Axios/Fetch not using next.config.js rewrite - reactjs

Question

Looking up several examples online, it appears all one would need to do to redirect requests to the backend is to add rewrites to the next.config.js file, and it should work. However, I must be missing or misunderstanding something as this alone doesn't seem to do the trick. Redirecting seems to work if I type the url in the browser, but calls from axios/fetch continue to try to use a path relative to my client. Here are my snippets:
next.config.js
module.exports = {
async rewrites() {
return [
{
source: '/api',
destination: 'http://localhost:3001',
},
]
},
};
components/MyComponent.js
import React, { useEffect } from "react";
import axios from "axios";
function MyComponent({projectName}) {
...
useEffect(() => {
axios.get("/api/project/" + projectName)
.then((res) => {
console.log(res);
});
return;
}, []);
...
};
export default MyComponent;
To clarify, if I hit http://localhost:8001/api/project/Name_of_Project from the browser, I get properly redirected to my server (hosted on port 3001) and receive data I'd expect. However, when I hit my client (http://localhost:8001/Name_of_Project), axios doesn't redirect and tries http://localhost:8001/api/project/Name_of_Project which obviously fails. I also tried the fetch equivalent instead of axios and get the same result.
Is there another step that I need to take? Does the rewrite not work for axios/fetch? I have also seen mentions of the next-http-proxy-middleware package in my search, but I am not sure if this is something that I need to use in conjunction with the rewrite or not.
I appreciate any insight!
EDIT 1:
After doing some more searching, I ran into this post, and discovered that my issue is because I am using relative pathing in my axios call. If I change it to:
axios.get("http://localhost:3001/api/project/" + projectName)
.then((res) => {
console.log(res);
});
then I get my data properly. I suppose this leads me to my next question: is there a way to use relative path alongside the rewrite in the config? I personally think it's a little ugly to have the hostname and port exposed like that (I eventually plan on hosting this app on a FQDN). So if there's anything that can be done about that, I'd love to know!
EDIT 2: Of course the change in my first edit works because I am hitting my server directly! Which is not the desired effect. I want to use the redirect set in the config to go to my api.

Answer 1

Aha! I WAS misunderstanding something. I assumed that the path in the rewrite would reattached my path params for free. This is not the case. A link to the documentation.
The relevant excerpt:
Wildcard Path Matching
To match a wildcard path you can use * after a parameter, for example /blog/:slug* will match /blog/a/b/c/d/hello-world:
module.exports = {
async rewrites() {
return [
{
source: '/blog/:slug*',
destination: '/news/:slug*', // Matched parameters can be used in the destination
},
]
},
}
So my corrected next.config.js:
module.exports = {
async rewrites() {
return [
{
source: '/api/:slug*',
destination: 'http://localhost:3001/api/:slug*',
},
]
},
};