Feluda

🔎 Feluda is a Rust-based command-line tool that analyzes the dependencies of a project, notes down their licenses, and flags any permissions that restrict personal or commercial usage or are incompatible with your project's license.

👋 It's still highly experimental, but fast iterating. Welcoming contributors and support to help bring out this project even better!

Features

• Parse your project to identify dependencies and their licenses.
• Classify licenses into permissive, restrictive, or unknown categories.
• Check license compatibility between dependencies and your project's license.
• Map licenses to OSI (Open Source Initiative) approval status and filter by OSI approval.
• Flag dependencies with licenses that may restrict personal or commercial use.
• Flag dependencies with licenses that may be incompatible with your project's license.
• Generate compliance files (NOTICE and THIRD_PARTY_LICENSES) for legal requirements.
• Generate Software Bill of Materials (SBOM) in SPDX format for security and compliance.
• Output results in plain text, JSON or TUI formats. There's also a gist format which is available in strict mode to output a single line only.
• CI/CD support for Github Actions and Jenkins.
• Verbose mode gives an enhanced view of all licenses.

Support Languages

Feluda supports analyzing dependencies across multiple languages simultaneously.

feluda

You can also filter the analysis to a specific language using the --language flag.

Installation

Official Distribution 🎉:

cargo install feluda

Community Maintained 🙌:

brew install feluda

paru -S feluda

pkgin install feluda

# Install the downloaded DEB package
sudo dpkg -i feluda_*.deb

# If there are dependency issues, fix them
sudo apt install -f

# Install the downloaded RPM package
sudo rpm -ivh feluda_*.rpm

# Or using dnf (Fedora/newer RHEL)
sudo dnf install feluda_*.rpm

# Or using yum (older RHEL/CentOS)
sudo yum install feluda_*.rpm

Package Managers 📦:

Track releases on github releases or via release feed.

git clone https://github.com/anistark/feluda.git
cd feluda

cargo build --release

sudo mv target/release/feluda /usr/local/bin/

Usage

Feluda provides license analysis by default, with an additional command for generating compliance files. Analyze your project's dependencies and their licenses:

# Basic usage
feluda

# Specify a path to your project directory
feluda --path /path/to/project/

# Check with specific language
feluda --language {rust|node|go|python|c|cpp}

# Filter by OSI approval status
feluda --osi approved        # Show only OSI approved licenses
feluda --osi not-approved   # Show only non-OSI approved licenses
feluda --osi unknown        # Show licenses with unknown OSI status

License File Generation

Generate compliance files for legal requirements:

# Interactive file generation
feluda generate

# Generate for specific language and license
feluda generate --language rust --project-license MIT

# Generate for specific path
feluda generate --path /path/to/project/

SBOM Generation

Generate Software Bill of Materials (SBOM) for your project:

# Generate SPDX format SBOM to console
feluda --sbom spdx

# Generate SPDX SBOM to file
feluda --sbom spdx --output-file project-name-sbom.json

# Generate all supported formats (currently only SPDX is implemented)
feluda --sbom all --output-file project-name-sbom

Supported SBOM Formats:

• SPDX 2.3 - Software Package Data Exchange format (JSON)
• CycloneDX - Coming soon

What's Included in SBOM:

• Package names and versions
• License information
• SPDX identifiers
• License compatibility flags
• Tool metadata and generation timestamp

Use Cases:

• 🔒 Security compliance - Track all dependencies for vulnerability management
• 📋 Supply chain transparency - Document your software's components
• 🏢 Enterprise requirements - Meet organizational SBOM mandates
• 🔍 Audit preparation - Provide comprehensive dependency documentation

Run feluda on a github repo directly

feluda --repo <repository_url> [--ssh-key <key_path>] [--ssh-passphrase <passphrase>] [--token <https_token>]

<repository_url>: The URL of the Git repository to clone (e.g., git@github.com:user/repo.git or https://github.com/user/repo.git).

--ssh-key <key_path>: (Optional) Path to a private SSH key for authentication.

--ssh-passphrase <passphrase>: (Optional) Passphrase for the SSH key.

--token <https_token>: (Optional) HTTPS token for authenticating with private repositories.

If you're using Feluda, feel free to grab a Scanned with Feluda badge for your project:

[![Scanned with Feluda](https://img.shields.io/badge/Scanned%20with-Feluda-brightgreen)](https://github.com/anistark/feluda)

Replace the repo name and username. Once you've the Feluda GitHub Action setup, this badge will be automatically updated.

License Compliance Files

Feluda can generate essential compliance files required for commercial software distribution and open source projects.

