@cambrianprotocol/anchor-listener NPM

Ceramic Anchor listener

ceramicnetwork

Getting started

Installation

$ npm install @ceramicnetwork/anchor-listener

Usage

import {
  createBlockProofsListener,
  createBlocksProofsLoader,
  createAncestorBlocksProofsLoader,
} from '@ceramicnetwork/anchor-listener'
import { take, timeout } from 'rxjs'

// Listen to new block events on the provider and load anchor proofs
const subsription = createBlockProofsListener({ chainId: 'eip155:1', confirmations: 20, provider: ... }).subscribe({
  next(event) {
    // event contains the `block` and `proofs`
  }
})
// Unsubscribe to stop listening
subscription.unsubscribe()

// Load proofs for a range of blocks
createBlocksProofsLoader({ chainId: 'eip155:1', fromBlock: 100, toBlock: 120, provider: ...  }).subscribe({
  next(event) {
    // event contains the `block` and `proofs`
  }
})

// Load proofs for blocks, walking up the parents until the expected ancestor hash is found
createAncestorBlocksProofsLoader({ chainId: 'eip155:1', initialBlock: 'latest', targetAncestorHash: '...', provider: ...  }).pipe(
  // Operators can be used to add stopping conditions
  take(50), // attempt to load maximum 50 blocks
  timeout(300_000), // timeout after 5 minutes
).subscribe({
  next(event) {
    // event contains the `block` and `proofs`
    // unless interrupted, `block.parentHash` will be `targetAncestorHash` in the last event
  }
})