Asset encoding cheat sheet

Use these tables to turn a market or token into the id, string or address an action expects. The reasoning behind each scheme is on asset ids and naming.

Asset ids for orders and cancels

Orders and cancels carry an integer asset a; info requests and WebSocket subscriptions take a coin string, derived from a different index.

Market	Asset id (a)	Coin string	Example
Validator-operated perp	index in meta.universe	the name in meta, for example BTC	BTC is asset 0 on mainnet
Spot pair	10000 + index in spotMeta.universe	@{index}; the legacy pair keeps PURR/USDC	PURR/USDC is asset 10000; mainnet HYPE/USDC is @107, asset 10107
HIP-3 perp	100000 + perp_dex_index * 10000 + index_in_meta	dex:COIN	testnet test:ABC, dex 1, index 0, is asset 110000
Outcome side	100000000 + 10 * outcome + side	#<encoding>	outcome 1, side 0 is #10, asset 100000010

• perpDexs[0] is null: the first, validator-operated perp dex.
• meta {dex} returns names already qualified as dex:COIN; prefixing again produced xyz:xyz:MU in one codebase.
• Each network has its own HIP-3 dexes and indices: include the network in cache keys.
• The app remaps some assets: its BTC/USDC is UBTC/USDC on HyperCore.

Outcome encoding: one number, three spellings

encoding = 10 * outcome + side        side is 0 or 1, nothing else
asset id = 100000000 + encoding

Where it appears	Spelling	Outcome 1, side 0	Outcome 1210, side 0
Info requests, WebSocket, fills	#<encoding>	#10	#12100
Token name, balances in spotClearinghouseState	+<encoding>	+10	+12100
Order asset id; precompiles 0x801 and 0x808	100000000 + encoding	100000010	100012100

Side 0 is the first sideSpecs entry in outcomeMeta (usually Yes; Long on scalar templates) and is paid settleFraction; side 1 (No; Short) is paid 1 - settleFraction.

• Outcome coins are not in meta.universe but in spotMetaAndAssetCtxs, keyed by the # coin.
• Outcome positions are spot balances; clearinghouseState shows nothing for them.
• activeAssetCtx on an outcome coin replies on the channel activeSpotAssetCtx.

Caution

Do not write an outcome as @<outcomeId>, as one SDK does: @N is the spot pair namespace, so @1210 is a spot pair, not outcome 1210.

Token index versus pair index

A token index names a token (spotSend, sendAsset, system addresses, most precompiles); a spot pair index names a book (@N coins, asset ids). For one token they differ.

Token	Network	Token index	Spot pair index	Source
USDC	mainnet	0	quote asset	measured (spotMeta)
PURR	mainnet	1	0 (PURR/USDC)	docs: HyperEVM transfers, asset ids
HYPE	mainnet	150	107	docs: asset ids
HYPE	testnet	1105	1035	docs: asset ids
UBTC	mainnet	197	not recorded	measured
USDT0	mainnet	268	not recorded	measured (spotMeta)
USDH	mainnet	360	230	SDK code
USDH	testnet	1452	1338	SDK code

• The spot index is not the array position: mainnet @367 points at token 479 in a 464-entry token array.
• Transfer actions name a token as "NAME:0x" plus 32 hex characters, such as the docs’ PURR:0xc4bf3f870c0e9465323c0b6ed28096c2; tokenDetails takes the same 34-character hex id.

Dex selectors

Where	Main perp dex	Spot balance	HIP-3 dex
sendAsset, agentSendAsset (sourceDex, destinationDex)	""	"spot"	the dex name
CoreWriter action 13 (srcDex, dstDex)	not recorded	4294967295 (type(uint32).max)	not recorded
Info requests with a dex field	"" or omitted	not applicable	the dex name

Caution

HyperCore to HyperEVM sendAsset must use destinationDex: "spot"; "" returns Invalid token.

System and fixed addresses

A token’s system address is 0x20 followed by the token index as a 19-byte big-endian integer; sending to it on either side crosses the token over. HYPE is the exception.

Address	What it is
0x2000000000000000000000000000000000000000	system address of token 0 (USDC)
0x2000000000000000000000000000000000000001	system address of token 1 (PURR)
0x20000000000000000000000000000000000000c8	system address of token 200 (the docs’ example)
0x200000000000000000000000000000000000010c	system address of token 268 (USDT0)
0x2222222222222222222222222222222222222222	HYPE system address; HYPE crosses as native value, not as an ERC20
0x3333333333333333333333333333333333333333	CoreWriter
0x0000000000000000000000000000000000000800 to ...0814	read precompiles; 0x815 to 0x8ff unassigned (measured 2026-08-17)
0x4000000000000000000000000000000000000000 plus the dex index	HIP-3 backstop liquidator; the first HIP-3 dex uses ...0001
0xfefefefefefefefefefefefefefefefefefefefe	Assistance Fund
0xbbb...b	portfolio margin backstop liquidator (abbreviated in the docs)
0x50...00 plus the token index	AQAv2 system interest address (abbreviated in the docs)
0x555...5	wrapped HYPE (abbreviated in the docs)
0x6b9e773128f453f5c2c60935ee2de2cbc5390a24	the mainnet HyperEVM contract linked to HyperCore USDC (token 0), per spotMeta
0xb88339cb7199b77e23db6e890353e22632ba630f	Circle’s USDC on the HyperEVM, the contract the official docs list; not linked to HyperCore token 0
0xb8ce59fc3717ada4c02eadf9682a9e934f625ebb	the HyperEVM contract linked to USDT0 (token 268), the same one HyperEVM lending markets use

