[](https://www.npmjs.com/package/@acurast/dapp)

Tools useful in dApp development.
``bash`
$ npm install @acurast/dapp
A client that can communicate with the Acurast P2P network.
To create a new instance call it constuctor and provide an Acurast P2P WebSocket server url and an optional connectionTimeoutMillis.
The connection timeout is the number of milliseconds to wait for an initial response from the server. If the server does not respond within the specified time, an error is thrown. If this parameter is omitted, the default value of 15 seconds is used.
`typescript`
constructor(url: string, connectionTimeoutMillis?: number / default: 15s /)
#### start
Opens a connection between the client and the server using the dApp's P256 keyPair.
`typescript
/*
interface KeyPair {
publicKey: string | Uint8Array
secretKey: string | Uint8Array
}
*/
start(keyPair: KeyPair): Promise
`
#### onMessage
Registers a new listener which will be notified on incoming message.
`typescript
/*
interface Message {
sender: Uint8Array
recipient: Uint8Array
payload: Uint8Array
}
*/
onMessage(listener: (message: Message) => void | Promise
`
#### send
Sends a new message with the payload to a peer that identifies with the publicKey.
If payload is not a valid raw bytes value (Uint8Array or a hex string), it will be encoded to UTF-8 bytes before sending.
`typescript`
send(publicKey: string | Uint8Array, payload: string | Uint8Array): Promise
#### close
Terminates the ongoing connection.
`typescript`
close(): Promise
#### Usage
##### Send messages to Acurast Processor
`typescript
import { AcurastClient, Message } from '@acurast/dapp'
const acurastClient = new AcurastClient('wss://example.com' / Acurast P2P WebSocket Server /)
await acurastClient.start({
secretKey: 'f816e59353c58627039fbf5e96747a871244194b9db12095189554e78a6d4a45',
publicKey: '04ae00462e82af267b42b477493450b04b8ed05e510eca2a40c6f7679b14e364b9d6f9c867a7e72b4880f9632450e5c2c03bd69424f786e10bb77e9bd09e322ef3'
} / P256 key pair /)
acurastClient.onMessage(async (message: Message) => {
console.log('Received Message', message)
await acurastClient.close()
})
await acurastClient.send(
'028aad55a45e1eba230e38243ee9221d765cdb59fde684bad516bffcc9970f3c15' / processor's public key /,
'my message'
)
``
See the example dApp.