AWS Lambda Web Functions

The AWS MCP server is recommended for sandboxed execution and audit logging.

If aws lambda-web is not recognized, update the AWS CLI (see references/deployment.md). A missing command means an outdated CLI, not an unavailable feature.

Help users build and deploy Node.js HTTP applications on AWS Lambda Web Functions. Your app listens on a port, handles HTTP natively, and gets a global HTTPS URL. Develop locally with node index.js, deploy the same code to AWS.

When to Use Web Functions

• Interactive HTTP traffic someone is waiting on: web app, HTTP API, or SSR site.
• The app is already a port-listening HTTP server (Express, Fastify, Hono) and should stay one — no handler rewrite, no adapter library.
• Handlers are I/O-bound (database, cache, another API, a model endpoint), so many requests share one execution environment and time spent waiting on I/O is not billed as CPU.
• Response streaming matters: SSE, chunked transfer, or proxying LLM tokens as they are produced.
• The endpoint should be reachable worldwide on one hostname without assembling CloudFront, API Gateway and Route53 by hand.
• Traffic is spiky or unpredictable and should scale to zero.

Hard preconditions