inter-service-sdk 1.0.4

Complete framework for inter-service communication with client, server utilities, auth and encryption

Inter-Service SDK

Generic HTTP client for secure service-to-service communication with bearer token authentication and optional ECC encryption.

Features

• 🔐 Bearer Token Auth - Automatic authentication headers
• 🔒 Optional ECC Encryption - End-to-end encryption for sensitive data
• 🎯 Path & Query Parameters - Clean parameter substitution
• 🔄 Automatic Retries - Exponential backoff for failed requests
• 📝 Structured Logging - Request/response tracking
• 🚀 Zero Dependencies - Only requests and cryptography (optional)

Installation

pip install inter-service-sdk

Quick Start

from inter_service_sdk import InterServiceClient

# Initialize client
client = InterServiceClient(
    base_url="https://api.example.com",
    api_key="your-secret-key"
)

# Make a request (correlation_id auto-generated)
response = client.request(
    endpoint="users/{user_id}",
    path_params={"user_id": 123}
)

if response["status"] == "success":
    print(response["data"])
else:
    print(f"Error: {response['error']}")

Usage

Basic GET Request

client = InterServiceClient(
    base_url="https://api.example.com",
    api_key="your-api-key"
)

# GET /api/v1/inter-service/users/123
# correlation_id auto-generated
response = client.request(
    endpoint="users/{user_id}",
    path_params={"user_id": 123}
)

With Query Parameters

# GET /api/v1/inter-service/users/search?q=john&type=email&limit=10
# correlation_id auto-generated and added to query params
response = client.request(
    endpoint="users/search",
    query_params={
        "q": "john",
        "type": "email",
        "limit": 10
    }
)

# Custom correlation_id (optional)
response = client.request(
    endpoint="users/search",
    query_params={
        "q": "john",
        "correlation_id": "my-custom-id-123"
    }
)

POST Request

# POST /api/v1/inter-service/users
new_user = client.request(
    endpoint="users",
    method="POST",
    data={
        "name": "John Doe",
        "email": "[e-mail]"
    }
)

With ECC Encryption

client = InterServiceClient(
    base_url="https://api.example.com",
    api_key="your-api-key",
    ecc_private_key=os.getenv("PRIVATE_KEY"),
    ecc_public_key=os.getenv("PUBLIC_KEY")
)

# Auto-decrypt response
credentials = client.request(
    endpoint="credentials/{id}",
    path_params={"id": 456},
    decrypt=True
)

# Auto-encrypt request
client.request(
    endpoint="secrets",
    method="POST",
    data={"secret": "sensitive data"},
    encrypt=True
)

Custom API Prefix

# Default prefix: /api/v1/inter-service
client = InterServiceClient(
    base_url="https://api.example.com",
    api_key="key",
    api_prefix="/v2/api"  # Custom prefix
)

# Override per request
response = client.request(
    endpoint="custom",
    api_prefix="/internal"
)

Server-Side Utilities

The SDK also provides FastAPI utilities for creating REST-compliant inter-service endpoints.

Creating a Router

from fastapi import FastAPI, Depends
from inter_service_sdk.server import create_inter_service_router, inter_service_endpoint

# Create router with authentication
router = create_inter_service_router(
    auth_dependency=Depends(your_auth_function)
)

app = FastAPI()
app.include_router(router)

Creating Endpoints

from fastapi import Request, HTTPException
from sqlalchemy.orm import Session

@router.get("/users/{user_id}")
@inter_service_endpoint("get_user")
async def get_user(
    user_id: int,
    correlation_id: str,
    request: Request,
    db: Session = Depends(get_db)
):
    # Business logic only - SDK handles logging and errors
    user = db.query(User).filter(User.id == user_id).first()

    if not user:
        raise HTTPException(status_code=404, detail="User not found")

    return {"id": user.id, "name": user.name}  # Direct return

Features

• Automatic Logging: Request/response logging with correlation IDs
• Error Handling: Converts exceptions to proper HTTP status codes
• REST Standard: Returns data directly (200) or raises HTTPException (404, 500)
• Authentication: Configurable auth dependency for entire router

