tendermint

A light client for Tendermint blockchains which works in Node.js and browsers.

Supports Tendermint v0.33.

NOTICE: This library has not undergone any kind of security review, so think twice before using it to secure any real value.

Usage

npm install tendermint

Light Node

Requests data over RPC and verifies blockchain headers

let Tendermint = require('tendermint')

// some full node's RPC port
let peer = 'ws://localhost:26657'

// `state` contains a part of the chain we know to be valid. If it's
// too old, we cannot safely verify the chain and need to get a newer
// state out-of-band.
let state = {
  // a header, in the same format as returned by RPC
  // (see http://localhost:26657/commit, under `"header":`)
  header: { ... },

  // the valdiator set for this header, in the same format as returned by RPC
  // (see http://localhost:26657/validators)
  validators: [ ... ],

  // the commit (validator signatures) for this header, in the same format as
  // returned by RPC (see http://localhost:26657/commit, under `"commit":`)
  commit: { ... }
}

// options
let opts = {
  // the maximum age of a state to be safely accepted,
  // e.g. the unbonding period
  // (in seconds)
  maxAge: 1728000 // defaults to 30 days
}

// instantiate client. will automatically start syncing to the latest state of
// the blockchain
let node = Tendermint(peer, state, opts)

// make sure to handle errors
node.on('error', (err) => { ... })
// emitted once we have caught up to the current chain tip
node.on('synced', () => { ... })
// emitted every time we have verified a new part of the blockchain
node.on('update', () => { ... })

// returns the height of the most recent header we have verified
node.height()

// returns the state object ({ header, validators, commit }) of the most recently
// verified header, should be stored and used to instantiate the light client
// the next time the user runs the app
node.state()

RPC Client

Simple client to make RPC requests to nodes

let { RpcClient } = require('tendermint')

let client = RpcClient('ws://localhost:26657')

// request a block
client.block({ height: 100 })
  .then((res) => console.log(res))

The following RPC methods are available:

- subscribe
- unsubscribe
- status
- netInfo
- dialSeeds
- blockchain
- genesis
- block
- validators
- dumpConsensusState
- broadcastTxCommit
- broadcastTxAsync
- broadcastTxSync
- unconfirmedTxs
- numUnconfirmedTxs
- abciQuery
- abciInfo
- abciProof
- unsafeFlushMempool
- unsafeSetConfig
- unsafeStartCpuProfiler
- unsafeStopCpuProfiler
- unsafeWriteHeapProfile