Routing

Lack uses your file and folder names for grouping your paths. To create actual paths you export functions from your JavaScript (or TypeScript) file.

File system

To define a group you can just create a file.

app/hello.js - /hello/

To create a path, export a function. The name will be used as the path.

export async function world() {
  // ...
}

Routes: GET /hello/world

A folder will also create a group.

export async function world() {
  // ...
}

Routes: GET /folder/hello/world

Special paths

To create a path on the index route export a function named $index

export async function $index() {
  // ...
}

Routes: GET /hello

Sometimes you dont want to split everything into a file. You can define deeper paths by using two underscores __

export async function a__b() {
  // ...
}
export async function a_b() {
  // ...
}

Routes:

GET /hello/a/b (1st function)

GET /hello/a_b (2nd function)

This can create path collisions, but Lack will notify you of them if they happen.

Path params

Path params are defined by using $<name>, so for a path like /post/:id, you would define it by exporting post$id.

export async function post$id() {
  // ...
}

Routes: GET /hello/post/:id

Path params are passed as a normal lambda handler, meaning the 1st argument is an "event" with an pathParameters object.

AWS Docs for the handler (opens in a new tab)

Methods

Methods are defined by prefixing the function name by one of four names.

If a function doesn't have a prefix, it will be set to the GET method.

Example post endpoint

export async function pos$create() {
  // ...
}

Routes: POST /hello/create

Defining the same path with a different method is supported, even in between files.