Sigma MCP Server Deployment Guide

Overview

This guide walks you through deploying the Sigma MCP Server to AWS Lambda with API Gateway.

Sample Questions to test the MCP Server

"What's the status of the Sigma MCP server?" "Check the Sigma MCP server connection" "Test the Sigma MCP server connectivity" "Is the Sigma MCP server working?" "Get the current status of the Sigma MCP server" "Verify the Sigma MCP server is operational"

Architecture

Claude/MCP Client → API Gateway → Lambda → DynamoDB (cache)
                                    ↓
                              Secrets Manager (credentials)
                                    ↓
                               Sigma API

Prerequisites

1. AWS CLI configured with appropriate permissions

2. Terraform installed (v1.0+)

3. Node.js 18+ and npm

4. Sigma API credentials (client ID and secret)

Step 1: Prepare the Lambda Package

# Install dependencies
npm install

# Build the TypeScript code
npm run build

# Create deployment package
npm run package

This creates sigma-mcp-server.zip with your compiled code and dependencies.

Step 2: Configure Terraform Variables

Create a terraform.tfvars file:

aws_region = "us-east-1"
environment = "dev"
sigma_base_url = "https://api.sigmacomputing.com"

Step 3: Deploy Infrastructure

# Initialize Terraform
terraform init

# Plan the deployment
terraform plan

# Apply the changes
terraform apply

Important: After deployment, update the Secrets Manager secret with your actual Sigma credentials:

aws secretsmanager update-secret \
  --secret-id "sigma-api-credentials-dev" \
  --secret-string '{"clientId":"YOUR_ACTUAL_CLIENT_ID","clientSecret":"YOUR_ACTUAL_SECRET"}'

Step 4: Initial Cache Population

The document cache needs to be populated before the MCP server can search documents. You can do this by:

Option A: One-time Script

Create a simple script to populate the cache:

// populate-cache.ts
import { SigmaApiClient } from './src/sigma-client.js';
import { DocumentCache } from './src/document-cache.js';

async function populateCache() {
  const client = new SigmaApiClient({
    baseUrl: process.env.SIGMA_BASE_URL!,
    clientId: process.env.SIGMA_CLIENT_ID!,
    clientSecret: process.env.SIGMA_CLIENT_SECRET!,
  });
  
  const cache = new DocumentCache(process.env.CACHE_TABLE_NAME!);
  
  await client.initialize();
  await cache.initialize();
  await cache.refreshCache(client);
  
  console.log('Cache populated successfully');
}

populateCache().catch(console.error);

Option B: Lambda Function Invocation

You can invoke the Lambda directly to trigger cache refresh (you'd need to add an endpoint for this).

Step 5: Configure Claude Desktop

Add your MCP server to Claude Desktop's configuration:

{
  "mcpServers": {
    "sigma-analytics": {
      "command": "node",
      "args": [
        "path/to/mcp-client-script.js"
      ],
      "env": {
        "API_GATEWAY_URL": "https://your-api-id.execute-api.region.amazonaws.com/dev"
      }
    }
  }
}

You'll need to create a client script that communicates with your API Gateway endpoint instead of stdio.

API Gateway Setup Details

The Terraform creates:

1. REST API - Main API Gateway resource

2. Proxy Resource - {proxy+} to catch all paths

3. ANY Method - Accepts all HTTP methods

4. Lambda Integration - Routes requests to your Lambda function

5. Deployment - Creates a stage (dev/prod) with invoke URL

API Gateway Flow:

1. Client sends HTTP POST with MCP request in body

2. API Gateway forwards to Lambda via AWS_PROXY integration

3. Lambda processes MCP request and returns response

4. API Gateway returns response to client

Environment Variables

The Lambda function uses these environment variables (set by Terraform):

• SIGMA_BASE_URL - Sigma API endpoint

• CACHE_TABLE_NAME - DynamoDB table name

• NODE_ENV - Environment (dev/prod)

Credentials are loaded from AWS Secrets Manager automatically.

