Expected response body OAuth flow

Developer Support APIs & Integrations
1

I’m implementing an OAuth flow for my public app. Currently, after clicking on the install url, the connecting page would send a request to my API endpoint to handle the incoming payload (including the code), and after handling the body, my endpoint would return a 200 code:

res.status(200);

However, I found that sometimes HubSpot would send the requests twice to my endpoint, causing unexpected behaviour. My guess is that the response I sent is not expected structure, but I couldn’t find what’s an expected response body looks like in any documentation. Could anyone provide my with information or documentation on this issue please?

2

Please go through this documentation to install the app:
HubSpot OAuth Quickstart Guide

After installation, you will receive a code in the redirect URL.
You can exchange this code for access and refresh tokens by following this step:
Exchange Authorization Code for Tokens