API reference · Chain & reference

Transaction

One transaction: status, gas, decoded transfers, swaps and liquidity, bridge legs and journey.

Not on HyperCore: HyperCore has no EVM transactions: an account’s actions are in POST /info (userFills, userNonFundingLedgerUpdates) and on the wallet page

GET https://api.femtos.xyz/v1/tx/{hash}

Parameters

Param	In	Example or values	Meaning
`hash`	path	(optional)	Transaction hash (0x + 64 hex)
`layer`	query	`(empty)`, `hyperevm`, `elysium`	Only this layer (default: HyperEVM, then Elysium)

Elysium

curl -H "Authorization: Bearer $FEMTOS_KEY" "https://api.femtos.xyz/v1/tx/?layer=elysium"

HyperEVM

curl -H "Authorization: Bearer $FEMTOS_KEY" "https://api.femtos.xyz/v1/tx/?layer=hyperevm"

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

Field	Type	Meaning
`status`	success \| reverted \| null
`block`	int \| null	Block
`from`	string \| null	Sender
`to`	string \| null	Recipient (null: contract creation)
`value`	decimal \| null	Native value (HYPE)
`source`	indexer \| rpc	indexer: our tables (decoded); rpc: not indexed (yet), the node's transaction, nothing decoded
`gas`	object	{limit, used, price, baseFee, feeRaw, fee, feeUsd}
`transfers[]`	object	ERC-20 transfers: {logIndex, token, symbol, decimals, from, to, amount, amountRaw, spam, spamReason}
`swaps[]`	object	Swaps: {logIndex, pair, dex, side, base, quote, baseAddress, quoteAddress, sz, vq, px, usd, …}
`liquidity[]`	object	Liquidity added / removed: {logIndex, kind, dex, pool, provider, amount0Raw, amount1Raw, usd, liquidityDelta}
`poolsCreated[]`	object	Pools created: {logIndex, dex, pool, factory}
`nfts[]`	object	NFT transfers: {logIndex, collection, standard, kind, tokenId, from, to}
`logs`	object \| null	From our node's receipt (raw logs); null when no node is configured: {total, decoded, undecoded, undecodedTotal, source, error}
`bridge`	object \| null	When the transaction is a bridge leg: `legs` (leg tables at its block: route core_evm / evm_elysium, direction, account, amountRaw), `rows` (the account's matched rows of /api/bridges that cite it, 7 days), `journeys` (the cross-layer journeys Core → HyperEVM → Elysium or back it is a hop of). null: not a bridge leg.

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.
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.