Ethereum Read Only

Foundry castを使用したウォレット不要のオンチェーン状態読み取り

Security Scan

Skill content is coherent with a read-only Ethereum helper, but the SKILL.md instructs installing software and setting RPC API keys that the registry metadata does not declare — and it uses a curl|bash installer and command-line tools not listed in requirements.

Purpose & Capability

The skill's name/description (read-only Ethereum queries via Foundry cast) matches the instructions. However the registry metadata declares no required environment variables or binaries while the instructions explicitly rely on ETH_RPC_URL/POLYGON_RPC_URL/ARB_RPC_URL (API keys or public RPC URLs) and on tools such as cast, jq, bc — a mismatch between declared requirements and actual needs.

Instruction Scope

SKILL.md instructs installing Foundry and exporting RPC environment variables (modifying ~/.bashrc), and contains many example scripts that call cast, jq, bc, date, etc. The instructions do not access unrelated system areas or other credentials, but they assume the presence of several binaries and they encourage running a remote installer and editing shell config without declaring those requirements.

Install Mechanism

There is no formal install spec in the registry; the SKILL.md tells the user to run curl -L https://foundry.paradigm.xyz | bash and foundryup. That URL is the official Foundry installer host (paradigm's installer), which is common practice but still executes a remote script. Because the skill is instruction-only, the platform won't manage or vet that install — the user should inspect the installer before running it.

Credentials

The instructions require RPC endpoints/API keys (Alchemy or other RPC providers) which are effectively credentials, but the skill metadata declares no required env vars or primary credential. This omission is significant: users may provide secrets without the platform treating them as sensitive, and the skill may reference credentials that were not communicated as needed.

Persistence & Privilege

always is false and autonomous invocation is allowed (platform default). The SKILL.md suggests adding exports to ~/.bashrc, which modifies shell profile, but the skill does not request persistent system-wide privileges or modify other skills. No 'always:true' or other escalations are present.

What to consider before installing

This skill appears to be a straightforward guide for read-only Ethereum queries using Foundry/cast, but metadata and README disagree on what the agent/user must provide. Before installing or running anything: (1) Inspect the Foundry installer script (https://foundry.paradigm.xyz) rather than blindly running curl | bash. (2) Note that the SKILL.md expects ETH_RPC_URL (and similar RPC keys) — treat those as secrets (API keys) and do not paste them into public places; the registry did not mark them as required so platform protections may not apply. (3) Ensure you have jq, bc, cast (Foundry), and other CLI tools available; the registry lists no required binaries. (4) If you prefer extra safety, use a public rate-limited RPC (e.g., rpc.ankr.com) or run your own node instead of supplying a paid Alchemy/Infura key. (5) If you want to install this skill in an automated agent, ask the author to update metadata to declare required env vars and binaries, and to provide an install spec or vetted release URL to avoid running unreviewed remote scripts.

Ethereum読み取り専用アクセス

Foundryのcastコマンドを使用してウォレットなしでEthereumブロックチェーンの状態を読み取る方法。ブロック情報、コントラクト状態、イベントログ、ENS解決の実装ガイドです。

セットアップ

Foundryインストール

# Foundryインストール
curl -L https://foundry.paradigm.xyz | bash
foundryup

# 動作確認
cast --version

RPC設定

# 環境変数設定（~/.bashrc または ~/.zshrc）
export ETH_RPC_URL="https://eth-mainnet.alchemyapi.io/v2/YOUR-API-KEY"
export POLYGON_RPC_URL="https://polygon-mainnet.g.alchemy.com/v2/YOUR-API-KEY"
export ARB_RPC_URL="https://arb-mainnet.g.alchemy.com/v2/YOUR-API-KEY"

# 無料RPCの使用（レート制限あり）
export ETH_RPC_URL="https://rpc.ankr.com/eth"
export POLYGON_RPC_URL="https://rpc.ankr.com/polygon"

# 設定確認
cast client --rpc-url $ETH_RPC_URL

ブロック情報取得

基本的なブロック検査

#!/bin/bash
# block-inspector.sh

# 最新ブロック番号取得
get_latest_block() {
    echo "最新ブロック番号:"
    cast block-number --rpc-url $ETH_RPC_URL
}

# ブロック基本情報
inspect_block() {
    local block_number="$1"
    
    echo "=== ブロック $block_number 基本情報 ==="
    cast block "$block_number" --rpc-url $ETH_RPC_URL
}

