Replace hardcoded mock prices in the oracle-feeds endpoint with a real price source

[priscaenoch]

Problem

src/api/oracle-feeds.ts exposes a price endpoint (GET /oracle-feeds/assets/{assetPair}/price) that returns values from a hardcoded mockPrices object (line 98); the response (line 107) sets price: mockPrices[assetPair], so callers receive fabricated figures presented as live oracle data, and an unknown pair returns undefined. The module has 9 routes built on this mock source. Doing this properly is more than a one-line swap: it means introducing a reusable price-provider layer with caching and configuration, refactoring all nine routes onto it, and covering it with tests.

What needs to be done

• Introduce a price-provider abstraction (interface) so the data source is swappable and testable.
• Implement a real provider (a Stellar/Soroban on-chain oracle or a configured external feed).
• Add a caching layer and rate-limit handling consistent with the other feed routes.
• Refactor all nine oracle-feeds routes to read from the provider, and return a documented 404/typed error for an unknown assetPair instead of undefined.
• Add provider and cache configuration via environment variables, documented in .env.example and the README.
• Gate any residual mock behind the shared MOCK_DATA flag (coordinate with the mock-data framework issue).

Files

• src/api/oracle-feeds.ts
• new src/services/pricing/provider.ts (interface) and a real implementation
• a caching module under src/services/pricing/ (or reuse the existing cache layer)
• src/config/ (provider + cache configuration)
• .env.example, README.md
• tests under tests/

Acceptance deliverables

• All nine routes read from the provider; no hardcoded prices remain in the response path.
• Unknown asset pairs return a documented error, not undefined.
• Any remaining mock is behind an explicit, default-off flag.
• All CI checks pass; the change cannot be merged until CI is green.

Tests to pass

• Test: the endpoint returns provider data (provider mocked) and a typed 404 for an unknown pair.
• Test: responses are served from cache within the configured TTL.
• Test: with MOCK_DATA unset, no fabricated price is served.

[DEV-DESIGN6]

I’d like to take on this task because it addresses an important reliability issue: configuration errors should be caught immediately at startup rather than appearing later as confusing runtime failures.

My approach would be to introduce a shared, Zod-based validation pattern for both the API and indexer, with centralized network resolution using STELLAR_NETWORK and NODE_ENV. I’ll ensure each service validates only the variables required for its active network, produces clear actionable errors listing the affected keys, and never exposes secret values in logs.

I’ll also update .env.example and the README so the documented configuration stays consistent with the validation schema. I’ll add focused tests covering both complete and incomplete environments for the API and indexer, including invalid configuration cases, and run the existing CI checks to ensure everything remains green.

I’m comfortable working across TypeScript/JavaScript codebases, configuration validation, testing, and documentation, and I’ll keep the implementation focused, maintainable, and aligned with the existing project structure.