extend HyperliquidAction with UserDexAbstraction variant

[BillyWooo]

extend HyperliquidAction with UserDexAbstraction variant

Add support for the UserDexAbstraction action type in the Hyperliquid signature data generation.

Changes:

• Import UserDexAbstraction from hyperliquid-rust-sdk
• Add UserDexAbstraction variant to HyperliquidActionType enum with user address and enabled flag
• Add UserDexAbstraction variant to HyperliquidAction enum
• Implement handling logic with address validation and EIP-712 signature generation
• Add comprehensive unit tests for signature generation and JSON deserialization

This extends the existing Hyperliquid action support to enable DEX abstraction functionality, following the same pattern as ApproveAgent, Withdraw3, ApproveBuilderFee, and SendAsset.

Also a new PR for upstream.

[linear]

P-1738 extend `HyperliquidAction` with `userDexAbstraction`

[vercel]

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Project	Deployment	Preview	Comments	Updated (UTC)
heima-aa-demo-app	Ready	Preview	Comment	Oct 24, 2025 7:34am

[claude]

Claude finished @BillyWooo's task —— View job

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Code Review Complete ✅

I've thoroughly reviewed the PR that extends HyperliquidAction with UserDexAbstraction variant. Overall, this is a well-implemented feature that follows the existing patterns in the codebase.

Todo List:

• Read and analyze the modified files
• Check code quality and best practices
• Look for potential bugs or issues
• Evaluate performance considerations
• Assess security concerns
• Review test coverage
• Provide comprehensive feedback

Review Feedback

✅ Strengths

1. Consistent Implementation Pattern: The implementation follows the exact same pattern as existing action types (ApproveAgent, Withdraw3, etc.), maintaining code consistency.

2. Proper Address Validation: Uses validate_ethereum_address() for the user field, ensuring proper Ethereum address format validation (get_hyperliquid_signature_data.rs:361).

3. Comprehensive Test Coverage: Includes both unit tests for signature generation and JSON deserialization, mirroring the test structure of other action types.

4. Correct SDK Integration: Properly imports and uses UserDexAbstraction from the hyperliquid-rust-sdk.

5. Proper Error Handling: Uses the existing error handling patterns with DetailedError for validation failures.

🔍 Code Quality Analysis

• Enum Structure: The HyperliquidActionType::UserDexAbstraction variant correctly includes user: String and enabled: bool fields (get_hyperliquid_signature_data.rs:57-60).
• Serialization: Proper serde annotations with #[serde(tag = "type", rename_all = "snake_case")] for JSON API compatibility.
• Type Safety: Uses strongly typed Address in the SDK struct while accepting String in the API for flexibility.

🛡️ Security Assessment

• Address Validation: ✅ Properly validates Ethereum addresses before use
• Input Sanitization: ✅ Uses existing validation patterns
• EIP-712 Signing: ✅ Follows the same secure signing flow as other actions
• Authentication: ✅ Uses the same authentication mechanisms as existing endpoints

🚀 Performance Considerations

• Minimal Overhead: The addition doesn't introduce any performance regressions
• Memory Usage: No additional allocations beyond what's needed for the new variant
• Signature Generation: Uses the same efficient EIP-712 signing process

🧪 Test Coverage

The test coverage is comprehensive and includes:

• EIP-712 signature generation validation (get_hyperliquid_signature_data.rs:674-696)
• JSON deserialization testing (get_hyperliquid_signature_data.rs:698-720)
• Domain, struct hash, and signing hash verification

⚠️ Minor Observations

1. Documentation: Consider adding inline documentation for the new UserDexAbstraction variant to explain its purpose in the context of DEX abstraction functionality.

2. Test Completeness: The tests cover the happy path well. Consider adding edge case tests for invalid addresses or malformed JSON.

📊 Change Summary

• Files Modified: 3 (Cargo.lock, Cargo.toml, implementation file)
• Lines Added: 72
• Lines Removed: 3
• New Action Type: UserDexAbstraction with user address and enabled flag
• SDK Version: Updated to use fork with new feature

Recommendation: ✅ APPROVE

This PR is well-implemented, follows established patterns, includes proper validation and testing, and poses no security concerns. The implementation is ready for merge.

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