Looking for ethers or viem-style providers? See our Provider Skills—copyable implementations you can customize. This page documents the low-level EIP-1193 interface that Skills build upon.

Source: Provider.ts • HttpProvider.ts • InMemoryProvider.ts • WebSocketProvider.tsTests: HttpProvider.test.ts • WebSocketProvider.test.ts • InMemoryProvider.test.ts • EIP1193Provider.test.ts

Future Plans: This page is planned and under active development. Examples are not final and will be replaced with accurate, tested content.

JSONRPCProvider

EIP-1193 compliant Ethereum JSON-RPC provider interface with branded primitive types and standard event emitter pattern. All types auto-generated from the official OpenRPC specification.

New to JSONRPCProvider? Start with Getting Started for installation and your first requests.

Overview

JSONRPCProvider implements the EIP-1193 provider interface for interacting with Ethereum nodes via JSON-RPC:

EIP-1193 compliant - Standard request(args) method
Branded primitives - Type-safe params using Address, Hash, Hex, Quantity
Throws on error - Standard error handling with exceptions
EventEmitter pattern - Standard on/removeListener for events
Auto-generated types - Generated from ethereum/execution-apis OpenRPC spec

Provider Interface

export interface Provider {
  // Single request method (EIP-1193)
  request(args: RequestArguments): Promise<unknown>;

  // Event emitter methods (EIP-1193)
  on(event: string, listener: (...args: any[]) => void): void;
  removeListener(event: string, listener: (...args: any[]) => void): void;
}

Request Arguments

Create requests using request builders:

import * as Rpc from '@tevm/voltaire/jsonrpc';

// Request builders return RequestArguments
const request = Rpc.Eth.BlockNumberRequest();
// { method: "eth_blockNumber", params: [] }

const result = await provider.request(request);
// Returns result directly or throws on error

Key Features

EIP-1193 Compliant

Standard request(args) method. Compatible with all EIP-1193 tools and libraries.

Branded Primitives

Compile-time type safety with Address, Hash, Hex, and Quantity branded types.

EventEmitter Pattern

Standard on/removeListener for accountsChanged, chainChanged, connect, disconnect events.

Auto-Generated Types

All types generated from ethereum/execution-apis OpenRPC specification. Always in sync.

Request Builders

Type-safe request constructors that return RequestArguments objects.

Error Handling

Throws standard EIP-1193 errors. Use try/catch for error handling.

Architecture

OpenRPC Specification (ethereum/execution-apis)
           ↓
  JSON-RPC Type Definitions
    (eth, debug, engine)
           ↓
   Request Builders
   (Rpc.Eth.*, Rpc.Debug.*, Rpc.Engine.*)
           ↓
   EIP-1193 Provider Interface
   (request(args) method)
           ↓
    Transport Layer
 (HTTP, WebSocket, IPC, Custom)

API Methods

Method Namespaces

eth Methods

40 standard Ethereum methods for blocks, transactions, state, logs, and gas estimation.

debug Methods

5 debugging methods for transaction tracing and block analysis.

engine Methods

20 consensus layer methods for Engine API integration.

Core Concepts

Method API

Direct method calls, parameters, response handling, and request options.

Type System

Auto-generated types, branded primitives, and type hierarchy.

Events

Async generator subscriptions for newHeads, logs, pending transactions.

Advanced Topics

Adapters

EIP-1193 adapter, HTTP handler, and creating custom providers.

Error Handling

Response structure, error codes, and retry strategies.

Performance

Batching, caching, connection pooling, and optimization.

Types

Provider
Request Builders
Error Handling
Common Types

export interface Provider {
  // Single request method (EIP-1193)
  request(args: RequestArguments): Promise<unknown>;

  // Event emitter methods (EIP-1193)
  on(event: string, listener: (...args: any[]) => void): void;
  removeListener(event: string, listener: (...args: any[]) => void): void;
}

interface RequestArguments {
  readonly method: string;
  readonly params?: readonly unknown[] | object;
}

import * as Rpc from '@tevm/voltaire/jsonrpc';

