0xTools - Solidity Developer Toolkit

A professional VS Code extension and CLI tool for automatically scanning and generating method signatures from Solidity smart contracts in Foundry and Hardhat projects.

Table of Contents

• Overview
• Features
• Installation
• Usage
  • VS Code Extension
  • Command Line Interface
• Output Structure
• Configuration
• Development
• Contributing
• License

Overview

0xTools is a comprehensive Solidity developer toolkit, shipping as both a VS Code extension and a CLI. At its core it extracts and organizes function selectors, event topics, and custom error selectors from your contracts, and layers on real-time inline gas estimation backed by a three-tier compilation pipeline (a Rust/revm runner → Foundry's forge → a solc-wasm fallback) so gas numbers stay accurate as you type. It works with both Foundry and Hardhat project structures.

Beyond signatures and gas, 0xTools provides deeper static analysis — storage-layout and function call-graph inspection, deployment-cost estimation, and a security/quality suite covering reentrancy, unchecked low-level calls, access control, dangerous patterns (tx.origin, selfdestruct, delegatecall), DeFi and MEV risks, NatSpec completeness, and custom-error suggestions — with optional Slither and Mythril integration for heavier audits.

For working against live and local chains, it includes on-chain inspection tools (transaction inspector, address/proxy inspector, event decoder, 4-byte selector lookup, and source verification) and a Remix-style Deploy & Run sidebar for deploying and interacting with contracts across multiple networks, complete with Anvil management, keystore accounts, block-explorer links, and source verification. Rounding it out are tight Foundry (forge/cast/anvil scripts and tests) and Hardhat integration, contract flattening, and Foundry test-stub generation.

Features

Core Functionality

• Automatic Contract Detection: Recursively scans your project for Solidity files
• Intelligent Categorization: Separates contracts, libraries, and tests automatically
• Signature Extraction: Extracts function selectors, event signatures, and error signatures
• Multiple Export Formats: Generates JSON, TXT, CSV, and Markdown outputs
• Deduplication: Eliminates duplicate signatures across your codebase
• Project-Aware: Creates output in the correct project root directory

Advanced Analysis Features

• Real-time Gas Analysis: Instant gas estimation with inline annotations and hover details
• Two-tier Analysis: Fast heuristic analysis (under 5ms) with optional solc compilation for accuracy
• Storage Layout Analyzer: Visualize storage slots, detect packing opportunities, estimate SSTORE/SLOAD costs
• Function Call Graph: Analyze call hierarchies, detect recursion, track external calls
• Deployment Cost Estimator: Calculate contract creation gas and costs at different gas prices
• Gas Regression Tracker: Compare gas usage across git branches and commits
• Runtime Profiler: Parse forge test reports and compare actual vs estimated gas
• ABI Generation: Transform signatures into standard Ethereum ABI format
• Contract Size Check: Verify contracts stay within 24KB deployment limit
• Complexity Analysis: Calculate cyclomatic and cognitive complexity metrics
• Performance Caching: SHA-256 based cache with intelligent invalidation

Real-time Analysis Engine

The extension uses solc for accurate gas analysis:

Compilation with Optimization

• Full solc analysis runs on every file open and change
• Compilation runs with optimization enabled for accurate estimates
• Content-hash based caching prevents redundant analysis for unchanged code
• Provides accurate gas estimates and warnings

Extended Analysis (Automatic Background)

• Runs automatically after main analysis completes when resources are available
• Monitors memory usage (< 500MB) and CPU before running
• Includes storage layout, call graph, and deployment cost analysis
• Sequential execution with delays prevents resource spikes
• Never blocks main analysis or editing experience

Performance Features:

• Automatic resource monitoring prevents execution during heavy load
• Extended features run intelligently in background when system is idle
• Intelligent caching prevents redundant analysis
• Manual commands available for immediate analysis when needed

