Examples / AWS

How do you diagram a serverless REST API on AWS?

Updated

Type the request path as text: API Gateway -> Lambda -> DynamoDB. Chartado draws the three services with AWS icons and animates a request flowing through the chain: API Gateway accepts the call, Lambda runs the logic, DynamoDB stores the result.
Serverless REST API Diagram: API Gateway, Lambda, DynamoDB. The request/response backbone of most serverless applications. Services drawn: API Gateway, Lambda, DynamoDB.
A still of the animation above. Every export embeds the diagram source.

THE TEXT THAT DRAWS IT

API Gateway -> Lambda -> DynamoDB

Edit it in the box above and the diagram redraws as you type. Export it as an animated GIF, WebM or WebP, or a still PNG. Every format embeds this text, so the file can be read back into the editor.

WHAT IT SHOWS

This is the shape almost every serverless application starts as, and the one most architecture diagrams are drawn to explain. A request arrives at API Gateway, which handles TLS, routing and throttling. It invokes a Lambda function, which holds the logic. The function reads and writes DynamoDB, which holds the state.

What the animation shows that a static diagram cannot is the direction and timing of a single request. The message travels left to right, and the reply comes back the same way. Three boxes and two arrows is a small drawing; watching one request traverse it is what makes the latency budget obvious.

Each hop is a place a request can fail, and each is billed separately. The diagram is a good place to talk about that: API Gateway charges per request, Lambda per millisecond of execution, DynamoDB per read and write unit.

QUESTIONS

What happens when Lambda scales under load?
Each concurrent request gets its own Lambda invocation while API Gateway and DynamoDB absorb the fan-in: the diagram stays three boxes because scaling replicates the middle box, not the architecture.
How do I add more routes or tables to the diagram?
Add lines. Each A -> B line is an edge, so API Gateway -> Lambda Orders -> DynamoDB Orders on a new line draws a second route alongside the first.

MORE AWS PATTERNS

Pub/sub fan-out diagram

One event, several independent consumers, none of them waiting on each other.

SNS -> {Lambda Emailer, Lambda Analytics, SQS Archive}

Queue worker diagram

Accept the request quickly, do the slow part somewhere else.

API Gateway -> Lambda -> SQS -> Lambda Worker -> DynamoDB

Event pipeline diagram

One event bus feeding both a processing chain and a raw archive.

EventBridge -> {(SQS -> Lambda -> DynamoDB), S3}

Also on this site: RAG pipeline diagram, Multi-agent router diagram, ReAct tool-calling diagram, Human-in-the-loop diagram, MCP architecture diagram and Cloudflare Workers diagram. See all 10 patterns.

Chartado is a text-to-diagram tool: you type lines like A -> B, it draws the architecture and animates the flow.