Two USDCs on the HyperEVM

HyperCore USDC (token 0) links to 0x6b9e7731..., an upgradeable proxy of unestablished provenance that carries the system transfers (133 Transfer events to the system address per 2,000 blocks when measured) but whose ERC20 views reverted on two RPCs. The USDC the official docs list for the HyperEVM, 0xb88339cb..., is a standard 6-decimal ERC20 used by HyperEVM lending markets and not linked to token 0: moving between them is a swap, not a transfer. The testnet link 0x0b80659a... is unusable (every view and transfer reverts). USDT0 has no split: token 268 and the lending markets use one contract.

Decimals and units

Quantity	Rule or unit
Perp price	at most 5 significant figures and at most 6 - szDecimals decimals; integer prices always allowed
Spot price	at most 5 significant figures and at most 8 - szDecimals decimals; integer prices always allowed
Size	a multiple of 10^-szDecimals
HIP-1 lot size	10^(weiDecimals - szDecimals) wei; szDecimals + 5 <= weiDecimals
Spot USDC	szDecimals = weiDecimals = 8
Permissionless quote asset	weiDecimals 8, szDecimals 2
Outcome price	whole ticks of 0.00001 from 0.00001 to 0.99999; szDecimals 0
HyperEVM decimals	weiDecimals + evmExtraWeiDecimals, with evmExtraWeiDecimals from -2 to 18
USDC	8 decimals on HyperCore, 6 on the HyperEVM (evmExtraWeiDecimals = -2)
HYPE	8 decimals on HyperCore (wei 1e8), 18 on the HyperEVM
PURR	5 weiDecimals on HyperCore, 18 on the HyperEVM (evmExtraWeiDecimals = 13)
CoreWriter action 1 limitPx, sz	1e8 times the human value
CoreWriter action 15 wei	HyperCore wei; USDC is 1e8
CoreWriter action 17 wei	1e8 per contract
settledValue from 0x814	1e8 = 1.0
updateIsolatedMargin.ntli, vaultTransfer.usd	integer, 1e6 = 1 USD
hip3LiquidatorTransfer.ntl	integer, 1e6 per collateral token; a multiple of 1e9 (1,000 tokens)
Order builder.f	tenths of a basis point: 10 = 1 bp
approveBuilderFee.maxFeeRate	percent string, for example "0.001%"
CoreWriter action 12 maxFeeRate	decibps: 10 = 0.01%
gossipPriorityBid.maxGas	HYPE wei, units of 0.00000001 HYPE
Order priority {"p": N}	N / 100000000 of notional; 80000 = 8 bps
Precompile perp prices	raw value divided by 10^(6 - szDecimals)
Precompile spot prices	raw value divided by 10^(8 - base szDecimals)
0x812 reserve state	rates in bps; amounts 1e8 for USDC
userOutcome amounts	decimal string, whole contracts, no trailing zero ("100", never "100.0")

Danger

HyperCore USDC has 8 decimals, HyperEVM USDC 6. Actions 1, 15 and 17 use 1e8; the ERC20 side of the same token uses 1e6. Mixing them is a 100x error.

Encoding HYPE, a scalar band, a split and a supply

HYPE on mainnet. Token 150, spot pair 107: coin @107, order asset 10000 + 107 = 10107. Crosses through 0x2222...2222 as native value, 8 decimals on HyperCore and 18 on the HyperEVM.

A testnet scalar band. Outcome 20351: Long (side 0) is asset 100000000 + 203510 = 100203510; Short (side 1) is 100203511.

Split one contract from a contract. Action 17, op 0, outcome 1121:

payload = 0x01 000011 || abi.encode(uint8 0, uint32 0, uint32 1121, uint64 100000000)

wei = 100000000 is one contract. question is zero because a split ignores it, and a non-zero unused field drops the whole action.

Supply USDC to lending from a contract. 4,014.923506 USDC at 1e8 is 401492350600 wei, 0x5d7acf1688:

payload = 0x0100000f || abi.encode(uint8 0, uint64 0, uint64 0x5d7acf1688)

Op 0 is supply, token 0 is USDC. Withdrawing 10 USDC is op 1, wei = 0x3b9aca00 (1,000,000,000).

For rounding prices and sizes safely, see Precision. System addresses in use, and the crossing fee, are on Moving assets between HyperCore and the HyperEVM.