fix(auth): allow implicit social signup

apps/web/src/features/auth/components/social-auth.tsx

@@ -11,23 +11,7 @@ import { cn } from "@reactive-resume/utils/style";
 import { authClient } from "@/libs/auth/client";
 import { orpc } from "@/libs/orpc/client";
 
-type SocialAuthProps = {
-	requestSignUp?: boolean;
-};
-
-type SocialSignInOptions = {
-	provider: string;
-	callbackURL: string;
-	requestSignUp?: true;
-};
-
-function getSocialSignInOptions(provider: string, requestSignUp: boolean): SocialSignInOptions {
-	const options: SocialSignInOptions = { provider, callbackURL: "/dashboard" };
-	if (requestSignUp) options.requestSignUp = true;
-	return options;
-}
-
-export function SocialAuth({ requestSignUp = false }: SocialAuthProps) {
+export function SocialAuth() {
 	const { data: providers = {}, isLoading } = useQuery(orpc.auth.providers.list.queryOptions());
 
 	return (
@@ -42,7 +26,7 @@ export function SocialAuth({ requestSignUp = false }: SocialAuthProps) {
 				<hr className="flex-1" />
 			</div>
 
-			{isLoading ? <SocialAuthSkeleton /> : <SocialAuthButtons providers={providers} requestSignUp={requestSignUp} />}
+			{isLoading ? <SocialAuthSkeleton /> : <SocialAuthButtons providers={providers} />}
 		</>
 	);
 }
@@ -60,10 +44,9 @@ function SocialAuthSkeleton() {
 
 type SocialAuthButtonsProps = {
 	providers: RouterOutput["auth"]["providers"]["list"];
-	requestSignUp: boolean;
 };
 
-function SocialAuthButtons({ providers, requestSignUp }: SocialAuthButtonsProps) {
+function SocialAuthButtons({ providers }: SocialAuthButtonsProps) {
 	const router = useRouter();
 
 	const runSignIn = async (fn: () => Promise<{ error: { message?: string } | null }>) => {
@@ -112,7 +95,7 @@ function SocialAuthButtons({ providers, requestSignUp }: SocialAuthButtonsProps)
 			</Button>
 
 			<Button
-				onClick={() => runSignIn(() => authClient.signIn.social(getSocialSignInOptions("google", requestSignUp)))}
+				onClick={() => runSignIn(() => authClient.signIn.social({ provider: "google", callbackURL: "/dashboard" }))}
 				className={cn(
 					"hidden flex-1 bg-[#4285F4] text-white hover:bg-[#4285F4]/80",
 					"google" in providers && "inline-flex",
@@ -123,7 +106,7 @@ function SocialAuthButtons({ providers, requestSignUp }: SocialAuthButtonsProps)
 			</Button>
 
 			<Button
-				onClick={() => runSignIn(() => authClient.signIn.social(getSocialSignInOptions("github", requestSignUp)))}
+				onClick={() => runSignIn(() => authClient.signIn.social({ provider: "github", callbackURL: "/dashboard" }))}
 				className={cn(
 					"hidden flex-1 bg-[#2b3137] text-white hover:bg-[#2b3137]/80",
 					"github" in providers && "inline-flex",
@@ -134,7 +117,7 @@ function SocialAuthButtons({ providers, requestSignUp }: SocialAuthButtonsProps)
 			</Button>
 
 			<Button
-				onClick={() => runSignIn(() => authClient.signIn.social(getSocialSignInOptions("linkedin", requestSignUp)))}
+				onClick={() => runSignIn(() => authClient.signIn.social({ provider: "linkedin", callbackURL: "/dashboard" }))}
 				className={cn(
 					"hidden flex-1 bg-[#0A66C2] text-white hover:bg-[#0A66C2]/80",
 					"linkedin" in providers && "inline-flex",

apps/web/src/features/auth/pages/register.tsx

@@ -242,7 +242,7 @@ export function RegisterPage({ disableEmailAuth }: Props) {
 				</form>
 			)}
 
-			<SocialAuth requestSignUp />
+			<SocialAuth />
 		</>
 	);
 }

docs/superpowers/plans/2026-08-13-implicit-social-signup.md

@@ -0,0 +1,152 @@
+# Implicit Social Signup Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Make every built-in social sign-in create an unknown user automatically while preserving the global signup restriction.
+
+**Architecture:** Use Better Auth's native implicit-signup behavior by removing the provider-level opt-out. Delete the client-side `requestSignUp` distinction so every page uses the same social sign-in call, while `disableSignUp: env.FLAG_DISABLE_SIGNUPS` remains the server-enforced hard stop.
+
+**Tech Stack:** TypeScript, Better Auth 1.6.26, React 19, Vitest, pnpm
+
+## Global Constraints
+
+- Do not add dependencies or new abstractions.
+- Apply the behavior to Google, GitHub, and LinkedIn.
+- Leave custom OAuth and passkey behavior unchanged.
+- Keep `FLAG_DISABLE_SIGNUPS` authoritative on the server.
+
+---
+
+## File Structure
+
+- `packages/auth/src/config.test.ts`: Characterizes Reactive Resume's built-in social-provider signup policy.
+- `packages/auth/src/config.ts`: Owns Better Auth provider configuration and the global signup restriction.
+- `apps/web/src/features/auth/components/social-auth.tsx`: Starts social sign-in without page-specific signup intent.
+- `apps/web/src/features/auth/pages/register.tsx`: Uses the shared social-auth component without signup-only props.
+
+### Task 1: Use Better Auth's Native Implicit Social Signup
+
+**Files:**
+- Create: `packages/auth/src/config.test.ts`
+- Modify: `packages/auth/src/config.ts:196-223`
+- Modify: `apps/web/src/features/auth/components/social-auth.tsx:14-66,115-137`
+- Modify: `apps/web/src/features/auth/pages/register.tsx:245`
+
+**Interfaces:**
+- Consumes: `auth.options.socialProviders`, `env.FLAG_DISABLE_SIGNUPS`, and `authClient.signIn.social({ provider, callbackURL })`.
+- Produces: One social-auth flow in which existing identities sign in, unknown identities sign up implicitly, and globally disabled signups remain rejected by Better Auth.
+
+- [ ] **Step 1: Write the failing configuration test**
+
+Create `packages/auth/src/config.test.ts`:
+
+```ts
+import { describe, expect, it } from "vitest";
+import { env } from "@reactive-resume/env/server";
+import { auth } from "./config";
+
+describe("social provider signup policy", () => {
+	it.each(["google", "github", "linkedin"] as const)(
+		"allows implicit signup through %s while honoring the global signup restriction",
+		(provider) => {
+			const config = auth.options.socialProviders?.[provider];
+
+			expect(config?.disableImplicitSignUp).toBeUndefined();
+			expect(config?.disableSignUp).toBe(env.FLAG_DISABLE_SIGNUPS);
+		},
+	);
+});
+```
+
+This test catches a provider being opted out of implicit signup or becoming detached from `FLAG_DISABLE_SIGNUPS`.
+
+- [ ] **Step 2: Run the test and verify the expected failure**
+
+Run:
+
+```bash
+pnpm --filter @reactive-resume/auth test -- src/config.test.ts
+```
+
+Expected: FAIL for Google, GitHub, and LinkedIn because `disableImplicitSignUp` is currently `true`, not `undefined`.
+
+- [ ] **Step 3: Enable native implicit signup and delete client-side signup intent**
+
+In `packages/auth/src/config.ts`, remove only the three `disableImplicitSignUp: true` properties. Keep each provider's existing line:
+
+```ts
+disableSignUp: env.FLAG_DISABLE_SIGNUPS,
+```
+
+In `apps/web/src/features/auth/components/social-auth.tsx`, delete `SocialAuthProps`, `SocialSignInOptions`, and `getSocialSignInOptions`. Change the component signature:
+
+```ts
+export function SocialAuth() {
+```
+
+Change the loading branch to:
+
+```tsx
+{isLoading ? <SocialAuthSkeleton /> : <SocialAuthButtons providers={providers} />}
+```
+
+Remove `requestSignUp` from the button props and function parameter:
+
+```ts
+type SocialAuthButtonsProps = {
+	providers: RouterOutput["auth"]["providers"]["list"];
+};
+
+function SocialAuthButtons({ providers }: SocialAuthButtonsProps) {
+```
+
+Replace the Google, GitHub, and LinkedIn calls with the native Better Auth input shape:
+
+```ts
+authClient.signIn.social({ provider: "google", callbackURL: "/dashboard" });
+authClient.signIn.social({ provider: "github", callbackURL: "/dashboard" });
+authClient.signIn.social({ provider: "linkedin", callbackURL: "/dashboard" });
+```
+
+In `apps/web/src/features/auth/pages/register.tsx`, change:
+
+```tsx
+<SocialAuth requestSignUp />
+```
+
+to:
+
+```tsx
+<SocialAuth />
+```
+
+Do not modify `LoginPage`; it already renders `<SocialAuth />`.
+
+- [ ] **Step 4: Run the focused test and verify it passes**
+
+Run:
+
+```bash
+pnpm --filter @reactive-resume/auth test -- src/config.test.ts
+```
+
+Expected: PASS for all three providers.
+
+- [ ] **Step 5: Run focused validation**
+
+Run:
+
+```bash
+pnpm --filter @reactive-resume/auth typecheck
+pnpm --filter web typecheck
+pnpm exec biome check packages/auth/src/config.test.ts packages/auth/src/config.ts apps/web/src/features/auth/components/social-auth.tsx apps/web/src/features/auth/pages/register.tsx
+```
+
+Expected: all commands exit successfully with no diagnostics and no file changes.
+
+- [ ] **Step 6: Commit the implementation**
+
+```bash
+git add packages/auth/src/config.test.ts packages/auth/src/config.ts apps/web/src/features/auth/components/social-auth.tsx apps/web/src/features/auth/pages/register.tsx
+git commit -m "fix(auth): allow implicit social signup"
+```

packages/auth/src/config.test.ts

@@ -0,0 +1,15 @@
+import { describe, expect, it } from "vitest";
+import { env } from "@reactive-resume/env/server";
+import { auth } from "./config";
+
+describe("social provider signup policy", () => {
+	it.each(["google", "github", "linkedin"] as const)(
+		"allows implicit signup through %s while honoring the global signup restriction",
+		(provider) => {
+			const config = auth.options.socialProviders?.[provider];
+
+			expect(config).not.toHaveProperty("disableImplicitSignUp");
+			expect(config?.disableSignUp).toBe(env.FLAG_DISABLE_SIGNUPS);
+		},
+	);
+});

packages/auth/src/config.ts

@@ -197,7 +197,6 @@ const getAuthConfig = () => {
 			google: {
 				enabled: !!env.GOOGLE_CLIENT_ID && !!env.GOOGLE_CLIENT_SECRET,
 				disableSignUp: env.FLAG_DISABLE_SIGNUPS,
-				disableImplicitSignUp: true,
 				clientId: env.GOOGLE_CLIENT_ID ?? "",
 				clientSecret: env.GOOGLE_CLIENT_SECRET ?? "",
 				mapProfileToUser: createProfileMapper({
@@ -210,7 +209,6 @@ const getAuthConfig = () => {
 			github: {
 				enabled: !!env.GITHUB_CLIENT_ID && !!env.GITHUB_CLIENT_SECRET,
 				disableSignUp: env.FLAG_DISABLE_SIGNUPS,
-				disableImplicitSignUp: true,
 				clientId: env.GITHUB_CLIENT_ID ?? "",
 				clientSecret: env.GITHUB_CLIENT_SECRET ?? "",
 				mapProfileToUser: createGithubProfileMapper(),
@@ -219,7 +217,6 @@ const getAuthConfig = () => {
 			linkedin: {
 				enabled: !!env.LINKEDIN_CLIENT_ID && !!env.LINKEDIN_CLIENT_SECRET,
 				disableSignUp: env.FLAG_DISABLE_SIGNUPS,
-				disableImplicitSignUp: true,
 				clientId: env.LINKEDIN_CLIENT_ID ?? "",
 				clientSecret: env.LINKEDIN_CLIENT_SECRET ?? "",
 				mapProfileToUser: createProfileMapper({