server-build-plan.md

Ding Payments — Server Build Plan

Master implementation document for the backend (ding-server)

Version: 1.0 · Date: 2026-06-17 · Scope: server MVP

Required references:

• ding-payments.md — product vision and UX flows
• payment-request.v1.md — canonical NFC contract (restore in SRV-031)
• Client repo: ding-payments/ — has its own task plan; this document is server-only

---

Table of contents

1. Document usage guide
2. Product context (server)
3. Target technical architecture
4. Data model (Prisma)
5. API Surface (MVP)
6. Payment state machine
7. Task summary table
8. Phases and detailed tasks
9. Client ↔ server dependency matrix
10. Risks and open decisions
11. Appendices

---

1. Document usage guide

Purpose

This document is the complete technical backlog for the Ding Payments server. Each task (SRV-###) is designed to be executed by an agent or developer without exploring the repository or reading other docs, except for the explicit references in each task.

Use it to:

• Split work into epics, sprints, and tickets
• Assign priorities and detect blockers
• Onboard AI agents with full context
• Coordinate integration with the client plan (ding-payments)

Identifier conventions

Prefix	Meaning	Example
SRV-###	Server task	SRV-035
EPIC-##	Grouping epic	EPIC-04
CLI-###	Client task (cross-reference)	CLI-042

Priorities

Level	Meaning	When to use
P0	MVP blocker	Without this there is no end-to-end payment
P1	Complete MVP	Required for release, does not block first demo
P2	Near post-MVP	Quality/ops improvement within 2-4 weeks post-MVP
P3	Future	Outside MVP; documented for roadmap

Complexity

Code	Level	Target distribution	Estimated time
E	Easy	~15%	1–2 h
M	Medium	~70%	3–5 h
H	Hard	~15%	6–10 h

Blockers

• blocked_by: tasks that must be completed before starting this one
• blocks: tasks that depend on this one

Rule: do not start a task if any blocked_by is incomplete.

Task template

Each task in Section 8 follows this structure:

### SRV-### — Title
| Field | Value |
**Context** — why it exists, what problem it solves
**Objective** — concrete outcome
**Acceptance criteria** — verifiable checklist
**Files** — exact create/modify paths
**Implementation** — steps and snippets
**Tests** — what to test and commands
**Client dependency** — what must exist in ding-payments
**Notes for agents** — pitfalls, skills, git references

Current server state (starting point)

Area	Status
Code	NestJS 11 starter: only GET / → "Hello World!"
Database	Prisma removed in commit 5d4e9de (reset)
NFC contract	Existed in git 5d4e9de^: payment-request.v1 — canonical
Auth	Not implemented
Stellar	Not implemented
CI	.github/workflows/ci-server.yml — lint, build, test

Confirmed architecture decisions

1. Hybrid auth: Supabase JWT for session/login + server-side WebAuthn for payment approval
2. Transaction relay: The client signs the XDR locally; the server receives the signed XDR, validates, broadcasts to Stellar, and monitors confirmation
3. Self-custodial: Private keys never leave the device; the server never custodies funds
4. NFC contract: payment-request.v1 is the official contract (not the simplified payload from ding-payments.md)

sequenceDiagram
    participant Receiver as ClientReceiver
    participant Sender as ClientSender
    participant Server as dingServer
    participant Stellar as StellarNetwork

    Receiver->>Receiver: Create payment_request NFC
    Receiver->>Sender: NFC tap payload
    Sender->>Server: POST /v1/payment-requests/validate
    Server-->>Sender: valid plus normalized
    Sender->>Server: POST /v1/payments
    Sender->>Server: POST /v1/payments/id/authorize WebAuthn
    Sender->>Sender: Sign XDR locally
    Sender->>Server: POST /v1/payments/id/submit signedXDR
    Server->>Stellar: Broadcast XDR
    Server->>Stellar: Poll confirmation
    Sender->>Server: GET /v1/payments/id
    Receiver->>Server: GET /v1/payments/id

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---

2. Product context (server)

Vision

Ding Payments enables instant P2P payments via NFC on Stellar. The experience should feel like Apple Pay / Google Pay, but with a self-custodial wallet and passkeys. Blockchain complexity is invisible to the user.

Source: ding-payments.md

Receiver flow (client — context for the server)

1. User opens app → "Receive Payment"
2. Enters amount and asset (XLM or USDC)
3. App enters NFC listening mode
4. Generates payment-request.v1 payload with recipient (Stellar pubkey), amount, expiresAt
5. Optionally registers the request on the server (POST /v1/payment-requests)
6. Transfers payload via NFC to the payer
7. Waits for confirmation — poll GET /v1/payments/:id or push notification (future)

Server role: persist request, anti-replay, expose payment status to the receiver.

Sender flow (client — context for the server)

1. User taps phone to receiver (NFC)
2. Receives NFC payload
3. Calls POST /v1/payment-requests/validate for server-side validation
4. Shows confirmation screen (amount, recipient, asset)
5. User confirms → WebAuthn passkey
6. Calls POST /v1/payments/:id/authorize with assertion
7. Optionally POST /v1/transactions/simulate before signing
8. Signs Stellar transaction locally (self-custodial)
9. Sends signed XDR: POST /v1/payments/:id/submit
10. Poll GET /v1/payments/:id until confirmed or failed

Server role: validate, authorize with passkey, relay broadcast, monitor, persist history.

Server vs client boundary

Responsibility	Server	Client (ding-payments)
NFC handshake	—	Yes
Create NFC payload	—	Yes (receiver)
Validate structural payload	Yes	Optional pre-validation
Payment confirmation UI	—	Yes
Passkey ceremony (WebAuthn)	Verify assertion	Execute navigator.credentials
Build Stellar transaction	Simulate (optional)	Yes (before signing)
Sign transaction	—	Yes (local key)
Broadcast to Stellar	Yes (relay)	—
Monitor on-chain confirmation	Yes	Poll API
Persistent history	Yes	Render UI
Login / session	Supabase JWT	Supabase client SDK
Wallet / key management	Link pubkey	Local custody

MVP scope (server)

Included:

• payment-request.v1 validation
• Supabase auth + WebAuthn for payments
• CRUD payment requests and payments
• Signed transaction relay
• Pre-sign simulation
• Basic transaction history
• Health checks

Excluded (MVP):

• Merchant mode
• QR payments
• Recurring payments
• Multi-sig
• Offline settlement
• Soroban / smart contracts
• Push notifications (documented as P3)

Supported assets (MVP)

Asset	Stellar type	Notes
XLM	Native	No issuer
USDC	Credit (Stellar Asset)	Requires STELLAR_USDC_ISSUER in env per network

Reference USDC issuers:

• Testnet: GBBD47IF6LWK7P7MDEVSCWR7DPUWV3NY3DTQEVFL4NAT4AQH3ZLLFLA5
• Mainnet: GA5ZSEJYB37JRC5AVCIA5MOP4RHTM335X2KGX5IHOJAO6A4CSJXHUA1T

---

3. Target technical architecture

Stack

Layer	Technology
Framework	NestJS 11
Language	TypeScript 5.7 (strict)
ORM	Prisma 6 + PostgreSQL
DB hosting	Supabase
Session auth	Supabase Auth (JWT)
Payment auth	@simplewebauthn/server
Blockchain	@stellar/stellar-sdk (Horizon + RPC)
Validation	class-validator, class-transformer
Config	@nestjs/config + Joi
API docs	@nestjs/swagger
Events	@nestjs/event-emitter
HTTP security	helmet, @nestjs/throttler
Tests	Jest + Supertest

Target folder structure

ding-server/
├── prisma/
│   ├── schema.prisma
│   ├── seed.ts
│   └── migrations/
├── docs/
│   ├── ding-payments.md
│   ├── payment-request.v1.md
│   ├── server-build-plan.md          # this file
│   ├── ARCHITECTURE.md               # SRV-095
│   └── API.md                        # SRV-096
├── src/
│   ├── main.ts
│   ├── app.module.ts
│   ├── config/
│   │   ├── config.module.ts
│   │   ├── env.validation.ts
│   │   └── configuration.ts
│   ├── common/
│   │   ├── filters/
│   │   ├── interceptors/
│   │   └── decorators/
│   ├── database/
│   │   ├── database.module.ts
│   │   ├── prisma.service.ts
│   │   └── index.ts
│   ├── auth/
│   │   ├── auth.module.ts
│   │   ├── strategies/supabase.strategy.ts
│   │   ├── guards/
│   │   └── decorators/
│   ├── stellar/
│   │   ├── stellar.module.ts
│   │   └── stellar.service.ts
│   ├── webauthn/
│   │   ├── webauthn.module.ts
│   │   └── webauthn.service.ts
│   ├── contracts/
│   │   └── payment-request.v1.ts
│   └── modules/
│       ├── users/
│       ├── payment-requests/
│       ├── payments/
│       └── transactions/
└── test/
    ├── jest-e2e.json
    └── *.e2e-spec.ts

HTTP request pipeline

flowchart LR
    Request --> Helmet
    Helmet --> CORS
    CORS --> Throttler
    Throttler --> AuthGuard
    AuthGuard --> Controller
    Controller --> Service
    Service --> Prisma
    Service --> Stellar
    Service --> EventEmitter

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NestJS modules and responsibilities

Module	Responsibility
ConfigModule	Validated environment variables
DatabaseModule	Global PrismaService
AuthModule	Supabase JWT, guards, decorators
WebAuthnModule	Passkey registration and verification
StellarModule	Horizon/RPC, build/simulate/submit
UsersModule	Profile, link wallet
PaymentRequestsModule	Validate and persist NFC requests
PaymentsModule	Payment lifecycle, relay
TransactionsModule	History and simulation

Environment variables (.env.example)

# App
NODE_ENV=development
PORT=3000
API_PREFIX=v1
CORS_ORIGINS=http://localhost:8081,exp://localhost:8081

# Database (Supabase PostgreSQL)
DATABASE_URL=postgresql://postgres:PASSWORD@PROJECT.pooler.supabase.com:6543/postgres?pgbouncer=true
DIRECT_URL=postgresql://postgres:PASSWORD@PROJECT.supabase.com:5432/postgres

# Supabase Auth
SUPABASE_URL=https://PROJECT.supabase.co
SUPABASE_JWT_SECRET=your-jwt-secret
SUPABASE_SERVICE_ROLE_KEY=your-service-role-key

# Stellar
STELLAR_NETWORK=testnet
STELLAR_HORIZON_URL=https://horizon-testnet.stellar.org
STELLAR_RPC_URL=https://soroban-testnet.stellar.org
STELLAR_USDC_ISSUER=GBBD47IF6LWK7P7MDEVSCWR7DPUWV3NY3DTQEVFL4NAT4AQH3ZLLFLA5
STELLAR_NETWORK_PASSPHRASE=Test SDF Network ; September 2015

# WebAuthn
WEBAUTHN_RP_ID=localhost
WEBAUTHN_RP_NAME=Ding Payments
WEBAUTHN_ORIGIN=http://localhost:8081

# Payments
PAYMENT_SUBMIT_TIMEOUT_MS=300000
PAYMENT_POLL_INTERVAL_MS=2000
PAYMENT_POLL_MAX_ATTEMPTS=30

# Rate limiting
THROTTLE_TTL_MS=60000
THROTTLE_LIMIT=100

Relevant agent skills

Skill	Path	When to use
NestJS best practices	.agents/skills/nestjs-best-practices/	Modules, guards, DTOs, tests
Prisma setup	.agents/skills/prisma-database-setup/	Schema, migrations, client
Stellar dev	.agents/skills/stellar-dev/	SDK, Horizon, RPC, assets
Writing plans	.agents/skills/writing-plans/	When breaking down a task

Git pre-reset reference

Commit 5d4e9de^ contains recoverable partial implementation:

File	Reuse	Rewrite
src/payments/contracts/payment-request.v1.ts	Yes (direct port)	—
docs/payment-request.v1.md	Yes (restore)	—
src/payment-requests/payment-requests.service.ts	—	Yes (had incorrect ETH/BTC logic)
prisma/schema.prisma	Partial (User base)	Yes (Stellar models)
src/prisma/prisma.service.ts	Yes (adapt paths)	—
src/supabase/supabase.service.ts	Yes (adapt)	—

---

4. Data model (Prisma)

Entity-relationship diagram

erDiagram
    User ||--o{ Wallet : has
    User ||--o{ PaymentRequest : creates
    User ||--o{ Payment : sends
    User ||--o{ Payment : receives
    User ||--o{ Transaction : owns
    User ||--o{ WebAuthnCredential : registers
    PaymentRequest ||--o| Payment : generates
    Payment ||--o| Transaction : records
    PaymentRequest ||--o| UsedRequestId : prevents_replay

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Enums

enum StellarNetwork {
  TESTNET
  MAINNET
}

enum AssetCode {
  XLM
  USDC
}

enum PaymentRequestStatus {
  CREATED
  SHARED
  EXPIRED
  CONSUMED
}

enum PaymentStatus {
  CREATED
  AUTHORIZED
  SUBMITTED
  CONFIRMED
  FAILED
}

enum TransactionDirection {
  SENT
  RECEIVED
}

User model

Links Supabase identity with Ding profile and Stellar wallet.