Developer Experience

• File Watching: Automatically regenerates signatures when contracts change
• Tree View Integration: Browse signatures directly in VS Code sidebar
• Command Palette: Quick access to all scanning and analysis functions
• CLI Support: Integrate into build scripts and CI/CD pipelines
• Configurable Filtering: Control visibility levels (public, external, internal, private)
• Lightweight: Optimized package size, extended analysis runs only when requested
• Non-blocking: Heavy operations never interfere with realtime gas estimation

Supported Project Types

• Foundry projects (foundry.toml)
• Hardhat projects (hardhat.config.js/ts)
• Mixed and monorepo structures

For detailed feature documentation, see FEATURES.md

Installation

From VS Code Marketplace

1. Open Visual Studio Code
2. Press Ctrl+P (Windows/Linux) or Cmd+P (macOS)
3. Type: ext install 0xshubhs.0xtools
4. Press Enter

From VSIX File

code --install-extension 0xtools-0.0.5.vsix

Command Line Installation

# Install globally via npm
npm install -g sigscan

# Or use directly with npx
npx sigscan scan ./my-project

Usage

VS Code Extension

Quick Start

1. Open a Foundry or Hardhat project in VS Code
2. Press Ctrl+Shift+P (Windows/Linux) or Cmd+Shift+P (macOS)
3. Type "0xTools: Scan Project"
4. Signatures will be generated in <project-root>/signatures/

Available Commands

Basic Operations:

• 0xTools: Scan Project - Scan all contracts in the current project
• 0xTools: Export Signatures - Export signatures to specific format
• 0xTools: Start/Stop Watching - Enable/disable automatic rescanning
• 0xTools: Refresh Signatures - Manually refresh signature tree view
• 0xTools: Toggle Real-time Gas Analysis - Enable/disable inline gas annotations

Advanced Analysis:

These features run automatically in the background after main analysis completes, when system resources are available:

• Storage Layout Analysis - Analyzes storage slot allocation and packing opportunities
• Function Call Graph - Maps function call dependencies and detects recursion
• Deployment Cost Estimation - Calculates deployment gas and ETH costs

Manual commands are also available for immediate execution:

• 0xTools: Show Storage Layout Analysis - View storage layout report
• 0xTools: Show Function Call Graph - View call graph visualization
• 0xTools: Show Deployment Cost Estimate - View deployment cost breakdown
• 0xTools: Compare Gas with Branch - Compare gas usage with another git branch (requires git)
• 0xTools: Show Runtime Profiler Report - Compare estimated vs actual gas from forge tests (requires Foundry)

Additional Analysis Tools:

• 0xTools: Generate ABI - Create ABI files from extracted signatures
• 0xTools: Estimate Gas - Analyze and estimate gas costs for functions
• 0xTools: Check Contract Size - Verify contract sizes against 24KB limit
• 0xTools: Analyze Complexity - Calculate code complexity metrics
• 0xTools: Generate All Reports - Run complete analysis suite

How It Works: Extended analysis features (storage layout, call graph, deployment) automatically run in the background after each successful compilation when:

• Main solc analysis is complete
• Memory usage is below 500MB
• CPU is not heavily loaded
• No other analysis is in progress

This ensures zero impact on your editing experience while providing comprehensive insights automatically.

Tree View

Access the 0xTools sidebar to:

• Browse contracts by category (contracts, libraries, tests)
• View function signatures and selectors
• Copy selectors to clipboard
• Navigate to contract definitions

Command Line Interface

Basic Usage

# Scan current directory
sigscan scan

# Scan specific project
sigscan scan /path/to/project

# Watch mode for continuous scanning
sigscan watch /path/to/project

# Export to specific format
sigscan export --format json /path/to/project
sigscan export --format txt /path/to/project

CLI Options

Options:
  -o, --output <path>         Output directory (default: ./signatures)
  -f, --format <type>         Export format: json, txt, or both (default: both)
  -w, --watch                 Watch mode for automatic rescanning
  -i, --include-internal      Include internal functions
  -p, --include-private       Include private functions
  --no-dedupe                 Disable signature deduplication
  -v, --verbose               Verbose logging
  -h, --help                  Display help information

