API reference · Chain & reference

Check your key

Answers the name your key is registered under, its tier, billing state and the limits in force.

GET https://api.femtos.xyz/v1/whoami

Example

Elysium, HyperCore, HyperEVM

curl -H "Authorization: Bearer $FEMTOS_KEY" "https://api.femtos.xyz/v1/whoami"

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

Field	Type	Meaning
`key`	string \| null	Name the key is registered under (never the key itself)
`tier`	free \| builder \| pro \| scale \| enterprise \| partner \| null	null: internal key
`billing`	ok \| exhausted \| capped \| exhausted_nofree \| capped_nofree \| debt \| unknown \| null	exhausted / capped: the key runs at the free tier limits, heavy calls answer 402 (no credits left; the monthly spending cap reached). exhausted_nofree / capped_nofree: the same for an account created by an x402 payment, which has no free tier: every metered call answers 402, no WebSocket. debt: the account owes a debt (plan overage past its float, or a payment taken back) that must be paid in full first: every call but status and whoami answers 402 naming the amount (debtUsd) on every API, no WebSocket, no webhook delivery, until it is paid in full (a partial payment lifts nothing). unknown: a state this server does not know, refused the same way. null: internal key
`limits`	object \| null	Limits in force (the free row while billing is exhausted / capped); null: no limit (internal key): {rps, burst, maxConns}

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.
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.
OpenAPI document GET /v1/openapi.json Elysium, HyperCore, HyperEVM
The OpenAPI 3.1 contract of every REST call, public.