Hi all, quick heads up for teams integrating with Jupiter Prediction Markets API.
We’re shipping a coordinated migration to add fractional contracts support, scheduled for Wednesday, 27 May 2026 at 6:00 AM UTC (2:00 PM SGT, UTC+8).
Estimated downtime: up to ~4 hours (may complete earlier if everything goes smoothly).
What’s changing
Contract quantities are migrating from whole-contract units to micro-contract units, enabling fractional positions.
Example:
- Before: 5
- After: 5000000 micro-contracts (= 5 contracts)
This enables positions such as 5.777773 contracts, partial fills with exact fractional accounting, and better compatibility with external liquidity venues.
Order sizing precision: Effective fill sizes will be floored to 0.01-contract increments on the keeper to stay aligned with external venue precision. You can submit finer-grained sizes, but executed amounts will round down to the nearest 0.01.
Compatibility (non-breaking at deploy time)
Existing legacy fields will continue to work for backwards compatibility:
- contracts
- filledContracts
- totalContracts
New exact fields will be added:
- contractsMicro
- contractsDecimal
USD fields remain unchanged (still micro-USD). Orderbook sizes will be returned as decimal strings.
During the migration window
- Trading and order creation will be paused
- Claims and settlement will be paused
- Read APIs may be temporarily stale or inconsistent
- Integrators generally do not need to make changes to keep working after the migration
Recommended action
Legacy whole-contract fields will be deprecated roughly one week after the migration. Within that week, please migrate to the new exact-quantity fields:
- Use *Micro fields for calculations and order creation
- Use *Decimal fields for UI display
- Treat legacy whole-contract fields as compatibility-only
We’ll post another reminder closer to the maintenance window and confirm once the migration is complete. If you’re unsure how this affects your integration, reach out to @anmoldotsol and we’ll help verify.
