Social Sign-In
Let users sign in with an identity they already have.
What it adds
OAuth used as authentication: first-time account creation from a provider identity, safe matching to existing accounts, and handling providers that return incomplete or unverified data.
What your agent is told to do
5
What your agent is told to do
5-
1
Key the account on the provider's stable subject identifier, not on the email address. Emails change hands; subject IDs do not.
-
2
Only auto-link to an existing account when the provider asserts the email is verified. An unverified email from a provider is an account-takeover route — send those users through an ownership check instead.
-
3
Request the minimum scopes needed to identify someone. Sign-in does not need calendar or contact access.
-
4
Handle missing profile fields as normal: many providers return no name, no avatar, and some return no email at all. Do not block account creation on data you cannot guarantee.
-
5
Adding or removing a sign-in method on an already-authenticated account is owned by Account Linking, and OAuth for data access is owned by OAuth Integration Connections. Extend those rather than duplicating them here.
Edge cases it handles
6
Edge cases it handles
6- A user who revoked access at the provider must get a clear reconnect prompt, not a generic failure, and must still be able to sign in another way.
- Two providers returning the same email must not silently become two accounts — or one account, without an explicit decision.
- The provider changing a user's email must not orphan the account or create a duplicate.
- A cancelled or denied consent screen returns an error, not a crash; land the user back on sign-in with an explanation.
- State must be validated on the callback, and the returned state must match a value tied to the originating session.
- The first sign-in for a brand-new user must still complete any required onboarding, not drop them into a half-configured account.
Definition of done
8
Definition of done
8- Accounts are keyed on the provider subject identifier.
- Auto-linking happens only for provider-verified email addresses.
- Only identity scopes are requested.
- Missing name, avatar, or email does not block account creation.
- Denied consent and revoked access produce clear, recoverable states.
- The callback rejects mismatched or missing state.
- The feature matches the existing design system.
- No existing functionality is broken.
Related features
User Roles
User Roles
Not everyone should be able to do everything.
What it does
Role-based permissions, enforced on the server, with a UI that reflects them.
How it works
-
1
Define roles and their permissions in ONE place. Scattering
if user.admin?through the codebase is how authorization bugs happen. - 2 Enforce every permission server-side, at the controller or service layer.
- 3 Hide UI the user can't use — but never rely on hiding as the enforcement.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/user-roles
Member Directory
Member Directory
Show who is in the workspace and how to identify them.
What it does
A searchable, read-only roster of workspace members with their role, status, and the profile fields they have chosen to share.
How it works
- 1 Build this as a read view. Inviting members is owned by Team Invitations, changing roles is owned by User Roles, and seat counts are owned by Seat Management — link out to those rather than duplicating their controls here.
- 2 Show each member's display name, avatar, role, and status. Status is not decoration: pending, active, suspended, deactivated, and external guest must be visually distinct and filterable.
- 3 Respect per-field profile visibility. A field the member marked private is not rendered, not returned by the API, and not searchable — hiding it in the template while shipping it in the payload is not privacy.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/member-directory
Account Linking
Account Linking
Let one account sign in several ways without spawning duplicates.
What it does
Attach and detach sign-in methods — password, OAuth providers, SSO — on a single existing account.
How it works
- 1 Model sign-in methods as separate identity records attached to one account, rather than columns on the user.
- 2 Require a fresh re-authentication before any link or unlink. A stale session is enough to read the app; it is not enough to change how the account is entered.
- 3 Refuse to link an identity that is already attached to another account. Explain the conflict and point the user at recovery — do not silently steal the identity or silently create a second account.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/account-linking
How it works
-
1
Copy the link
Grab the Markdown instruction URL for this feature.
-
2
Give it to your AI
Paste it into Claude Code, Cursor, v0, Lovable — whatever you build with.
-
3
It inspects, then implements
Your agent reads your existing app first, then adds the feature to fit it.
Works with your stack
These instructions are written to adapt. They tell the agent to detect your framework, match your existing design system, and reuse what you already have — rather than assuming a particular stack.
Need it tighter than that? Customize the feature and tell it exactly what you're running.