HAVAH (HVH)

Sign HAVAH transactions. HAVAH is an ICON-family chain, so transactions use the ICON-native wire shape (from/to/value/stepLimit/stepPrice/timestamp/nonce). The bridge converts this wire into a HavahTransaction before the device signs.

Field	Value
coinType	858
keyPath	m/44'/858'/<accountIdx>'/0/0
amount unit	loop
chainId	havah:mainnet/slip44:858
chainId · Testnet	havah:testnet/slip44:858

Supported Methods

Method	Supported
getAddress	✓
signTransaction	✓
signMessage	✗
signTypedData	✗
signData	✗
signAuthEntry	✗

Requirements

Minimum firmware for each method. The two models are on different version lines, so DCENT Biometric Wallet and DCENT X are listed separately (the numbers are not comparable across models). Below this the request returns the firmware-update error (5005) and the bridge prompts to update.

Method	DCENT Biometric Wallet	DCENT X
`getAddress`	`2.26.0` or higher	`1.0.0` or higher
`signTransaction`	`2.26.0` or higher	`1.0.0` or higher

getAddress — account address

Retrieves the HAVAH account address for a chainId + keyPath. HAVAH uses the ICON-family hx… address format (there are no address variants). Call this before building a transaction so from matches the device account.

Field	Type	Required	Source	Description
`chainId`	string	Required	App	Full CAIP-19 id — `havah:mainnet/slip44:858`
`keyPath`	string	Required	App	BIP-44 derivation path — default `m/44'/858'/0'/0/0`

Request

await dcent.getAddress({
  chainId: 'havah:mainnet/slip44:858',
  keyPath: "m/44'/858'/0'/0/0"
})

Response

Field	Type	Description
`header.status`	string	`success` on a completed request
`body.command`	string	Echoes the method — `getAddress`
`body.parameter.address`	string	HAVAH account address in ICON-family `hx…` format

{
  "header": {
    "version": "1.0",
    "status": "success",
    "response_from": "getAddress"
  },
  "body": {
    "command": "getAddress",
    "parameter": {
      "address": "hx…"
    }
  }
}

signTransaction — ICON-native wire

Variant — native HVH transfer

payload.transaction:

{
  "from": "hx0000000000000000000000000000000000000000",
  "to": "hx0000000000000000000000000000000000000000",
  "value": "0xDE0B6B3A7640001",
  "stepLimit": "0x186a0",
  "stepPrice": "0x2e90edd000",
  "timestamp": "<current time in µs, hex>",
  "nid": "0x100",
  "nonce": "0x1",
  "version": "0x3"
}

Field	Type	Required	Source	Description
`from`	string	Required-Real	Wallet	Device HAVAH account (`hx…`). Not checked against the keyPath account — a different address is signed as sent
`to`	string	Required-Real	App	Recipient (`hx…` for native send)
`value`	hex	Required	App	Amount in loop, 0x-prefixed hex (1 HVH = 1e18 loop); a plain decimal string is read as base-10. Send it as a string — values exceed MAX_SAFE_INTEGER
`stepLimit`	hex	Required	App	Step (gas) limit, hex. When provided together with `stepPrice` the bridge builds a self-contained `preparedFee`
`stepPrice`	hex	Required-Real	App	Real, current step price, hex. Missing or zero → `-32602`; a stale value is not detected. Not part of the signed transaction — it sets the fee sent to the device (`stepPrice` × `stepLimit`)
`timestamp`	hex	Required-Real	App	ICON microsecond epoch. The wallet never fills this in — the value you send is the one that is signed. Omitting it fails with `-32602`
`nid`	hex	Optional	App	Ignored — the wallet signs `0x100` on mainnet and `0x101` on testnet, from the chainId
`nonce`	hex	Optional	App	Transaction nonce, hex. Defaults to `0x1` if omitted; `0x0` (or `0`) is dropped from the signed transaction
`version`	hex	Optional	App	Ignored — the wallet always signs version `0x3`

js — Request:

await dcent.sign({
  method: 'signTransaction',
  chainId: 'havah:mainnet/slip44:858',
  payload: {
    keyPath: "m/44'/858'/0'/0/0",
    transaction: {
      from: "hx0000000000000000000000000000000000000000",
      to: "hx0000000000000000000000000000000000000000",
      value: "0xDE0B6B3A7640001",
      stepLimit: "0x186a0",
      stepPrice: "0x2e90edd000",
      timestamp: "<current time in µs, hex>",
      nid: "0x100",
      nonce: "0x1",
      version: "0x3"
    }
  }
})  // → body.parameter.signature

