Market Data Services

Provides external market data integration for equity and bond pricing. Production code uses DSEApiService, while tests may continue relying on the legacy stub exported as DseMarketDataService.

Location: worker/services/market-data/

Production: DSEApiService

Source: worker/services/market-data/dse-api-service.ts

Dependencies

• @shared/dse-api OpenAPI client (fetch wrapper)
• Zod schemas in dse-api-schemas.ts
• createLogger for structured telemetry

Public Methods

getEquities(): Promise<EquityEntity[]> : Fetches active equities from /securities, validates responses with Zod, and throws DSEApiError on network/validation failures.

getSecurityBySymbol(symbol: string): Promise<EquityEntity | null> : Retrieves a single equity; returns null on 404, throws DSEApiError otherwise.

getSecurityDetails(symbol: string): Promise<DSESecurityDetail | null> : Low-level accessor for detailed security metadata.

getLastTradedPrices(symbols: string[]): Promise<DSEPrice[]> : Batch price lookup for equities.

getBondPrices(isins: string[]): Promise<Array<{ isin: string; price: number | null }>> : Fetches bond prices when available.

getSyncStatus(): Promise<SyncStatus> : Returns API operational status.

Error Handling

• All failures throw DSEApiError (message, endpoint, optional statusCode, and originalError).
• Unexpected throwables are wrapped in DSEApiError with context and logged.
• Callers must try/catch and map to domain errors (createBusinessLogicError) before surfacing to tRPC.

Example

import { DSEApiService, DSEApiError } from "@worker/services/market-data";

const dseApi = new DSEApiService();

try {
  const equities = await dseApi.getEquities();
  // ... use equities ...
} catch (error) {
  if (error instanceof DSEApiError) {
    logger.warn(
      { endpoint: error.endpoint, status: error.statusCode },
      "DSE API failure",
    );
    throw createBusinessLogicError(`Market data unavailable: ${error.message}`);
  }
  throw error;
}

Legacy/Test Stub: DseMarketDataService

Source: worker/services/market-data/index.ts

A minimal stub retained for backwards compatibility in tests. Methods resolve to null, empty maps, or placeholder values. Prefer injecting mocks of DSEApiService for new tests.

Placeholder Bond Market Data

Source: worker/services/market-data/bond-index.ts

PlaceholderBondMarketDataService returns synthetic bond prices (typically face value) and accrued interest for deterministic testing.

Integration

Market data services are consumed by:

• Equity Portfolio Service – generateDailySnapshot, ensureEquities
• Bond Portfolio Service – generateDailySnapshot (with pricing fallbacks)
• EOD Operations – portfolio valuation flows

Migration Notes

• Production code should inject DSEApiService and convert DSEApiError into domain-friendly errors before reaching tRPC.
• The legacy stub will be removed after all tests migrate to explicit mocks.

Last Validated: 2025-11-10 against commit 0342a62e