Quick Start

Connect a device and sign an Ethereum transaction end-to-end.

info

The bridge popup requires a browser that exposes WebHID (navigator.hid) or Web Bluetooth (navigator.bluetooth) — today the Chromium-based desktop browsers such as Chrome and Edge — and it is blocked on mobile user agents; elsewhere it shows an unsupported-browser screen.

Integration flow

A typical integration runs top to bottom. The Handled by column says which side owns each step:

#	Step	Description	Handled by
0	Import import dcent from 'dcent-web-connector'	Add the connector to your app.	App
1	Select transport setTransport()	Choose the transport method.	Connector
2	Connect device in the DCENT popup	A USB device that already has permission connects automatically; otherwise (always for Bluetooth) the user picks it in the popup.	DCENT popup / user
3	Get address getAddress()	Read an address from the connected device.	Connector
4	Build transaction construct the payload	Build the transaction to send.	App
5	Sign sign()	Sign the transaction on the device.	Connector
6	Broadcast send to the network	Send the signed transaction to the network.	App

Handled by Connector · Handled in the DCENT popup / by the user · Handled by your app

Steps 4 (build payload) and 6 (broadcast) are handled in your app.

1 · Select transport

Call once before the first device interaction. If you omit it, the popup offers the transports the browser supports — but a USB device this browser already has permission for connects automatically without a choice.

import dcent from 'dcent-web-connector'

dcent.setTransport('hid')   // WebHID over USB. Use 'ble' for Bluetooth.

2 · Get an address

const res = await dcent.getAddress({
  chainId: 'eip155:1/slip44:60',
  keyPath: "m/44'/60'/0'/0/0",
})
const address = res.body.parameter.address   // "0x6A5C…"

3 · Sign a transaction

const signed = await dcent.sign({
  method: 'signTransaction',
  chainId: 'eip155:1/slip44:60',
  payload: {
    keyPath: "m/44'/60'/0'/0/0",
    transaction: {
      type: 2,
      to: '0x000000000000000000000000000000000000dEaD',
      value: '0x2386f26fc10000',          // 0.01 ETH (wei, hex)
      gasLimit: '0x5208',
      maxFeePerGas: '0x77359400',
      maxPriorityFeePerGas: '0x3b9aca00',
      nonce: '0x0',
      data: '0x',
    },
  },
})

if (signed.header.status === 'success') {
  const rawTx = signed.body.parameter.signature   // RLP-encoded signed tx
  // 4 · broadcast: provider.send('eth_sendRawTransaction', [rawTx])
}

warning

Always pair request + response. A successful sign returns body.parameter.signature; a failure returns body.error.code (a string — see the Error Codes page).

Handle the result

try {
  const r = await dcent.sign({ /* … */ })
  if (r.header.status === 'success') use(r.body.parameter)
  else handleError(r.body.error.code)          // 'user_cancel', 'param_error', …
} catch (e) {
  // only input validation throws (e.g. missing keyPath, bad chainId) — before anything is sent;
  // transport failures (popup closed, timeout) resolve as failure above
}

info

Stuck on the first call? Email contact@iotrust.kr with the chainId, the method, and the response you received.