Response Format

• Success: Return data directly → FastAPI returns HTTP 200 with data
• Errors: Raise HTTPException → FastAPI returns HTTP 404/500 with error detail

# ✅ Correct
return {"user_id": 123, "name": "John"}

# ✅ Correct
raise HTTPException(status_code=404, detail="Not found")

# ❌ Incorrect - Don't wrap in envelope
return {"status": "success", "data": {...}}

API Reference

InterServiceClient

InterServiceClient(
    base_url: str,
    api_key: str,
    api_prefix: str = "/api/v1/inter-service",
    timeout: int = 30,
    retry_attempts: int = 3,
    ecc_private_key: str = None,
    ecc_public_key: str = None
)

Parameters

• base_url (str): Base URL of the API (e.g., "https://api.example.com")
• api_key (str): Bearer token for authentication
• api_prefix (str, optional): API prefix. Default: "/api/v1/inter-service"
• timeout (int, optional): Request timeout in seconds. Default: 30
• retry_attempts (int, optional): Number of retry attempts. Default: 3
• ecc_private_key (str, optional): ECC private key for decryption
• ecc_public_key (str, optional): ECC public key for encryption

request()

client.request(
    endpoint: str,
    path_params: dict = None,
    query_params: dict = None,
    method: str = "GET",
    data: dict = None,
    headers: dict = None,
    encrypt: bool = False,
    decrypt: bool = False,
    timeout: int = None,
    api_prefix: str = None
) -> dict

Parameters

• endpoint (str): Endpoint template (e.g., "users/{user_id}")
• path_params (dict, optional): Path parameters for substitution
• query_params (dict, optional): Query string parameters
• method (str, optional): HTTP method. Default: "GET"
• data (dict, optional): Request body (JSON)
• headers (dict, optional): Additional headers
• encrypt (bool, optional): Auto-encrypt request data. Default: False
• decrypt (bool, optional): Auto-decrypt response. Default: False
• timeout (int, optional): Override default timeout
• api_prefix (str, optional): Override default API prefix

Returns

{
    "status": "success" | "error",
    "data": {...} | None,
    "status_code": int,
    "error": None | str
}

Error Handling

response = client.request(endpoint="users/123")

if response["status"] == "success":
    user = response["data"]
    print(user)
else:
    print(f"Error: {response['error']}")
    print(f"Status code: {response['status_code']}")

Configuration

Environment Variables

# Recommended approach
export API_BASE_URL="https://api.example.com"
export API_KEY="your-secret-key"
export ECC_PRIVATE_KEY="-----BEGIN PRIVATE KEY-----..."
export ECC_PUBLIC_KEY="-----BEGIN PUBLIC KEY-----..."

import os
from inter_service_sdk import InterServiceClient

client = InterServiceClient(
    base_url=os.getenv("API_BASE_URL"),
    api_key=os.getenv("API_KEY"),
    ecc_private_key=os.getenv("ECC_PRIVATE_KEY"),
    ecc_public_key=os.getenv("ECC_PUBLIC_KEY")
)

Development

Install Development Dependencies

pip install -r requirements-dev.txt

Run Tests

pytest tests/ -v

Run Tests with Coverage

pytest tests/ --cov=inter_service_sdk --cov-report=html

Code Formatting

black inter_service_sdk tests

Type Checking

mypy inter_service_sdk

Examples

See the examples/ directory for more usage examples:

• basic_usage.py - Simple GET request
• with_encryption.py - ECC encryption example
• search_example.py - Query parameters example
• post_example.py - POST request example

License

MIT License - see LICENSE file for details.

Contributing

Contributions are welcome! Please open an issue or submit a pull request.

Support

For questions or issues, please open a GitHub issue.