
              "currency": {
                "type": "string",
                "enum": ["USD", "USDC", "SOL"],
                "description": "Currency."
              },
              "protocol": {
                "type": "string",
                "enum": ["x402", "stripe", "none"],
                "description": "Payment protocol."
              }
            }
          },
          "testSuite": {
            "type": "object",
            "description": "URL to a test suite that can be run against the live endpoint.",
            "required": ["url"],
            "properties": {
              "url": {
                "type": "string",
                "format": "uri",
                "description": "Test suite URL."
              },
              "type": {
                "type": "string",
                "enum": ["http-roundtrip", "json-schema-validation"],
                "description": "Test format."
              }
            }
          }
        }
      }
    },
    "tags": {
      "type": "array",
      "items": { "type": "string" },
      "description": "Searchable tags for the agent."
    },
    "license": { "type": "string", "description": "SPDX license identifier." },
    "links": {
      "type": "object",
      "description": "Related links.",
      "properties": {
        "documentation": {
          "type": "string",
          "format": "uri",
          "description": "Documentation URL."
        },
        "repository": {
          "type": "string",
          "format": "uri",
          "description": "Source code repository."
        }
      }
    },
    "delegation": {
      "type": "object",
      "description": "If this agent wraps another agent.",
      "properties": {
        "delegatedFrom": {
          "type": "string",
          "description": "Spec ID of the upstream agent being wrapped."
        },
        "terms": {
          "type": "string",
          "format": "uri",
          "description": "URL to delegation agreement."
        }
      }
    },
    "interop": {
      "type": "object",
      "description": "Interoperability with other protocols.",
      "properties": {
        "mcp": {
          "type": "object",
          "properties": {
            "serverUrl": {
              "type": "string",
              "format": "uri",
              "description": "MCP server endpoint."
            },
            "tools": {
              "type": "array",
              "items": { "type": "string" },
              "description": "MCP tool names."
            }
          }
        },
        "openapi": {
          "type": "object",
          "properties": {
            "specUrl": {
              "type": "string",
              "format": "uri",
              "description": "OpenAPI spec URL."
            }
          }
        },
        "acp": {
          "type": "object",
          "properties": {
            "supported": {
              "type": "boolean",
              "description": "Whether ACP sessions are supported."
            },
            "sessionTypes": {
              "type": "array",
              "items": { "type": "string" },
              "description": "Supported session types."
            }
          }
        }
      }
    }
  }
}