@alchemy.run/aws

AWS for Alchemy. Declare Lambda functions, S3, SQS, DynamoDB, ECS, EKS and 200 more services in the same TypeScript program as the code that uses them. Bindings write the least-privilege IAM policy for you.

npm install alchemy @alchemy.run/aws effect

A Lambda function binds two S3 operations on a bucket:

// src/api.ts
import * as AWS from "@alchemy.run/aws";
import * as Effect from "effect/Effect";
import { HttpServerRequest } from "effect/http/HttpServerRequest";
import * as HttpServerResponse from "effect/http/HttpServerResponse";
import * as Layer from "effect/Layer";

export default class Api extends AWS.Lambda.Function<Api>()(
  "Api",
  { main: import.meta.url, functionUrl: true },
  Effect.gen(function* () {
    const bucket = yield* AWS.S3.Bucket("Bucket");
    // Each binding adds exactly one IAM permission to the function's role.
    const putObject = yield* AWS.S3.PutObject(bucket);
    const getObject = yield* AWS.S3.GetObject(bucket);

    return {
      fetch: Effect.gen(function* () {
        const request = yield* HttpServerRequest;
        const key = request.url.split("/").pop()!;
        if (request.method === "PUT") {
          yield* putObject({ Key: key, Body: yield* request.text });
          return HttpServerResponse.empty({ status: 201 });
        }
        const object = yield* getObject({ Key: key }).pipe(
          Effect.catchTag("NoSuchKey", () => Effect.succeed(undefined)),
        );
        if (!object?.Body) {
          return HttpServerResponse.text("Not found", { status: 404 });
        }
        return HttpServerResponse.stream(object.Body);
      }).pipe(Effect.orDie),
    };
  }).pipe(Effect.provide(Layer.mergeAll(AWS.S3.PutObjectHttp, AWS.S3.GetObjectHttp))),
) {}

The Stack deploys it:

// alchemy.run.ts
import * as Alchemy from "alchemy";
import * as AWS from "@alchemy.run/aws";
import * as Effect from "effect/Effect";
import Api from "./src/api.ts";

export default Alchemy.Stack(
  "MyApp",
  {
    providers: AWS.providers(),
    state: AWS.state(),
  },
  Effect.gen(function* () {
    const api = yield* Api;
    return { url: api.functionUrl };
  }),
);

alchemy deploy creates the bucket, the function, its role, and a policy that allows s3:PutObject and s3:GetObject on that bucket only.

Learn more

• AWS on alchemy.run
• Setup
• Tutorial
• API reference