# Etherscan API

> Query Etherscan V2 API for gas prices, account transactions, balances, token transfers, contract source code, and compilation metadata via Nethereum.DataServices

- Skill: `nethereum/etherscan-api` (Agent Skill)
- Install (CLI): `npx skillmds@latest add nethereum/etherscan-api`
- Raw SKILL.md: https://api.skillmd.com/api/skills/nethereum/etherscan-api/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Integrations & APIs
- Author: nethereum (https://skillmd.com/u/nethereum)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/nethereum/etherscan-api

---


# Etherscan API

Query the Etherscan V2 unified API across all Etherscan-supported chains using `Nethereum.DataServices`.

**NuGet Package:** `Nethereum.DataServices`

## Installation

```bash
dotnet add package Nethereum.DataServices
```

## Quick Start

```csharp
using Nethereum.DataServices.Etherscan;

var etherscan = new EtherscanApiService(chain: 1, apiKey: "YOUR_ETHERSCAN_API_KEY");

// Gas prices
var gas = await etherscan.GasTracker.GetGasOracleAsync();
Console.WriteLine($"Safe: {gas.Result.SafeGasPrice} Gwei");
Console.WriteLine($"Proposed: {gas.Result.ProposeGasPrice} Gwei");
Console.WriteLine($"Fast: {gas.Result.FastGasPrice} Gwei");

// Account balance
var balance = await etherscan.Accounts.GetBalanceAsync("0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045");
Console.WriteLine($"Balance: {balance.Result} Wei");

// Contract ABI
var abi = await etherscan.Contracts.GetAbiAsync("0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48");
```

## Sub-Services

| Property | Class | Description |
|----------|-------|-------------|
| `Contracts` | `EtherscanApiContractsService` | ABI, source code, contract creator |
| `Accounts` | `EtherscanApiAccountsService` | Balances, transactions, token transfers |
| `GasTracker` | `EtherscanApiGasTrackerService` | Gas oracle, confirmation estimates |

## Gas Tracker

```csharp
// Gas oracle with price tiers
var response = await etherscan.GasTracker.GetGasOracleAsync();
var gas = response.Result;
// gas.SafeGasPrice, gas.ProposeGasPrice, gas.FastGasPrice, gas.SuggestBaseFee, gas.GasUsedRatio

// Confirmation time estimate (gas price in Wei)
var estimate = await etherscan.GasTracker.GetEstimatedConfirmationTimeAsync(gasPriceInWei: 30_000_000_000);
Console.WriteLine($"Seconds to confirm: {estimate.Result}");
```

## Account Queries

```csharp
// Single balance
var balance = await etherscan.Accounts.GetBalanceAsync("0x...");

// Multiple balances
var balances = await etherscan.Accounts.GetBalancesAsync(new[] { "0x...", "0x..." });

// Transaction history (paginated)
var txns = await etherscan.Accounts.GetAccountTransactionsAsync("0x...", page: 1, offset: 10, sort: "desc");

// Internal transactions
var internal = await etherscan.Accounts.GetAccountInternalTransactionsAsync("0x...", page: 1, offset: 10, sort: "desc");

// ERC-20 token transfers
var transfers = await etherscan.Accounts.GetTokenTransfersAsync("0x...");

// ERC-721 (NFT) transfers
var nfts = await etherscan.Accounts.GetErc721TransfersAsync("0x...");

// ERC-1155 transfers
var multi = await etherscan.Accounts.GetErc1155TransfersAsync("0x...");

// Funded by
var funded = await etherscan.Accounts.GetFundedByAsync("0x...");
```

## Contract Data

```csharp
// ABI as JSON string
var abiResponse = await etherscan.Contracts.GetAbiAsync("0x...");
string abi = abiResponse.Result;

// Source code and compilation metadata
var source = await etherscan.Contracts.GetSourceCodeAsync("0x...");
var info = source.Result.First();
Console.WriteLine($"Name: {info.ContractName}, Compiler: {info.CompilerVersion}");

// Contract creator and deployment tx
var creator = await etherscan.Contracts.GetContractCreatorAndCreationTxHashAsync("0x...");
```

## Multi-Chain Usage

Same API key works across all Etherscan V2 chains:

```csharp
var polygonApi = new EtherscanApiService(chain: 137, apiKey: "YOUR_KEY");
var arbApi = new EtherscanApiService(chain: 42161, apiKey: "YOUR_KEY");
var baseApi = new EtherscanApiService(chain: 8453, apiKey: "YOUR_KEY");
```

## Sourcify Parquet Exports

```csharp
using Nethereum.DataServices.Sourcify;

var parquet = new SourcifyParquetExportService();
var files = await parquet.ListTableFilesAsync("verified_contracts");
using var stream = await parquet.DownloadFileAsync(files.First().Key);
```

## Key Namespaces

- `Nethereum.DataServices.Etherscan` — Etherscan API service and response models
- `Nethereum.DataServices.Sourcify` — Sourcify Parquet export service

## Documentation

- [Etherscan API Guide](https://nethereum.com/docs/data-services/guide-etherscan-api)
- [Data Services Package Reference](https://nethereum.com/docs/data-services/nethereum-dataservices)