Response

Field	Type	Description
`header.status`	string	`success` on a completed signature
`body.command`	string	Signing command echo — `signTransaction`
`body.parameter.signature`	string	The device signature (65 bytes, r‖s‖recovery id, on DCENT X) as base64 — not a serialized transaction. To broadcast, set it as the `signature` field of the ICON transaction exactly as it was signed — `nid` from the chainId, `version` `0x3`, the `nonce` you sent (or `0x1`; a `0x0` nonce is left out), and numeric fields as lowercase `0x` hex — and call `icx_sendTransaction`

{
  "header": {
    "version": "1.0",
    "status": "success",
    "response_from": "signTransaction"
  },
  "body": {
    "command": "signTransaction",
    "parameter": {
      "signature": "<base64 signature>"
    }
  }
}

Variant — HSP-20 token transfer

info

Token model: form-D descriptor. A token on DCENT's supported list is signed with its registered symbol and decimals. For any other token, send a form-D descriptor under transaction.token — contract, to, amount, decimals and optionally symbol (without contract — or its aliases assetId / address — the descriptor is ignored) — the bridge signs with no network access and uses the decimals you supply. See Core Concepts → Token descriptors.

HSP-20 (IRC-2-like) tokens use the ICON call data shape. to is the token contract (cx…), the real recipient is data.params._to, and native value stays 0x0 (no native HVH moves).

payload.transaction:

{
  "dataType": "call",
  "from": "hx0000000000000000000000000000000000000000",
  "to": "cxd7fed2ae1d9b2314087520efe1870c33e5c5baa4",
  "value": "0x0",
  "stepLimit": "0x186a0",
  "stepPrice": "0x2e90edd000",
  "timestamp": "<current time in µs, hex>",
  "nid": "0x100",
  "nonce": "0x1",
  "version": "0x3",
  "data": {
    "method": "transfer",
    "params": {
      "_to": "hx0000000000000000000000000000000000000000",
      "_value": "0xDE0B6B3A7640001"
    }
  }
}

Field	Type	Required	Source	Description
`dataType`	enum	Required-Real	App	Must be `call` for a contract call — not checked: without it the request is signed as a native HVH transfer to the `cx…` address and `data` is dropped
`to`	string	Required-Real	App	Token contract address (`cx…`), not the recipient
`value`	hex	Required	App	Must be present and non-negative; it is not part of the signed call — keep `0x0`
`data.method`	string	Required	App	Contract method — `transfer`
`data.params._to`	string	Required-Real	App	Real token recipient (`hx…`)
`data.params._value`	hex	Required	App	Token amount in base units, 0x-prefixed hex (PER has 18 decimals; `0xF4240` = 1e6 for a 6-decimal token)
`timestamp`	hex	Required-Real	App	ICON microsecond epoch — the wire path never fills it in; omitting it fails with `-32602`

js — Request:

await dcent.sign({
  method: 'signTransaction',
  chainId: 'havah:mainnet/slip44:858',
  payload: {
    keyPath: "m/44'/858'/0'/0/0",
    transaction: {
      dataType: "call",
      from: "hx0000000000000000000000000000000000000000",
      to: "cxd7fed2ae1d9b2314087520efe1870c33e5c5baa4",
      value: "0x0",
      stepLimit: "0x186a0",
      stepPrice: "0x2e90edd000",
      timestamp: "<current time in µs, hex>",
      nid: "0x100",
      nonce: "0x1",
      version: "0x3",
      data: { method: "transfer",
        params: { _to: "hx0000000000000000000000000000000000000000",
                  _value: "0xDE0B6B3A7640001" } }
    }
  }
})  // → body.parameter.signature

Response

Field	Type	Description
`header.status`	string	`success` on a completed signature
`body.command`	string	Signing command echo — `signTransaction`
`body.parameter.signature`	string	The device signature (65 bytes, r‖s‖recovery id, on DCENT X) as base64 — not a serialized transaction. To broadcast, set it as the `signature` field of the ICON transaction exactly as it was signed — `nid` from the chainId, `version` `0x3`, the `nonce` you sent (or `0x1`; a `0x0` nonce is left out), no `value` field for the HSP-20 `call`, and numeric fields (including `_value`) as lowercase `0x` hex — and call `icx_sendTransaction`