Field	Type	Rules
id	UUID	PK, @default(uuid())
supabaseUserId	String	Unique, from JWT sub
email	String	Unique, from JWT
displayName	String?	Optional
createdAt	DateTime	@default(now())
updatedAt	DateTime	@updatedAt

Relations: wallets[], paymentRequests[], sentPayments[], receivedPayments[], transactions[], webauthnCredentials[]

Wallet model

Field	Type	Rules
id	UUID	PK
userId	UUID	FK → User
stellarPublicKey	String	^G[A-Z2-7]{55}$, unique per network
network	StellarNetwork	TESTNET o MAINNET
isPrimary	Boolean	Only one primary per user+network
label	String?	E.g.: "iPhone"
createdAt	DateTime

Composite index: @@unique([stellarPublicKey, network]) Index: @@index([userId, isPrimary])

PaymentRequest model

Represents an NFC request generated by the receiver.

Field	Type	Rules
id	UUID	Internal PK
externalRequestId	String?	requestId from NFC payload; unique if present
receiverUserId	UUID	FK → User
recipient	String	Stellar pubkey G...
asset	AssetCode	XLM o USDC
amount	Decimal	@db.Decimal(20, 7) — never Float
memo	String?	Max 280 chars
status	PaymentRequestStatus	Default CREATED
payloadTimestamp	DateTime	From contract timestamp field
expiresAt	DateTime	From contract
metadata	Json?	Optional contract field
createdAt	DateTime

Indexes: @@index([receiverUserId, status]), @@unique([externalRequestId])

Payment model

Full lifecycle of a P2P payment.

Field	Type	Rules
id	UUID	PK
paymentRequestId	UUID?	FK → PaymentRequest
senderUserId	UUID	FK → User
receiverUserId	UUID	FK → User
recipient	String	Stellar pubkey (denormalized)
senderPublicKey	String	Pubkey that signs the XDR
asset	AssetCode
amount	Decimal	@db.Decimal(20, 7)
status	PaymentStatus	Default CREATED
stellarTxHash	String?	Unique when present
failureReason	String?	Code + message
failureCode	String?	E.g.: STELLAR_TX_FAILED
authorizedAt	DateTime?	After WebAuthn
submittedAt	DateTime?	After relay
confirmedAt	DateTime?	After ledger inclusion
expiresAt	DateTime	Inherited from request
createdAt	DateTime
updatedAt	DateTime

Indexes: @@index([senderUserId, status]), @@index([receiverUserId, status]), @@unique([stellarTxHash])

Transaction model

Indexed history for history UI.

Field	Type	Rules
id	UUID	PK
userId	UUID	FK → User (history owner)
paymentId	UUID?	FK → Payment
stellarTxHash	String
direction	TransactionDirection	SENT o RECEIVED
counterparty	String	Other party pubkey
asset	AssetCode
amount	Decimal
memo	String?
ledger	Int?
network	StellarNetwork
createdAt	DateTime	On-chain or confirmation timestamp

Index: @@index([userId, createdAt(sort: Desc)])

WebAuthnCredential model

Field	Type	Rules
id	UUID	PK
userId	UUID	FK → User
credentialId	String	Base64url, unique
publicKey	Bytes
counter	BigInt	Anti-clone
deviceName	String?
createdAt	DateTime
lastUsedAt	DateTime?

WebAuthnChallenge model

Temporary challenges for registration and authentication.

Field	Type	Rules
id	UUID	PK
userId	UUID	FK → User
challenge	String	Base64url
type	String	registration or authentication
paymentId	UUID?	If payment challenge
expiresAt	DateTime	TTL 5 min
createdAt	DateTime

Index: @@index([userId, type, expiresAt])

UsedRequestId model

Anti-replay for NFC requestId.

Field	Type	Rules
id	UUID	PK
requestId	String	Unique
paymentRequestId	UUID	FK
consumedAt	DateTime	@default(now())

AuditLog model (SRV-085)

Field	Type	Rules
id	UUID	PK
userId	UUID?
action	String	E.g.: payment.submitted
resourceType	String	payment, payment_request
resourceId	String
metadata	Json?
ipAddress	String?
createdAt	DateTime

---

5. API Surface (MVP)

API conventions

• Base path: /v1
• Auth header: Authorization: Bearer <supabase_jwt>
• Content-Type: application/json
• Errors: { "statusCode": number, "message": string, "code"?: string, "errors"?: [] }
• Pagination: ?page=1&limit=20 → { data: [], meta: { page, limit, total } }
• Correlation: header X-Request-Id (UUID, optional; server generates if absent)

Endpoints

Method	Route	Auth	Module	Description
POST	/v1/payment-requests/validate	Public	payment-requests	Validate NFC payload without persisting
POST	/v1/payment-requests	JWT	payment-requests	Register receiver request
GET	/v1/payment-requests/:id	JWT	payment-requests	Query request
POST	/v1/payments	JWT	payments	Create payment intent (sender)
POST	/v1/payments/:id/authorize	JWT + WebAuthn	payments	Verify passkey and authorize
POST	/v1/payments/:id/submit	JWT	payments	Receive signed XDR and relay
GET	/v1/payments/:id	JWT	payments	Status and details
POST	/v1/transactions/simulate	JWT	transactions	Simulate tx before signing
GET	/v1/transactions	JWT	transactions	Paginated history
GET	/v1/users/me	JWT	users	Profile and wallets
POST	/v1/users/me/wallet	JWT	users	Link Stellar pubkey
POST	/v1/webauthn/register/options	JWT	webauthn	Passkey registration options
POST	/v1/webauthn/register/verify	JWT	webauthn	Verify registration
POST	/v1/webauthn/authenticate/options	JWT	webauthn	Challenge for payment
GET	/health	Public	—	Liveness
GET	/health/ready	Public	—	Readiness (DB + Stellar)
GET	/health/stellar	Public	—	Horizon/RPC status

Key responses

POST /v1/payment-requests/validate — success:

{
  "valid": true,
  "normalized": {
    "type": "payment-request",
    "version": 1,
    "recipient": "GAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",
    "asset": "USDC",
    "amount": "25.00",
    "timestamp": "2026-06-17T12:00:00.000Z",
    "expiresAt": "2026-06-17T12:00:30.000Z"
  },
  "errors": []
}

POST /v1/payments — success:

{
  "id": "550e8400-e29b-41d4-a716-446655440000",
  "status": "CREATED",
  "recipient": "G...",
  "asset": "USDC",
  "amount": "25.00",
  "expiresAt": "2026-06-17T12:00:30.000Z"
}

GET /v1/payments/:id — confirmed:

{
  "id": "550e8400-e29b-41d4-a716-446655440000",
  "status": "CONFIRMED",
  "asset": "USDC",
  "amount": "25.00",
  "recipient": "G...",
  "senderPublicKey": "G...",
  "stellarTxHash": "abc123...",
  "confirmedAt": "2026-06-17T12:00:05.000Z",
  "explorerUrl": "https://stellar.expert/explorer/testnet/tx/abc123"
}

---

6. Payment state machine

States

stateDiagram-v2
    [*] --> CREATED: POST payments
    CREATED --> AUTHORIZED: POST authorize WebAuthn OK
    AUTHORIZED --> SUBMITTED: POST submit XDR relay OK
    SUBMITTED --> CONFIRMED: Poll Stellar success
    SUBMITTED --> FAILED: Poll Stellar fail
    CREATED --> FAILED: Timeout without authorize
    AUTHORIZED --> FAILED: Timeout without submit
    CREATED --> FAILED: Request expired
    AUTHORIZED --> FAILED: Request expired

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Transitions and rules

From	To	Trigger	Validations
—	CREATED	POST /v1/payments	Valid request, not expired, sender ≠ receiver
CREATED	AUTHORIZED	POST /v1/payments/:id/authorize	Valid WebAuthn assertion, payment not expired
AUTHORIZED	SUBMITTED	POST /v1/payments/:id/submit	Valid XDR, matches intent, broadcast OK
SUBMITTED	CONFIRMED	Poll Stellar	Tx included in ledger, success result
SUBMITTED	FAILED	Poll Stellar	Tx failed or poll timeout
CREATED	FAILED	Cron/timeout	PAYMENT_SUBMIT_TIMEOUT_MS without authorize
AUTHORIZED	FAILED	Cron/timeout	Timeout without submit
*	FAILED	Expiration	expiresAt passed

EventEmitter2 events

Event	Payload	Consumers
payment.created	{ paymentId, senderUserId, receiverUserId }	AuditLog
payment.authorized	{ paymentId, userId }	AuditLog
payment.submitted	{ paymentId, stellarTxHash }	Poll worker, AuditLog
payment.confirmed	{ paymentId, stellarTxHash, ledger }	Transaction indexer, AuditLog
payment.failed	{ paymentId, failureCode, failureReason }	AuditLog

Configurable timeouts

Variable	Default	Description
PAYMENT_SUBMIT_TIMEOUT_MS	300000 (5 min)	Max time in CREATED/AUTHORIZED before FAILED
PAYMENT_POLL_INTERVAL_MS	2000	Interval between confirmation polls
PAYMENT_POLL_MAX_ATTEMPTS	30	~60s total polling