Integration Examples

Package.json Script:

{
  "scripts": {
    "signatures": "sigscan scan",
    "signatures:watch": "sigscan watch"
  }
}

CI/CD Pipeline:

- name: Generate Signatures
  run: npx sigscan scan --format json
  
- name: Upload Signatures
  uses: actions/upload-artifact@v3
  with:
    name: contract-signatures
    path: signatures/

Output Structure

0xTools generates organized signature files in your project's signatures/ directory:

signatures/
├── signatures_2025-11-30T12-00-00.json
├── signatures_2025-11-30T12-00-00.txt
└── signatures-contracts.json (latest symlink)

Example Projects

The examples/ directory contains complete sample projects demonstrating best practices and folder structure conventions with production-grade contracts:

Foundry Projects

foundry-defi/ - DeFi Protocol Example

foundry-defi/
├── foundry.toml
├── src/
│   ├── LiquidityPool.sol      # AMM liquidity pool implementation
│   └── StakingRewards.sol     # Token staking with rewards
├── lib/
│   └── SafeMath.sol            # Math utility library
├── test/
│   └── LiquidityPool.t.sol    # Contract tests
└── signatures/
    ├── signatures_2025-11-30T12-00-00.json
    └── signatures_2025-11-30T12-00-00.txt

Features demonstrated:

• AMM liquidity pool with swap functionality
• Staking rewards distribution system
• Library usage and organization
• Comprehensive function signatures
• Event and error definitions

foundry-dao/ - Advanced DAO Governance System

foundry-dao/
├── foundry.toml
├── src/
│   ├── GovernanceToken.sol     # ERC20 with delegation & checkpoints
│   ├── GovernorAlpha.sol       # On-chain governance
│   ├── Timelock.sol            # Delayed execution
│   └── Treasury.sol            # DAO fund management
├── test/
│   └── Governance.t.sol        # Governance tests
└── signatures/
    ├── signatures_2025-11-30T16-00-00.json
    └── signatures_2025-11-30T16-00-00.txt

Features demonstrated:

• Vote delegation with checkpoint system
• Proposal lifecycle management (propose, vote, queue, execute)
• Binary search for historical vote queries
• EIP-712 signature support for gasless voting
• Timelock with grace period and delay controls
• Treasury with budget management and spending proposals
• Complex state machine patterns
• Advanced access control and security mechanisms

foundry-options/ - Options Trading Protocol

foundry-options/
├── foundry.toml
├── src/
│   ├── OptionsMarket.sol       # Options writing and trading
│   └── VolatilityOracle.sol    # Implied volatility tracking
├── test/
│   └── OptionsMarket.t.sol     # Options tests
└── signatures/
    ├── signatures-contracts.json
    └── signatures-contracts.txt

Features demonstrated:

• Call and put option contracts
• Black-Scholes pricing model implementation
• Collateral management with margin requirements
• Option lifecycle (write, buy, exercise, expire)
• Volatility oracle with historical price tracking
• Premium calculation with time decay
• Intrinsic and time value calculations
• Advanced mathematical operations (square root for volatility)

foundry-oracle/ - Multi-Source Price Oracle

foundry-oracle/
├── foundry.toml
├── src/
│   ├── PriceAggregator.sol     # Multi-oracle price aggregation
│   └── ChainlinkAdapter.sol    # Chainlink feed adapter
├── test/
│   └── PriceAggregator.t.sol   # Oracle tests
└── signatures/
    ├── signatures-contracts.json
    └── signatures-contracts.txt

Features demonstrated:

• Median price calculation from multiple sources
• Weighted price aggregation
• Outlier detection and circuit breaker
• Heartbeat monitoring for stale prices
• Oracle reputation system with success/failure tracking
• Deviation calculations and confidence scoring
• Emergency stop mechanism
• Statistical functions (median, standard deviation)

