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Money is a Float throughout the GraphQL schema #371
Description
Background
price: Float!
sdexPrice: Float!
ammPrice: Float!
vwap: Float!
volume: Float!GraphQL's Float is an IEEE 754 double. Prices are stored as
Decimal(36, 18) in schema.prisma and are already cast ::float in 18 places
in the SQL — this schema is the last step of that chain, and it makes the loss
permanent and caller-visible.
For an asset priced around 0.18 this rarely matters. For a long-tail asset
priced at 0.000000000000001234, or a volume in the billions, doubles start
eating digits — and the whole purpose of this API is being the number other
systems trust.
What to build
This is a design change, so propose it before building it.
- A custom
Decimalscalar serialising as a string, preserving the stored
precision end to end. - Decide what happens to existing clients: adding a new field alongside the
Floatand deprecating the old one is the usual path, and it is a breaking
change either way, so the migration needs stating. - Audit where the
::floatcasts happen — fixing the schema while the SQL still
rounds achieves nothing. - A test with a value that genuinely cannot survive a double round-trip.
Acceptance criteria
- Monetary values can be requested at full stored precision
- The precision survives the whole path, SQL included
- Existing clients have a documented migration
- A test asserts a value that a double would round is returned exactly
- The trade-off and the migration are written down
Drips Wave · Complexity: Advanced · 200 points
Repo: Divinity-Labs/Lens. Node + TypeScript, Fastify, mercurius for
GraphQL at POST /graphql, Prisma on Postgres, Redis, Prometheus.
Run the tests: npm test. The tests are vitest, not jest. Running jest
here reports "66 suites, 0 tests" and means nothing. A single file is
npx vitest run src/__tests__/graphqlSubscription.test.ts.
Load test (prices) is already failing on main and has been for some
time. It is not your PR. Everything else should be green.
Read src/__tests__/graphqlSubscription.test.ts before you start. It is the
house pattern for testing this surface and it is good — it drives a real
subscription through a real server and asserts on what a client receives.
This service prices real assets on Stellar mainnet. A wrong number is worse
than a missing one, because the caller cannot tell.
Never elide an address, a contract id or a key in code, comments or test
fixtures. A previous batch shortened a contract id in an issue and five
contributors invented plausible-looking ids to fill the gap. Write it in full or
not at all.
Required: Before submitting, join the contributor Telegram so your work can be tracked and counted toward the Stellar Wave: https://t.me/+fxHXq8f1SwlkZDBk
Activity
Jossy-ossy commentedon Oct 16, 2026
@Jossy-ossy has applied to work on this issue as part of the Stellar Wave Program's 10th wave.
ℹ️ Repo Maintainers: To accept this application, review their application or assign @Jossy-ossy to this issue.
drips-wave commentedon Oct 16, 2026
Congratulations, @Jossy-ossy! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on October 22, 2026.
🧑💻 @Jossy-ossy: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.
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Jossy-ossy commentedon Oct 16, 2026
Proposed approach before implementation:
This keeps existing clients working while establishing a lossless path for new clients. Please let me know if you want a different field naming or migration policy before I build it.
fix: preserve decimal precision in GraphQL prices (Divinity-Labs#371)