---

7. Task summary table

ID	Title	Epic	Phase	P	C	Blocked by
SRV-001	Update README with Ding Payments branding	EPIC-00	0	P0	E	—
SRV-002	Create .env.example with all variables	EPIC-00	0	P0	E	—
SRV-003	Install core server dependencies	EPIC-00	0	P0	M	—
SRV-004	Configure ConfigModule and env validation	EPIC-00	0	P0	M	002, 003
SRV-005	Bootstrap production-ready main.ts	EPIC-00	0	P0	M	003, 004
SRV-006	Global exception filter and error format	EPIC-00	0	P0	M	005
SRV-007	Base src/ folder structure	EPIC-00	0	P0	E	—
SRV-008	Update .cursor/rules to flat layout	EPIC-00	0	P1	E	—
SRV-009	Install Prisma and npm scripts	EPIC-01	1	P0	E	003
SRV-010	Initial Prisma schema User and Wallet	EPIC-01	1	P0	M	009
SRV-011	DatabaseModule and PrismaService	EPIC-01	1	P0	M	004, 007, 009
SRV-012	Initial database migration	EPIC-01	1	P0	M	010, 011
SRV-013	Extend schema PaymentRequest and Payment	EPIC-01	1	P0	M	012
SRV-014	Extend schema Transaction WebAuthn UsedRequestId	EPIC-01	1	P0	M	013
SRV-015	Database indexes and constraints	EPIC-01	1	P0	M	013, 014
SRV-016	Development seed script	EPIC-01	1	P1	M	012
SRV-017	Document Supabase connection in README	EPIC-01	1	P1	E	001
SRV-018	Optional RLS script for Supabase	EPIC-01	1	P2	M	012
SRV-019	Document Prisma inline transaction patterns	EPIC-01	1	P1	E	011
SRV-020	CI prisma generate in workflow	EPIC-01	1	P0	E	009
SRV-021	SupabaseModule and SupabaseService	EPIC-02	2	P0	M	003, 004
SRV-022	SupabaseStrategy Passport JWT	EPIC-02	2	P0	M	021
SRV-023	Global SupabaseAuthGuard and Public decorator	EPIC-02	2	P0	M	022
SRV-024	CurrentUser decorator and AuthenticatedUser interface	EPIC-02	2	P0	E	022
SRV-025	UsersModule sync user on first login	EPIC-02	2	P0	M	011, 024
SRV-026	GET /v1/users/me	EPIC-02	2	P0	M	025
SRV-027	POST /v1/users/me/wallet link pubkey	EPIC-02	2	P0	M	025
SRV-028	Validate Stellar G... format in wallet	EPIC-02	2	P0	E	027
SRV-029	Unit tests auth guards and strategy	EPIC-02	2	P0	M	023
SRV-030	E2E auth with JWT mock	EPIC-02	2	P0	M	005, 023
SRV-031	Restore docs/payment-request.v1.md	EPIC-03	3	P0	E	—
SRV-032	Port payment-request.v1.ts from git	EPIC-03	3	P0	M	031, 007
SRV-033	Unit tests payment-request.v1 contract	EPIC-03	3	P0	M	032
SRV-034	PaymentRequestsModule scaffold	EPIC-03	3	P0	E	007
SRV-035	POST /v1/payment-requests/validate	EPIC-03	3	P0	M	032, 034, 023
SRV-036	DTO and Swagger for validate endpoint	EPIC-03	3	P0	E	035
SRV-037	E2E validate valid and invalid Stellar cases	EPIC-03	3	P0	M	005, 035
SRV-038	POST /v1/payment-requests persist receiver	EPIC-03	3	P0	M	013, 035
SRV-039	Anti-replay requestId in UsedRequestId	EPIC-03	3	P0	M	014, 038
SRV-040	GET /v1/payment-requests/:id	EPIC-03	3	P0	M	038
SRV-041	Install @simplewebauthn/server	EPIC-02	4	P0	E	—
SRV-042	WebAuthnModule and challenge store DB	EPIC-02	4	P0	M	SRV-014, SRV-041
SRV-043	POST webauthn register options and verify	EPIC-02	4	P0	M	SRV-042
SRV-044	POST webauthn authenticate options	EPIC-02	4	P0	M	SRV-042
SRV-045	POST /v1/payments/:id/authorize WebAuthn	EPIC-04	4	P0	H	SRV-043, SRV-044, SRV-061
SRV-046	Per-device credentials policy	EPIC-02	4	P1	M	SRV-043
SRV-047	WebAuthn tests with mocks	EPIC-02	4	P0	M	SRV-043
SRV-048	Document hybrid auth flow in ARCHITECTURE	EPIC-02	4	P1	E	SRV-045
SRV-049	StellarModule and network configuration	EPIC-05	5	P0	M	SRV-003, SRV-004
SRV-050	StellarService getAccount and health	EPIC-05	5	P0	M	SRV-049
SRV-051	Resolve asset codes XLM and USDC	EPIC-05	5	P0	M	SRV-049
SRV-052	buildPaymentTransaction unsigned	EPIC-05	5	P0	M	SRV-051
SRV-053	simulateTransaction via RPC	EPIC-05	5	P0	M	SRV-052
SRV-054	submitTransaction broadcast XDR	EPIC-05	5	P0	M	SRV-049
SRV-055	pollTransactionStatus with timeout	EPIC-05	5	P0	M	SRV-054
SRV-056	POST /v1/transactions/simulate	EPIC-05	5	P0	M	SRV-053
SRV-057	Validate XDR matches payment intent	EPIC-05	5	P0	H	SRV-054, SRV-061
SRV-058	Horizon error handling and Stellar codes	EPIC-05	5	P0	M	SRV-054
SRV-059	GET /health/stellar	EPIC-05	5	P1	E	SRV-050
SRV-060	StellarService tests with SDK mocks	EPIC-05	5	P0	M	SRV-054
SRV-061	PaymentsModule and state machine service	EPIC-04	6	P0	M	SRV-007, SRV-013
SRV-062	POST /v1/payments create intent	EPIC-04	6	P0	M	SRV-038, SRV-040, SRV-061
SRV-063	Validate sender distinct from receiver and hints	EPIC-04	6	P0	M	SRV-062
SRV-064	Transition CREATED to AUTHORIZED	EPIC-04	6	P0	M	SRV-045, SRV-062
SRV-065	POST /v1/payments/:id/submit relay XDR	EPIC-04	6	P0	H	SRV-054, SRV-057, SRV-064
SRV-066	Transition AUTHORIZED to SUBMITTED	EPIC-04	6	P0	M	SRV-065
SRV-067	Event listener polling confirmation	EPIC-04	6	P0	M	SRV-055, SRV-066
SRV-068	Transition SUBMITTED to CONFIRMED or FAILED	EPIC-04	6	P0	M	SRV-067, SRV-058
SRV-069	GET /v1/payments/:id full status	EPIC-04	6	P0	M	SRV-068
SRV-070	Event payment.confirmed index Transaction	EPIC-04	6	P0	M	SRV-014, SRV-068
SRV-071	Idempotency on submit same paymentId	EPIC-04	6	P0	M	SRV-065
SRV-072	Timeout FAILED if no submit in time	EPIC-04	6	P0	M	SRV-061
SRV-073	E2E full flow with mock Stellar	EPIC-04	6	P0	H	SRV-005, SRV-065, SRV-069, SRV-016
SRV-074	Complete Swagger payments module	EPIC-04	6	P1	E	SRV-056
SRV-075	TransactionsModule GET /v1/transactions	EPIC-06	7	P1	M	SRV-070
SRV-076	History filters asset date role status	EPIC-06	7	P1	M	SRV-075
SRV-077	Reconciliation sync from Horizon	EPIC-06	7	P2	H	SRV-075, SRV-050
SRV-078	Response DTO memo counterparty explorer link	EPIC-06	7	P1	E	SRV-075
SRV-079	DB indexes for history queries	EPIC-06	7	P1	M	SRV-015
SRV-080	Tests list and filters transactions	EPIC-06	7	P1	M	SRV-076
SRV-081	Rate limiting ThrottlerModule per endpoint	EPIC-07	8	P0	M	SRV-003
SRV-082	Validate 5 min clock skew on requests	EPIC-07	8	P0	E	SRV-032
SRV-083	NFC expiration policy default 30s	EPIC-07	8	P0	E	SRV-032
SRV-084	Sanitize outputs without internal leak	EPIC-07	8	P0	M	SRV-006
SRV-085	AuditLog table and critical events	EPIC-07	8	P1	M	SRV-014
SRV-086	Restrictive CORS per environment	EPIC-07	8	P0	E	SRV-005
SRV-087	Request ID correlation X-Request-Id	EPIC-07	8	P1	M	SRV-005
SRV-088	Validate wallet JWT matches signer XDR	EPIC-07	8	P0	H	SRV-027, SRV-028, SRV-057
SRV-089	Replay protection stellarTxHash unique	EPIC-07	8	P0	M	SRV-015
SRV-090	Documented security review checklist	EPIC-07	8	P1	E	—
SRV-091	Structured logging Pino or Nest Logger	EPIC-08	9	P1	M	SRV-005
SRV-092	GET /health readiness and liveness	EPIC-08	9	P0	M	SRV-012, SRV-059
SRV-093	Payment success rate metrics endpoint	EPIC-08	9	P2	M	SRV-068
SRV-094	Swagger tags and complete examples	EPIC-09	9	P1	M	SRV-036, SRV-074
SRV-095	docs/ARCHITECTURE.md server	EPIC-09	9	P1	M	SRV-048
SRV-096	docs/API.md endpoint reference	EPIC-09	9	P1	M	SRV-094
SRV-097	80% test coverage critical modules	EPIC-09	9	P1	M	SRV-029, SRV-047, SRV-060, SRV-080
SRV-098	Complete E2E suite in CI	EPIC-09	9	P0	M	SRV-020, SRV-030, SRV-037, SRV-073, SRV-097
SRV-099	Contract tests payment-request.v1	EPIC-09	9	P1	M	SRV-033
SRV-100	Basic load test validate endpoint	EPIC-09	9	P2	M	SRV-081, SRV-035
SRV-101	Multi-stage production Dockerfile	EPIC-10	10	P1	M	SRV-005
SRV-102	docker-compose dev local postgres	EPIC-10	10	P2	M	SRV-012
SRV-103	GitHub Actions deploy staging	EPIC-10	10	P1	H	SRV-092, SRV-101
SRV-104	prisma migrate deploy in CI/CD	EPIC-10	10	P1	M	SRV-012, SRV-103
SRV-105	Operational runbook Stellar down	EPIC-10	10	P1	E	—
SRV-106	Server MVP release checklist	EPIC-10	10	P1	E	SRV-098, SRV-104

8. Phases and detailed tasks

Phase 0 — Project foundation (EPIC-00)

Summary: 8 tasks. Dominant priority: P0.

SRV-001 — Update README with Ding Payments branding

Field	Value
Epic	EPIC-00
Phase	0
Priority	P0
Complexity	E
Blocked by	—
Blocks	SRV-017
Est. effort	1-2h

Context: The current README is the default NestJS template. New agents and developers have no project context.

Objective: Complete "Update README with Ding Payments branding" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 0.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-002 — Create .env.example with all variables

Field	Value
Epic	EPIC-00
Phase	0
Priority	P0
Complexity	E
Blocked by	—
Blocks	SRV-004
Est. effort	1h

Context: Without .env.example, each agent invents different variables. Blocks ConfigModule.

Objective: Complete "Create .env.example with all variables" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 0.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-003 — Install core server dependencies

Field	Value
Epic	EPIC-00
Phase	0
Priority	P0
Complexity	M
Blocked by	—
Blocks	SRV-004, SRV-005, SRV-021, SRV-041, SRV-049
Est. effort	2h

Context: The current package.json only has @nestjs/common, core, platform-express. All deps from the target stack are missing.

Objective: Complete "Install core server dependencies" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 0.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-004 — Configure ConfigModule and env validation

Field	Value
Epic	EPIC-00
Phase	0
Priority	P0
Complexity	M
Blocked by	SRV-002, SRV-003
Blocks	SRV-005, SRV-011, SRV-021, SRV-049
Est. effort	3h

Context: Task 004 of phase 0, epic EPIC-00. Part of the Ding Payments server MVP build plan.

Objective: Complete "Configure ConfigModule and env validation" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 0.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-005 — Bootstrap production-ready main.ts

Field	Value
Epic	EPIC-00
Phase	0
Priority	P0
Complexity	M
Blocked by	SRV-003, SRV-004
Blocks	SRV-006, SRV-030, SRV-037, SRV-073
Est. effort	4h

Context: Task 005 of phase 0, epic EPIC-00. Part of the Ding Payments server MVP build plan.

Objective: Complete "Bootstrap production-ready main.ts" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 0.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-006 — Global exception filter and error format

Field	Value
Epic	EPIC-00
Phase	0
Priority	P0
Complexity	M
Blocked by	SRV-005
Blocks	SRV-084
Est. effort	3h

Context: Task 006 of phase 0, epic EPIC-00. Part of the Ding Payments server MVP build plan.

Objective: Complete "Global exception filter and error format" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 0.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-007 — Base src/ folder structure

Field	Value
Epic	EPIC-00
Phase	0
Priority	P0
Complexity	E
Blocked by	—
Blocks	SRV-011, SRV-021, SRV-034, SRV-049, SRV-061
Est. effort	1h

Context: Task 007 of phase 0, epic EPIC-00. Part of the Ding Payments server MVP build plan.

Objective: Complete "Base src/ folder structure" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 0.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-008 — Update .cursor/rules to flat layout

Field	Value
Epic	EPIC-00
Phase	0
Priority	P1
Complexity	E
Blocked by	—
Blocks	—
Est. effort	1h

Context: Task 008 of phase 0, epic EPIC-00. Part of the Ding Payments server MVP build plan.

Objective: Complete "Update .cursor/rules to flat layout" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 0.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

Phase 1 — Database and persistence (EPIC-01)

Summary: 12 tasks. Dominant priority: P0.

SRV-009 — Install Prisma and npm scripts

Field	Value
Epic	EPIC-01
Phase	1
Priority	P0
Complexity	E
Blocked by	SRV-003
Blocks	SRV-010, SRV-011, SRV-020
Est. effort	1h

Context: Task 009 of phase 1, epic EPIC-01. Part of the Ding Payments server MVP build plan.

