Claude Project Tracker

After BRD + design review are locked, produce the formal technical design doc covering: - Sequence diagram (customer → Razorpay → backend → OCPP → charger) - Data model changes (schema migration text) - API contracts (webhook handler, admin QR provisioning, guest-mode read endpoints) - Idempotency + concurrency model - Failure/retry semantics (webhook re-fires, gun offline, RemoteStart rejected, refund flow) - SMS content + provider integration details - Observability (metrics + logs to add) - Test plan (unit + integration + one live pilot station) - Rollout / rollback plan - Estimated effort per phase Commit finalized TDD to docs/TDD-walkin-qr.md in the backend repo. Only after this ships do we start implementation items.</body>

Vajra Volt Mobile App · vajra-mobile-app · by saravanan@scrumclaw.ai

DLT SMS registration is NOT done. 2–4 weeks external timeline. Track in parallel to Phase 1 build. Templates needed (send via Fast2SMS post-approval): - **wk_session_start** — "Vajra Volt: Charging started at {station}·Gun {gun}. ₹{reserved} reserved. Support: 88831-61155." - **wk_session_low_balance** — "Vajra Volt: Wallet running low (₹{remaining}). Scan QR to add money and keep charging." - **wk_session_end** — "Vajra Volt: Session complete. Used {kwh} kWh, cost ₹{cost}. Balance ₹{remaining}. Reply CLAIM to link this account." - **wk_payment_gun_busy** — "Vajra Volt: Payment ₹{amount} received but Gun {gun} is unavailable. Amount saved to your wallet. Support: 88831-61155." - **wk_refund_initiated** — "Vajra Volt: Refund of ₹{amount} initiated to your UPI. Reflects in 1–3 business days." All 4 languages (Q11 answer). English variants can be filed immediately; regional translations need vendor. Phase 1 launches WITHOUT SMS (see decision item). SMS goes live in Phase 1.5 once DLT approved.</body>

Vajra Volt Mobile App · vajra-mobile-app · by saravanan@scrumclaw.ai

DLT registration is 2–4 weeks. Rather than delay walk-in launch, Phase 1 will ship with LED-based confirmation only: - Customer knows charging started when the green LED on the gun activates (Q5 confirmed). - No SMS on session start, low balance, or session end for Phase 1 walk-ins. - App users still get all their existing notifications (unaffected). - After DLT approval + template registration, Phase 1.5 patches SMS in as a config flip — no schema change needed. Trade-off: walk-in session-end UX is worse. If a customer left their car and walked away, they won't know when charging finished. Mitigation: - Set the 2-hour hard cap (Q6) so guns don't stay locked forever. - Print the phone number on the QR sticker so customers can call to check status. - Auto-stop threshold of ₹50 remaining (Q7) reduces the "session died silently" scenario for underpayers. If DLT lands earlier than expected we'll enable SMS immediately.</body>

Vajra Volt Mobile App · vajra-mobile-app · by saravanan@scrumclaw.ai

Pre-launch gate for Phase 1. Test matrix:\n\n- App: BHIM, Google Pay, PhonePe, Paytm, WhatsApp Pay (5 apps)\n- Amount: ₹100, ₹500, ₹1000 (3 amounts)\n- Scenario: happy path, gun offline (simulate), gun already charging, RemoteStart rejected (simulate)\n\nTotal ~30 test runs at pilot station. Log any UPI-app-specific quirks (BHIM in particular has stricter parsing).\n\nWhoever pilots — use throwaway UPI-linked phone number so we can also validate the walk-in-user creation path (not an existing app user's phone).\n\nBlocked on Phase 1 implementation complete + QR sticker printed.</body>

Vajra Volt Mobile App · vajra-mobile-app · by saravanan@scrumclaw.ai

Physical rollout for Phase 1 pilot.\n\n- Confirm which station is the pilot (default VAJRA0001)\n- Send print design (#56) to signage vendor (#Q17 answer: existing vendor)\n- Receive 2 laminated A5 stickers (Gun 1 + Gun 2)\n- Physically apply to gun/panel\n- Coordinate with ops staff to be on-site during pilot testing window\n- Document station-owner communications (landlord awareness of pilot)\n\nBlocked on #56 (design finalized) + Razorpay QR issued (#52 + #61).</body>

