Lambda
v2/deploy/lambda/template.yaml is the AWS layout. It is one API Lambda, a private Aurora Postgres, an S3 bucket, and a Fargate service for site processes.
The template’s description is the contract: Reactor on one Lambda, private Aurora Serverless v2, S3, and a Fargate site service.
The API Lambda
Section titled “The API Lambda”The function is the Reactor image, PackageType: Image, arm64, behind an HTTP API that forwards ANY / and ANY /{proxy+}.
It runs with REACTOR_RUNTIME__MODE=lambda. The database URL uses the Aurora endpoint and sslmode=require. The JWT private key and the operator token come from Secrets Manager. Storage is the stack’s bucket in the same region. PostgREST is expected on 127.0.0.1:3000 inside that environment. The console files are at /app/console.
PublicUrl, BaseDomain, and CertificateArn are parameters. The committed defaults are placeholders. Set them before you treat the stack as a real host.
User functions
Section titled “User functions”The binary can publish a user function as its own Lambda when functions.runtime is lambda and functions.publisher is aws. Invoke then calls that function. The API process does not run the user’s code.
The template ships with functions.runtime=bun and functions.publisher=fake. In that mode, invoke still runs Bun inside the API Lambda, the same way Compose does. A Bun layer and an IAM role for user functions are in the template so a real publisher has something to attach. Switching the publisher is a configuration change, not a new client API.
Presigned S3 URLs are the upload path either way.
Static files are objects in the bucket. A deployment with a command is not run inside the API Lambda. The template runs a Fargate service behind a load balancer for that work. The API Lambda still authorizes and records the deployment.
What stays the same
Section titled “What stays the same”Project resolution, tokens, schemas, grants, the PostgREST pre-request, and the blob key layout. A client that works against Compose works against this stack without a new SDK.
REACTOR_HANDLER can still limit a process to auth, storage, sites, fn, or platform. The template does not split the API that way. It sends every path to one function.