[Backend] Token Metadata & Verified Asset Registry Service

[blurbeast]

Overview & Background

FlowFi streams can be created using any valid Soroban token contract or Stellar Asset Contract (SAC). To display human-readable symbols (e.g. USDC, EURC, XLM), icons, decimals, and verification badges in the frontend, the backend needs a Token Registry service that indexes on-chain asset details and caches metadata.

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Technical Specification & Architecture

1. Database Schema (prisma/schema.prisma)

model TokenRegistry {
  id              String   @id @default(uuid())
  contractAddress String   @unique // C... or SAC address
  symbol          String
  name            String
  decimals        Int
  iconUrl         String?
  issuerAddress   String?  // G... for Stellar classic assets
  isVerified      Boolean  @default(false)
  updatedAt       DateTime @updatedAt
  createdAt       DateTime @default(now())

  @@index([contractAddress])
  @@index([symbol])
}

2. Service Implementation (backend/src/services/token-registry.service.ts)

1. On-Chain Probe:
   • Query Soroban token contract decimals and symbol via RPC simulation.
   • If SAC, resolve asset code and issuer via Stellar Horizon.
2. Caching:
   • Cache token metadata in Redis with 24-hour TTL.
3. API Endpoint:
   • GET /api/v1/tokens: List verified tokens.
   • GET /api/v1/tokens/:address: Fetch or resolve metadata for a specific token contract.

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Target Files

• backend/prisma/schema.prisma
• backend/src/services/token-registry.service.ts
• backend/src/controllers/token.controller.ts
• backend/src/routes/v1/token.routes.ts

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Acceptance Criteria

• Automatically resolves decimals and symbol for any Soroban or SAC token address.
• Caches asset metadata in database and Redis to minimize Horizon RPC traffic.
• REST API endpoints for token listing and metadata lookup.

[jchinedu]

let me work on this issue