# トランザクション込みの詳細ブロック情報
inspect_block_full() {
    local block_number="$1"
    
    echo "=== ブロック $block_number 詳細情報（トランザクション含む）==="
    cast block "$block_number" --full --rpc-url $ETH_RPC_URL
}

# ブロック統計
block_stats() {
    local block_number="$1"
    
    echo "=== ブロック $block_number 統計 ==="
    
    # トランザクション数
    local tx_count="$(cast block "$block_number" --rpc-url $ETH_RPC_URL | jq -r '.transactions | length')"
    echo "トランザクション数: $tx_count"
    
    # ガス使用量
    local gas_used="$(cast block "$block_number" --rpc-url $ETH_RPC_URL | jq -r '.gasUsed')"
    echo "ガス使用量: $gas_used"
    
    # タイムスタンプ
    local timestamp="$(cast block "$block_number" --rpc-url $ETH_RPC_URL | jq -r '.timestamp')"
    echo "ブロック時刻: $(date -d @$((timestamp)) +'%Y-%m-%d %H:%M:%S')"
}

# 使用例
get_latest_block
inspect_block "latest"
block_stats "latest"

ブロック範囲分析

# block-range-analyzer.sh

analyze_block_range() {
    local start_block="$1"
    local end_block="$2"
    
    echo "=== ブロック範囲分析: $start_block - $end_block ==="
    
    local total_tx=0
    local total_gas=0
    
    for ((block=$start_block; block<=$end_block; block++)); do
        echo "ブロック $block を処理中..."
        
        local block_data="$(cast block "$block" --rpc-url $ETH_RPC_URL)"
        local tx_count="$(echo "$block_data" | jq -r '.transactions | length')"
        local gas_used="$(echo "$block_data" | jq -r '.gasUsed')"
        
        total_tx=$((total_tx + tx_count))
        total_gas=$((total_gas + gas_used))
        
        echo "  TX: $tx_count, Gas: $gas_used"
    done
    
    echo ""
    echo "=== サマリー ==="
    echo "総トランザクション数: $total_tx"
    echo "総ガス使用量: $total_gas"
    echo "平均TX/ブロック: $((total_tx / (end_block - start_block + 1)))"
}

# 使用例
analyze_block_range 19000000 19000010

コントラクト状態読み取り

基本的なコントラクト呼び出し

#!/bin/bash
# contract-reader.sh

# ERC20トークン残高確認
check_erc20_balance() {
    local token_address="$1"
    local wallet_address="$2"
    
    echo "=== ERC20残高確認 ==="
    echo "トークン: $token_address"
    echo "ウォレット: $wallet_address"
    
    # balanceOf(address) 関数呼び出し
    local balance="$(cast call "$token_address" \
        "balanceOf(address)(uint256)" \
        "$wallet_address" \
        --rpc-url $ETH_RPC_URL)"
    
    echo "残高: $balance"
    
    # トークン名取得
    local name="$(cast call "$token_address" \
        "name()(string)" \
        --rpc-url $ETH_RPC_URL)"
    
    # トークンシンボル取得
    local symbol="$(cast call "$token_address" \
        "symbol()(string)" \
        --rpc-url $ETH_RPC_URL)"
    
    # 小数点桁数取得
    local decimals="$(cast call "$token_address" \
        "decimals()(uint8)" \
        --rpc-url $ETH_RPC_URL)"
    
    echo "トークン名: $name"
    echo "シンボル: $symbol"
    echo "小数点桁数: $decimals"
    
    # 人間が読める形式に変換
    local human_balance="$(cast to-dec "$balance")"
    local scaled_balance="$(echo "scale=6; $human_balance / 10^$decimals" | bc -l)"
    echo "表示用残高: $scaled_balance $symbol"
}

# Uniswap V3プール情報取得
check_uniswap_pool() {
    local pool_address="$1"
    
    echo "=== Uniswap V3 プール情報 ==="
    echo "プールアドレス: $pool_address"
    
