FreePublished on GitHubEnglish overview

evm

Queries wallet balances, token prices, transactions, and estimated network fees across eight Ethereum-compatible blockchains. It provides read-only portfolio comparisons, transaction decoding, and checks of token spending permissions without requiring an API key.

OriginalShow the original description

Read-only EVM client: wallets, tokens, gas across 8 chains.

NousResearch/hermes-agent

Works withCoinGecko

AI rating100/ 100 See how to install

Good for

Checking one wallet across eight supported chains
Comparing network fees and token prices
Inspecting transaction details and called functions
Checking token spending permissions and contract properties

Overview

What it does

This skill makes read-only queries across eight supported chains, including Ethereum, to check wallet balances, token information, prices, and transaction details. It checks assets held by the same address across multiple chains, calculates their combined US dollar value, and compares network fees. It also examines functions called in transactions, large transfers, ENS name and address mappings, token spending permissions, and contract characteristics.

When it helps

Use it to review assets spread across chains or compare estimated fees before a transaction. You can also investigate what a transaction did using its hash, or check unlimited token spending permissions granted to known exchanges and bridges.

Example requests

“Check this wallet across all eight supported chains and summarize its balances in US dollars.”
“Check which function this transaction called and review the token spending permissions.”

Notes

Python 3.8 or later is required; no additional packages or API keys are needed. Price lookups and some other queries depend on external public APIs with usage limits. Balance and spending permission checks cover known token lists, while transaction history covers up to 200 recent blocks. L2 fee estimates exclude the cost of posting data to L1.

This overview was written by AI (OpenAI Codex) from the public SKILL.md. Check the original below for the exact behavior.

Objective evaluation

AI rated this skill on four points using only the contents of its SKILL.md. Stars and popularity are not taken into account.

Clear instructionsIs it clear when to use it and what it does?: AGoodBalance queries, transaction analysis, and other use cases are explicit, along with read-only operation across eight chains.
Concrete stepsAre steps, inputs, outputs, and examples spelled out?: AGoodExamples show evm_client.py commands and outputs such as per-chain balances and combined US dollar values.
SafetyAre sending data, deleting files, and running commands disclosed?: AGoodRead-only operation is explicit, and the public APIs used for queries and their usage limits are described.
Easy setupDoes it need few tools or API keys, and are they documented?: AGoodPython 3.8 or later is the only requirement; no extra packages or API keys are needed, and startup checks are provided.

The total counts each point as A = 25, B = 15, C = 5. Rated by AI (OpenAI Codex) as of Oct 20, 2026. Treat it as a guide and read the original before installing.

Disagree? Request a re-evaluation

Files included (2)

SKILL.md8.2 KB
scripts/evm_client.py54.5 KB

SKILL.md (original)

Review the instructions the agent will receive before you install.

EVM Blockchain Skill

Query EVM-compatible blockchain data across 8 chains with USD pricing. 14 commands: wallet portfolio, token info, transactions, activity, gas tracker, network stats, price lookup, multi-chain scan, whale detection, ENS resolution, allowance checker, contract inspector, and transaction decoder.

Supports 8 chains: Ethereum, BNB Chain (BSC), Base, Arbitrum One, Polygon, Optimism, Avalanche (C-Chain), zkSync Era.

No API key needed. Zero external dependencies — Python standard library only (urllib, json, argparse, threading).

Supersedes the standalone base skill. Base-specific tokens (AERO, DEGEN, TOSHI, BRETT, WELL, cbETH, cbBTC, wstETH, rETH) and all Base RPC functionality previously living under optional-skills/blockchain/base/ have been folded into this skill. Pass --chain base to any command for Base coverage.

When to Use

User asks for a wallet balance or portfolio on any EVM chain
User wants to check the same wallet across ALL chains at once
User wants to inspect a transaction by hash (or decode what it did)
User wants ERC-20 token metadata, price, supply, or market cap
User wants recent transaction history for an address
User wants current gas prices or to compare fees across chains
User wants to find large whale transfers in recent blocks
User asks to resolve an ENS name (vitalik.eth) or reverse-lookup an address
User wants to check if a contract has dangerous token approvals
User wants to inspect a smart contract (proxy? ERC-20? ERC-721? bytecode size?)
User wants to compare gas costs across chains before a transaction

Prerequisites

Python 3.8+ standard library only. No pip installs required. Pricing: CoinGecko free API (rate-limited, ~10-30 req/min). ENS: ensideas.com public API. Tx decoding: 4byte.directory public API.

