API reference, Builder codes
Builder fills stream
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.
- Elysium: not served
- HyperCore
- HyperEVM: not served
- Not on Elysium or HyperEVM: a channel of HyperCore only
WebSocket channel hc.builder.fills on wss://api.femtos.xyz/v1/ws
Parameters
| Param | In | Example or values | Meaning |
|---|---|---|---|
builder | filter | 0xb84168cf3be63c6b8dad05ff5d755e97432ff80b | Builder address (0x, as orders name it in `builder.b`), or a named wallet's handle |
coin | filter | (optional) | HyperCore market (BTC, @107, xyz:TSLA) |
user | filter | (optional) | Account: 0x address or a named wallet's handle |
min_notional | filter | (optional) | Minimum notional (px × sz, in the quote of the market) |
Subscribe
{"op":"subscribe","channel":"hc.builder.fills","filter":{"builder":"0xb84168cf3be63c6b8dad05ff5d755e97432ff80b"}}Key: Authorization: Bearer $FEMTOS_KEY. Get a free key, or with no browser through agent onboarding.
Response fields
| Field | Type | Meaning |
|---|---|---|
snapshot: true | WsBuilderFill[] | the builder's last 50 fills (matching the filter) seen since hl-flows started, oldest first |
data | WsBuilderFill[] | each fill carrying the builder's code, with its builder fee, the block it happens, from our node's fills before they reach ClickHouse: one frame per HyperCore block, `data` the block's matching events in order (a block with none sends nothing): {block, eventIdx, time, user, entity, coin, side, px, sz, notional, crossed, dir, …} |
data[].builderFee | decimal | Builder fee of the fill, in feeToken |
data[].notional | decimal | px × sz, quote units |
latency_ms.source_to_sent | int | block → sent by the server |
batch | "block" | every live frame: one block, `data` its matching events |
Related: Builder codes
- Builder leaderboard GET /v1/hypercore/builders HyperCore
Every builder code ranked by fees, volume, users or orders, over 24 h to all time. - 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.
More
- This page as Markdown
- The whole API reference
- What HyperCore serves
- The whole API in one Markdown file
- OpenAPI 3.1 document
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