    # プール基本情報
    local token0="$(cast call "$pool_address" "token0()(address)" --rpc-url $ETH_RPC_URL)"
    local token1="$(cast call "$pool_address" "token1()(address)" --rpc-url $ETH_RPC_URL)"
    local fee="$(cast call "$pool_address" "fee()(uint24)" --rpc-url $ETH_RPC_URL)"
    
    echo "Token0: $token0"
    echo "Token1: $token1"
    echo "手数料: $(cast to-dec "$fee") (0.01% = 100)"
    
    # 現在の流動性とプライス
    local liquidity="$(cast call "$pool_address" "liquidity()(uint128)" --rpc-url $ETH_RPC_URL)"
    echo "流動性: $(cast to-dec "$liquidity")"
    
    # slot0情報（価格、ティック等）
    local slot0="$(cast call "$pool_address" "slot0()(uint160,int24,uint16,uint16,uint16,uint8,bool)" --rpc-url $ETH_RPC_URL)"
    echo "Slot0: $slot0"
}

# ENSリバースルックアップ
resolve_ens() {
    local address="$1"
    
    echo "=== ENS解決 ==="
    echo "アドレス: $address"
    
    # ENS名前解決
    local ens_name="$(cast lookup-address "$address" --rpc-url $ETH_RPC_URL 2>/dev/null || echo "なし")"
    echo "ENS名: $ens_name"
}

# 使用例
check_erc20_balance "0xA0b86a33E6441b04B9b73f9251e9b49Cd2B3a64" "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"  # USDC, Vitalik
check_uniswap_pool "0x8ad599c3A0ff1De082011EFDDc58f1908eb6e6D8"  # USDC/ETH 0.3%
resolve_ens "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"

イベントログ検索

ログ検索システム

#!/bin/bash
# event-log-searcher.sh

# Transfer イベント検索
search_transfer_events() {
    local contract_address="$1"
    local from_block="$2"
    local to_block="$3"
    local sender="${4:-}"
    local receiver="${5:-}"
    
    echo "=== Transfer イベント検索 ==="
    echo "コントラクト: $contract_address"
    echo "ブロック範囲: $from_block - $to_block"
    
    # Transfer(address,address,uint256) イベントシグネチャ
    local transfer_sig="0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef"
    
    # 基本検索コマンド構築
    local cmd="cast logs --rpc-url $ETH_RPC_URL"
    cmd="$cmd --address $contract_address"
    cmd="$cmd --from-block $from_block"
    cmd="$cmd --to-block $to_block"
    cmd="$cmd $transfer_sig"
    
    # フィルター追加
    if [[ -n "$sender" ]]; then
        cmd="$cmd $sender"
    fi
    
    if [[ -n "$receiver" ]]; then
        if [[ -z "$sender" ]]; then
            cmd="$cmd '' $receiver"  # sender未指定の場合は空文字
        else
            cmd="$cmd $receiver"
        fi
    fi
    
    echo "実行コマンド: $cmd"
    
    # ログ実行と結果パース
    eval "$cmd" | jq -r '.[] | "ブロック: \(.blockNumber), TX: \(.transactionHash), ログインデックス: \(.logIndex)"'
}

# 汎用イベント検索
search_custom_events() {
    local contract_address="$1"
    local event_signature="$2"
    local from_block="$3"
    local to_block="$4"
    
    echo "=== カスタムイベント検索 ==="
    echo "シグネチャ: $event_signature"
    
    cast logs \
        --address "$contract_address" \
        --from-block "$from_block" \
        --to-block "$to_block" \
        "$event_signature" \
        --rpc-url $ETH_RPC_URL \
        | jq '.'
}

# DEX取引分析
analyze_dex_trades() {
    local pool_address="$1"
    local from_block="$2"
    local to_block="$3"
    
    echo "=== DEX取引分析 ==="
    
    # Swap イベント (Uniswap V3: Swap(address,address,int256,int256,uint160,uint128,int24))
    local swap_sig="0xc42079f94a6350d7e6235f29174924f928cc2ac818eb64fed8004e115fbcca67"
    
    cast logs \
        --address "$pool_address" \
        --from-block "$from_block" \
        --to-block "$to_block" \
        "$swap_sig" \
        --rpc-url $ETH_RPC_URL \
        | jq -r '.[] | "取引: ブロック \(.blockNumber), TX \(.transactionHash), ガス使用: \(.gasUsed)"'
}