Vajra Volt Mobile App · vajra-mobile-app · by saravanan@scrumclaw.ai

BRD Q8 spec locked: - A5 landscape (5.8" × 8.3"), vinyl, laminated for outdoor durability - Contents: Razorpay QR image (large, centered) + human-readable station+gun ID (e.g., "Vajra Volt · VAJRA0001 · Gun 2") + typical-cost hint ("Typical 30-min charge ≈ ₹150–300") - Support phone number visible - English only (Q20 answer) - Print files: SVG + PDF at 300 DPI - Vendor: existing signage vendor already identified (Q17) Sample layout: [ Vajra Volt logo ] [ QR CODE 4"x4" ] VAJRA0001 · Gun 2 Scan any UPI app to pay Typical charge ≈ ₹150–300 Support: 88831-61155 Deliverable: printable design ready for vendor.</body>

Vajra Volt Mobile App · vajra-mobile-app · by saravanan@scrumclaw.ai

Behind WALKIN_QR_SMS_ENABLED flag. 5 templates × 4 languages (see #53).\n\nBackend changes:\n- Templates stored in Go source (map[templateKey]map[lang]string) with DLT template IDs from #53\n- Language selection: prefer user.preferred_language if set; fallback to English\n- Dispatch service reuses existing Fast2SMS integration (already in codebase for OTP)\n- Fire-and-forget from webhook handler (async goroutine); log failures but don't block webhook response\n\nBlocked on DLT approval (#53).</body>

Vajra Volt Mobile App · vajra-mobile-app · by saravanan@scrumclaw.ai

Useful for ops debugging (missing webhook, dispute lookup, reconciliation). Wraps Razorpay: GET https://api.razorpay.com/v1/payments/qr_codes/:qr_id/payments Backend endpoint: GET /admin/chargers/:charger_id/connectors/:connector_id/payments Returns array of payments captured against that gun's QR (all-time), each with vpa, contact, email, amount, timestamp, status. Enables ops to answer "who paid at this gun today" without querying our DB. Small addition to the admin endpoints in #65. Roughly 1 hour of Go + admin console UI work.</body>

Vajra Volt Mobile App · vajra-mobile-app · by saravanan@scrumclaw.ai

Where to find each customer field in the qr_code.credited webhook payload. Confirmed from Razorpay official docs (docs/webhooks/qr-codes). **Payload path for VPA:** `payload.payment.entity.vpa` **Trimmed sample:** ```json { "event": "qr_code.credited", "contains": ["payment", "qr_code"], "payload": { "payment": { "entity": { "id": "pay_HO2fEpc9JeOQU5", "amount": 200, "method": "upi", "vpa": "gauri.kumar@okhdfcbank", "email": "gauri.kumari@example.com", "contact": "+919000090000", "customer_id": "cust_HKsR5se84c5LTO", "notes": {}, "acquirer_data": { "rrn": "116812981837" } } }, "qr_code": { "entity": { "id": "qr_HO2e0813YlchUn", "notes": { "charger_id": "VAJRA0001", "connector_id": "2" } } } } } ``` **Two subtle gotchas:** 1. **Two separate `notes` blocks** — `payload.payment.entity.notes` is per-payment (usually empty for QR), and `payload.qr_code.entity.notes` is the QR's notes (where we set charger_id + connector_id at QR creation). Read the second one for gun identification. 2. **VPA presence:** always present for QR-triggered payments (method is always upi). Fallback: null. **Go struct extraction:** see TDD §4.3 `qrCreditedPayload`. **Fallback retrieval (webhook lost):** - `GET /v1/payments/pay_XXX` — fetch single payment; includes vpa - `GET /v1/payments/qr_codes/qr_XXX/payments` — list all payments for a QR (great for admin ops "show all payments to this gun") Sources: - https://razorpay.com/docs/webhooks/qr-codes/ - https://razorpay.com/docs/webhooks/payloads/payments/</body>

Vajra Volt Mobile App · vajra-mobile-app · by saravanan@scrumclaw.ai