// eth namespace (40 methods)
Rpc.Eth.BlockNumberRequest();
Rpc.Eth.GetBalanceRequest(address, blockTag);
Rpc.Eth.GetTransactionCountRequest(address, blockTag);
Rpc.Eth.GetCodeRequest(address, blockTag);
Rpc.Eth.GetStorageAtRequest(address, slot, blockTag);
Rpc.Eth.CallRequest(params, blockTag);
Rpc.Eth.EstimateGasRequest(params);
Rpc.Eth.SendRawTransactionRequest(signedTx);
Rpc.Eth.GetTransactionByHashRequest(hash);
Rpc.Eth.GetTransactionReceiptRequest(hash);
Rpc.Eth.GetLogsRequest(filter);
// ... 29 more eth methods

// debug namespace (5 methods)
Rpc.Debug.TraceTransactionRequest(hash, options);
// ... 4 more debug methods

// engine namespace (20 methods)
Rpc.Engine.NewPayloadV3Request(payload);
// ... 19 more engine methods

// All return RequestArguments: { method: string, params: unknown[] }

// Provider throws on error (EIP-1193)
try {
  const blockNumber = await provider.request(
    Rpc.Eth.BlockNumberRequest()
  );
  console.log('Block number:', blockNumber);
} catch (error) {
  if (error.code) {
    console.error('RPC error:', error.code, error.message);
  } else {
    console.error('Unexpected error:', error);
  }
}

EIP-1193 Error Structure:

interface ProviderRpcError extends Error {
  code: number;
  data?: unknown;
}

// Block tags
type BlockTag = 'latest' | 'earliest' | 'pending' | 'safe' | 'finalized' | Quantity;

// Branded primitives
import type { brand } from '@tevm/voltaire/brand';

type Address = Uint8Array & { readonly [brand]: "Address" };
type Hash = Uint8Array & { readonly [brand]: "Hash" };
type Hex = string & { readonly [brand]: "Hex" };
type Quantity = string & { readonly [brand]: "Quantity" };  // Hex-encoded numbers

// Request types
interface CallParams {
  from?: Address;
  to: Address;
  gas?: Quantity;
  gasPrice?: Quantity;
  value?: Quantity;
  data?: Hex;
}

interface LogFilter {
  fromBlock?: BlockTag;
  toBlock?: BlockTag;
  address?: Address | Address[];
  topics?: (Hash | Hash[] | null)[];
}

Usage Patterns

Check Balance and Nonce

import * as Rpc from '@tevm/voltaire/jsonrpc';
import { Address } from '@tevm/voltaire/Address';

const address = Address('0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb0');

// Create requests using builders
const balanceReq = Rpc.Eth.GetBalanceRequest(address, 'latest');
const nonceReq = Rpc.Eth.GetTransactionCountRequest(address, 'latest');

try {
  const [balance, nonce] = await Promise.all([
    provider.request(balanceReq),
    provider.request(nonceReq)
  ]);

  console.log('Balance:', balance);
  console.log('Nonce:', nonce);
} catch (error) {
  console.error('RPC error:', error.message);
}

Query Contract State

import * as Rpc from '@tevm/voltaire/jsonrpc';
import { Address } from '@tevm/voltaire/Address';
import { Hex } from '@tevm/voltaire/Hex';

const contractAddress = Address('0x...');

try {
  // Check if contract exists
  const code = await provider.request(
    Rpc.Eth.GetCodeRequest(contractAddress, 'latest')
  );

  if (code !== '0x') {
    // Contract exists, call totalSupply()
    const result = await provider.request(
      Rpc.Eth.CallRequest({
        to: contractAddress,
        data: Hex('0x18160ddd')  // totalSupply() selector
      }, 'latest')
    );

    console.log('Total supply:', result);
  }
} catch (error) {
  console.error('Query failed:', error.message);
}

Monitor Contract Events

import { Address } from '@tevm/voltaire/Address';
import { Hash } from '@tevm/voltaire/Hash';

const contractAddress = Address('0x...');
const transferSignature = Hash(
  '0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef'
);

// Subscribe using EIP-1193 event emitter
provider.on('message', (event) => {
  if (event.type === 'eth_subscription') {
    const log = event.data.result;
    console.log('Transfer event:');
    console.log('  Block:', log.blockNumber);
    console.log('  Transaction:', log.transactionHash);
    console.log('  From:', log.topics[1]);
    console.log('  To:', log.topics[2]);
  }
});

