The HTTP API

Hub › AWS › Intermediate › The HTTP API

Goal

After this page you will have an API Gateway HTTP API wired to your Lambda function and a placeholder invoke URL you can curl to verify the connection.

Prerequisites

• The Lambda function — your items-api Lambda is deployed.

What API Gateway is

API Gateway is the AWS service that accepts HTTP requests and routes them to a backend — in this case, your Lambda function. The HTTP API type (as opposed to REST API) is the simpler, lower-cost option. It covers most use cases and is what this tier uses.

Every HTTP API gets a unique invoke URL. Requests to that URL trigger your Lambda and return whatever the Lambda returns.

Create the HTTP API and wire the Lambda

# All identifiers below are PLACEHOLDERS — replace with your own; never commit real values.
aws apigatewayv2 create-api \
  --name items-api \
  --protocol-type HTTP \
  --target arn:aws:lambda:us-east-1:123456789012:function:items-api

# Grant API Gateway permission to invoke the function.
aws lambda add-permission \
  --function-name items-api \
  --statement-id apigw-invoke \
  --action lambda:InvokeFunction \
  --principal apigateway.amazonaws.com

--target is a shortcut that creates a default route ($default) and integrates it with the Lambda ARN in one step. The ARN arn:aws:lambda:us-east-1:123456789012:function:items-api is a placeholder — use your real region, account ID, and function name.

The add-permission call is required: without it, API Gateway will receive a 403 when it tries to invoke the Lambda.

The invoke URL

After create-api succeeds, the response includes an ApiEndpoint field. Your invoke URL follows this shape:

https://abcd1234.execute-api.us-east-1.amazonaws.com/items

• abcd1234 — a random ID assigned by API Gateway. Yours will be different.
• us-east-1 — the region you deployed into (placeholder).
• /items — the path. Because --target creates a $default catch-all route, any path works; /items is the convention used in this tier.

Checkpoint

Paste your real invoke URL into a terminal:

curl https://abcd1234.execute-api.us-east-1.amazonaws.com/items

Expected response:

[{"id":1,"name":"Notebook"},{"id":2,"name":"Pen"},{"id":3,"name":"Sticky notes"}]

The page ships only the placeholder URL above. Use your own real invoke URL when running this command — do not share it publicly or commit it to the docs repo.

Next → Fetch from the page