Changelog

1.0.0

Initial release.

Core

• Transport interface with request(), subscribe(), connect(), close()
• Spread-style parameters — request('method', param1, param2) instead of array wrapping
• Schema-based generics for type-safe method names, parameters, and return types
• BatchScheduler for automatic request batching with configurable batch size and wait time
• withRetry() utility with exponential backoff
• parse() for creating transports from URL strings (supports nested meta-transports and query-string options)
• createParse() for building custom parse functions with overridden package maps
• createParseSync() for building synchronous parse functions using pre-imported factory functions
• ElectrumCashSchema type definitions (protocol v1.5 and v1.6)
• EthereumSchema type definitions (EIP-1474 standard methods)

Transports

• WebSocket — Full-duplex communication with subscriptions, keep-alive, reconnection, connection pooling
• TCP — Newline-delimited JSON-RPC with TLS support, keep-alive, reconnection (Node.js)
• HTTP — Stateless JSON-RPC over HTTP POST with custom headers, fetch options, and raw mode

All transports support lazy connections — no resources are allocated until the first request(), subscribe(), or connect() call.

Meta-Transports

• Fallback — Automatic failover across multiple transports with optional health-based ranking
  • Default shouldThrow stops fallback on deterministic JSON-RPC errors (parse error, invalid request, invalid params)
  • eagerConnect prioritizes the fastest-connecting transport
  • onScores listener and scores property for monitoring transport health
  • onResponse hook for observing requests across all transports
• Cluster — m-of-n quorum consensus with deep-equality response matching
  • onResponse hook for observing individual transport responses
• Single-element passthrough — fallback([t]) and cluster([t]) return the input transport directly

Electrum Cash Variants

Protocol-specific subpath imports (@rpckit/*/electrum-cash) with pre-configured defaults:

• server.version handshake with configurable clientName and protocolVersion
• server.ping keep-alive
• subscribe/unsubscribe method convention
• server.version HTTP header
• Fallback variant with server.ping health probing and protocol-aware shouldThrow (retries transient server errors like OOM, warmup, syncing)

Ethereum Variants

Protocol-specific subpath imports (@rpckit/*/ethereum) for Ethereum JSON-RPC:

• eth_subscription notification routing by subscription ID
• eth_unsubscribe called automatically on cleanup
• Subscription ID suppressed from callbacks (handled internally)
• Custom parse() function for Ethereum transports

Features

• Automatic request batching with configurable batch size and wait time
• Subscription support with automatic resubscription on reconnect
• Handshake re-execution on reconnect (WebSocket and TCP)
• Connection pooling with ref counting for WebSocket and TCP transports
• Retry with exponential backoff on all transports
• Raw mode for HTTP transport (return full JSON-RPC envelopes instead of throwing on error)
• Request/response hooks on HTTP transport
• Socket access via getSocket() and getSocketAsync() on WebSocket and TCP transports
• Subscription sharing — multiple listeners on the same method+params share one server subscription
• Smart unsubscribe — server unsubscribe only sent when last listener removes
• Fresh data for new subscribers — new listeners receive most recent notification, not stale initial result
• Race condition prevention — concurrent subscription calls safely coalesce
• notificationFilter callback for protocol-specific notification routing
• transformInitialResult option to normalize or suppress initial subscription results
• HTTP transport includes response body in error messages for better debugging