// Or use chainChanged, accountsChanged events
provider.on('chainChanged', (chainId) => {
  console.log('Chain changed to:', chainId);
});

Wait for Transaction Confirmation

import * as Rpc from '@tevm/voltaire/jsonrpc';
import { Hash } from '@tevm/voltaire/Hash';

async function waitForConfirmation(
  txHash: Hash,
  confirmations: number = 3
): Promise<void> {
  try {
    const receipt = await provider.request(
      Rpc.Eth.GetTransactionReceiptRequest(txHash)
    );

    if (!receipt) {
      throw new Error('Transaction not found');
    }

    const targetBlock = BigInt(receipt.blockNumber) + BigInt(confirmations);

    // Poll for block number
    while (true) {
      const currentBlock = await provider.request(
        Rpc.Eth.BlockNumberRequest()
      );

      if (BigInt(currentBlock) >= targetBlock) {
        console.log(`Transaction confirmed with ${confirmations} confirmations`);
        break;
      }

      await new Promise(resolve => setTimeout(resolve, 1000));
    }
  } catch (error) {
    console.error('Confirmation failed:', error.message);
    throw error;
  }
}

Tree-Shaking

Import only what you need for optimal bundle size:

// Import Provider interface (no implementations)
import type { Provider } from '@tevm/voltaire/provider';

// Import specific primitives used
import { Address } from '@tevm/voltaire/Address';
import { Hash } from '@tevm/voltaire/Hash';

// Only these primitives included in bundle
// Unused primitives (Bytecode, Transaction, etc.) excluded

Importing primitives individually enables tree-shaking. Unused methods and types are excluded from your bundle.

Key Features Compared to Other Libraries

Feature	Standard EIP-1193	Voltaire JSONRPCProvider
Method calls	`request({ method, params })`	`request(Rpc.Eth.MethodRequest())`
Parameters	Plain strings/objects	Branded primitive types
Events	`on(event, listener)`	`on(event, listener)`
Errors	Throws exceptions	Throws exceptions
Type safety	Basic inference	Full inference with brands
Request builders	Manual object creation	Type-safe builder functions

See Comparison for detailed differences and migration guides.

Primitives

Address - 20-byte Ethereum addresses with EIP-55 checksumming
Keccak256 - 32-byte keccak256 hashes
Hex - Hex-encoded byte strings
Transaction - Transaction types and encoding

Cryptography

Keccak256 - Hashing for address derivation
Secp256k1 - Signature verification

Guides

Usage Patterns - Recipe collection for common tasks
Comparison - vs EIP-1193, ethers, viem

Specifications

EIP-1193 - Ethereum Provider JavaScript API
ethereum/execution-apis - JSON-RPC specification
OpenRPC - JSON-RPC API description format
EIP-3675 - Upgrade consensus to Proof-of-Stake (Engine API)
EIP-4844 - Shard Blob Transactions

​JSONRPCProvider

​Overview

​Provider Interface

​Request Arguments

​Key Features

EIP-1193 Compliant

Branded Primitives

EventEmitter Pattern

Auto-Generated Types

Request Builders

Error Handling

​Architecture

​API Methods

​Method Namespaces

eth Methods

debug Methods

engine Methods

​Core Concepts

Method API

Type System

Events

​Advanced Topics

Adapters

Error Handling

Performance

​Types

​Usage Patterns

​Check Balance and Nonce

​Query Contract State

​Monitor Contract Events

​Wait for Transaction Confirmation

​Tree-Shaking

​Key Features Compared to Other Libraries

​Related

​Primitives

​Cryptography

​Guides

​Specifications

JSONRPCProvider

Overview

Provider Interface

Request Arguments

Key Features

Architecture

API Methods

Method Namespaces

Core Concepts

Advanced Topics

Types

Usage Patterns

Check Balance and Nonce

Query Contract State

Monitor Contract Events

Wait for Transaction Confirmation

Tree-Shaking

Key Features Compared to Other Libraries

Related

Primitives

Cryptography

Guides

Specifications