NOTICE File

A NOTICE file is a concise summary document that provides attribution for third-party components:

• Purpose: Quick overview of all third-party components and their licenses
• Content: Organized by license type, lists all dependencies with their versions
• Use Cases:
  • Legal compliance documentation
  • Quick reference for license audits
  • Attribution requirements for many open source licenses

THIRD_PARTY_LICENSES File

A THIRD_PARTY_LICENSES file provides comprehensive license documentation:

• Purpose: Complete legal documentation for all dependencies
• Content: Full license texts, compatibility analysis, package URLs, and copyright information
• Use Cases:
  • Commercial software distribution requirements
  • Legal compliance for enterprise applications
  • Due diligence for acquisitions and audits
  • App store submissions (iOS, Android, etc.)

Why These Files Are Important

Legal Protection: Many open source licenses require attribution when redistributing code. These files ensure compliance and protect your organization from legal issues.

Transparency: Shows exactly what third-party code is included in your application, building trust with users and stakeholders.

Commercial Readiness: Essential for commercial software, enterprise deployments, and app store submissions.

Audit Preparation: Makes license audits faster and easier by providing all necessary documentation in standard formats.

Important Legal Notice

⚠️ DISCLAIMER: Feluda is still in early stages. While we're trying to follow through all compliances, users are responsible for:

• Verifying accuracy of all license information
• Ensuring compliance with all applicable license terms
• Consulting legal counsel for license compliance matters
• Checking official repositories for up-to-date license information

Feluda and its contributors disclaim all warranties and are not liable for any legal issues arising from the use of this information. Use at your own risk.

When You Need These Files

• 📱 Mobile app distribution (iOS App Store, Google Play)
• 🏢 Enterprise software deployment
• 💼 Commercial product releases
• 🔍 Legal compliance audits
• 🤝 Open source project attribution
• 📄 Regulatory compliance (GDPR, SOX, etc.)

Output Format

JSON

• Default: Plain text.
• JSON: Use the --json flag for JSON output.

feluda --json

Sample Output for a sample cargo.toml file containing serde and tokio dependencies:

[
  {
    "name": "serde",
    "version": "1.0.151",
    "license": "MIT",
    "is_restrictive": false,
    "compatibility": "Compatible",
    "osi_status": "Approved"
  },
  {
    "name": "tokio",
    "version": "1.0.2",
    "license": "MIT",
    "is_restrictive": false,
    "compatibility": "Compatible",
    "osi_status": "Approved"
  }
]

YAML

Use the --yaml flag for YAML output

feluda --yaml

Sample Output for a sample cargo.toml file containing serde and tokio dependencies:

- name: serde
  version: 1.0.151
  license: MIT
  is_restrictive: false
  compatibility: Compatible
  osi_status: Approved
- name: tokio
  version: 1.0.2
  license: MIT
  is_restrictive: false
  compatibility: Compatible
  osi_status: Approved

Gist Mode

For a short summary, in case you don't want all that output covering your screen:

feluda --gist

Verbose Mode

For detailed information about each dependency:

feluda --verbose

The verbose mode displays a table with an additional "OSI Status" column showing whether each license is approved by the Open Source Initiative (OSI).

OSI Integration

Feluda integrates with the Open Source Initiative (OSI) to provide license approval status information. This feature helps you identify whether the licenses used by your dependencies are officially approved by the OSI.

OSI Status Values

• approved: License is officially approved by the OSI
• unknown: License status with OSI is unknown or the license is not OSI approved

OSI Filtering

Filter dependencies by their OSI approval status:

# Show only OSI approved licenses
feluda --osi approved --verbose

# Show only non-approved or unknown OSI status licenses
feluda --osi not-approved --verbose

# Show licenses with unknown OSI status
feluda --osi unknown --verbose

# Combine with JSON output
feluda --osi approved --json

Note: OSI status information is only displayed in --verbose mode, --gui mode, or when using structured output formats (JSON/YAML) to keep the default output clean.

License Compatibility

Feluda can check if dependency licenses are compatible with your project's license:

feluda --project-license MIT

You can also filter for incompatible licenses only:

feluda --incompatible

And fail CI builds if incompatible licenses are found:

feluda --fail-on-incompatible

Strict Mode

In case you strictly need only the restrictive dependencies:

feluda --strict

Terminal User Interface (TUI) Mode

We've an awesome ✨ TUI mode available to browse through the dependencies in a visually appealing way as well:

feluda --gui

CI/CD Integration

Feluda provides several options for CI integration:

• --ci-format <github|jenkins>: Generate output compatible with the specified CI system
• --fail-on-restrictive: Make the CI build fail when restrictive licenses are found
• --fail-on-incompatible: Make the CI build fail when incompatible licenses are found
• --osi <approved|not-approved|unknown>: Filter by OSI license approval status
• --output-file <path>: Write the output to a file instead of stdout

Feluda can be easily integrated into your CI/CD pipelines with built-in support for GitHub Actions and Jenkins.

