solana_kit_rpc_spec_types 0.1.0

RPC spec type definitions for the Solana Kit Dart SDK.

solana_kit_rpc_spec_types

RPC spec type definitions for the Solana Kit Dart SDK.

This is the Dart port of @solana/rpc-spec-types from the Solana TypeScript SDK.

Installation

Install with:

dart pub add solana_kit_rpc_spec_types

If you are working within the solana_kit monorepo, the package resolves through the Dart workspace. Otherwise, specify a version or path as needed.

Documentation

• Package page: https://pub.dev/packages/solana_kit_rpc_spec_types
• API reference: https://pub.dev/documentation/solana_kit_rpc_spec_types/latest/

Usage

RpcRequest

The RpcRequest class describes an RPC request with a method name and parameters.

import 'package:solana_kit_rpc_spec_types/solana_kit_rpc_spec_types.dart';

final request = RpcRequest<List<Object?>>(
  methodName: 'getBalance',
  params: ['83astBRguLMdt2h5U1Tbd4hU5SkfAWRkzG2HPM88BREAK'],
);

print(request.methodName); // 'getBalance'
print(request.params); // ['83astBRguLMdt2h5U1Tbd4hU5SkfAWRkzG2HPM88BREAK']

Request transformers

An RpcRequestTransformer is a function that transforms an RpcRequest before it is sent. This enables patterns like applying defaults, renaming methods, or serializing values.

import 'package:solana_kit_rpc_spec_types/solana_kit_rpc_spec_types.dart';

// A transformer that prefixes all method names.
RpcRequestTransformer prefixTransformer = (request) {
  return RpcRequest(
    methodName: 'custom_${request.methodName}',
    params: request.params,
  );
};

final original = RpcRequest<Object?>(
  methodName: 'getSlot',
  params: [],
);
final transformed = prefixTransformer(original);
print(transformed.methodName); // 'custom_getSlot'

RPC response types

The RpcResponseData sealed class represents the data in an RPC response, which is either a successful result or an error.

import 'package:solana_kit_rpc_spec_types/solana_kit_rpc_spec_types.dart';

// A successful response.
const success = RpcResponseResult<int>(id: '1', result: 42);
print(success.result); // 42

// An error response.
const error = RpcResponseError<int>(
  id: '1',
  error: RpcErrorResponsePayload(
    code: -32601,
    message: 'Method not found',
  ),
);
print(error.error.code); // -32601
print(error.error.message); // 'Method not found'

// Pattern matching on sealed types.
void handleResponse(RpcResponseData<int> data) {
  switch (data) {
    case RpcResponseResult<int>(:final result):
      print('Got result: $result');
    case RpcResponseError<int>(:final error):
      print('Got error: ${error.message}');
  }
}

Response transformers

An RpcResponseTransformer transforms a raw response before returning it to the caller. It receives both the response and the original request for context.

import 'package:solana_kit_rpc_spec_types/solana_kit_rpc_spec_types.dart';

// A transformer that doubles numeric results.
RpcResponseTransformer<Object?> doubleTransformer = (response, request) {
  if (response is int) {
    return response * 2;
  }
  return response;
};

Creating JSON-RPC messages

The createRpcMessage function builds a spec-compliant JSON-RPC 2.0 message with an auto-incrementing string ID.

import 'package:solana_kit_rpc_spec_types/solana_kit_rpc_spec_types.dart';

final message = createRpcMessage(RpcRequest(
  methodName: 'getSlot',
  params: [],
));
print(message);
// {id: '0', jsonrpc: '2.0', method: 'getSlot', params: []}

// Each call gets a new ID.
final message2 = createRpcMessage(RpcRequest(
  methodName: 'getBalance',
  params: ['address123'],
));
print(message2['id']); // '1'

BigInt-aware JSON parsing

The parseJsonWithBigInts and stringifyJsonWithBigInts functions handle the fact that Solana RPC responses can contain integers larger than what IEEE 754 doubles can represent. All non-floating-point numbers are parsed as BigInt.

import 'package:solana_kit_rpc_spec_types/solana_kit_rpc_spec_types.dart';

// Parse JSON with BigInt support.
final parsed = parseJsonWithBigInts('{"balance": 9007199254740993, "rate": 1.5}');
final map = parsed as Map<String, Object?>;
print(map['balance'] is BigInt); // true
print(map['balance']); // 9007199254740993 (as BigInt, no precision loss)
print(map['rate'] is double); // true (floating-point preserved as double)

// Stringify with BigInt support.
final json = stringifyJsonWithBigInts({
  'balance': BigInt.parse('9007199254740993'),
  'rate': 1.5,
});
print(json); // {"balance":9007199254740993,"rate":1.5}
// Note: BigInt values are rendered as raw integers, not quoted strings.

API Reference

Classes

• RpcRequest<TParams> -- Describes an RPC request with methodName (String) and params (TParams).
• RpcResponseData<T> -- Sealed class representing an RPC response: either RpcResponseResult<T> or RpcResponseError<T>.
• RpcResponseResult<T> -- A successful RPC response with id and result.
• RpcResponseError<T> -- An error RPC response with id and error.
• RpcErrorResponsePayload -- Error payload with code (int), message (String), and optional data.

Functions

• createRpcMessage<TParams>(RpcRequest<TParams> request) -- Creates a JSON-RPC 2.0 message map with auto-incrementing ID.
• parseJsonWithBigInts(String json) -- Parses JSON, converting all integer values to BigInt while preserving floating-point numbers as double.
• stringifyJsonWithBigInts(Object? value) -- Converts a value to JSON, rendering BigInt values as unquoted large integers.

Typedefs

• RpcRequestTransformer -- RpcRequest<Object?> Function(RpcRequest<Object?> request) -- Transforms an RPC request before sending.
• RpcResponseTransformer<T> -- T Function(Object? response, RpcRequest<Object?> request) -- Transforms an RPC response before returning.