# Functions

Functions are units of execution in the AssemblyLift framework. They are grouped into services, and are themselves structured according to the chosen language (e.g with Rust each function is a Cargo crate).

Each function is compiled to a WebAssembly module, compatible with the AssemblyLift ABI.

## Make a New Function

You can create a new function in an existing service with the `make` command:

```
$ asml make function myservice.myfunction
```

where `myservice` is the name of the service in which you would like to make the function named `myfunction`.

## Defining an API

AssemblyLift functions can be exposed via an HTTP API. When using the AWS Lambda backend, this API is deployed to [Amazon API Gateway](https://aws.amazon.com/api-gateway/).

{% code title="service.toml" %}

```
[service]
name = "myservice"

[api.functions.myfunction]
name = "myfunction"
http = { verb = "GET", path = "/" }
```

{% endcode %}

You define an API for a function using the `http` field, which accepts `verb` and `path`.

## Defining an Authorizer

AssemblyLift supports defining authorizers and attaching them per-function. Authorizers *require* an HTTP API to be defined for the function.

The Lambda backend currently supports IAM and JWT authorizers.

{% code title="service.toml" %}

```
[service]
name = "myservice"

[api.functions.myfunction]
name = "myfunction"
http = { verb = "GET", path = "/" }
authorizer_id = "cognito"

[api.authorizers.cognito]
auth_type = "JWT"
audience = ["clientid"]
issuer = "https://cognito-idp.us-east-1.amazonaws.com/myuserpoolid"
```

{% endcode %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.assemblylift.akkoro.io/master/learn-assemblylift/functions.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.