Private Key Support (Optional)

[savageops]

Add Private Key Authentication Support

Description

This PR adds support for private key authentication as an alternative to mnemonic-based authentication for the Akash MCP server. Users can now authenticate using either a mnemonic phrase or a raw private key, providing more flexibility in wallet management and integration scenarios.

Motivation

Current implementation only supports mnemonic-based authentication via AKASH_MNEMONIC. This enhancement addresses several use cases:

• Production Deployments: Many production systems manage raw private keys rather than mnemonics
• Security Preferences: Some users prefer managing private keys directly
• Integration: Easier integration with existing infrastructure that uses private key authentication
• Automation: Simplified automated deployments and CI/CD pipelines

Changes

Modified Files (5 total):

1. src/config.ts - Added privateKey configuration field
2. src/utils/load-wallet.ts - Implemented private key authentication logic
3. src/utils/load-certificate.ts - Updated type signatures to support both wallet types
4. src/types/index.ts - Updated ToolContext interface types
5. src/AkashMCP.ts - Updated wallet property types

Key Features:

• ✅ Support for hex-encoded private key authentication
• ✅ Automatic selection between private key and mnemonic methods
• ✅ Clear error messaging when neither authentication method is provided
• ✅ Full backward compatibility with existing mnemonic authentication
• ✅ Type-safe implementation using union types

Technical Implementation

Authentication Priority:

1. Check for AKASH_MNEMONIC environment variable
2. If not present, check for AKASH_PRIVATE_KEY environment variable
3. Throw error if neither is provided

Type System:

Uses union types (DirectSecp256k1HdWallet | DirectSecp256k1Wallet) to maintain type safety while supporting both authentication methods. Both wallet types implement compatible interfaces for signing and account management.

Private Key Format:

• Expected: Hex string (64 characters, 32 bytes)
• Example: e4b1c2d3a5f60798b2e1f3c4d5a6b7c8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4
• Automatically converted to Uint8Array for wallet initialization

Testing

Manual Testing:

• ✅ Successfully initialized MCP server with private key authentication
• ✅ Verified private key authentication flow: Using privateKey authentication for Akash
• ✅ MCP server starts without errors
• ✅ Akash adapter initializes successfully
• ✅ All dependent services initialize properly
• ✅ Verified backward compatibility with mnemonic authentication

Test Environment:

• Node.js v18.19.1
• @cosmjs/proto-signing v0.32.4
• Production deployment environment

Backward Compatibility

• ✅ No Breaking Changes: Existing mnemonic authentication continues to work unchanged
• ✅ Default Behavior Preserved: When only mnemonic is provided, existing behavior is maintained
• ✅ Graceful Degradation: Clear error messages guide users when configuration is missing

Environment Variables

New:

AKASH_PRIVATE_KEY  # Optional: Hex-encoded private key (32 bytes/64 chars)

Usage Examples:

# Option 1: Using private key (NEW)
export AKASH_PRIVATE_KEY="e4b1c2d3a5f60798b2e1f3c4d5a6b7c8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4"

# Option 2: Using mnemonic (EXISTING)
export AKASH_MNEMONIC="word1 word2 word3 ... word24"

Dependencies

• ✅ No new dependencies added
• ✅ Uses existing @cosmjs/proto-signing package
• ✅ No version bumps required

Checklist

• Code follows project conventions
• Changes are backward compatible
• No breaking changes to existing functionality
• Manual testing completed successfully
• All modified files included in PR
• Clear description of changes provided
• Type definitions updated

Related Issues

N/A - Enhancement for authentication flexibility

Additional Notes

This implementation prioritizes mnemonic authentication over private key when both are provided.

[zJuuu]

Hey @savageops, thanks for your PR! Please adhere to the Conventional Commits specification in your future commits.
I plan to review and test this code in the coming days.