Hardhat Projects

hardhat-nft/ - NFT Marketplace Example

hardhat-nft/
├── hardhat.config.js
├── contracts/
│   ├── ERC721A.sol             # Optimized NFT implementation
│   └── NFTMarketplace.sol      # Marketplace with auctions
├── test/
│   └── ERC721A.test.js         # Contract tests
└── signatures/
    ├── signatures_2025-11-30T14-30-00.json
    └── signatures_2025-11-30T14-30-00.txt

Features demonstrated:

• ERC721A batch minting optimization
• NFT marketplace with listing and auction support
• Complex contract interactions
• Structured event emissions
• Custom error handling

hardhat-marketplace/ - Advanced Trading Platform

hardhat-marketplace/
├── hardhat.config.js
├── contracts/
│   ├── OrderBook.sol           # Decentralized order book exchange
│   └── LendingPool.sol         # Variable rate lending protocol
├── test/
│   └── OrderBook.test.js       # Exchange tests
└── signatures/
    ├── signatures_2025-11-30T18-00-00.json
    └── signatures_2025-11-30T18-00-00.txt

Features demonstrated:

• Limit and market order matching engine
• Order book depth and best bid/ask queries
• Variable interest rate calculations
• Utilization-based rate curves
• Liquidation mechanism for undercollateralized positions
• Health factor calculations
• Fee collection and distribution
• Complex state management with multiple data structures

hardhat-bridge/ - Cross-Chain Bridge Infrastructure

hardhat-bridge/
├── hardhat.config.js
├── contracts/
│   ├── CrossChainBridge.sol    # Multi-sig bridge with validation
│   └── RelayerNetwork.sol      # Decentralized relayer system
├── test/
│   └── Bridge.test.js          # Bridge tests
└── signatures/
    ├── signatures_2025-11-30T19-00-00.json
    └── signatures_2025-11-30T19-00-00.txt

Features demonstrated:

• Multi-signature validation with weighted voting
• Validator network with reputation system
• Transfer lifecycle management (pending, validated, completed)
• Timeout and cancellation mechanisms
• Relayer staking and slashing
• Message delivery with cryptographic proofs
• Cross-chain communication patterns
• Dispute resolution system
• Dynamic threshold calculations

hardhat-amm/ - Concentrated Liquidity AMM

hardhat-amm/
├── hardhat.config.js
├── contracts/
│   ├── ConcentratedLiquidity.sol  # Uniswap V3 style AMM
│   └── RouterV3.sol                # Multi-hop swap router
├── test/
│   └── ConcentratedLiquidity.test.js
└── signatures/
    ├── signatures-contracts.json
    └── signatures-contracts.txt

Features demonstrated:

• Tick-based concentrated liquidity positions
• Position management (mint, burn, collect fees)
• Fee growth tracking per position
• Multi-hop swap routing with path encoding
• Price oracle with time-weighted average prices (TWAP)
• Liquidity range management
• SqrtPriceX96 math for precision
• Gas-optimized position updates
• Complex data structure handling (nested mappings)