Monitoring and Logs

• CloudWatch Logs: /aws/lambda/sigma-mcp-server-{environment}

• API Gateway Logs: Can be enabled in the API Gateway console

• DynamoDB Metrics: Available in CloudWatch

Outputs

After deployment, Terraform provides:

# Get the API Gateway URL
terraform output api_gateway_url

# Get other resource names
terraform output lambda_function_name
terraform output dynamodb_table_name
terraform output secrets_manager_secret_name

Local Testing

Before deploying to AWS, you can test the MCP server locally:

1. Set up Environment Variables

Create a .env file in the project root (this file is already in .gitignore):

# Sigma API Configuration
SIGMA_CLIENT_ID=your_actual_sigma_client_id
SIGMA_CLIENT_SECRET=your_actual_sigma_client_secret
SIGMA_BASE_URL=https://api.sigmacomputing.com

# Cache Configuration
# Set to 'true' to skip caching entirely (for local testing)
# Set to 'false' or omit to use DynamoDB cache (for production)
SKIP_CACHE=true

# AWS Configuration (for local testing, these can be empty or use localstack)
AWS_REGION=us-east-1
CACHE_TABLE_NAME=sigma-documents-cache

# Environment
NODE_ENV=development

2. Install Dependencies

npm install

3. Test the Heartbeat

Run the local test script to verify connectivity:

npm run test:local

This will:

• Check your environment variables

• Build the TypeScript code

• Start the MCP server

• Send a heartbeat request

• Display the response with server status

4. Manual Testing

You can also run the server manually and interact with it:

# Build the project
npm run build

# Start the server
npm start

The server will run on stdio and wait for MCP requests.

Note: When using SKIP_CACHE=true, the server will fetch data directly from the Sigma API for each request, which is useful for testing but may be slower than using cached data.

Testing

Test the deployment:

Debugging

The MCP server includes comprehensive debugging capabilities to help troubleshoot issues with REST API calls to Sigma.

Enabling Debug Mode

To enable debug mode, set the DEBUG_MODE environment variable:

export DEBUG_MODE=true

Or add it to your .env file:

DEBUG_MODE=true

Debug Output

When debug mode is enabled, you'll see detailed logging for:

• MCP Server Operations: Tool calls, resource requests, error handling

• Sigma API Calls: HTTP requests, responses, authentication

• Document Analytics: Cache operations, data fetching, parsing

• Token Management: Token refresh, expiry, authentication status

Testing with Debug Mode

Use the test script to run the analyze_documents tool with debugging:

# Build the project first
npm run build

# Run the test with debugging
node test-analyze-documents.js

Debug Log Format

Debug messages follow this format:

• 🔍 [DEBUG] - Information and progress

• ✅ [DEBUG] - Success messages

• ❌ [DEBUG] - Error messages

• ⚠️ [DEBUG] - Warnings

Common Debug Scenarios

1. Authentication Issues: Check token refresh logs

2. API Call Failures: Look for HTTP status codes and error responses

3. Data Parsing Issues: Check JSONL parsing logs

4. Cache Problems: Verify cache hit/miss patterns

Troubleshooting Steps

1. Check Environment Variables: Ensure all required variables are set

2. Verify Sigma API Credentials: Test with the heartbeat tool first

3. Review Network Connectivity: Check if Sigma API endpoints are reachable

4. Examine Cache Status: Verify document cache is working properly

Security Considerations

1. API Gateway has no authentication in this prototype - consider adding API keys or IAM auth for production

2. Secrets Manager stores credentials securely with automatic rotation capability

3. IAM roles follow least-privilege principle

4. VPC - Consider deploying Lambda in VPC for additional network security

Scaling and Performance

• Lambda: Auto-scales, cold starts ~1-2 seconds

• DynamoDB: On-demand billing scales automatically

• API Gateway: Handles up to 10,000 requests per second by default

• Cache Strategy: In-memory cache in Lambda for fast lookups, DynamoDB for persistence

Troubleshooting

Common issues:

1. "Secret not found" - Update Secrets Manager with real credentials

2. "Table not found" - Ensure DynamoDB table exists and Lambda has permissions

3. Cold starts - First request after idle time takes longer

4. CORS errors - API Gateway includes CORS headers

Check CloudWatch Logs for detailed error information.