Objective: Complete "Install Prisma and npm scripts" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 1.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-010 — Initial Prisma schema User and Wallet

Field	Value
Epic	EPIC-01
Phase	1
Priority	P0
Complexity	M
Blocked by	SRV-009
Blocks	SRV-012, SRV-013
Est. effort	3h

Context: Task 010 of phase 1, epic EPIC-01. Part of the Ding Payments server MVP build plan.

Objective: Complete "Initial Prisma schema User and Wallet" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 1.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-011 — DatabaseModule and PrismaService

Field	Value
Epic	EPIC-01
Phase	1
Priority	P0
Complexity	M
Blocked by	SRV-004, SRV-007, SRV-009
Blocks	SRV-012, SRV-025, SRV-038
Est. effort	3h

Context: Task 011 of phase 1, epic EPIC-01. Part of the Ding Payments server MVP build plan.

Objective: Complete "DatabaseModule and PrismaService" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 1.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-012 — Initial database migration

Field	Value
Epic	EPIC-01
Phase	1
Priority	P0
Complexity	M
Blocked by	SRV-010, SRV-011
Blocks	SRV-013, SRV-016, SRV-092
Est. effort	2h

Context: Task 012 of phase 1, epic EPIC-01. Part of the Ding Payments server MVP build plan.

Objective: Complete "Initial database migration" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 1.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-013 — Extend schema PaymentRequest and Payment

Field	Value
Epic	EPIC-01
Phase	1
Priority	P0
Complexity	M
Blocked by	SRV-012
Blocks	SRV-014, SRV-015, SRV-038, SRV-062
Est. effort	4h

Context: Task 013 of phase 1, epic EPIC-01. Part of the Ding Payments server MVP build plan.

Objective: Complete "Extend schema PaymentRequest and Payment" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 1.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-014 — Extend schema Transaction WebAuthn UsedRequestId

Field	Value
Epic	EPIC-01
Phase	1
Priority	P0
Complexity	M
Blocked by	SRV-013
Blocks	SRV-015, SRV-042, SRV-039, SRV-070
Est. effort	4h

Context: Task 014 of phase 1, epic EPIC-01. Part of the Ding Payments server MVP build plan.

Objective: Complete "Extend schema Transaction WebAuthn UsedRequestId" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 1.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-015 — Database indexes and constraints

Field	Value
Epic	EPIC-01
Phase	1
Priority	P0
Complexity	M
Blocked by	SRV-013, SRV-014
Blocks	SRV-079, SRV-089
Est. effort	3h

Context: Task 015 of phase 1, epic EPIC-01. Part of the Ding Payments server MVP build plan.

Objective: Complete "Database indexes and constraints" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 1.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-016 — Development seed script

Field	Value
Epic	EPIC-01
Phase	1
Priority	P1
Complexity	M
Blocked by	SRV-012
Blocks	SRV-073
Est. effort	3h

Context: Task 016 of phase 1, epic EPIC-01. Part of the Ding Payments server MVP build plan.

Objective: Complete "Development seed script" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 1.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-017 — Document Supabase connection in README

Field	Value
Epic	EPIC-01
Phase	1
Priority	P1
Complexity	E
Blocked by	SRV-001
Blocks	—
Est. effort	1h

Context: Task 017 of phase 1, epic EPIC-01. Part of the Ding Payments server MVP build plan.

Objective: Complete "Document Supabase connection in README" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 1.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-018 — Optional RLS script for Supabase

Field	Value
Epic	EPIC-01
Phase	1
Priority	P2
Complexity	M
Blocked by	SRV-012
Blocks	—
Est. effort	3h

Context: Task 018 of phase 1, epic EPIC-01. Part of the Ding Payments server MVP build plan.

Objective: Complete "Optional RLS script for Supabase" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 1.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-019 — Document Prisma inline transaction patterns

Field	Value
Epic	EPIC-01
Phase	1
Priority	P1
Complexity	E
Blocked by	SRV-011
Blocks	—
Est. effort	1h

Context: Task 019 of phase 1, epic EPIC-01. Part of the Ding Payments server MVP build plan.

Objective: Complete "Document Prisma inline transaction patterns" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 1.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-020 — CI prisma generate in workflow

Field	Value
Epic	EPIC-01
Phase	1
Priority	P0
Complexity	E
Blocked by	SRV-009
Blocks	SRV-098
Est. effort	1h

Context: Task 020 of phase 1, epic EPIC-01. Part of the Ding Payments server MVP build plan.

Objective: Complete "CI prisma generate in workflow" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 1.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

Phase 2 — Supabase authentication (EPIC-02)

Summary: 10 tasks. Dominant priority: P0.

SRV-021 — SupabaseModule and SupabaseService

Field	Value
Epic	EPIC-02
Phase	2
Priority	P0
Complexity	M
Blocked by	SRV-003, SRV-004
Blocks	SRV-022
Est. effort	3h

Context: Task 021 of phase 2, epic EPIC-02. Part of the Ding Payments server MVP build plan.

Objective: Complete "SupabaseModule and SupabaseService" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 2.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-022 — SupabaseStrategy Passport JWT

Field	Value
Epic	EPIC-02
Phase	2
Priority	P0
Complexity	M
Blocked by	SRV-021
Blocks	SRV-023
Est. effort	4h

Context: Task 022 of phase 2, epic EPIC-02. Part of the Ding Payments server MVP build plan.

Objective: Complete "SupabaseStrategy Passport JWT" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 2.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-023 — Global SupabaseAuthGuard and Public decorator

Field	Value
Epic	EPIC-02
Phase	2
Priority	P0
Complexity	M
Blocked by	SRV-022
Blocks	SRV-029, SRV-035, SRV-062
Est. effort	3h

Context: Task 023 of phase 2, epic EPIC-02. Part of the Ding Payments server MVP build plan.

Objective: Complete "Global SupabaseAuthGuard and Public decorator" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 2.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-024 — CurrentUser decorator and AuthenticatedUser interface

Field	Value
Epic	EPIC-02
Phase	2
Priority	P0
Complexity	E
Blocked by	SRV-022
Blocks	SRV-025, SRV-026
Est. effort	2h

Context: Task 024 of phase 2, epic EPIC-02. Part of the Ding Payments server MVP build plan.

Objective: Complete "CurrentUser decorator and AuthenticatedUser interface" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 2.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-025 — UsersModule sync user on first login

Field	Value
Epic	EPIC-02
Phase	2
Priority	P0
Complexity	M
Blocked by	SRV-011, SRV-024
Blocks	SRV-026, SRV-027
Est. effort	4h

Context: Task 025 of phase 2, epic EPIC-02. Part of the Ding Payments server MVP build plan.

Objective: Complete "UsersModule sync user on first login" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 2.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-026 — GET /v1/users/me

Field	Value
Epic	EPIC-02
Phase	2
Priority	P0
Complexity	M
Blocked by	SRV-025
Blocks	SRV-088
Est. effort	3h

Context: Task 026 of phase 2, epic EPIC-02. Part of the Ding Payments server MVP build plan.

Objective: Complete "GET /v1/users/me" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 2.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-027 — POST /v1/users/me/wallet link pubkey

Field	Value
Epic	EPIC-02
Phase	2
Priority	P0
Complexity	M
Blocked by	SRV-025
Blocks	SRV-028, SRV-088
Est. effort	4h

Context: Task 027 of phase 2, epic EPIC-02. Part of the Ding Payments server MVP build plan.

Objective: Complete "POST /v1/users/me/wallet link pubkey" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 2.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-028 — Validate Stellar G... format in wallet

Field	Value
Epic	EPIC-02
Phase	2
Priority	P0
Complexity	E
Blocked by	SRV-027
Blocks	SRV-088
Est. effort	2h

Context: Task 028 of phase 2, epic EPIC-02. Part of the Ding Payments server MVP build plan.

Objective: Complete "Validate Stellar G... format in wallet" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 2.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-029 — Unit tests auth guards and strategy

Field	Value
Epic	EPIC-02
Phase	2
Priority	P0
Complexity	M
Blocked by	SRV-023
Blocks	SRV-097
Est. effort	4h

Context: Task 029 of phase 2, epic EPIC-02. Part of the Ding Payments server MVP build plan.

Objective: Complete "Unit tests auth guards and strategy" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 2.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-030 — E2E auth with JWT mock

Field	Value
Epic	EPIC-02
Phase	2
Priority	P0
Complexity	M
Blocked by	SRV-005, SRV-023
Blocks	SRV-098
Est. effort	4h

Context: Task 030 of phase 2, epic EPIC-02. Part of the Ding Payments server MVP build plan.

Objective: Complete "E2E auth with JWT mock" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 2.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

Phase 3 — payment-request.v1 contract (EPIC-03)

Summary: 10 tasks. Dominant priority: P0.

SRV-031 — Restore docs/payment-request.v1.md

Field	Value
Epic	EPIC-03
Phase	3
Priority	P0
Complexity	E
Blocked by	—
Blocks	SRV-032
Est. effort	1h

Context: Task 031 of phase 3, epic EPIC-03. Part of the Ding Payments server MVP build plan.

Objective: Complete "Restore docs/payment-request.v1.md" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 3.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-032 — Port payment-request.v1.ts from git

Field	Value
Epic	EPIC-03
Phase	3
Priority	P0
Complexity	M
Blocked by	SRV-031, SRV-007
Blocks	SRV-033, SRV-035
Est. effort	3h

Context: Task 032 of phase 3, epic EPIC-03. Part of the Ding Payments server MVP build plan.

Objective: Complete "Port payment-request.v1.ts from git" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 3.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-033 — Unit tests payment-request.v1 contract

Field	Value
Epic	EPIC-03
Phase	3
Priority	P0
Complexity	M
Blocked by	SRV-032
Blocks	SRV-099
Est. effort	5h

Context: Task 033 of phase 3, epic EPIC-03. Part of the Ding Payments server MVP build plan.

Objective: Complete "Unit tests payment-request.v1 contract" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 3.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-034 — PaymentRequestsModule scaffold

Field	Value
Epic	EPIC-03
Phase	3
Priority	P0
Complexity	E
Blocked by	SRV-007
Blocks	SRV-035
Est. effort	2h

Context: Task 034 of phase 3, epic EPIC-03. Part of the Ding Payments server MVP build plan.

Objective: Complete "PaymentRequestsModule scaffold" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 3.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-035 — POST /v1/payment-requests/validate

Field	Value
Epic	EPIC-03
Phase	3
Priority	P0
Complexity	M
Blocked by	SRV-032, SRV-034, SRV-023
Blocks	SRV-036, SRV-037, SRV-038
Est. effort	4h

Context: The pre-reset service validated ETH/BTC/SOL. Must be rewritten using validatePaymentRequestV1() from the Stellar contract.

Objective: Complete "POST /v1/payment-requests/validate" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 3.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-036 — DTO and Swagger for validate endpoint

Field	Value
Epic	EPIC-03
Phase	3
Priority	P0
Complexity	E
Blocked by	SRV-035
Blocks	SRV-094
Est. effort	2h

Context: Task 036 of phase 3, epic EPIC-03. Part of the Ding Payments server MVP build plan.

Objective: Complete "DTO and Swagger for validate endpoint" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 3.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-037 — E2E validate valid and invalid Stellar cases

Field	Value
Epic	EPIC-03
Phase	3
Priority	P0
Complexity	M
Blocked by	SRV-005, SRV-035
Blocks	SRV-098
Est. effort	4h

Context: Task 037 of phase 3, epic EPIC-03. Part of the Ding Payments server MVP build plan.

Objective: Complete "E2E validate valid and invalid Stellar cases" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 3.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-038 — POST /v1/payment-requests persist receiver

Field	Value
Epic	EPIC-03
Phase	3
Priority	P0
Complexity	M
Blocked by	SRV-013, SRV-035
Blocks	SRV-039, SRV-040, SRV-062
Est. effort	4h

Context: Task 038 of phase 3, epic EPIC-03. Part of the Ding Payments server MVP build plan.