{
  "header": {
    "version": "1.0",
    "status": "success",
    "response_from": "signTransaction"
  },
  "body": {
    "command": "signTransaction",
    "parameter": {
      "signature": "<base64 signature>"
    }
  }
}

info

Registered HSP-20 tokens are looked up on the selected network — HAVAH mainnet and testnet each have their own list. A transfer call to an unregistered HSP-20 contract is rejected with -32602 — to sign one, use the form-D descriptor below with token.decimals (see Core Concepts → Token descriptors). A dataType:"call" whose to is not a cx… SCORE address → -32602; a SCORE method other than transfer → -32601.

Variant — HSP-20 form-D descriptor

Send a compact token descriptor instead of a full ICON dataType:"call" envelope. The bridge builds the transfer(_to,_value) SCORE call from { contract, to, amount }, rewrites to to the contract address, and sets value to 0x0. The other envelope fields (from, stepLimit, stepPrice, timestamp, nonce) are handled as in the table below; nid and version are ignored (nid comes from the chainId, version is 0x3). amount is a base-unit string (not rescaled by decimals).

payload.transaction:

{
  "token": {
    "contract": "cxd8303731bf989a1597a6d38505d7a9483c4d9a38",
    "to": "hx0000000000000000000000000000000000000000",
    "amount": "1000000",
    "decimals": 6,
    "symbol": "GODH"
  },
  "from": "hx0000000000000000000000000000000000000000",
  "stepLimit": "0x186a0",
  "stepPrice": "0x2e90edd000",
  "timestamp": "<current time in µs, hex>",
  "nid": "0x100",
  "nonce": "0x1",
  "version": "0x3"
}

Field	Type	Required	Notes
`token.contract`	string	Required	SCORE address; must match `cx` + 40 hex chars. Unregistered tokens allowed.
`token.to`	string	Required	Recipient (`hx…`). Becomes `data.params._to`.
`token.amount`	string	Required	Base-unit integer string; not rescaled by `decimals`. `0` is allowed.
`token.decimals`	number	Optional (Required for an unregistered token)	Base-unit exponent; lets the bridge resolve an unregistered token (the device receives it for display). An unregistered token without `token.decimals` is rejected with `-32602`.
`token.symbol`	string	Optional	Display metadata only.
`from`	string	Required-Real	Device HAVAH account that signs (`hx…`). Omitting it fails with `-32602`.
`stepLimit` / `stepPrice`	string	Required	Map to the fee gate (`gasLimit` / `fee`). Zero or missing fails the gate.
`nid` / `nonce` / `version`	string	Optional	`nonce` is signed as sent (`0x1` if omitted; `0x0` is left out); `nid` and `version` are ignored (`nid` from the chainId, `version` `0x3`).
`timestamp`	hex	Required-Real	ICON microsecond epoch — the wire path never fills it in; omitting it fails with `-32602`

info

This descriptor is signed as 1.0 GODH — amount "1000000" at decimals 6. Replace from with your own device HAVAH account (hx…) and token.to with the recipient.

Common Mistakes

danger

Decimal amounts — value / _value are integer loop amounts: 0x-prefixed hex, or a plain decimal string read as base-10. Send them as strings because values exceed MAX_SAFE_INTEGER. Token to vs recipient — for HSP-20, to is the contract (cx…) and the recipient is data.params._to (hx…). Putting the recipient (hx…) in to of a dataType:"call" transaction is rejected with -32602. value on a token transfer — for HSP-20 the native value is ignored (it is not part of the signed call); leave it 0x0. Missing stepLimit — without it the bridge cannot build preparedFee. Missing stepPrice — the app must supply a real, current step price; it is not auto-filled.

Supported Methods​

Requirements​

getAddress — account address​

signTransaction — ICON-native wire​

Variant — native HVH transfer​

Variant — HSP-20 token transfer​

Variant — HSP-20 form-D descriptor​

Common Mistakes​

Supported Methods

Requirements

getAddress — account address

signTransaction — ICON-native wire

Variant — native HVH transfer

Variant — HSP-20 token transfer

Variant — HSP-20 form-D descriptor

Common Mistakes