# Migration Guidance: 007 to 008 Pricing Awareness

> For the complete documentation index, see [llms.txt](https://deploy-preview-472--lucky-concha-f3599f.netlify.app/llms.txt).

## Goal

Add pricing behavior on top of state `006` messaging/runtime without breaking existing baseline trade/account workflows.

## Backend Service Changes

### trade-service

*   Fetch current price from `price-publisher` (`GET /prices/{ticker}`).
*   Stamp `tradeOrder.price` before publishing on `/trades`.

### trade-processor

*   Persist `trade.price`.
*   Update and persist `position.averageCostBasis` during position aggregation.
*   Continue publishing account-scoped events with enriched payloads.

### position-service

*   Expose enriched persisted trade/position fields through existing REST endpoints.

### price-publisher (new)

*   Bootstrap baseline open/close values from:
    *   snapshot file (default), or
    *   yfinance (startup-only mode).
*   Emit `pricing.<TICKER>` NATS updates on randomized interval (`750-1500ms` default), publishing randomized subset per cycle (`25%` default, configurable).
*   Align supported symbol universe with reference-data and normalize legacy `FB` to `META` in reference-data output.

## Frontend Changes

*   Keep account-scoped subscriptions from `006`.
*   Add `pricing.*` subscription to update market valuation fields in real time.
*   Display:
    *   trade execution `price`,
    *   relative execution time,
    *   position `marketPrice`, value, and P&L,
    *   portfolio totals for value and cost basis.

## Cutover Strategy

1.  Add `price-publisher` runtime and pricing subject map.
2.  Enrich trade submission + persistence with execution price.
3.  Enrich position persistence with average cost basis.
4.  Extend frontend valuation rendering and totals.

## Post-Migration

*   Validate baseline flows F2/F4 still pass with pricing additions.
*   Keep advanced pricing engines and risk analytics out of scope for this state.