Module 05: The Customer Portal

Anchor outcome Document turnaround time: 3–5 days → same-day. 34% portal adoption among active customers in the first 30 days. Consignor “checking in” calls down 70%.

Era 3 also included the customer portal — OAuth login with Google, Apple, and Microsoft; a consignor view showing real-time unit status and inquiry counts; and signed time-limited document download links that replaced email attachments. The portal shipped minimum-feature-set: two high-value use cases, nothing else.

The 4 lessons

Lesson 5.1

When Self-Service Makes Sense (and When It Doesn’t)

The three-criteria test (repeat customers, ongoing status changes, document exchange), a ROI framework by use case, and what "minimum portal" means. Most businesses skip this step and build the wrong features first.

Lesson 5.2

OAuth Across Google, Apple, and Microsoft

The OAuth flow, state parameter CSRF protection, wp_insert_user() with a restricted custom role, email-matching across providers, linking portal users to their CRM lead record, and Apple's first-login-only name behavior.

Lesson 5.3

Seller Portal: Giving Consignors Visibility

Querying consignment records from the owned_units table, displaying inquiry counts without exposing lead data, the price change request flow that routes through staff review, and the ownership verification gate on every portal request.

Lesson 5.4

Document Exchange: Upload, Store, Deliver

Private media storage with MIME-type validation, HMAC-signed time-limited download tokens, hash_equals() for constant-time signature comparison, customer-side upload handler, and why email attachments are the wrong document delivery tool.