Contract Delta: 010 Pricing Awareness and Market Data

Parent state: 005-messaging-nats-replacement

REST/OpenAPI Changes

• trade-service request/response schema extends TradeOrder with price.
• position-service payloads include averageCostBasis in positions and price in trades.
• New local service endpoint:
  • price-publisher: GET /prices, GET /prices/{ticker}, GET /health.
  • price-publisher /health includes active publish cadence config (minMs, maxMs, ratio).

Event Contract Changes

• Existing account-scoped topics remain:
  • /accounts/<accountId>/trades
  • /accounts/<accountId>/positions
• New market data topic family:
  • pricing.<TICKER>

Expected pricing payload:

{
  "ticker": "IBM",
  "price": 187.245,
  "openPrice": 186.000,
  "closePrice": 187.400,
  "asOf": "2026-03-31T11:00:00.000Z",
  "source": "snapshot"
}

Reference Data Symbol Contract Notes

• State 010 normalizes legacy FB symbol to META for returned stock identifiers.
• Runtime supported symbol set is expected to match between reference-data and price-publisher.