docs/TOKEN_VALIDATION_FIX.md

Hugging Face Token Validation Fix

Problem Description

The original launch script was using the hf CLI command to validate Hugging Face tokens, which was causing authentication failures even with valid tokens. This was due to:

1. CLI installation issues
2. Inconsistent token format handling
3. Poor error reporting

Solution Implementation

New Python-Based Validation System

We've implemented a robust Python-based token validation system using the official huggingface_hub API:

Key Components

1. scripts/validate_hf_token.py - Main validation script
2. Updated launch.sh - Modified to use Python validation
3. tests/test_token_validation.py - Test suite for validation
4. scripts/check_dependencies.py - Dependency verification

Features

• ✅ Robust Error Handling: Detailed error messages for different failure types
• ✅ JSON Output: Structured responses for easy parsing
• ✅ Multiple Input Methods: Command line arguments or environment variables
• ✅ Username Extraction: Automatically retrieves username from valid tokens
• ✅ Dependency Checking: Verifies required packages are installed

Usage

Direct Script Usage

# Using command line argument
python scripts/validate_hf_token.py hf_your_token_here

# Using environment variable
export HF_TOKEN=hf_your_token_here
python scripts/validate_hf_token.py

Expected Output

Success:

{"success": true, "username": "YourUsername", "error": null}

Failure:

{"success": false, "username": null, "error": "Invalid token - unauthorized access"}

Integration with Launch Script

The launch.sh script now automatically:

1. Prompts for your HF token
2. Validates it using the Python script
3. Extracts your username automatically
4. Provides detailed error messages if validation fails

Error Types and Solutions

Common Error Messages

Error Message	Cause	Solution
"Invalid token - unauthorized access"	Token is invalid or expired	Generate new token at https://huggingface.co/settings/tokens
"Token lacks required permissions"	Token doesn't have write access	Ensure token has write permissions
"Network error"	Connection issues	Check internet connection
"Failed to run token validation script"	Missing dependencies	Run pip install huggingface_hub

Dependency Installation

# Install required dependencies
pip install huggingface_hub

# Check all dependencies
python scripts/check_dependencies.py

# Install all requirements
pip install -r requirements/requirements.txt

Testing

Run the Test Suite

python tests/test_token_validation.py

Manual Testing

# Test with your token
python scripts/validate_hf_token.py hf_your_token_here

# Test dependency check
python scripts/check_dependencies.py

Troubleshooting

If Token Validation Still Fails

1. Check Token Format: Ensure token starts with hf_
2. Verify Token Permissions: Token needs read/write access
3. Check Network: Ensure internet connection is stable
4. Update Dependencies: Run pip install --upgrade huggingface_hub

If Launch Script Fails

1. Check Python Path: Ensure python3 is available
2. Verify Script Permissions: Script should be executable
3. Check JSON Parsing: Ensure Python can parse JSON output
4. Review Error Messages: Check the specific error in launch.sh output

Technical Details

Token Validation Process

1. Environment Setup: Sets HUGGING_FACE_HUB_TOKEN environment variable
2. API Client Creation: Initializes HfApi() client
3. User Info Retrieval: Calls api.whoami() to validate token
4. Username Extraction: Extracts username from user info
5. Error Handling: Catches and categorizes different error types

JSON Parsing in Shell

The launch script uses Python's JSON parser to safely extract values:

local success=$(echo "$result" | python3 -c "
import sys, json
try:
    data = json.load(sys.stdin)
    print(data.get('success', False))
except:
    print('False')
")

Migration from Old System

Before (CLI-based)

if hf whoami >/dev/null 2>&1; then
    HF_USERNAME=$(hf whoami | head -n1 | tr -d '\n')

After (Python-based)

if result=$(python3 scripts/validate_hf_token.py "$token" 2>/dev/null); then
    # Parse JSON result with error handling
    local success=$(echo "$result" | python3 -c "...")
    local username=$(echo "$result" | python3 -c "...")

Benefits

1. Reliability: Uses official Python API instead of CLI
2. Error Reporting: Detailed error messages for debugging
3. Cross-Platform: Works on Windows, Linux, and macOS
4. Maintainability: Easy to update and extend
5. Testing: Comprehensive test suite included

Future Enhancements

• Add token expiration checking
• Implement token refresh functionality
• Add support for organization tokens
• Create GUI for token management
• Add token security validation

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Note: This fix ensures that valid Hugging Face tokens are properly recognized and that users get clear feedback when there are authentication issues.