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Add SSO to Your Rust App in 10 Lines

Flux TeamMarch 20, 20263 min read

Enterprise customers want SSO. It’s not a feature request — it’s a procurement requirement. Without it, deals stall.

The problem is that implementing SSO is genuinely painful. SAML, the standard most enterprises use, involves XML parsing, certificate management, metadata exchange, and a redirect-based flow that’s tricky to test. OIDC is cleaner, but enterprises often have SAML-only identity providers they can’t change. Supporting both doubles the work.

With Flux, you can add SSO to your Rust app in about 10 lines of code. Here’s how.

Without Flux: The Pain

A minimal SAML implementation requires:

  • Parsing IdP metadata XML (a format that varies by provider)
  • Generating AuthnRequests with the correct signing
  • Handling the POST-binding callback and parsing SAMLResponses
  • Validating signatures against the IdP’s certificate
  • Managing certificate rotation when the IdP updates their cert
  • Building an admin UI so your customers can enter their metadata URL

That’s weeks of work before you’ve added a single enterprise customer. And when their IdP rotates their certificate — which they will, without warning you — you’ll get a 2am support ticket.

With Flux: 10 Lines

Add the dependency:

[dependencies]
flux_sdk = "0.1"

Then, in your app:

use flux_sdk::Flux;

let flux = Flux::init("your-api-key");

// Redirect to the SSO login flow for an organization
let sso = flux.auth().sso();
let redirect_url = sso.initiate(&org_id, &return_url)?;
return Response::redirect(redirect_url);

// In your callback handler — verify the returned session
let user = flux.auth().verify_session(&token)?;
println!("Logged in: {} (org: {})", user.email, user.org_id);

That’s the whole integration. Flux generates the redirect URL, handles the SAML round-trip with the customer’s identity provider, and returns a verified session token that you consume the same way you consume every other Flux session.

What’s Happening Under the Hood

When you call sso.initiate(), Flux:

  1. Looks up the SSO configuration for that organization (set up by your customer via a self-serve admin portal)
  2. Generates a signed SAML AuthnRequest or OIDC authorization URL, depending on the IdP
  3. Returns a redirect URL that takes the user to their identity provider

When the IdP redirects back to your callback URL, Flux:

  1. Receives and validates the SAML response or OIDC token
  2. Verifies the signature against the IdP’s current certificate
  3. Maps the IdP attributes to a Flux user (creating one if needed)
  4. Returns a session token your app uses like any other

Certificate rotation, metadata updates, and provider-specific quirks are handled by Flux. Your code never changes.

The Self-Serve Admin Portal

One of the less obvious benefits: Flux includes a hosted SSO configuration portal that your customers can use to enter their IdP metadata without any help from you. They paste a metadata URL or upload XML, Flux validates it, and the connection is live.

This means your support team doesn’t become an amateur SAML debugging service. Your customers configure their own SSO, and it works.

Your Enterprise Customers Will Thank You

Enterprise security teams have a checklist. SSO is near the top of it. When you can tell them “yes, we support SAML SSO with your identity provider, and your IT team can configure it themselves,” you remove a blocker from the deal.

The 10 lines of integration code are the easy part. Flux handles the rest.