# 使用例
search_transfer_events "0xA0b86a33E6441b04B9b73f9251e9b49Cd2B3a64" "19000000" "19000100"  # USDC transfers
search_custom_events "0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984" "0x8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b925" "19000000" "19000050"  # UNI Approval

ENS操作

ENS解決システム

#!/bin/bash
# ens-resolver.sh

# ENS名からアドレス解決
resolve_ens_to_address() {
    local ens_name="$1"
    
    echo "=== ENS → アドレス解決 ==="
    echo "ENS名: $ens_name"
    
    # 基本的なアドレス解決
    local address="$(cast resolve-name "$ens_name" --rpc-url $ETH_RPC_URL)"
    echo "アドレス: $address"
    
    # コンテンツハッシュ取得（IPFS等）
    local content_hash="$(cast call 0x231b0Ee14048e9dCcD1d247744d114a4EB5E8E63 \
        "contenthash(bytes32)(bytes)" \
        "$(cast namehash "$ens_name")" \
        --rpc-url $ETH_RPC_URL 2>/dev/null || echo "なし")"
    echo "コンテンツハッシュ: $content_hash"
    
    # テキストレコード取得
    echo "テキストレコード:"
    for key in "email" "url" "avatar" "description" "notice" "keywords" "com.github" "com.twitter"; do
        local value="$(cast call 0x231b0Ee14048e9dCcD1d247744d114a4EB5E8E63 \
            "text(bytes32,string)(string)" \
            "$(cast namehash "$ens_name")" \
            "$key" \
            --rpc-url $ETH_RPC_URL 2>/dev/null || echo "")"
        if [[ -n "$value" && "$value" != '""' ]]; then
            echo "  $key: $value"
        fi
    done
}

# アドレスからENS名解決
resolve_address_to_ens() {
    local address="$1"
    
    echo "=== アドレス → ENS解決 ==="
    echo "アドレス: $address"
    
    local ens_name="$(cast lookup-address "$address" --rpc-url $ETH_RPC_URL 2>/dev/null || echo "なし")"
    echo "ENS名: $ens_name"
    
    # プライマリ名確認
    if [[ "$ens_name" != "なし" ]]; then
        local reverse_address="$(cast resolve-name "$ens_name" --rpc-url $ETH_RPC_URL)"
        if [[ "$reverse_address" == "$address" ]]; then
            echo "プライマリ名: はい"
        else
            echo "プライマリ名: いいえ（$reverse_address）"
        fi
    fi
}

# ENSドメイン情報詳細
ens_domain_info() {
    local ens_name="$1"
    
    echo "=== ENSドメイン詳細情報 ==="
    
    # 所有者情報
    local owner="$(cast call 0x00000000000C2E074eC69A0dFb2997BA6C7d2e1e \
        "owner(bytes32)(address)" \
        "$(cast namehash "$ens_name")" \
        --rpc-url $ETH_RPC_URL)"
    echo "所有者: $owner"
    
    # レジストラ情報（.ethドメインの場合）
    if [[ "$ens_name" == *.eth ]]; then
        local registrar="0x57f1887a8BF19b14fC0dF6Fd9B2acc9Af147eA85"
        local token_id="$(cast keccak "$(echo -n "${ens_name%.eth}")")"
        
        local registrant="$(cast call "$registrar" \
            "ownerOf(uint256)(address)" \
            "$token_id" \
            --rpc-url $ETH_RPC_URL 2>/dev/null || echo "なし")"
        echo "登録者: $registrant"
        
        # 有効期限
        local expires="$(cast call "$registrar" \
            "nameExpires(uint256)(uint256)" \
            "$token_id" \
            --rpc-url $ETH_RPC_URL 2>/dev/null || echo "0")"
        if [[ "$expires" != "0" ]]; then
            echo "有効期限: $(date -d @$((expires)) +'%Y-%m-%d %H:%M:%S')"
        fi
    fi
}

# 使用例
resolve_ens_to_address "vitalik.eth"
resolve_address_to_ens "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"
ens_domain_info "uniswap.eth"

ABI デコーディング

トランザクション・ログ解析

#!/bin/bash
# abi-decoder.sh

# 関数呼び出しデコード
decode_function_call() {
    local tx_hash="$1"
    local abi_file="$2"  # JSONファイルまたはEtherscan署名
    
    echo "=== 関数呼び出しデコード ==="
    echo "TX: $tx_hash"
    
    # トランザクション詳細取得
    local tx_data="$(cast tx "$tx_hash" --rpc-url $ETH_RPC_URL)"
    local input_data="$(echo "$tx_data" | jq -r '.input')"
    local to_address="$(echo "$tx_data" | jq -r '.to')"
    
    echo "送信先: $to_address"
    echo "入力データ: ${input_data:0:50}..."
    