Running Examples

# Scan the DeFi example
cd examples/foundry-defi
sigscan scan

# Scan the DAO governance example
cd examples/foundry-dao
sigscan scan

# Scan the options trading example
cd examples/foundry-options
sigscan scan

# Scan the oracle aggregator example
cd examples/foundry-oracle
sigscan scan

# Scan the NFT marketplace example
cd examples/hardhat-nft
sigscan scan

# Scan the trading platform example
cd examples/hardhat-marketplace
sigscan scan

# Scan the bridge example
cd examples/hardhat-bridge
sigscan scan

# Scan the concentrated liquidity AMM example
cd examples/hardhat-amm
sigscan scan

# Watch mode for development
sigscan watch

JSON Format

{
  "metadata": {
    "generatedAt": "2025-11-30T12:00:00.000Z",
    "projectType": "foundry",
    "totalContracts": 5,
    "totalFunctions": 25,
    "totalEvents": 8,
    "totalErrors": 3
  },
  "contracts": {
    "SimpleToken": {
      "path": "src/SimpleToken.sol",
      "category": "contracts",
      "functions": [
        {
          "name": "transfer",
          "signature": "transfer(address,uint256)",
          "selector": "0xa9059cbb",
          "visibility": "public"
        }
      ],
      "events": [
        {
          "name": "Transfer",
          "signature": "Transfer(address,address,uint256)",
          "hash": "0xddf252ad..."
        }
      ]
    }
  }
}

TXT Format

# Contract Signatures
# Generated: 2025-11-30T12:00:00.000Z

## SimpleToken (src/SimpleToken.sol)

### Functions
transfer(address,uint256) -> 0xa9059cbb
approve(address,uint256) -> 0x095ea7b3
balanceOf(address) -> 0x70a08231

### Events
Transfer(address,address,uint256) -> 0xddf252ad...
Approval(address,address,uint256) -> 0x8c5be1e5...

Configuration

VS Code Settings

Configure 0xTools through VS Code settings (File > Preferences > Settings):

{
  "sigscan.autoScan": true,
  "sigscan.watchMode": false,
  "sigscan.includeInternal": false,
  "sigscan.includePrivate": false,
  "sigscan.outputFormat": "both",
  "sigscan.deduplicate": true,
  "sigscan.excludePaths": ["node_modules", "lib"]
}

Configuration File

Create a .sigscanrc.json in your project root:

{
  "includeInternal": false,
  "includePrivate": false,
  "outputFormat": "both",
  "deduplicate": true,
  "excludePaths": [
    "node_modules",
    "lib",
    "cache"
  ]
}

Development

Building from Source

# Clone the repository
git clone https://github.com/0xshubhs/0xtools.git
cd 0xtools

# Install dependencies
npm install

# Build the extension
npm run compile

# Run tests
npm test

# Package the extension
npm run package

Running Tests

# Run all tests
npm test

# Run tests in watch mode
npm run test:watch

# Run tests with coverage
npm run test:coverage

Project Structure

0xtools/
├── src/
│   ├── cli/              # Command-line interface
│   ├── core/             # Core scanning logic
│   │   ├── parser.ts     # Solidity parser
│   │   ├── scanner.ts    # Project scanner
│   │   ├── exporter.ts   # Signature exporter
│   │   └── watcher.ts    # File watcher
│   ├── extension/        # VS Code extension
│   │   ├── extension.ts  # Extension entry point
│   │   ├── manager.ts    # Scan manager
│   │   └── providers/    # Tree view providers
│   └── utils/            # Utility functions
├── .github/
│   └── workflows/        # CI/CD workflows
├── test/                 # Test files
└── docs/                 # Documentation

Contributing

Contributions are welcome! Please follow these guidelines:

1. Fork the repository and create a feature branch
2. Follow the existing code style (enforced by ESLint and Prettier)
3. Write tests for new features
4. Update documentation as needed
5. Submit a pull request with a clear description

Development Guidelines

• Use TypeScript for all new code
• Follow conventional commit messages (feat, fix, docs, etc.)
• Ensure all tests pass before submitting PR
• Add unit tests for new functionality
• Update README for user-facing changes

Reporting Issues

When reporting issues, please include:

• VS Code version
• Extension version
• Project type (Foundry/Hardhat)
• Steps to reproduce
• Expected vs actual behavior
• Relevant error messages or logs

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments

• Built with the VS Code Extension API
• Solidity parsing powered by regular expressions and AST analysis
• Inspired by tools like Foundry's forge and Hardhat's contract interaction utilities

Links

• VS Code Marketplace
• GitHub Repository
• Issue Tracker
• Changelog

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Maintained by: 0xshubhs
Version: 0.0.5
Last Updated: June 2026