Worked on the NousResearch/hermes-agent repository to enhance reliability in Anthropic API integration by addressing a critical bug related to model compatibility. Using Python and backend development skills, implemented a targeted code adjustment that restricts the fast mode feature exclusively to the Opus 4.6 model, preventing its activation on unsupported models and eliminating related API errors and session wedging. This change aligns the agent’s behavior with Anthropic’s API contract and improves user experience by ensuring stable sessions when switching models. The solution focused on robust error handling and model configuration, with clear commit traceability and minimal risk to existing functionality.