    # 4byteセレクタ抽出
    local selector="${input_data:2:8}"
    echo "関数セレクタ: 0x$selector"
    
    # 4byte.directory から関数名取得
    local function_sig="$(curl -s "https://www.4byte.directory/api/v1/signatures/?hex_signature=0x$selector" | jq -r '.results[0].text_signature')"
    echo "関数署名: $function_sig"
    
    # デコード（ABIファイルがある場合）
    if [[ -f "$abi_file" ]]; then
        cast 4byte-decode "$input_data" --abi-path "$abi_file"
    fi
}

# ログイベントデコード  
decode_event_log() {
    local tx_hash="$1"
    local log_index="$2"
    local abi_file="$3"
    
    echo "=== イベントログデコード ==="
    
    # ログ取得
    local logs="$(cast receipt "$tx_hash" --rpc-url $ETH_RPC_URL | jq ".logs[$log_index]")"
    local topics="$(echo "$logs" | jq -r '.topics[]')"
    local data="$(echo "$logs" | jq -r '.data')"
    
    echo "トピック: $topics"
    echo "データ: $data"
    
    # イベント署名解決
    local event_sig="$(echo "$topics" | head -1 | cut -c3-)"
    local event_name="$(curl -s "https://www.4byte.directory/api/v1/event-signatures/?hex_signature=0x$event_sig" | jq -r '.results[0].text_signature')"
    echo "イベント署名: $event_name"
    
    # ABIデコード
    if [[ -f "$abi_file" ]]; then
        # Foundryでのログデコードは限定的なので、手動実装が必要
        echo "詳細デコードにはABIファイルと追加ツールが必要です"
    fi
}

# よく使われる関数セレクタ辞書
common_selectors() {
    echo "=== よく使われる関数セレクタ ==="
    cat << 'EOF'
0xa9059cbb: transfer(address,uint256)
0x095ea7b3: approve(address,uint256)
0x23b872dd: transferFrom(address,address,uint256)
0x70a08231: balanceOf(address)
0x18160ddd: totalSupply()
0xdd62ed3e: allowance(address,address)
0x40c10f19: mint(address,uint256)
0x42966c68: burn(uint256)
0x7ff36ab5: swapExactETHForTokens(uint256,address[],address,uint256)
0x38ed1739: swapExactTokensForTokens(uint256,uint256,address[],address,uint256)
EOF
}

# 使用例
common_selectors
# decode_function_call "0x..." "./erc20.abi.json"

実用的なスクリプト例

DeFi ポートフォリオチェッカー

#!/bin/bash
# defi-portfolio-checker.sh

check_defi_portfolio() {
    local wallet="$1"
    
    echo "=== DeFi ポートフォリオ: $wallet ==="
    
    # ETH残高
    local eth_balance="$(cast balance "$wallet" --rpc-url $ETH_RPC_URL)"
    echo "ETH: $(cast to-ether "$eth_balance") ETH"
    
    # 主要トークン残高
    local tokens=(
        "0xA0b86a33E6441b04B9b73f9251e9b49Cd2B3a64:USDC:6"
        "0xdAC17F958D2ee523a2206206994597C13D831ec7:USDT:6" 
        "0x6B175474E89094C44Da98b954EedeAC495271d0F:DAI:18"
        "0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984:UNI:18"
    )
    
    for token in "${tokens[@]}"; do
        IFS=':' read -r address symbol decimals <<< "$token"
        local balance="$(cast call "$address" "balanceOf(address)(uint256)" "$wallet" --rpc-url $ETH_RPC_URL)"
        local human_balance="$(echo "scale=4; $(cast to-dec "$balance") / 10^$decimals" | bc -l)"
        echo "$symbol: $human_balance"
    done
}

# 使用例
check_defi_portfolio "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"

ウォレット管理やトランザクション送信を含む完全なcast CLIガイドは kairyuu.net/exchange/ での取引で入手可能です。