Objective: Complete "POST /v1/payment-requests persist receiver" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 3.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-039 — Anti-replay requestId in UsedRequestId

Field	Value
Epic	EPIC-03
Phase	3
Priority	P0
Complexity	M
Blocked by	SRV-014, SRV-038
Blocks	SRV-062
Est. effort	3h

Context: Task 039 of phase 3, epic EPIC-03. Part of the Ding Payments server MVP build plan.

Objective: Complete "Anti-replay requestId in UsedRequestId" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 3.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-040 — GET /v1/payment-requests/:id

Field	Value
Epic	EPIC-03
Phase	3
Priority	P0
Complexity	M
Blocked by	SRV-038
Blocks	SRV-062
Est. effort	3h

Context: Task 040 of phase 3, epic EPIC-03. Part of the Ding Payments server MVP build plan.

Objective: Complete "GET /v1/payment-requests/:id" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 3.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

Phase 4 — WebAuthn and Passkey (EPIC-02 ext.)

Summary: 8 tasks. Dominant priority: P0.

SRV-041 — Install @simplewebauthn/server

Field	Value
Epic	EPIC-02
Phase	4
Priority	P0
Complexity	E
Blocked by	—
Blocks	SRV-042
Est. effort	3-5h

Context: Task 041 of phase 4, epic EPIC-02. Part of the Ding Payments server MVP build plan.

Objective: Complete "Install @simplewebauthn/server" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 4.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-042 — WebAuthnModule and challenge store DB

Field	Value
Epic	EPIC-02
Phase	4
Priority	P0
Complexity	M
Blocked by	SRV-014, SRV-041
Blocks	SRV-043, SRV-044, SRV-045
Est. effort	3-5h

Context: Task 042 of phase 4, epic EPIC-02. Part of the Ding Payments server MVP build plan.

Objective: Complete "WebAuthnModule and challenge store DB" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 4.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-043 — POST webauthn register options and verify

Field	Value
Epic	EPIC-02
Phase	4
Priority	P0
Complexity	M
Blocked by	SRV-042
Blocks	SRV-045, SRV-047
Est. effort	3-5h

Context: Task 043 of phase 4, epic EPIC-02. Part of the Ding Payments server MVP build plan.

Objective: Complete "POST webauthn register options and verify" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 4.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-044 — POST webauthn authenticate options

Field	Value
Epic	EPIC-02
Phase	4
Priority	P0
Complexity	M
Blocked by	SRV-042
Blocks	SRV-045
Est. effort	3-5h

Context: Task 044 of phase 4, epic EPIC-02. Part of the Ding Payments server MVP build plan.

Objective: Complete "POST webauthn authenticate options" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 4.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-045 — POST /v1/payments/:id/authorize WebAuthn

Field	Value
Epic	EPIC-04
Phase	4
Priority	P0
Complexity	H
Blocked by	SRV-043, SRV-044, SRV-061
Blocks	SRV-064
Est. effort	3-5h

Context: Critical point of hybrid auth: the server verifies WebAuthn assertion before allowing submit.

Objective: Complete "POST /v1/payments/:id/authorize WebAuthn" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 4.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-046 — Per-device credentials policy

Field	Value
Epic	EPIC-02
Phase	4
Priority	P1
Complexity	M
Blocked by	SRV-043
Blocks	—
Est. effort	3-5h

Context: Task 046 of phase 4, epic EPIC-02. Part of the Ding Payments server MVP build plan.

Objective: Complete "Per-device credentials policy" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 4.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-047 — WebAuthn tests with mocks

Field	Value
Epic	EPIC-02
Phase	4
Priority	P0
Complexity	M
Blocked by	SRV-043
Blocks	SRV-097
Est. effort	3-5h

Context: Task 047 of phase 4, epic EPIC-02. Part of the Ding Payments server MVP build plan.

Objective: Complete "WebAuthn tests with mocks" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 4.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-048 — Document hybrid auth flow in ARCHITECTURE

Field	Value
Epic	EPIC-02
Phase	4
Priority	P1
Complexity	E
Blocked by	SRV-045
Blocks	SRV-095
Est. effort	3-5h

Context: Task 048 of phase 4, epic EPIC-02. Part of the Ding Payments server MVP build plan.

Objective: Complete "Document hybrid auth flow in ARCHITECTURE" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 4.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

Phase 5 — Stellar integration (EPIC-05)

Summary: 12 tasks. Dominant priority: P0.

SRV-049 — StellarModule and network configuration

Field	Value
Epic	EPIC-05
Phase	5
Priority	P0
Complexity	M
Blocked by	SRV-003, SRV-004
Blocks	SRV-050, SRV-051
Est. effort	3-5h

Context: Task 049 of phase 5, epic EPIC-05. Part of the Ding Payments server MVP build plan.

Objective: Complete "StellarModule and network configuration" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 5.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-050 — StellarService getAccount and health

Field	Value
Epic	EPIC-05
Phase	5
Priority	P0
Complexity	M
Blocked by	SRV-049
Blocks	SRV-059
Est. effort	3-5h

Context: Task 050 of phase 5, epic EPIC-05. Part of the Ding Payments server MVP build plan.

Objective: Complete "StellarService getAccount and health" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 5.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-051 — Resolve asset codes XLM and USDC

Field	Value
Epic	EPIC-05
Phase	5
Priority	P0
Complexity	M
Blocked by	SRV-049
Blocks	SRV-052, SRV-056
Est. effort	3-5h

Context: Task 051 of phase 5, epic EPIC-05. Part of the Ding Payments server MVP build plan.

Objective: Complete "Resolve asset codes XLM and USDC" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 5.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-052 — buildPaymentTransaction unsigned

Field	Value
Epic	EPIC-05
Phase	5
Priority	P0
Complexity	M
Blocked by	SRV-051
Blocks	SRV-053, SRV-056
Est. effort	3-5h

Context: Task 052 of phase 5, epic EPIC-05. Part of the Ding Payments server MVP build plan.

Objective: Complete "buildPaymentTransaction unsigned" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 5.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-053 — simulateTransaction via RPC

Field	Value
Epic	EPIC-05
Phase	5
Priority	P0
Complexity	M
Blocked by	SRV-052
Blocks	SRV-056
Est. effort	3-5h

Context: Task 053 of phase 5, epic EPIC-05. Part of the Ding Payments server MVP build plan.

Objective: Complete "simulateTransaction via RPC" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 5.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-054 — submitTransaction broadcast XDR

Field	Value
Epic	EPIC-05
Phase	5
Priority	P0
Complexity	M
Blocked by	SRV-049
Blocks	SRV-065, SRV-057
Est. effort	3-5h

Context: Task 054 of phase 5, epic EPIC-05. Part of the Ding Payments server MVP build plan.

Objective: Complete "submitTransaction broadcast XDR" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 5.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-055 — pollTransactionStatus with timeout

Field	Value
Epic	EPIC-05
Phase	5
Priority	P0
Complexity	M
Blocked by	SRV-054
Blocks	SRV-067, SRV-068
Est. effort	3-5h

Context: Task 055 of phase 5, epic EPIC-05. Part of the Ding Payments server MVP build plan.

Objective: Complete "pollTransactionStatus with timeout" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 5.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-056 — POST /v1/transactions/simulate

Field	Value
Epic	EPIC-05
Phase	5
Priority	P0
Complexity	M
Blocked by	SRV-053
Blocks	SRV-074
Est. effort	3-5h

Context: Task 056 of phase 5, epic EPIC-05. Part of the Ding Payments server MVP build plan.

Objective: Complete "POST /v1/transactions/simulate" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 5.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-057 — Validate XDR matches payment intent

Field	Value
Epic	EPIC-05
Phase	5
Priority	P0
Complexity	H
Blocked by	SRV-054, SRV-061
Blocks	SRV-065
Est. effort	3-5h

Context: Before relay, the server must parse the XDR and verify amount, destination, and asset match the Payment.

Objective: Complete "Validate XDR matches payment intent" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 5.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-058 — Horizon error handling and Stellar codes

Field	Value
Epic	EPIC-05
Phase	5
Priority	P0
Complexity	M
Blocked by	SRV-054
Blocks	SRV-068
Est. effort	3-5h

Context: Task 058 of phase 5, epic EPIC-05. Part of the Ding Payments server MVP build plan.

Objective: Complete "Horizon error handling and Stellar codes" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 5.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-059 — GET /health/stellar

Field	Value
Epic	EPIC-05
Phase	5
Priority	P1
Complexity	E
Blocked by	SRV-050
Blocks	SRV-092
Est. effort	3-5h

Context: Task 059 of phase 5, epic EPIC-05. Part of the Ding Payments server MVP build plan.

Objective: Complete "GET /health/stellar" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 5.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-060 — StellarService tests with SDK mocks

Field	Value
Epic	EPIC-05
Phase	5
Priority	P0
Complexity	M
Blocked by	SRV-054
Blocks	SRV-097
Est. effort	3-5h

Context: Task 060 of phase 5, epic EPIC-05. Part of the Ding Payments server MVP build plan.

Objective: Complete "StellarService tests with SDK mocks" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 5.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

Phase 6 — Payment lifecycle (EPIC-04)

Summary: 14 tasks. Dominant priority: P0.

SRV-061 — PaymentsModule and state machine service

Field	Value
Epic	EPIC-04
Phase	6
Priority	P0
Complexity	M
Blocked by	SRV-007, SRV-013
Blocks	SRV-062, SRV-045
Est. effort	3-5h

Context: Task 061 of phase 6, epic EPIC-04. Part of the Ding Payments server MVP build plan.

Objective: Complete "PaymentsModule and state machine service" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 6.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-062 — POST /v1/payments create intent

Field	Value
Epic	EPIC-04
Phase	6
Priority	P0
Complexity	M
Blocked by	SRV-038, SRV-040, SRV-061
Blocks	SRV-063, SRV-064
Est. effort	3-5h

Context: Task 062 of phase 6, epic EPIC-04. Part of the Ding Payments server MVP build plan.

Objective: Complete "POST /v1/payments create intent" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 6.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-063 — Validate sender distinct from receiver and hints

Field	Value
Epic	EPIC-04
Phase	6
Priority	P0
Complexity	M
Blocked by	SRV-062
Blocks	—
Est. effort	3-5h

Context: Task 063 of phase 6, epic EPIC-04. Part of the Ding Payments server MVP build plan.

Objective: Complete "Validate sender distinct from receiver and hints" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 6.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-064 — Transition CREATED to AUTHORIZED

Field	Value
Epic	EPIC-04
Phase	6
Priority	P0
Complexity	M
Blocked by	SRV-045, SRV-062
Blocks	SRV-065
Est. effort	3-5h

Context: Task 064 of phase 6, epic EPIC-04. Part of the Ding Payments server MVP build plan.

Objective: Complete "Transition CREATED to AUTHORIZED" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 6.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-065 — POST /v1/payments/:id/submit relay XDR

Field	Value
Epic	EPIC-04
Phase	6
Priority	P0
Complexity	H
Blocked by	SRV-054, SRV-057, SRV-064
Blocks	SRV-066, SRV-073
Est. effort	3-5h

Context: Core of the relay model: receives signed XDR, validates, submitTransaction(), emits payment.submitted.

Objective: Complete "POST /v1/payments/:id/submit relay XDR" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 6.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-066 — Transition AUTHORIZED to SUBMITTED

Field	Value
Epic	EPIC-04
Phase	6
Priority	P0
Complexity	M
Blocked by	SRV-065
Blocks	SRV-067
Est. effort	3-5h

Context: Task 066 of phase 6, epic EPIC-04. Part of the Ding Payments server MVP build plan.

Objective: Complete "Transition AUTHORIZED to SUBMITTED" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 6.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-067 — Event listener polling confirmation

Field	Value
Epic	EPIC-04
Phase	6
Priority	P0
Complexity	M
Blocked by	SRV-055, SRV-066
Blocks	SRV-068
Est. effort	3-5h

Context: Task 067 of phase 6, epic EPIC-04. Part of the Ding Payments server MVP build plan.

Objective: Complete "Event listener polling confirmation" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 6.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-068 — Transition SUBMITTED to CONFIRMED or FAILED

Field	Value
Epic	EPIC-04
Phase	6
Priority	P0
Complexity	M
Blocked by	SRV-067, SRV-058
Blocks	SRV-069, SRV-070
Est. effort	3-5h

Context: Task 068 of phase 6, epic EPIC-04. Part of the Ding Payments server MVP build plan.

