lambda-middleware 0.3.1

Python client for AWS Lambda middleware functions

Lambda Middleware

A Python client library for calling AWS Lambda functions. This package simplifies Lambda invocations by providing a clean, typed interface with full AWS integration.

Features

• Simple API: Just instantiate LambdaMiddleware and call methods
• Flexible Configuration: Environment variables or programmatic configuration
• CLI Interface: Invoke Lambda functions from the command line
• Type Safe: Full type hints with Pydantic validation
• AWS Integration: Built on boto3 for seamless AWS authentication

Installation

Install via pip or uv:

pip install lambda-middleware
# OR
uv add lambda-middleware

Configuration

Set the Lambda function name via environment variable:

export LAMBDA_FUNCTION_NAME=your-lambda-function

Or create a .env file:

LAMBDA_FUNCTION_NAME=your-lambda-function

Usage

Programmatic Usage

import asyncio
from lambda_middleware import LambdaMiddleware

# Initialize with environment config
middleware = LambdaMiddleware()

# Or provide custom config
from lambda_middleware.config import Config
config = Config(lambda_function_name="my-function")
middleware = LambdaMiddleware(config=config)

# Call the Lambda function
async def main():
    response = await middleware.call_lambda({
        "action": "your_action",
        "params": {}
    })
    print(response)

asyncio.run(main())

CLI Usage

Check AWS credentials:

lambda-middleware middleware caller-identity

Call the Lambda function:

lambda-middleware middleware call --function-name my-lambda-function --message "test payload"

Dry Run Mode

Test IAM permissions without invoking the function:

response = await middleware.call_lambda(
    {"action": "your_action"},
    dry_run=True
)

Requirements

• Python 3.13+
• AWS credentials configured (via ~/.aws/credentials, environment variables, or IAM role)
• Access to the target Lambda function

Development

Install development dependencies:

uv add --dev pytest pytest-mock pytest-asyncio

Run tests:

pytest

License

Internal use only - Factored organization.