Why is the API giving me a 403 Forbidden?

Lemmy@lemmy.ml – 8 points – 1 years ago

I'm toying about with writing a client in Rust.

Example code online uses the API endpoint https://lemmy.ml/api/v3/post/list, and when I go to this link in a browser, it doe indeed load data. However, when I try to load it from a program, it gives me a 403 Forbidden. Does anyone know why this could be?

(code)

FYI: !lemmydev@lemm.ee

Didnt know about this, thanks

This one got me too.

lemmy.ml specifically is running requests through a user agent checker - and if it's empty, which reqwest is by default, you will get a 403.

You can see an example here of using ClientBuilder to set a user agent string: https://github.com/CMahaff/lasim/blob/main/src/lemmy/api.rs

So set any string (should be your project name) and then it should work.

Oh great thank you

I don't see anything wrong initially. Can you also test with something like postman? It'll allow you to control the headers etc.. that you send.

You can also compare to what I have here and see if that helps: https://github.com/marsara9/lemmy-search/blob/b6c88355aba49abca52862473650526821ee165a/server/src/api/lemmy/fetcher.rs#L123

Ah I'll try that, thanks. This is unrelated, but is it normal for my project folder for this to have 3GB, given that these are my dependencies?:

lemmy_api_common = "0.18.2"
reqwest = "0.11.18"
tokio = "1.29.1"

I'm quite new to rust and I realize that some languages don;t share dependencies between projects

The target folder may be quite large. You can look at the dependencies for my project but my end binary is only a few MB.

Not familiar with Lemmy's API specifically but you might need to be logged in for that...

Do you get a 403 when using a private browser window, logged out of lemmy?

Oh, didn't think of this. True I did make the request from the browser that I use to browse Lemmy. Edit: Nope, wtill loads in Incognito... 🤔

Can you run the code against another instance, and curl https://lemmy.ml/api/v3/post/list?

Strange, you're right, it does seem to work when I run it on lemmy.world instead

I know very little about Lemmy specifically, but 403 generally means you’re not auth’d or don’t have permission.

Do you need to set an auth header perhaps? Your best bet would be to bring up browser dev tools and see what request the working browser is doing.