Objective: Complete "Transition SUBMITTED to CONFIRMED or FAILED" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 6.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-069 — GET /v1/payments/:id full status

Field	Value
Epic	EPIC-04
Phase	6
Priority	P0
Complexity	M
Blocked by	SRV-068
Blocks	SRV-073
Est. effort	3-5h

Context: Task 069 of phase 6, epic EPIC-04. Part of the Ding Payments server MVP build plan.

Objective: Complete "GET /v1/payments/:id full status" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 6.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-070 — Event payment.confirmed index Transaction

Field	Value
Epic	EPIC-04
Phase	6
Priority	P0
Complexity	M
Blocked by	SRV-014, SRV-068
Blocks	SRV-075
Est. effort	3-5h

Context: Task 070 of phase 6, epic EPIC-04. Part of the Ding Payments server MVP build plan.

Objective: Complete "Event payment.confirmed index Transaction" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 6.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-071 — Idempotency on submit same paymentId

Field	Value
Epic	EPIC-04
Phase	6
Priority	P0
Complexity	M
Blocked by	SRV-065
Blocks	—
Est. effort	3-5h

Context: Task 071 of phase 6, epic EPIC-04. Part of the Ding Payments server MVP build plan.

Objective: Complete "Idempotency on submit same paymentId" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 6.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-072 — Timeout FAILED if no submit in time

Field	Value
Epic	EPIC-04
Phase	6
Priority	P0
Complexity	M
Blocked by	SRV-061
Blocks	SRV-068
Est. effort	3-5h

Context: Task 072 of phase 6, epic EPIC-04. Part of the Ding Payments server MVP build plan.

Objective: Complete "Timeout FAILED if no submit in time" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 6.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-073 — E2E full flow with mock Stellar

Field	Value
Epic	EPIC-04
Phase	6
Priority	P0
Complexity	H
Blocked by	SRV-005, SRV-065, SRV-069, SRV-016
Blocks	SRV-098
Est. effort	3-5h

Context: Task 073 of phase 6, epic EPIC-04. Part of the Ding Payments server MVP build plan.

Objective: Complete "E2E full flow with mock Stellar" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 6.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-074 — Complete Swagger payments module

Field	Value
Epic	EPIC-04
Phase	6
Priority	P1
Complexity	E
Blocked by	SRV-056
Blocks	SRV-094
Est. effort	3-5h

Context: Task 074 of phase 6, epic EPIC-04. Part of the Ding Payments server MVP build plan.

Objective: Complete "Complete Swagger payments module" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 6.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

Phase 7 — Transaction history (EPIC-06)

Summary: 6 tasks. Dominant priority: P1.

SRV-075 — TransactionsModule GET /v1/transactions

Field	Value
Epic	EPIC-06
Phase	7
Priority	P1
Complexity	M
Blocked by	SRV-070
Blocks	SRV-076, SRV-080
Est. effort	3-5h

Context: Task 075 of phase 7, epic EPIC-06. Part of the Ding Payments server MVP build plan.

Objective: Complete "TransactionsModule GET /v1/transactions" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 7.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-076 — History filters asset date role status

Field	Value
Epic	EPIC-06
Phase	7
Priority	P1
Complexity	M
Blocked by	SRV-075
Blocks	SRV-080
Est. effort	3-5h

Context: Task 076 of phase 7, epic EPIC-06. Part of the Ding Payments server MVP build plan.

Objective: Complete "History filters asset date role status" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 7.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-077 — Reconciliation sync from Horizon

Field	Value
Epic	EPIC-06
Phase	7
Priority	P2
Complexity	H
Blocked by	SRV-075, SRV-050
Blocks	—
Est. effort	3-5h

Context: Task 077 of phase 7, epic EPIC-06. Part of the Ding Payments server MVP build plan.

Objective: Complete "Reconciliation sync from Horizon" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 7.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-078 — Response DTO memo counterparty explorer link

Field	Value
Epic	EPIC-06
Phase	7
Priority	P1
Complexity	E
Blocked by	SRV-075
Blocks	—
Est. effort	3-5h

Context: Task 078 of phase 7, epic EPIC-06. Part of the Ding Payments server MVP build plan.

Objective: Complete "Response DTO memo counterparty explorer link" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 7.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-079 — DB indexes for history queries

Field	Value
Epic	EPIC-06
Phase	7
Priority	P1
Complexity	M
Blocked by	SRV-015
Blocks	SRV-076
Est. effort	3-5h

Context: Task 079 of phase 7, epic EPIC-06. Part of the Ding Payments server MVP build plan.

Objective: Complete "DB indexes for history queries" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 7.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-080 — Tests list and filters transactions

Field	Value
Epic	EPIC-06
Phase	7
Priority	P1
Complexity	M
Blocked by	SRV-076
Blocks	SRV-097
Est. effort	3-5h

Context: Task 080 of phase 7, epic EPIC-06. Part of the Ding Payments server MVP build plan.

Objective: Complete "Tests list and filters transactions" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 7.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

Phase 8 — Security and hardening (EPIC-07)

Summary: 10 tasks. Dominant priority: P0.

SRV-081 — Rate limiting ThrottlerModule per endpoint

Field	Value
Epic	EPIC-07
Phase	8
Priority	P0
Complexity	M
Blocked by	SRV-003
Blocks	SRV-100
Est. effort	3-5h

Context: Task 081 of phase 8, epic EPIC-07. Part of the Ding Payments server MVP build plan.

Objective: Complete "Rate limiting ThrottlerModule per endpoint" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 8.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-082 — Validate 5 min clock skew on requests

Field	Value
Epic	EPIC-07
Phase	8
Priority	P0
Complexity	E
Blocked by	SRV-032
Blocks	—
Est. effort	3-5h

Context: Task 082 of phase 8, epic EPIC-07. Part of the Ding Payments server MVP build plan.

Objective: Complete "Validate 5 min clock skew on requests" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 8.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-083 — NFC expiration policy default 30s

Field	Value
Epic	EPIC-07
Phase	8
Priority	P0
Complexity	E
Blocked by	SRV-032
Blocks	—
Est. effort	3-5h

Context: Task 083 of phase 8, epic EPIC-07. Part of the Ding Payments server MVP build plan.

Objective: Complete "NFC expiration policy default 30s" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 8.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-084 — Sanitize outputs without internal leak

Field	Value
Epic	EPIC-07
Phase	8
Priority	P0
Complexity	M
Blocked by	SRV-006
Blocks	—
Est. effort	3-5h

Context: Task 084 of phase 8, epic EPIC-07. Part of the Ding Payments server MVP build plan.

Objective: Complete "Sanitize outputs without internal leak" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 8.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-085 — AuditLog table and critical events

Field	Value
Epic	EPIC-07
Phase	8
Priority	P1
Complexity	M
Blocked by	SRV-014
Blocks	—
Est. effort	3-5h

Context: Task 085 of phase 8, epic EPIC-07. Part of the Ding Payments server MVP build plan.

Objective: Complete "AuditLog table and critical events" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 8.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-086 — Restrictive CORS per environment

Field	Value
Epic	EPIC-07
Phase	8
Priority	P0
Complexity	E
Blocked by	SRV-005
Blocks	—
Est. effort	3-5h

Context: Task 086 of phase 8, epic EPIC-07. Part of the Ding Payments server MVP build plan.

Objective: Complete "Restrictive CORS per environment" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 8.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-087 — Request ID correlation X-Request-Id

Field	Value
Epic	EPIC-07
Phase	8
Priority	P1
Complexity	M
Blocked by	SRV-005
Blocks	—
Est. effort	3-5h

Context: Task 087 of phase 8, epic EPIC-07. Part of the Ding Payments server MVP build plan.

Objective: Complete "Request ID correlation X-Request-Id" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 8.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-088 — Validate wallet JWT matches signer XDR

Field	Value
Epic	EPIC-07
Phase	8
Priority	P0
Complexity	H
Blocked by	SRV-027, SRV-028, SRV-057
Blocks	SRV-065
Est. effort	3-5h

Context: Task 088 of phase 8, epic EPIC-07. Part of the Ding Payments server MVP build plan.

Objective: Complete "Validate wallet JWT matches signer XDR" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 8.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-089 — Replay protection stellarTxHash unique

Field	Value
Epic	EPIC-07
Phase	8
Priority	P0
Complexity	M
Blocked by	SRV-015
Blocks	SRV-065
Est. effort	3-5h

Context: Task 089 of phase 8, epic EPIC-07. Part of the Ding Payments server MVP build plan.

Objective: Complete "Replay protection stellarTxHash unique" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 8.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-090 — Documented security review checklist

Field	Value
Epic	EPIC-07
Phase	8
Priority	P1
Complexity	E
Blocked by	—
Blocks	—
Est. effort	3-5h

Context: Task 090 of phase 8, epic EPIC-07. Part of the Ding Payments server MVP build plan.

Objective: Complete "Documented security review checklist" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 8.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

Phase 9 — Observability and quality (EPIC-08/09)

Summary: 10 tasks. Dominant priority: P1.

SRV-091 — Structured logging Pino or Nest Logger

Field	Value
Epic	EPIC-08
Phase	9
Priority	P1
Complexity	M
Blocked by	SRV-005
Blocks	—
Est. effort	3-5h

Context: Task 091 of phase 9, epic EPIC-08. Part of the Ding Payments server MVP build plan.

Objective: Complete "Structured logging Pino or Nest Logger" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 9.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-092 — GET /health readiness and liveness

Field	Value
Epic	EPIC-08
Phase	9
Priority	P0
Complexity	M
Blocked by	SRV-012, SRV-059
Blocks	SRV-103
Est. effort	3-5h

Context: Task 092 of phase 9, epic EPIC-08. Part of the Ding Payments server MVP build plan.

Objective: Complete "GET /health readiness and liveness" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 9.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-093 — Payment success rate metrics endpoint

Field	Value
Epic	EPIC-08
Phase	9
Priority	P2
Complexity	M
Blocked by	SRV-068
Blocks	—
Est. effort	3-5h

Context: Task 093 of phase 9, epic EPIC-08. Part of the Ding Payments server MVP build plan.

Objective: Complete "Payment success rate metrics endpoint" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 9.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-094 — Swagger tags and complete examples

Field	Value
Epic	EPIC-09
Phase	9
Priority	P1
Complexity	M
Blocked by	SRV-036, SRV-074
Blocks	—
Est. effort	3-5h

Context: Task 094 of phase 9, epic EPIC-09. Part of the Ding Payments server MVP build plan.

Objective: Complete "Swagger tags and complete examples" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 9.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-095 — docs/ARCHITECTURE.md server

Field	Value
Epic	EPIC-09
Phase	9
Priority	P1
Complexity	M
Blocked by	SRV-048
Blocks	—
Est. effort	3-5h

Context: Task 095 of phase 9, epic EPIC-09. Part of the Ding Payments server MVP build plan.

Objective: Complete "docs/ARCHITECTURE.md server" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 9.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-096 — docs/API.md endpoint reference

Field	Value
Epic	EPIC-09
Phase	9
Priority	P1
Complexity	M
Blocked by	SRV-094
Blocks	—
Est. effort	3-5h

Context: Task 096 of phase 9, epic EPIC-09. Part of the Ding Payments server MVP build plan.

Objective: Complete "docs/API.md endpoint reference" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 9.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-097 — 80% test coverage critical modules

Field	Value
Epic	EPIC-09
Phase	9
Priority	P1
Complexity	M
Blocked by	SRV-029, SRV-047, SRV-060, SRV-080
Blocks	SRV-098
Est. effort	3-5h

Context: Task 097 of phase 9, epic EPIC-09. Part of the Ding Payments server MVP build plan.

Objective: Complete "80% test coverage critical modules" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 9.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-098 — Complete E2E suite in CI

Field	Value
Epic	EPIC-09
Phase	9
Priority	P0
Complexity	M
Blocked by	SRV-020, SRV-030, SRV-037, SRV-073, SRV-097
Blocks	SRV-106
Est. effort	3-5h

Context: Task 098 of phase 9, epic EPIC-09. Part of the Ding Payments server MVP build plan.

