Dynamic Contract Protocol (DCP)

A contract-first, dynamic API protocol for AI-driven applications.

Why DCP?

DCP eliminates the need for static documentation like Swagger or Postman by enabling contract-driven API interactions. It supports REST, GraphQL, OData, and Protobuf with JWT-based authorization and regional data compliance.

Features

✅ Dynamic API generation
✅ JSON & Protobuf support
✅ JWT and API Key authorization
✅ AI-powered schema generation
✅ Lite mode for edge devices

Usage Journey

Client sends a ContractMessage describing needed data.
Server responds with a ContractAcknowledgement if accepted.
Client sends a DataRequest using the agreed structure.
Server replies with a DataResponse containing results.

Contract Flow Diagram

sequenceDiagram participant Client participant AuthService participant DCP Client->>AuthService: Get JWT AuthService->>Client: Return token Client->>DCP: Submit ContractMessage DCP->>AuthService: Validate JWT AuthService-->>DCP: OK DCP->>Client: ContractAcknowledgement Client->>DCP: Send DataRequest DCP-->>Client: Return DataResponse

ContractMessage Example

{
  "type": "ContractMessage",
  "protocol_version": "1.0",
  "contract": {
    "resources": [
      {
        "name": "Product",
        "operations": ["get", "list"],
        "fields": ["id", "name", "price"],
        "filters": ["price > 100"]
      }
    ],
    "response_formats": ["json"]
  }
}

ContractAcknowledgement Example

{
  "type": "ContractAcknowledgement",
  "status": "accepted",
  "endpoints": {
    "rest": "/dcp/client_123/products"
  },
  "expires_at": "2025-03-25T00:00:00Z"
}

DataRequest Example

{
  "type": "DataRequest",
  "resource": "Product",
  "operation": "list",
  "parameters": {
    "filters": ["price < 200"],
    "page": 1
  }
}

DataResponse Example

{
  "type": "DataResponse",
  "data": [
    { "id": 1, "name": "Phone", "price": 199 }
  ],
  "metadata": {
    "total_records": 1,
    "current_page": 1
  }
}

Contract Schema Discovery

{
  "schemas": {
    "ContractMessage": "/schemas/contract.schema.json",
    "DataRequest": "/schemas/data-request.schema.json"
  }
}

OPA Policy Example

{
  "contract": {
    "resources": [
      {
        "name": "products",
        "operations": ["get", "list"],
        "fields": ["id", "name", "price", "stock"],
        "filters": ["price > 100", "stock > 0"]
      }
    ],
    "policies": [
      {
        "name": "read_only_policy",
        "source": "package dcp.read\nallow { input.method == \"GET\" }"
      }
    ]
  }
}

Contributing

We welcome contributions!

Fork the repository
Create a feature branch: git checkout -b feature/my-feature
Commit your changes
Open a pull request

See CONTRIBUTING.md for guidelines.

License

This project is licensed under the Apache 2.0 License.