Onboarding Flow

Flow

1. App backend calls POST /v1/link-token with user_id.
2. Gateway returns token, expires_at, and deep_link.
3. End-user opens deep link and triggers /start <token>.
4. Gateway validates token from KV and upserts (developer_id, app_user_id) -> tg_chat_id in D1.
5. Link token is deleted (single-use).

Important behavior

• Link tokens expire after 15 minutes.
• Token payload stores a branding snapshot.
• Successful link automatically transitions user to phone verification pending and prompts contact-share.