Setting up OAuth 2.0 Server for Zapier Authentication
Hey everyone! I’m working on a project where I need to make my ASP.NET application act as an OAuth 2.0 provider. The goal is to allow Zapier to authenticate users from my system.
I’ve been searching for examples on how to configure an ASP.NET Web API 2 application to work as an OAuth server using OWIN middleware. This isn’t about logging into external services like Facebook or Google. Instead, I want my app to be the OAuth provider that Zapier can connect to.
Has anyone successfully implemented this setup before? I’m particularly interested in:
- Configuring OWIN OAuth authorization server
- Setting up the necessary endpoints for Zapier
- Managing client credentials and user authorization flow
Any code examples or guidance would be really helpful. Thanks in advance!
Been there with OWIN OAuth - total pain at first. Here’s what saved me hours of debugging: implement proper scope validation in your provider. Zapier sends specific scopes, so your ValidateClientAuthentication method has to handle those right. I also hit issues with token expiration timing - give your access tokens reasonable expiry times since Zapier polls your API constantly. Don’t skip the refresh token implementation either. They cache tokens between runs. Your auth server needs proper CORS handling if you’re serving auth pages from the same domain. I had to customize the AuthorizationCodeProvider to store codes in a database instead of the default in-memory storage - way more reliable for production. Test everything with Zapier’s webhook testing tools before you go live.
totally! i struggled with that too. make sure ur /token endpoint returns valid json and supports authorization_code. also, don’t forget to set zapier’s callback urls in ur client config, or else it’ll mess up the redirects.
I did this exact setup last year for a SaaS app. You’ll need OAuthAuthorizationServerMiddleware in your Startup.cs and a custom OAuthAuthorizationServerProvider that handles ValidateClientAuthentication and GrantAuthorizationCode methods. For Zapier, make sure your authorization endpoint supports the state parameter properly - they rely on it for security. Your token endpoint needs to return access_token, token_type, and expires_in fields. One gotcha: Zapier expects the refresh token flow to work seamlessly, so be careful with the GrantRefreshToken method. Also set up your TokenEndpointPath and AuthorizeEndpointPath correctly in OAuthAuthorizationServerOptions. The docs are pretty sparse, but Microsoft.Owin.Security.OAuth handles most of the heavy lifting once you get it configured right.