# Third-party auth (Firebase, Auth0, Clerk, Cognito)
Source: https://sovaria.in/docs/third-party-auth

Keep your existing sign-in and use Sovaria for data: exchange a Firebase Auth, Auth0, Clerk, Cognito, WorkOS or any OIDC token for a Sovaria session.

Moving the backend doesn't have to mean moving sign-in. Trust your current auth system's issuer, and the app swaps that system's token for a Sovaria session of the same person. Row-level security, Guard policies, storage and realtime then work as with any Sovaria user.

1. **Connect the issuer** — Authentication › **Third-party auth**: Firebase (its project ID), Auth0 / Clerk / WorkOS (the tenant domain), Cognito (region + user pool) or any OIDC issuer (issuer + JWKS URL). Sovaria reads the signing keys right away to check the address.
```bash
sov auth-third-party add firebase --firebase-project-id my-app
sov auth-third-party add auth0 --domain acme.us.auth0.com --audience https://api.acme.com
```
2. **Exchange the token in the app**
```js
const idToken = await firebase.auth().currentUser.getIdToken()
await sovaria.auth.signInWithThirdPartyToken(idToken)   // a normal Sovaria session from here on
```
```swift
try await sovaria.auth.signInWithThirdPartyToken(idToken)
```
```kotlin
sovaria.auth.signInWithThirdPartyToken(idToken)
```

- Sovaria checks the signature against the issuer's keys (cached, rotation-aware), `iss`, `aud` (when you list audiences), `exp` and `nbf`.
- The person becomes an app user linked to `tp:<issuer>:<sub>` on first use, even with public sign-ups off (the issuer decides who exists). A verified email links to an existing user with that address.
- The token's role claim (`role` by default) is kept as the custom claim `third_party_role`, so policies can use it: `auth.jwt() -> 'ctx' ->> 'third_party_role'`.
- Exchanges use the sign-in rate limit; MFA, MAU limits and your before-sign-in hook apply.

## Plans

|  | Free | Pro | Ultra | Team | Enterprise |
|---|---|---|---|---|---|
| Third-party auth issuers (Firebase, Auth0, Clerk, Cognito, OIDC) | 1 | 3 | 5 | 10 | 50 |