Compute Units

Every request costs Compute Units (CU) — a weight that reflects how much work the method puts on a node. Light lookups cost 1 CU, heavy scans up to 75. Your plan sets the price per CU (Rate limits); the free plan meters usage but bills nothing.

How metering works

• Weight is per (chain, method); any method not listed below costs 1 CU.
• Cached responses (X-Cache: HIT) are still metered — the weight pays for the API call, not only node I/O.
• Batch requests are metered per inner call.
• Each project has a daily CU quota (default 100,000). Exceeding it returns JSON-RPC -32005 (compute unit quota exceeded) until the 24-hour window rolls over.

Method weights

Ethereum (and EVM chains)

Method	CU
eth_chainId, net_version, web3_clientVersion	0
eth_blockNumber	1
eth_getBalance, eth_getTransactionCount	5
eth_getTransactionByHash, eth_getTransactionReceipt	5
eth_getBlockByNumber, eth_getBlockByHash	10
eth_getCode, eth_getStorageAt	10
eth_call, eth_estimateGas	15
eth_sendRawTransaction	20
eth_getLogs	75
anything else	1

Bitcoin (and bitcoind-family chains)

Method	CU
getblockcount, getblockhash, getnetworkinfo	1
getmempoolinfo	5
getblock, getrawtransaction	10
sendrawtransaction	20
anything else	1

TRON

Method	CU
getnowblock	1
gettransactionbyid, getaccount	5
getblockbynum	10
triggersmartcontract, broadcasttransaction	20
anything else	1

Reading your usage

Per project, last 24 h / day / month:

curl "https://api.lab.au.ro/api/v1/projects/$PROJECT_ID/usage?period=day" \
  -H "Authorization: Bearer $TOKEN"

{
  "project_id": "1ea310a1-...",
  "total_cu": 2,
  "request_count": 2,
  "period": "24h",
  "by_chain": {
    "btc": { "cu": 1, "request_count": 1 },
    "eth": { "cu": 1, "request_count": 1 }
  }
}

period accepts day (default 24 h) and month (last 30 days). The dashboard's Usage page renders the same data as charts, including a per-method breakdown.

Budgeting tips

• eth_getLogs at 75 CU dominates most EVM bills — narrow block ranges and prefer event-indexing services for large scans.
• Static lookups (eth_chainId, net_version) are free (0 CU) — call away.
• Cached short-TTL methods (eth_blockNumber, eth_gasPrice) are cheap and fast; don't build your own cache for them.