## Summary
Fixes the consent-modal-not-reopening half of
[#20535](https://github.com/twentyhq/twenty/issues/20535): when a
signed-out user opens an OAuth `/authorize?...` URL (e.g. ChatGPT
connecting to `api.twenty.com/mcp`) and signs in with **Google or
Microsoft**, the original `/authorize` request was lost and the consent
screen never reopened.
### Root cause
`PageChangeEffect` already saves the deep link as `returnToPath` (Jotai
atom) before navigating to `/welcome`. That atom is in-memory: it
survives SPA navigation, and the cross-subdomain workspace hop is
handled by `useBuildSearchParamsFromUrlSyncedStates` round-tripping the
value through the URL.
But the social-SSO path leaves `app.twenty.com` entirely —
`app.twenty.com/welcome` → `api.twenty.com/auth/google` → Google →
`api.twenty.com/auth/google/redirect` → frontend — so the atom is wiped.
None of the existing code paths plumbed `returnToPath` through that hop:
- `useAuth.buildRedirectUrl` packed `workspaceInviteHash`/`action`/etc.
but not `returnToPath`.
- `SocialSSOState` / the Google + Microsoft strategies didn't carry it
through the OAuth `state` blob.
- `signInUpWithSocialSSO` + `computeRedirectURI` didn't re-emit it on
the redirect back to the frontend.
The email path worked because all transitions stay on the default
frontend domain, so the atom survives until `SignInUpGlobalScopeForm`
bakes it into the workspace URL.
### What changed
Plumb `returnToPath` through the SSO state the same way
`workspaceInviteHash` and `action` already flow:
- **Frontend** (`useAuth.buildRedirectUrl`): read `returnToPath` from
the Jotai store and append it to `/auth/google` / `/auth/microsoft` when
set and structurally valid.
- **Server types** (`SocialSSOState`, `GoogleRequest['user']`,
`MicrosoftRequest['user']`): add optional `returnToPath`.
- **Strategies** (`google.auth.strategy.ts`,
`microsoft.auth.strategy.ts`): include `returnToPath:
req.query.returnToPath` in the JSON `state` and read it back in
`validate`.
- **auth.service.ts** (`signInUpWithSocialSSO`, `computeRedirectURI`):
forward `returnToPath` on both branches — the multi-workspace redirect
to `AppPath.SignInUp?tokenPair=...` and the single-workspace redirect to
`<workspace>/verify?loginToken=...`. Validated via a new
`isValidReturnToPath` helper so a tampered query value can't become an
open-redirect vector.
After the round-trip, `useInitializeQueryParamState` rehydrates the atom
from the URL and `usePageChangeEffectNavigateLocation` resolves it as
the post-auth destination — same mechanism the email path already relied
on.
Out of scope: the OAuth `resource` parameter handling tracked in
[#20296](https://github.com/twentyhq/twenty/issues/20296) is independent
and not addressed here.
## Test plan
- [x] `npx jest src/engine/core-modules/auth` (twenty-server) — 27
suites / 183 tests pass, including new
`is-valid-return-to-path.util.spec.ts`.
- [x] `npx jest src/modules/auth` (twenty-front) — 13 suites / 52 tests
pass, including two new cases in `useAuth.test.tsx` covering the happy
path and the protocol-relative open-redirect guard.
- [x] `npx nx typecheck twenty-server` / `twenty-front` — clean.
- [x] `npx oxlint` + `prettier --check` on touched files — clean.
- [ ] Manual: signed-out user opens
`https://app.twenty.com/authorize?client_id=...` → Continue with Google
→ completes Google → selects workspace → consent screen renders.
- [ ] Manual: same flow, single workspace — lands on consent screen
directly after Verify.
- [ ] Manual: email path still works (regression).
- [ ] Manual: tamper `returnToPath=//evil.com` on the `/auth/google` URL
→ server validation rejects, user lands at default home, not at
`evil.com`.
E2E note: existing `return-to-path.spec.ts` already covers deep links
with query params through the email path. A mock OAuth provider would be
needed to cover the SSO path end-to-end; unit coverage stands in for
now.
Félix Malfait
49b9660420