Biprayan Choudhuri

Open-Source AI Companion

• —Built a Windows desktop voice companion (v0.13, 200+ commits) on a real-time loop: Silero VAD and Whisper speech-to-text, a LangGraph agent, and streamed text-to-speech that users can interrupt mid-reply.
• —Gave the agent permission-gated tools (web search, plus Gmail, Google Calendar and Notion via Composio): every action waits for the user’s approval before it runs.
• —Designed long-term memory in local SQLite: full-text search over every past conversation, session summaries, and a fact store the agent writes and corrects itself.
• —Private by design, with no account or telemetry and a fully offline mode (local Whisper, Kokoro, Ollama); installs with one PowerShell command.

Agentic Medication Safety Copilot

• —Built a clinical agent as a cyclic LangGraph state machine that extracts a structured patient profile from free-text notes, plans research steps, retrieves guideline evidence from FAISS, and reasons about medication risk.
• —Added a Safety Critic node that rejects any finding without explicit guideline citations and sends the agent back to re-plan; a retry cap and a confidence check end hard cases in a safe report instead of a loop.
• —Runs fully locally (MedGemma-4B via Ollama, EmbeddingGemma embeddings), so patient notes never leave the machine; every node returns Pydantic-validated JSON, and a Streamlit UI streams each reasoning step live.

Hybrid-Search RAG Chatbot

• —Built a 3-stage retrieval pipeline: multi-query expansion, hybrid search (FAISS dense + BM25 sparse), and cross-encoder re-ranking with FlashRank, answering with Llama 3.3 70B on Groq.
• —Split the app into an async FastAPI backend and a stateless Streamlit client, containerized with Docker Compose using multi-stage uv builds and CPU-only PyTorch to keep images small.
• —Persisted the vector store and chat memory on Docker volumes so both survive restarts, with pytest unit and integration tests for the API.

Cricket Scoring App

• —Built and shipped a cricket scoring app for Android for RevenueCat Shipaton 2026, now live on Google Play.