# glambda

Write AWS Lambda functions in Gleam!

[![Package Version](https://img.shields.io/hexpm/v/glambda)](https://hex.pm/packages/glambda)
[![Hex Docs](https://img.shields.io/badge/hex-docs-ffaff3)](https://hexdocs.pm/glambda/)

Write your Lambda function as an [http](https://github.com/gleam-lang/http) handler, or accept direct events as normal Gleam types.

Glambda only supports the JavaScript target. Your compiled code uses the AWS Lambda Node.js runtime.

```sh
gleam add glambda
```

## HTTP Handler

```gleam
import glambda.{type Context}
import gleam/http/request.{type Request}
import gleam/http/response.{type Response, Response}
import gleam/javascript/promise.{type Promise}
import gleam/option.{type Option, Some}

fn handle_request(
  _req: Request(Option(String)),
  ctx: Context,
) -> Promise(Response(Option(String))) {
  let json = "{\"functionName\": \"" <> ctx.function_name <> "\"}"
  Response(
    200,
    [#("content-type", "application/json; charset=utf-8")],
    Some(json),
  )
  |> promise.resolve
}

// This is the actual function lambda invokes
pub fn handler(event, ctx) {
  glambda.http_handler(handle_request)(event, ctx)
}
```

## Event Handler

```gleam
import glambda.{
  type ApiGatewayProxyEventV2, type ApiGatewayProxyResultV2, type Context,
  ApiGatewayProxyResultV2,
}
import gleam/dict
import gleam/javascript/promise.{type Promise}
import gleam/option.{Some}

fn event_handler(
  _event: ApiGatewayProxyEventV2,
  ctx: Context,
) -> Promise(ApiGatewayProxyResultV2) {
  ApiGatewayProxyResultV2(
    status_code: 200,
    headers: dict.from_list([#("content-type", "application/json")]),
    body: Some("{\"functionName\": \"" <> ctx.function_name <> "\"}"),
    is_base64_encoded: False,
    cookies: [],
  )
  |> promise.resolve
}

// This is the actual function lambda invokes
pub fn handler(event, ctx) {
  glambda.api_gateway_proxy_v2_handler(event_handler)(event, ctx)
}
```

Check out the [examples](https://github.com/ryanmiville/glambda/tree/main/examples) directory for examples of each supported event type, deployable with [SST](https://github.com/sst/sst).

## Supported Events
* `ApiGatewayProxyEventV2` (can be handled directly or as a `Request(Option(String))`)
* `EventBridgeEvent`
* `SqsEvent`

Further documentation can be found at <https://hexdocs.pm/glambda>.

## Development

```sh
gleam run   # Run the project
gleam test  # Run the tests
```