GitHub Actions

To use Feluda with GitHub Actions, simply use the published action. For detailed documentation, see the GitHub Action README.

name: License Check

on:
  push:
    branches: [ main ]
  pull_request:
    branches: [ main ]

jobs:
  license-check:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v4

      - name: Scan licenses
        uses: anistark/feluda@v1
        with:
          fail-on-restrictive: true
          fail-on-incompatible: true

Advanced usage with compliance files:

      - name: Scan licenses
        uses: anistark/feluda@v1
        with:
          fail-on-restrictive: true
          project-license: 'MIT'
          update-badge: true

      - name: Generate compliance files
        run: |
          echo "1" | feluda generate  # Auto-select NOTICE file
          echo "2" | feluda generate  # Auto-select THIRD_PARTY_LICENSES file

      - name: Generate SBOM
        run: feluda --sbom spdx --output-file sbom.spdx.json

      - name: Upload compliance artifacts
        uses: actions/upload-artifact@v4
        with:
          name: license-compliance
          path: |
            NOTICE
            THIRD_PARTY_LICENSES.md
            sbom.spdx.json

Checkout contributing guidelines if you are looking to contribute to this project.

Currently, using choosealicense license directory for source of truth.

Configuration (Optional)

Feluda allows you to customize which licenses are considered restrictive through configuration. This can be done in three ways, listed in order of precedence (highest to lowest):

1. Environment variables
2. .feluda.toml configuration file
3. Default values

Default Restrictive Licenses

By default, Feluda considers the following licenses as restrictive:

• GPL-3.0
• AGPL-3.0
• LGPL-3.0
• MPL-2.0
• SEE LICENSE IN LICENSE
• CC-BY-SA-4.0
• EPL-2.0

Configuration File

Create a .feluda.toml file in your project root to override the default restrictive licenses:

[licenses]
# Override the default list of restrictive licenses
restrictive = [
    "GPL-3.0",      # GNU General Public License v3.0
    "AGPL-3.0",     # GNU Affero General Public License v3.0
    "Custom-1.0",   # Your custom license identifier
]

Environment Variables

You can also override the configuration using environment variables:

# Override restrictive licenses list
export FELUDA_LICENSES_RESTRICTIVE='["GPL-3.0","AGPL-3.0","Custom-1.0"]'

The environment variables take precedence over both the configuration file and default values.

License Compatibility Matrix

Feluda uses a comprehensive license compatibility matrix to determine whether dependency licenses are compatible with your project's license. This matrix is maintained in an external TOML configuration file for easy updates and maintenance.

How It Works

When you use the --project-license flag or Feluda auto-detects your project license, it checks each dependency's license against a compatibility matrix to determine:

• ✅ Compatible: Safe to use with your project license
• ❌ Incompatible: May create legal issues or licensing conflicts
• ❓ Unknown: License compatibility cannot be determined

Compatibility Matrix Location

The license compatibility rules are stored in:

config/license_compatibility.toml

This file defines which dependency licenses are compatible with each project license type. For example:

[MIT]
compatible_with = [
    "MIT",
    "BSD-2-Clause", 
    "BSD-3-Clause",
    "Apache-2.0",
    "ISC",
    # ... more permissive licenses
]

[GPL-3.0]
compatible_with = [
    "MIT",
    "BSD-2-Clause",
    "Apache-2.0",
    "LGPL-2.1",
    "LGPL-3.0", 
    "GPL-2.0",
    "GPL-3.0",
    # ... GPL-compatible licenses
]

Supported Project Licenses

The matrix currently supports compatibility checking for:

• MIT - Most permissive, allows only permissive dependency licenses
• Apache-2.0 - Permissive license compatible with most open source licenses
• GPL-3.0 - Copyleft license with broad compatibility including LGPL and other GPL versions
• GPL-2.0 - Stricter copyleft (cannot include Apache-2.0 dependencies)
• AGPL-3.0 - Network copyleft with GPL-3.0 compatibility plus AGPL
• LGPL-3.0 / LGPL-2.1 - Lesser GPL variants with limited compatibility
• MPL-2.0 - Mozilla Public License with moderate compatibility
• BSD-3-Clause / BSD-2-Clause - BSD variants with permissive-only compatibility
• ISC, 0BSD, Unlicense, WTFPL - Various permissive licenses

Custom Compatibility Rules

Advanced users can customize compatibility rules by:

1. User-specific overrides: Create .feluda/license_compatibility.toml in your home directory
2. Project-specific rules: The local config/license_compatibility.toml takes precedence

Important: Modifying compatibility rules requires legal expertise. Consult legal counsel before making changes that could affect your project's compliance.

Limitations and Disclaimers

⚠️ Legal Disclaimer: The license compatibility matrix is provided as a helpful tool, but:

• Not legal advice: Always consult qualified legal counsel for license compliance
• Your responsibility: Users must verify all license compatibility decisions
• No warranty: Feluda and its contributors provide no warranties regarding license compatibility
• Complexity: License compatibility can depend on specific use cases, distribution methods, and jurisdictions

Happy coding with Feluda! 🚀