Local Development

Set up LocalStack for asyncmcp development

Overview

Set up a complete local development environment for asyncmcp using LocalStack to simulate AWS services.

Prerequisites

1. Install LocalStack

   # Using pip
   pip install localstack
   
   # Using Docker
   docker pull localstack/localstack
   
   # Using Homebrew (macOS)
   brew install localstack
   

2. Install AWS CLI

   # Configure for LocalStack
   aws configure set aws_access_key_id test
   aws configure set aws_secret_access_key test
   aws configure set region us-east-1
   

3. Install asyncmcp

   # Clone repository
   git clone https://github.com/bh-rat/asyncmcp.git
   cd asyncmcp
   
   # Install with uv
   uv sync
   

Starting LocalStack

CLI

# Start LocalStack
localstack start

# Verify it's running
localstack status

Setting Up Resources

Create SQS Queues

#!/usr/bin/env python3
import boto3

# LocalStack configuration
config = {
    "endpoint_url": "http://localhost:4566",
    "region_name": "us-east-1",
    "aws_access_key_id": "test",
    "aws_secret_access_key": "test"
}

sqs = boto3.client("sqs", **config)

# Create queues
queues = [
    "mcp-requests",
    "mcp-responses",
    "mcp-processor",
    "mcp-consumer"
]

for queue_name in queues:
    response = sqs.create_queue(
        QueueName=queue_name,
        Attributes={
            'ReceiveMessageWaitTimeSeconds': '20',
            'VisibilityTimeout': '30'
        }
    )
    print(f"✅ Created queue: {response['QueueUrl']}")

Create SNS Topics

sns = boto3.client("sns", **config)

# Create topics
topics = [
    "mcp-requests",
    "mcp-responses"
]

for topic_name in topics:
    response = sns.create_topic(Name=topic_name)
    print(f"✅ Created topic: {response['TopicArn']}")
    
    # Subscribe queues to topics
    if topic_name == "mcp-requests":
        sns.subscribe(
            TopicArn=response['TopicArn'],
            Protocol='sqs',
            Endpoint=f"arn:aws:sqs:us-east-1:000000000000:mcp-processor"
        )

Running Examples

Basic SQS Example

# Terminal 1: Start server
uv run examples/website_server.py --transport sqs

# Terminal 2: Start client
uv run examples/website_client.py --transport sqs

SNS+SQS Example

# Terminal 1: Start server
uv run examples/website_server.py

# Terminal 2: Start client
uv run examples/website_client.py

Webhook Example

# Terminal 1: Start server
uv run examples/webhook_server.py --server-port 8000

# Terminal 2: Start client
uv run examples/webhook_client.py --server-port 8000 --webhook-port 8001

Development Workflow

1. Start LocalStack

   localstack start
   

2. Setup Resources

   uv run examples/setup.py
   

3. Run Tests

   uv run pytest tests/
   

4. Start Development

   # Run your MCP server/client
   uv run your_server.py
   

Debugging Tips

View LocalStack logs

localstack logs -f

List created resources

# List SQS queues
aws --endpoint-url=http://localhost:4566 sqs list-queues

# List SNS topics
aws --endpoint-url=http://localhost:4566 sns list-topics

Monitor queue messages

# Check queue depth
aws --endpoint-url=http://localhost:4566 sqs get-queue-attributes \
  --queue-url http://localhost:4566/000000000000/mcp-requests \
  --attribute-names ApproximateNumberOfMessages

Environment Variables

# .env file for development
AWS_ENDPOINT_URL=http://localhost:4566
AWS_REGION=us-east-1
AWS_ACCESS_KEY_ID=test
AWS_SECRET_ACCESS_KEY=test
LOCALSTACK_HOST=localhost:4566

Running Tests

# Run all tests
uv run pytest

# Run with coverage
uv run pytest --cov=asyncmcp --cov-report=html

# Run specific markers
uv run pytest -m unit
uv run pytest -m integration

# Run specific test module
uv run pytest tests/sqs/test_integration.py

# Run tests with specific markers
uv run pytest -m integration
uv run pytest -m unit

Next Steps

Quickstart

Run your first example

Examples

Browse examples