@rpckit/core

Core types, schema utilities, and batch scheduler for communication with JSON-RPC servers.

Installation

npm install @rpckit/core

Usage

import type { Schema, Transport } from '@rpckit/core'
import { webSocket } from '@rpckit/websocket'

type MySchema = {
  requests: [
    { method: 'getblockcount'; params: []; return: number }
  ]
  subscriptions: []
}

const transport = webSocket<MySchema>('wss://example.com')
const blockCount = await transport.request('getblockcount')
await transport.close()

Electrum Cash Subpackage

Electrum Cash schema types and a pre-configured parse() variant are available under the electrum-cash subpath:

import type { ElectrumCashSchema } from '@rpckit/core/electrum-cash'
import { parse } from '@rpckit/core/electrum-cash'

const transport = await parse('wss://electrum.example.com')

Ethereum Subpackage

Ethereum schema types and a pre-configured parse() variant are available under the ethereum subpath:

import type { EthereumSchema } from '@rpckit/core/ethereum'
import { parse } from '@rpckit/core/ethereum'

const transport = await parse('wss://ethereum-rpc.publicnode.com')

Parse Utility

Create transports from one-liner configuration strings:

import { parse } from '@rpckit/core'

// Simple transports (uses base, protocol-agnostic packages)
const ws = await parse('wss://example.com:50004')
const tcp = await parse('tcp+tls://example.com:50002?timeout=10000')

// With options
const batched = await parse('wss://example.com?batchSize=10&batchWait=50')

// Fallback with ranking
const fb = await parse('fallback(wss://a.com,tcp://b.com)?rank=true')

// Cluster with quorum
const cl = await parse('cluster(2,ws://1.com,ws://2.com,ws://3.com)')

// Nested
const nested = await parse('fallback(wss://primary.com,cluster(2,ws://1.com,ws://2.com,ws://3.com))')

createParse

Create a custom parse function that uses different packages for transport creation:

import { createParse } from '@rpckit/core'

// Use electrum-cash variants for all transports
const electrumParse = createParse({
  websocket: '@rpckit/websocket/electrum-cash',
  tcp: '@rpckit/tcp/electrum-cash',
  http: '@rpckit/http/electrum-cash',
})

const transport = await electrumParse('wss://electrum.example.com')

A pre-built Electrum Cash parse is available at @rpckit/core/electrum-cash.

createParseSync

Create a synchronous parse function using pre-imported factory functions. Unlike createParse which uses dynamic imports, this variant accepts already-loaded factories:

import { createParseSync } from '@rpckit/core'
import { webSocket } from '@rpckit/websocket/electrum-cash'
import { fallback } from '@rpckit/fallback'

const parseSync = createParseSync({ webSocket, fallback })
const transport = parseSync('fallback(wss://a.com,wss://b.com)?eagerConnect=true')

Supported schemes: wss://, ws://, tcp://, tcp+tls://, http://, https://

Supported options: timeout, retryCount, retryDelay, keepAlive, batch, batchSize, batchWait, rank, eagerConnect

Exports

Main (@rpckit/core)

• BatchScheduler - Request batching utility
• parse - One-liner transport configuration parser
• createParse - Factory for custom parse functions with overridden package maps
• createParseSync - Synchronous factory using pre-imported transport functions
• withRetry - Async retry utility with exponential backoff
• Transport - Transport interface for implementing custom transports
• Type utilities: ExtractReturn, ExtractParams, ExtractMethod, FilterMethods, OverrideRequests, PackageMap, FactoryMap, etc.

Electrum Cash (@rpckit/core/electrum-cash)

• parse - Pre-configured parse using Electrum Cash transport variants
• ElectrumCashSchema - Type definitions for Electrum Cash protocol (v1.5 and v1.6)

Ethereum (@rpckit/core/ethereum)

• parse - Pre-configured parse using Ethereum transport variants
• EthereumSchema - Type definitions for Ethereum JSON-RPC (EIP-1474 standard methods)