Pi is built on Inflection-2.5, Inflection AI's proprietary large language model trained with a strong emphasis on conversational fluency, safety, and emotional resonance. The model is optimized for long-form, multi-turn dialogue rather than short-answer or task-completion workflows. Pi does not currently expose a public API for third-party developers, positioning it as a consumer-facing product rather than a developer platform. The service is hosted entirely by Inflection AI and is accessible via HTTPS on web and native mobile apps (iOS/Android), with WebSocket-based real-time streaming for low-latency responses.