API reference, Builder codes

Builder leaderboard

Every builder code ranked by fees, volume, users or orders, over 24 h to all time.

GET https://api.femtos.xyz/v1/hypercore/builders

Parameters

Param	In	Example or values	Meaning
`window`	query	`(empty)`, `24h`, `7d`, `30d`, `90d`, `all`	Window, whole hours ending with the current one: 24h, 7d, 30d, 90d, or all (since 2025-07-19)
`sort`	query	`(empty)`, `fees`, `volume`, `fills`, `users`, `orders`	Order, largest first
`limit`	query	`20`	Builders

curl -H "Authorization: Bearer $FEMTOS_KEY" "https://api.femtos.xyz/v1/hypercore/builders?window=7d&sort=fees&limit=20"

Key: Authorization: Bearer $FEMTOS_KEY. Get a free key, or with no browser through agent onboarding.

Field	Type	Meaning
`builders[]`	object	Ranked by `sort`: {builder, app, entity, fees, feesByToken, volume, fills, takerFills, users, feeRate, feeShare, orders}
`builders[].fees`	decimal	Builder fees earned: Σ builder fee of its fills, in USD stablecoins at par (USDC, USDH, USDE, USDT0)
`builders[].volume`	decimal	Σ px × sz of its fills, on markets quoted in USD stablecoins at par (USDC, USDH, USDE, USDT0); both sides of a trade it routed are counted only when both carry its code
`builders[].users`	int	Distinct accounts behind those fills
`builders[].feeShare`	decimal \| null	Its share of every builder's fees in the window, 0..1 (exact to 40 significant digits); null when none earned any
`builders[].orders`	object \| null	Its order statuses in the window; null for a window ending before order coverage: {orders, filled, canceled, rejected, triggered, feeTenthsBp}
`total`	object	Every builder together (users: distinct across them): {fees, feesByToken, volume, fills, takerFills, users, feeRate, builders}
`asOf`	int \| null	When the rollups read were last recomputed (Unix ms, every 5 minutes); null when the window has none
`ordersFrom`	ms	Start of the order-status coverage (2026-10-13 15:50 UTC); fills go back to 2025-07-19

Builder GET /v1/hypercore/builders/{builder} HyperCore
One builder code: totals and rank, day by day, per market, order outcomes and fee rates.
Builder orders GET /v1/hypercore/builders/{builder}/orders HyperCore
Every status of the orders sent with one builder code, rejections and their reasons included.
Builder orders stream WS hc.builder.orders HyperCore
Every status of the orders sent with one builder code as it happens, rejections and their reasons included. One frame per block with all its matching events.
Builder fills GET /v1/hypercore/builders/{builder}/fills HyperCore
Every fill of one builder code, with its builder fee, oid, tid and hash.
Builder fills stream WS hc.builder.fills HyperCore
Every fill of one builder code as it happens, with its builder fee: the rows of the builder fills route, pushed per block. One frame per block with all its matching events.