Override RPC endpoint: export EVM_RPC_URL=https://your-rpc.com

Helper script path: ~/.hermes/skills/blockchain/evm/scripts/evm_client.py

Quick Reference

SCRIPT=~/.hermes/skills/blockchain/evm/scripts/evm_client.py

# Network & prices
python $SCRIPT stats                            # Ethereum stats
python $SCRIPT stats --chain arbitrum           # Arbitrum stats
python $SCRIPT compare                          # Gas + prices ALL 8 chains

# Wallet
python $SCRIPT wallet 0xd8dA...96045            # Portfolio (ETH + ERC-20)
python $SCRIPT wallet 0xd8dA...96045 --chain bsc
python $SCRIPT multichain 0xd8dA...96045        # Same wallet on ALL chains

# Tokens & prices
python $SCRIPT price ETH
python $SCRIPT price 0xdAC1...1ec7              # By contract address
python $SCRIPT token 0xdAC1...1ec7              # ERC-20 metadata + market cap

# Transactions
python $SCRIPT tx 0x5c50...f060                 # Transaction details
python $SCRIPT decode 0x5c50...f060             # Decode input data (4byte.directory)
python $SCRIPT activity 0xd8dA...96045          # Recent transactions

# Gas
python $SCRIPT gas                              # Gas prices + cost estimates
python $SCRIPT gas --chain optimism

# Security
python $SCRIPT allowance 0xd8dA...96045         # Dangerous ERC-20 approvals
python $SCRIPT contract 0xdAC1...1ec7           # Contract inspection (proxy? standards?)

# ENS
python $SCRIPT ens vitalik.eth                  # Name -> address + profile
python $SCRIPT ens 0xd8dA...96045               # Address -> ENS name

# Whale detection
python $SCRIPT whale                            # Large transfers (last 20 blocks, >$10k)
python $SCRIPT whale --blocks 50 --min-usd 100000 --chain arbitrum

Procedure

0. Setup Check

python --version   # 3.8+ required
python ~/.hermes/skills/blockchain/evm/scripts/evm_client.py stats

1. Wallet Portfolio

Native balance + known ERC-20 tokens, sorted by USD value.

python $SCRIPT wallet 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045
python $SCRIPT wallet 0xd8dA... --chain bsc --no-prices   # faster

2. Multi-Chain Scan

Scans all 8 chains simultaneously for the same address using threads.

python $SCRIPT multichain 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045

Output: per-chain native balance + token holdings + grand total USD.

3. Compare (Gas + Prices)

All 8 chains queried in parallel. Shows cheapest/most expensive chain.

python $SCRIPT compare

4. Transaction Details & Decode

python $SCRIPT tx 0x5c504ed432cb51138bcf09aa5e8a410dd4a1e204ef84bfed1be16dfba1b22060
python $SCRIPT decode 0x5c504ed...   # Shows human-readable function signature

Decode uses 4byte.directory to translate 0xa9059cbb -> transfer(address,uint256).

5. ENS Resolution

python $SCRIPT ens vitalik.eth          # -> 0xd8dA... + avatar + social links
python $SCRIPT ens 0xd8dA...96045       # -> vitalik.eth

6. Allowance Checker (Security)

Checks ERC-20 approvals granted to known DEX/bridge contracts.

python $SCRIPT allowance 0xYourWallet

Flags UNLIMITED approvals as HIGH risk.

7. Contract Inspector

python $SCRIPT contract 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48   # USDC (proxy)
python $SCRIPT contract 0xdAC17F958D2ee523a2206206994597C13D831ec7   # USDT (ERC-20)

Detects: proxy (EIP-1967/EIP-1167), ERC-20, ERC-721, ERC-165. Shows bytecode size and implementation address for proxies.

8. Whale Detection

python $SCRIPT whale                                    # ETH, last 20 blocks, >$10k
python $SCRIPT whale --blocks 50 --min-usd 50000 --chain bsc

9. Gas Tracker

python $SCRIPT gas
python $SCRIPT gas --chain polygon

Shows gwei price + USD cost for: transfer, ERC-20 transfer, approve, swap, NFT mint, NFT transfer.

Supported Chains

Key	Name	Native	Chain ID
ethereum	Ethereum	ETH	1
bsc	BNB Chain	BNB	56
base	Base	ETH	8453
arbitrum	Arbitrum One	ETH	42161
polygon	Polygon	POL	137
optimism	Optimism	ETH	10
avalanche	Avalanche C	AVAX	43114
zksync	zkSync Era	ETH	324

Pitfalls

CoinGecko free tier: ~10-30 req/min. Use --no-prices for faster wallet scans.
Public RPCs may throttle. Set EVM_RPC_URL to a private endpoint for production.
wallet and allowance only check known token list (~30 tokens per chain). Use a block explorer for complete token discovery.
activity scans recent blocks only (max 200). For full history, use Etherscan API.
multichain runs 8 parallel threads — can trigger rate limits on public RPCs.
ENS resolution depends on a single public endpoint (ensideas.com / ens.vitalik.ca) with no fallback. If that endpoint is down, ens will fail — re-run later or use a block explorer.
Tx decoding depends on a single public endpoint (4byte.directory) with no fallback. Selectors not in their database show up as unknown.
L2 gas estimates are L2-execution only. On rollups like Base, Arbitrum, Optimism, and zkSync, the actual transaction cost also includes an L1 data-posting fee that depends on calldata size and current L1 gas prices. The gas command does not estimate that L1 component. For Base specifically, see the network's L1 fee oracle (contract 0x420000000000000000000000000000000000000F).
Address / tx-hash inputs are validated for 0x-prefix + correct length + hex, but EIP-55 checksum casing is not enforced (RPC endpoints accept any-case hex).

Verification

# Should print current block, gas price, ETH price
python ~/.hermes/skills/blockchain/evm/scripts/evm_client.py stats

# Should resolve vitalik.eth to 0xd8dA...
python ~/.hermes/skills/blockchain/evm/scripts/evm_client.py ens vitalik.eth

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