Objective: Complete "Complete E2E suite in CI" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 9.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-099 — Contract tests payment-request.v1

Field	Value
Epic	EPIC-09
Phase	9
Priority	P1
Complexity	M
Blocked by	SRV-033
Blocks	—
Est. effort	3-5h

Context: Task 099 of phase 9, epic EPIC-09. Part of the Ding Payments server MVP build plan.

Objective: Complete "Contract tests payment-request.v1" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 9.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-100 — Basic load test validate endpoint

Field	Value
Epic	EPIC-09
Phase	9
Priority	P2
Complexity	M
Blocked by	SRV-081, SRV-035
Blocks	—
Est. effort	3-5h

Context: Task 100 of phase 9, epic EPIC-09. Part of the Ding Payments server MVP build plan.

Objective: Complete "Basic load test validate endpoint" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 9.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

Phase 10 — Deploy and MVP release (EPIC-10)

Summary: 6 tasks. Dominant priority: P1.

SRV-101 — Multi-stage production Dockerfile

Field	Value
Epic	EPIC-10
Phase	10
Priority	P1
Complexity	M
Blocked by	SRV-005
Blocks	SRV-103
Est. effort	3-5h

Context: Task 101 of phase 10, epic EPIC-10. Part of the Ding Payments server MVP build plan.

Objective: Complete "Multi-stage production Dockerfile" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 10.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-102 — docker-compose dev local postgres

Field	Value
Epic	EPIC-10
Phase	10
Priority	P2
Complexity	M
Blocked by	SRV-012
Blocks	—
Est. effort	3-5h

Context: Task 102 of phase 10, epic EPIC-10. Part of the Ding Payments server MVP build plan.

Objective: Complete "docker-compose dev local postgres" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 10.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-103 — GitHub Actions deploy staging

Field	Value
Epic	EPIC-10
Phase	10
Priority	P1
Complexity	H
Blocked by	SRV-092, SRV-101
Blocks	SRV-104
Est. effort	3-5h

Context: Task 103 of phase 10, epic EPIC-10. Part of the Ding Payments server MVP build plan.

Objective: Complete "GitHub Actions deploy staging" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 10.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-104 — prisma migrate deploy in CI/CD

Field	Value
Epic	EPIC-10
Phase	10
Priority	P1
Complexity	M
Blocked by	SRV-012, SRV-103
Blocks	SRV-106
Est. effort	3-5h

Context: Task 104 of phase 10, epic EPIC-10. Part of the Ding Payments server MVP build plan.

Objective: Complete "prisma migrate deploy in CI/CD" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 10.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-105 — Operational runbook Stellar down

Field	Value
Epic	EPIC-10
Phase	10
Priority	P1
Complexity	E
Blocked by	—
Blocks	—
Est. effort	3-5h

Context: Task 105 of phase 10, epic EPIC-10. Part of the Ding Payments server MVP build plan.

Objective: Complete "Operational runbook Stellar down" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 10.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

SRV-106 — Server MVP release checklist

Field	Value
Epic	EPIC-10
Phase	10
Priority	P1
Complexity	E
Blocked by	SRV-098, SRV-104
Blocks	—
Est. effort	3-5h

Context: Task 106 of phase 10, epic EPIC-10. Part of the Ding Payments server MVP build plan.

Objective: Complete "Server MVP release checklist" per the architecture defined in Sections 3–6 of this document.

Acceptance criteria:

• Implementation compiles without TypeScript errors
• Associated tests pass (npm test / npm run test:e2e as applicable)
• Code follows conventions in .cursor/rules/BACKEND-ARCHITECTURE.mdc
• Swagger updated if the task exposes endpoints
• No secrets introduced in the repository

Files: See specific implementation in Section 8 — Phase 10.

Tests: Unit tests in co-located *.spec.ts; E2E in test/ if applicable.

Client dependency: See Section 9 — Client ↔ server matrix.

Notes for agents: Run from ding-server/. Atomic commit per task. Skills: .agents/skills/nestjs-best-practices/.

Detailed implementations — Phase 0

SRV-001 — README

• Modify: ding-server/README.md
• Include: Ding Payments description, prerequisites (Node 20+, Supabase), setup (cp .env.example .env), scripts, module structure, link to docs/

SRV-002 — .env.example

• Create: ding-server/.env.example
• Copy variables from Section 3 of this document

SRV-003 — Dependencies

cd ding-server
npm install @nestjs/config @nestjs/swagger @nestjs/throttler @nestjs/event-emitter @nestjs/passport passport passport-jwt class-validator class-transformer helmet joi @supabase/supabase-js @prisma/client @stellar/stellar-sdk @simplewebauthn/server
npm install -D prisma @types/passport-jwt

SRV-004 — ConfigModule

• Create: src/config/config.module.ts, src/config/env.validation.ts, src/config/configuration.ts
• Validate all .env.example vars with Joi
• Register in app.module.ts as global

SRV-005 — main.ts

• Modify: src/main.ts
• Add: ValidationPipe (whitelist, transform), Helmet, CORS from env, Swagger at /docs, prefix /v1, enableShutdownHooks

SRV-006 — Exception filter

• Create: src/common/filters/http-exception.filter.ts
• Formato: { statusCode, message, code?, errors?, timestamp, path }

SRV-007 — Folders

• Create dirs: src/config, src/common/filters, src/database, src/auth, src/stellar, src/webauthn, src/contracts, src/modules/users, src/modules/payment-requests, src/modules/payments, src/modules/transactions

SRV-008 — Cursor rules

• Modify: .cursor/rules/BACKEND-ARCHITECTURE.mdc, CORE-API.mdc, DATABASE.mdc
• Replace apps/core-api/ → ding-server/src/

Detailed implementations — Phase 1

SRV-009 — Prisma install

npx prisma init

• Add scripts: prisma:generate, prisma:migrate, prisma:push, prisma:studio, prisma:seed

SRV-010/013/014 — Schema

• Create: prisma/schema.prisma with models from Section 4
• Use Decimal for amounts, never Float

SRV-011 — PrismaService

• Create: src/database/database.module.ts, src/database/prisma.service.ts
• Implement OnModuleInit/OnModuleDestroy ($connect/$disconnect)
• Export global from DatabaseModule

SRV-012 — Migration

npx prisma migrate dev --name init

SRV-016 — Seed

• Create: prisma/seed.ts — 2 users test, wallets testnet, sample payment request

Detailed implementations — Phase 2

SRV-021-023 — Auth

• Create: src/auth/auth.module.ts, src/supabase/supabase.service.ts
• JWT validation with SUPABASE_JWT_SECRET
• @Public() on validate and health endpoints

SRV-025-027 — Users

• Create: src/modules/users/users.module.ts, controller, service, dto/
• Upsert user from JWT on first request
• Wallet link with unique constraint per network

Detailed implementations — Phase 3

SRV-031 — Restore contract doc

git show 5d4e9de^:docs/payment-request.v1.md > docs/payment-request.v1.md

SRV-032 — Port contract

git show 5d4e9de^:src/payments/contracts/payment-request.v1.ts > src/contracts/payment-request.v1.ts
git show 5d4e9de^:src/payments/contracts/payment-request.v1.spec.ts > src/contracts/payment-request.v1.spec.ts

SRV-035 — Validate endpoint

• Create: src/modules/payment-requests/payment-requests.service.ts
• Call validatePaymentRequestV1(body) — do NOT reuse ETH/BTC logic from pre-reset
• Controller: POST validate, @Public()

SRV-038-040 — Request persistence

• Save PaymentRequest after successful validation
• Mark UsedRequestId if requestId present
• GET by id with auth — owner or participant only

Detailed implementations — Phase 4

SRV-042-044 — WebAuthn

• Create: src/webauthn/webauthn.module.ts, webauthn.service.ts, webauthn.controller.ts
• Store challenges in WebAuthnChallenge table, TTL 5 min
• RP ID and origin from env

SRV-045 — Authorize payment

• POST body: { credentialId, authenticatorData, clientDataJSON, signature }
• Verify with verifyAuthenticationResponse
• Transition payment CREATED → AUTHORIZED

Detailed implementations — Phase 5

SRV-049-055 — Stellar

• Create: src/stellar/stellar.module.ts, stellar.service.ts
• Usar StellarSdk.Horizon.Server y StellarSdk.rpc.Server
• USDC: new StellarSdk.Asset('USDC', issuer)
• buildPaymentTransaction: Operation.payment, load account, set timeout

SRV-057 — XDR validation

• Parse Transaction from XDR
• Extract operation type payment, compare destination, amount, asset

Detailed implementations — Phase 6

SRV-061-072 — Payments lifecycle

• Create: src/modules/payments/payments.module.ts, payments.service.ts, payment-state.machine.ts
• @OnEvent('payment.submitted') → poll loop
• Idempotency: if duplicate submit with same XDR, return 200 with current state

Detailed implementations — Phases 7-10

SRV-075-080 — Transactions history

• Paginate with Prisma skip/take
• Query filters: asset, from, to, direction

SRV-081-090 — Security

• Throttle: validate 30/min, submit 10/min per user
• AuditLog listener on all payment.* events

SRV-091-100 — Observability

• Logger middleware with requestId
• /health/ready checks prisma.$queryRaw and stellar.getHealth

SRV-101-106 — Deploy

• Dockerfile: node:20-alpine, multi-stage build
• CI: deploy on push to develop

8.1 Critical tasks — extended implementation

The following P0 tasks have additional instructions for agents. They complement the individual entries above.

---

SRV-011 — DatabaseModule and PrismaService (extended)

Files:

• Create: ding-server/src/database/database.module.ts
• Create: ding-server/src/database/prisma.service.ts
• Create: ding-server/src/database/index.ts
• Modify: ding-server/src/app.module.ts

Implementation:

// prisma.service.ts
@Injectable()
export class PrismaService extends PrismaClient implements OnModuleInit, OnModuleDestroy {
  async onModuleInit() { await this.$connect(); }
  async onModuleDestroy() { await this.$disconnect(); }
}

// database.module.ts
@Global()
@Module({ providers: [PrismaService], exports: [PrismaService] })
export class DatabaseModule {}

Tests: Mock PrismaService in e2e with $connect, $disconnect, and required delegates.

Client dependency: None.

---

SRV-023 — Global SupabaseAuthGuard (extended)

Files:

• Create: ding-server/src/auth/decorators/public.decorator.ts
• Create: ding-server/src/auth/guards/supabase-auth.guard.ts
• Modify: ding-server/src/app.module.ts — { provide: APP_GUARD, useClass: SupabaseAuthGuard }

Specific criteria:

• Endpoints with @Public(): POST /v1/payment-requests/validate, GET /health, GET /health/*
• Invalid JWT → 401 { statusCode: 401, message: 'Unauthorized' }
• Valid JWT → request.user populated with { supabaseUserId, email }

Client dependency: Client must send Authorization: Bearer <token> from Supabase Auth on all protected endpoints.

---

SRV-035 — POST /v1/payment-requests/validate (extended)

Files:

• Create: ding-server/src/modules/payment-requests/payment-requests.controller.ts
• Create: ding-server/src/modules/payment-requests/payment-requests.service.ts
• Create: ding-server/src/modules/payment-requests/payment-requests.module.ts
• Create: ding-server/src/modules/payment-requests/dto/validate-payment-request.dto.ts
• Test: ding-server/test/payment-requests-validate.e2e-spec.ts

Service implementation:

@Injectable()
export class PaymentRequestsService {
  validate(payload: unknown): PaymentRequestValidationResult {
    return validatePaymentRequestV1(payload, new Date());
  }
}

Specific criteria:

• Accepts direct v1 contract JSON body (no { payload: ... } wrapper)
• 200 response for both valid and invalid; valid: boolean field
• Errors use PAYMENT_REQUEST_* codes from the contract
• Do NOT support ETH/BTC/SOL assets from pre-reset code

Required e2e tests:

1. Valid USDC payload → valid: true
2. Asset BTC → PAYMENT_REQUEST_ASSET_UNSUPPORTED
3. Recipient 0x... → PAYMENT_REQUEST_RECIPIENT_INVALID
4. expiresAt in the past → PAYMENT_REQUEST_EXPIRES_AT_OUT_OF_WINDOW

Client dependency: Receiver client must generate payload per payment-request.v1.md before NFC transfer.

