LayerVersion

Source: src/AWS/Lambda/LayerVersion.ts

A version of a Lambda layer — a zip archive of libraries, a custom runtime, or other dependencies that Lambda extracts into /opt alongside your function code.

Layer versions are immutable, so changing the content or any publish setting publishes a new version under the same layer and retires the one it supersedes. layerVersionArn and version therefore change on update; layerName and layerArn stay put.

Publishing a Layer

Package a Local Directory

// ./layers/deps contains nodejs/node_modules/...
const deps = yield* LayerVersion("Deps", {
  path: "./layers/deps",
  compatibleRuntimes: ["nodejs22.x"],
});

Publish an Existing Archive

const layer = yield* LayerVersion("Ffmpeg", {
  path: "./dist/ffmpeg-layer.zip",
  description: "static ffmpeg build",
  compatibleArchitectures: ["arm64"],
});

Publish From S3

const layer = yield* LayerVersion("BigLayer", {
  s3: {
    bucket,
    key: "layers/big-layer.zip",
  },
});

Attaching to a Function

const fn = yield* Function("Handler", {
  main: import.meta.resolve("./handler.ts"),
  layers: [deps],
});