Create a X/Twitter application

Create a new project and a sub application, with access to API v2 and OAuth. Read here (opens in a new tab) for more details.

If you go for the Free plan, remember that you (and all other enabled users in Reposter.app) can only publish 50 requests / 24 hours.

Once created the application, go to the "Settings" -> "User authentication settings" and edit the "User authentication set up":

App permissions
- Read and write
Type of App
- Web App, Automated App or Bot
App info:
- Callback URI / Redirect URL:
  - http://localhost:3000/api/auth/callback/twitter (opens in a new tab) (for local development)
  - https://vercel-app-url/api/auth/callback/twitter (once deployed)
- Website URL
  - add you main site url
- Terms of service
  - add you main site tos
- Privacy policy
  - add you main site privacy policy

Once created the application, go to the "Keys and tokens" -> "OAuth 2.0 Client ID and Client Secret" section and get:

Client ID and fill the X_OAUTH2_CLIENT_ID variable in the .env file
Client Secret and fill the X_OAUTH2_CLIENT_SECRET variable in the .env file

At this point you have setup all necessary configuration to publish textual only posts.

To enable image upload, you need to get also some additional keys.

From the Developer Portal (opens in a new tab), open your application and go to the "Keys and tokens" section.

From "Consumer Keys" section and get:

From "Authentication Tokens" -> "Access Token and Secret" section and get: