Chockfull

backend/Makefile

@@ -37,7 +37,7 @@ tidy:
 
 # Database setup
 db-setup:
-	psql -d koin_ping_dev -f infra/schema.sql
+	psql -d koin_ping -f infra/schema.sql
 
 vet:
 	go vet ./...

backend/cmd/api/main.go

@@ -82,6 +82,9 @@ func main() {
 	// Stripe webhook (public — called by Stripe, not authenticated)
 	mux.HandleFunc("POST "+b+"/stripe/webhook", stripeHandler.HandleWebhook)
 
+	// Onboarding checkout (public — account doesn't exist yet)
+	mux.HandleFunc("POST "+b+"/stripe/create-onboarding-checkout", stripeHandler.CreateOnboardingCheckout)
+
 	// Stripe routes (auth required, NO subscription required)
 	mux.Handle("POST "+b+"/stripe/create-checkout-session",
 		authenticate(http.HandlerFunc(stripeHandler.CreateCheckoutSession)))

backend/internal/handlers/stripe.go

@@ -145,7 +145,7 @@ func (h *StripeHandler) VerifyCheckoutSession(w http.ResponseWriter, r *http.Req
 		return
 	}
 
-	if s.ClientReferenceID != userID {
+	if s.ClientReferenceID != "" && s.ClientReferenceID != userID {
 		writeError(w, http.StatusForbidden, "FORBIDDEN", "Session does not belong to this user")
 		return
 	}
@@ -204,6 +204,65 @@ func (h *StripeHandler) ActivateFreeTier(w http.ResponseWriter, r *http.Request)
 	})
 }
 
+// CreateOnboardingCheckout creates a Stripe Checkout session for a user who
+// has not yet created an account. This is a public endpoint (no auth required).
+// The Firebase account is created on the frontend only after payment succeeds.
+func (h *StripeHandler) CreateOnboardingCheckout(w http.ResponseWriter, r *http.Request) {
+	var body struct {
+		Email string `json:"email"`
+		Tier  string `json:"tier"`
+	}
+	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+		writeError(w, http.StatusBadRequest, "BAD_REQUEST", "Invalid request body")
+		return
+	}
+
+	if body.Email == "" {
+		writeError(w, http.StatusBadRequest, "VALIDATION_ERROR", "Email is required")
+		return
+	}
+
+	if body.Tier == "" {
+		body.Tier = "premium"
+	}
+
+	tier := domain.SubscriptionTier(body.Tier)
+	if tier != domain.TierPremium && tier != domain.TierPro {
+		writeError(w, http.StatusBadRequest, "VALIDATION_ERROR", "Tier must be 'premium' or 'pro'")
+		return
+	}
+
+	priceID, err := h.priceIDForTier(tier)
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "VALIDATION_ERROR", err.Error())
+		return
+	}
+
+	params := &stripe.CheckoutSessionParams{
+		Mode: stripe.String(string(stripe.CheckoutSessionModeSubscription)),
+		LineItems: []*stripe.CheckoutSessionLineItemParams{
+			{
+				Price:    stripe.String(priceID),
+				Quantity: stripe.Int64(1),
+			},
+		},
+		SuccessURL:    stripe.String(h.cfg.FrontendURL + "/subscribe?payment=success&session_id={CHECKOUT_SESSION_ID}"),
+		CancelURL:     stripe.String(h.cfg.FrontendURL + "/subscribe?payment=cancelled"),
+		CustomerEmail: stripe.String(body.Email),
+	}
+	params.AddMetadata("tier", string(tier))
+	params.AddMetadata("onboarding", "true")
+
+	s, err := checkoutsession.New(params)
+	if err != nil {
+		log.Printf("Failed to create onboarding checkout session: %v", err)
+		writeError(w, http.StatusInternalServerError, "STRIPE_ERROR", "Failed to create checkout session")
+		return
+	}
+
+	writeJSON(w, http.StatusOK, map[string]string{"url": s.URL})
+}
+
 // CreatePortalSession creates a Stripe Billing Portal session so the user can
 // manage their subscription (cancel, update payment method, view invoices).
 func (h *StripeHandler) CreatePortalSession(w http.ResponseWriter, r *http.Request) {