---

SRV-045 — POST /v1/payments/:id/authorize (extended)

Files:

• Create: ding-server/src/modules/payments/dto/authorize-payment.dto.ts
• Modify: ding-server/src/modules/payments/payments.controller.ts
• Modify: ding-server/src/modules/payments/payments.service.ts

Flow:

1. Client calls POST /v1/webauthn/authenticate/options with { paymentId }
2. Server generates challenge, stores it in WebAuthnChallenge with 5 min TTL
3. Client executes navigator.credentials.get() with the challenge
4. Client sends assertion to POST /v1/payments/:id/authorize
5. Server verifies with verifyAuthenticationResponse() from @simplewebauthn/server
6. If OK: payment.status = AUTHORIZED, authorizedAt = now(), emit payment.authorized

Specific criteria:

• Payment must be in CREATED
• Payment not expired (expiresAt > now)
• Challenge not expired and not reused
• Only senderUserId can authorize

Client dependency: Confirmation screen + passkey authenticate (CLI plan). Must send complete assertion.

---

SRV-057 — Validate XDR matches payment intent (extended)

Files:

• Create: ding-server/src/stellar/xdr-validator.service.ts
• Test: ding-server/src/stellar/xdr-validator.service.spec.ts

Implementation:

import * as StellarSdk from '@stellar/stellar-sdk';

validatePaymentXdr(signedXdr: string, intent: PaymentIntent): void {
  const tx = new StellarSdk.Transaction(signedXdr, networkPassphrase);
  const op = tx.operations[0];
  if (op.type !== 'payment') throw new BadRequestException({ code: 'PAYMENT_XDR_INVALID' });
  // Compare op.destination, op.amount, op.asset with intent
  // Verify source account === intent.senderPublicKey
}

Specific criteria:

• Reject XDR with multiple operations in MVP
• Reject fee bump transactions
• Amount must match exactly (7 decimals max)
• USDC: compare asset code + issuer

Client dependency: Client builds tx with same parameters as payment intent.

---

SRV-065 — POST /v1/payments/:id/submit relay XDR (extended)

Files:

• Create: ding-server/src/modules/payments/dto/submit-payment.dto.ts
• Modify: ding-server/src/modules/payments/payments.service.ts

Full flow:

1. Verify payment AUTHORIZED
2. Call xdrValidator.validatePaymentXdr(dto.signedXdr, payment)
3. Verify payment senderPublicKey matches XDR signer (SRV-088)
4. stellarService.submitTransaction(dto.signedXdr)
5. Guardar stellarTxHash, status = SUBMITTED, submittedAt = now()
6. Emit payment.submitted → listener starts poll (SRV-067)
7. Mark PaymentRequest as CONSUMED

DTO:

export class SubmitPaymentDto {
  @IsString()
  @IsNotEmpty()
  signedXdr: string;
}

Specific criteria:

• Idempotent: second submit with same XDR → 200 with current state
• Submit with different XDR → 409 PAYMENT_ALREADY_SUBMITTED
• Horizon error op_underfunded → status = FAILED, failureCode = STELLAR_OP_UNDERFUNDED

Client dependency: Client signs tx locally and sends base64 XDR. Do not send secret seed to the server.

---

SRV-067 — Event listener polling confirmation (extended)

Files:

• Create: ding-server/src/modules/payments/payment-confirmation.listener.ts

Implementation:

@Injectable()
export class PaymentConfirmationListener {
  @OnEvent('payment.submitted')
  async handleSubmitted(event: PaymentSubmittedEvent) {
    const result = await this.stellarService.pollTransactionStatus(
      event.stellarTxHash,
      { intervalMs: config.PAYMENT_POLL_INTERVAL_MS, maxAttempts: config.PAYMENT_POLL_MAX_ATTEMPTS }
    );
    if (result.confirmed) {
      await this.paymentsService.markConfirmed(event.paymentId, result);
      this.eventEmitter.emit('payment.confirmed', { ... });
    } else {
      await this.paymentsService.markFailed(event.paymentId, result.failureCode);
    }
  }
}

Client dependency: Client polls GET /v1/payments/:id every 2s until CONFIRMED or FAILED.

---

SRV-013 — Prisma schema PaymentRequest and Payment (extended)

Schema snippet:

model PaymentRequest {
  id                String               @id @default(uuid())
  externalRequestId String?              @unique
  receiverUserId    String
  receiver          User                 @relation(fields: [receiverUserId], references: [id])
  recipient         String
  asset             AssetCode
  amount            Decimal              @db.Decimal(20, 7)
  memo              String?              @db.VarChar(280)
  status            PaymentRequestStatus @default(CREATED)
  payloadTimestamp  DateTime
  expiresAt         DateTime
  metadata          Json?
  createdAt         DateTime             @default(now())
  payments          Payment[]
  @@index([receiverUserId, status])
}

model Payment {
  id               String        @id @default(uuid())
  paymentRequestId String?
  paymentRequest   PaymentRequest? @relation(fields: [paymentRequestId], references: [id])
  senderUserId     String
  receiverUserId   String
  sender           User          @relation("SentPayments", fields: [senderUserId], references: [id])
  receiver         User          @relation("ReceivedPayments", fields: [receiverUserId], references: [id])
  recipient        String
  senderPublicKey  String
  asset            AssetCode
  amount           Decimal       @db.Decimal(20, 7)
  status           PaymentStatus @default(CREATED)
  stellarTxHash    String?       @unique
  failureReason    String?
  failureCode      String?
  authorizedAt     DateTime?
  submittedAt      DateTime?
  confirmedAt      DateTime?
  expiresAt        DateTime
  createdAt        DateTime      @default(now())
  updatedAt        DateTime      @updatedAt
  @@index([senderUserId, status])
  @@index([receiverUserId, status])
}

---

9. Client ↔ server dependency matrix

Integration point	Server endpoint	Server task	Required on client	Order
Validate NFC payload	POST /v1/payment-requests/validate	SRV-035	payment-request.v1 payload emitter	Client can develop in parallel with mock
Register request	POST /v1/payment-requests	SRV-038	Receiver flow + auth JWT	After SRV-038 + client auth
Create payment	POST /v1/payments	SRV-062	Sender flow post-NFC	After validate
Passkey registration	POST /v1/webauthn/register/*	SRV-043	WebAuthn register UI	Parallel phase 4
Authorize payment	POST /v1/payments/:id/authorize	SRV-045	Passkey authenticate UI	After SRV-045
Simulate tx	POST /v1/transactions/simulate	SRV-056	Local tx builder	Optional pre-sign
Sign and submit	POST /v1/payments/:id/submit	SRV-065	Local signing + XDR	After authorize
Poll status	GET /v1/payments/:id	SRV-069	Confirmation UI both users	After submit
History	GET /v1/transactions	SRV-075	History screen	P1
Link wallet	POST /v1/users/me/wallet	SRV-027	Wallet setup onboarding	Before first payment

NFC contract — mandatory alignment

The client must emit payment-request.v1:

{
  "type": "payment-request",
  "version": 1,
  "recipient": "GAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",
  "asset": "USDC",
  "amount": "25.00",
  "timestamp": "2026-06-17T12:00:00.000Z",
  "expiresAt": "2026-06-17T12:00:30.000Z",
  "requestId": "req_unique_123",
  "memo": "Coffee"
}

Do not use the simplified format from ding-payments.md (unix timestamps, type payment_request with underscore).

---

10. Risks and open decisions

Question	Decision in this plan	Task
Sign NFC payment request?	Not in MVP; structural validation + requestId anti-replay	SRV-039
Pre-simulate transactions?	Yes, simulate endpoint	SRV-056
USDC issuer per network?	Env var STELLAR_USDC_ISSUER	SRV-049
Who broadcasts?	Server (relay)	SRV-065
Payment auth?	Hybrid Supabase + WebAuthn	SRV-045
Push notifications on confirmation?	Outside MVP (P3)	—
Usernames?	Outside MVP	—

Technical risks

Risk	Impact	Mitigation
Stellar RPC down	Payments do not confirm	SRV-059 health, SRV-105 runbook, retry poll
Clock skew between devices	Requests rejected	SRV-082, 5 min window
Malicious XDR on submit	User fund loss	SRV-057 strict validation
Replay requestId	Double charge	SRV-039 UsedRequestId
WebAuthn origin mismatch	Auth fails in prod	WEBAUTHN_ORIGIN per env

---

11. Appendices

Appendix A — Error codes

Payment Request (PAYMENT_REQUEST_*):

• PAYMENT_REQUEST_PAYLOAD_INVALID
• PAYMENT_REQUEST_FIELD_REQUIRED
• PAYMENT_REQUEST_FIELD_UNKNOWN
• PAYMENT_REQUEST_TYPE_UNSUPPORTED
• PAYMENT_REQUEST_VERSION_UNSUPPORTED
• PAYMENT_REQUEST_RECIPIENT_INVALID
• PAYMENT_REQUEST_ASSET_UNSUPPORTED
• PAYMENT_REQUEST_AMOUNT_INVALID
• PAYMENT_REQUEST_TIMESTAMP_INVALID
• PAYMENT_REQUEST_TIMESTAMP_OUT_OF_WINDOW
• PAYMENT_REQUEST_EXPIRES_AT_INVALID
• PAYMENT_REQUEST_EXPIRES_AT_OUT_OF_WINDOW
• PAYMENT_REQUEST_METADATA_INVALID

Payment (PAYMENT_*):

• PAYMENT_NOT_FOUND
• PAYMENT_EXPIRED
• PAYMENT_INVALID_STATE
• PAYMENT_SENDER_IS_RECEIVER
• PAYMENT_UNAUTHORIZED
• PAYMENT_XDR_MISMATCH
• PAYMENT_XDR_INVALID
• PAYMENT_ALREADY_SUBMITTED
• PAYMENT_REQUEST_ID_REPLAY

Stellar (STELLAR_*):

• STELLAR_ACCOUNT_NOT_FOUND
• STELLAR_INSUFFICIENT_BALANCE
• STELLAR_TX_FAILED
• STELLAR_OP_UNDERFUNDED
• STELLAR_NETWORK_ERROR
• STELLAR_TIMEOUT

WebAuthn (WEBAUTHN_*):

• WEBAUTHN_CHALLENGE_EXPIRED
• WEBAUTHN_VERIFICATION_FAILED
• WEBAUTHN_CREDENTIAL_NOT_FOUND

Appendix B — Additional examples

POST /v1/payments/:id/submit

// Request
{ "signedXdr": "AAAA..." }

// Response 200
{
  "id": "550e8400-e29b-41d4-a716-446655440000",
  "status": "SUBMITTED",
  "stellarTxHash": "abc123def456..."
}

POST /v1/payments/:id/authorize

// Request
{
  "id": "credential-id-base64",
  "rawId": "...",
  "response": {
    "authenticatorData": "...",
    "clientDataJSON": "...",
    "signature": "..."
  }
}

Appendix C — Useful commands

# Development
cd ding-server
cp .env.example .env
npm install
npm run prisma:generate
npm run prisma:migrate
npm run start:dev

# Tests
npm test
npm run test:e2e
npm run test:cov

# Prisma
npm run prisma:studio
npm run prisma:seed

# Build
npm run build
npm run lint

Appendix D — Git pre-reset

# View previous implementation
git show 5d4e9de^:src/payments/contracts/payment-request.v1.ts
git show 5d4e9de^:docs/payment-request.v1.md
git diff 5d4e9de^ 5d4e9de --stat

Appendix E — Epics summary

Epic	Name	Tasks	Phase
EPIC-00	Foundation	SRV-001–008	0
EPIC-01	Database	SRV-009–020	1
EPIC-02	Auth (Supabase + WebAuthn)	SRV-021–030, 041–048	2, 4
EPIC-03	NFC contract	SRV-031–040	3
EPIC-04	Payment Lifecycle	SRV-061–074, 045	4, 6
EPIC-05	Stellar Integration	SRV-049–060	5
EPIC-06	Transaction History	SRV-075–080	7
EPIC-07	Security	SRV-081–090	8
EPIC-08	Observability	SRV-091–093	9
EPIC-09	Quality	SRV-094–100	9
EPIC-10	Deploy	SRV-101–106	10

---

End of Server Build Plan — Ding Payments v1.0