Problem

The RPC service currently has inconsistent error handling for different HTTP status codes. Some status codes are handled with generic errors, making it difficult to:

• Debug issues
• Handle specific error cases in the application
• Provide meaningful error messages to users

Proposed Solution

Improve error handling by implementing specific error types for different HTTP status codes:

• 401: Unauthorized error
• 402/404/5xx: Resource unavailable error
• 405/501: Method not found error
• 429: Rate limiting error
• Other 4xx: Invalid request error
• Invalid JSON: Parse error

Benefits

• More predictable error handling
• Better debugging capabilities
• Clearer error messages for users
• Consistent error data structure
• Improved test coverage and documentation

Testing

• Verify all HTTP status codes are handled correctly
• Ensure error messages are consistent
• Check that error data includes necessary information
• Run existing test suite to confirm no regressions