API reference, Chain & reference

Freshness stream

The GET /v1/status answer (head and lag of each layer, live feeds), pushed whole on subscribe and at most once a second when it changes.

WebSocket channel status on wss://api.femtos.xyz/v1/ws

Elysium, HyperCore, HyperEVM

{"op":"subscribe","channel":"status","filter":{}}

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

Response fields

Field	Type	Meaning
`snapshot: true`	object	every frame: the full GET /v1/status answer

Freshness GET /v1/status Elysium, HyperCore, HyperEVM
Head and lag of each layer, measured now.
Blocks stream WS elysium.blocks | hyperevm.blocks Elysium, HyperEVM
Each new HyperEVM block header, small and big blocks, from our node.
Gas tracker GET /v1/gas Elysium, HyperEVM
Every HyperEVM block's base fee, gas used and tips over 1h to 7d, with stats and the latest block.
Gas stream WS elysium.gas | hyperevm.gas Elysium, HyperEVM
Each new HyperEVM block's base fee, gas used and tips, from our node; the history is GET /v1/gas.
Block GET /v1/blocks/{number} Elysium, HyperEVM
One HyperEVM block and every transaction in it: who called what, swaps, gas and fees.
Transaction GET /v1/tx/{hash} Elysium, HyperEVM
One transaction: status, gas, decoded transfers, swaps and liquidity, bridge legs and journey.
Elysium RPC POST /v1/elysium/rpc Elysium
Free public Elysium mainnet RPC by Femtos (chain 99901), no key, read only (no transaction sending), for wallets and dapps, not for indexing (use the Femtos API for history): per IP 5 requests a second and 60 a minute, batches of 5, eth_getLogs over 1,000 blocks at most, state of the last 128 blocks only.
Stream stats WS stats HyperCore
Our HyperCore stream health, once a second.
Check your key GET /v1/whoami Elysium, HyperCore, HyperEVM
Answers the name your key is registered under, its tier, billing state and the limits in force.
OpenAPI document GET /v1/openapi.json Elysium, HyperCore, HyperEVM
The OpenAPI 3.1 contract of every REST call, public.