API Connector Builder helps an agent build a new API connector or provider by matching the target repository's existing integration pattern exactly rather than inventing a second architecture. It walks through learning the house style by inspecting existing connectors, narrowing the target integration, building in repo-native layers, and validating against the source pattern. Reach for it when the job is to add a repo-native integration surface that blends seamlessly with the codebase layout, auth model, config schema, error handling, test style, and registration wiring.