laf/docs/en/guide/function/function-param.md

title
Cloud Function Parameters and Return Values

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Parameters

In the main function, you can access the request information passed by the user through the first parameter ctx. The following example reads the Query parameter username passed by the front-end:

export default async function (ctx: FunctionContext) {
  return `hello, ${ctx.query.username}`;
};

Similarly, you can read the body parameter passed by the front-end:

export default async function (ctx: FunctionContext) {
  return `hello, ${ctx.body}`;
};

The ctx object contains the following properties:

Property	Description
ctx.requestId	The unique ID of the current request
ctx.method	The method of the current request, such as GET or POST
ctx.headers	All headers of the request
ctx.auth	The token value parsed when using Http Bearer Token authentication
ctx.query	The query parameters of the current request
ctx.body	The body parameters of the current request
ctx.response	The HTTP response, consistent with the Response instance in express
ctx.socket	WebSocket instance (WebSocket)
ctx.files	Uploaded files (an array of File objects)

Return Value

So how do we pass data to the frontend? It's simple, just return it in the cloud function.

export default async function (ctx: FunctionContext) {
  // Here is an example using a string, but you can return any data type.
  return "This is the data returned to the frontend";
};