The ledger
Reading a record
Every machine publishes one signed record per hour. This page walks through one of them field by field, so you can read a record without writing code.
Every machine publishes one signed record per hour. A record is a short JSON file, and you can read one without writing any code. This page takes a single hour on one sled and goes through it line by line.
Where records live
You can find the same record in three places, and they should always agree:
| Where | What you get |
|---|---|
| The machine's page | Each hour as a row, with a link to the raw file. |
| IPFS | The full records and proofs for a site and hour, e.g. IAD-4/2026-09-27T14/, under the content ID stored on-chain. |
| The Ledger contract | One root per site and hour, the record count, the content ID and the time it was posted. |
One record
This is sled 04 in rack 07 at IAD-4, Ashburn, for the hour from 14:00 to 15:00 UTC on 27 September 2026. The file is CR-IAD4-07-04.json in the bundle bafybe…kyzi.
{
"version": 1,
"machineId": "CR-IAD4-07-04",
"site": "IAD-4",
"hourStart": "2026-09-27T14:00:00Z",
"samples": 60,
"gpuSeconds": 27360,
"energyWh": 3412,
"rateUsdcPerGpuHour": "900000",
"grossUsdc": "6840000",
"tenantRef": "0x0c8cd80cce96009df9951c850001abc39fd9b223a6f84b15e0bd76abd00b1ca0",
"prevHash": "0x7ca51bc8863732f78385de4cc3937ca9de359d9631485e529af615726b6f4d8c",
"custodian": "0xa089De365d429dcEC7ccF29756d7C5fEA57a836D",
"signature": "0xcbe834e6b8127bed16b6fd5b5edd4d99a3dced5c115ffe5d312d224859ef8990cbd3f9e6a510d739183d018ddb9940178407c421c734fe06e7ca20ef080e1e2b1b"
}Field by field
| Field | What it means |
|---|---|
| version | The record format. Currently 1. |
| machineId | Site, rack and slot: IAD-4, rack 07, slot 04. Listed in the Registry with the sled's serial numbers. |
| site | The data center. It decides which custodian key must have signed. |
| hourStart | The start of the hour, in UTC. The record covers the next 3,600 seconds. |
| samples | How many of the 60 one-minute samples the meter took. Fewer than 60 means minutes were missed and not billed. |
| gpuSeconds | Seconds of GPU time on a paying lease, summed over all 8 GPUs. The most an hour can hold is 28,800. |
| energyWh | Energy the sled drew at its PDU outlet, in watt-hours. |
| rateUsdcPerGpuHour | The contracted price, in USDC base units (6 decimals). 900000 is $0.90. |
| grossUsdc | Rent owed for the hour before any costs, in USDC base units. 6840000 is $6.84. |
| tenantRef | A hash of the rental contract. It links hours of the same lease without naming the tenant. |
| prevHash | The hash of this sled's record for the hour before. It chains hours together. |
| custodian | The address of the key that signed. It must match the Registry entry for the site. |
| signature | The custodian's EIP-712 signature over every field above except itself and custodian. |
Checking it by hand
You can check the money with a calculator. GPU-seconds become GPU-hours, and GPU-hours times the rate is the gross.
- GPU-hours27,360 ÷ 3,600
- 7.6
- Utilisation this hour7.6 of a possible 8
- 95%
- Rate900,000 ÷ 10⁶
- $0.90
- Energy3,412 Wh
- 3.412 kWh
- Gross rent7.6 × $0.90 = 6,840,000 base units
- $6.84
The energy is a sanity check. An L40S sled draws up to about 3.8 kW. With 7.6 of its 8 GPUs working on average, a little over 3.4 kWh for the hour is what you would expect. A record claiming 8 GPUs leased while the sled drew 0.8 kWh would be flagged.
What a record does not tell you
Reading a record tells you what it claims. To check that the claim is genuine, that the right key signed it and that it is the same record anchored on Ethereum, go to Verifying a record.
Last updated 5 October 2026.