Hello, I have a problem with CORS and I think this is right community to get help.

When I use this code:

import { LemmyHttp } from 'lemmy-js-client';
const client = new LemmyHttp('https://lemmy.ml');
const { posts } = await client.getPosts({
    limit: 10,
    page: 1
});

to get posts from lemmy.ml (using lemmy-js-client), I get:

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://lemmy.ml/api/v3/post/list?limit=10&page=1. (Reason: CORS header ‘Access-Control-Allow-Origin’ missing). Status code: 400.

I have tried to add header like this:

const client = new LemmyHttp('https://lemmy.ml', {
    headers: {
        'Access-Control-Allow-Origin': '*'
    }
});

but result is the same.

Can someone help me with this?

  • data0@programming.devEnglish
    3·
    1 year ago

    The Access-Control-Allow-Origin is meant to be set on the server side and is part of a mechanism called CORS. MDN has a good guide on CORS (It might seem too long and complex to read if you just want to access some data on an API, but knowing how it works is essential if you plan to work with HTTP-based APIs.)

    In short, lemmy.ml (and probably most other Lemmy instances) doesn’t seem to allow API access from within a browser. You’ll have to build a Node.js proxy (with lemmy-js-client) and use that to connect the browser to.