Reference

Limits

Rate limits, batch sizes, gas caps and other limits of the public Lib Testnet services, in one place.

The public services are shared. These limits keep them fast for everyone. All rate limits are per IP address; exceeding one returns HTTP 429 Too Many Requests.

#JSON-RPC

Requests	About 25 per second, bursts up to 50
Open connections	20
Batch size	20 requests
Request body	256 KB
`eth_call` / `eth_estimateGas` gas	30,000,000
`eth_getLogs` range	5,000 blocks per query
Request timeout	30 seconds
WebSocket	Not public

#Lib Explorer API

Requests	About 30 per second, bursts up to 60
Open connections	60

#Faucet

Amount	10 tLIB per request
Cooldown	24 hours per address and per IP
API calls	6 per minute, bursts of 3
Whole faucet	200 requests an hour

#Chain

Block gas limit	30,000,000
Block time	2 s with transactions, 60 s when idle
Contract size	24,576 bytes (EIP-170), as on Ethereum
Initcode size	49,152 bytes (EIP-3860)

#Staying under the limits

Batch reads (up to 20 per request) instead of firing them one by one.
Cache: a block arrives at most every 2 seconds, so polling faster gains nothing.
Split log queries into 5,000-block windows.
Use the shared live feed for new blocks instead of polling.
On a 429, wait and retry with backoff.