Contexa RealTime Multilingual Conversation Copilot

You understand the topic, but not the language it is discussed in. At an English webinar, a demo day in Japan, or a client call, live captions tell you what was said, but not what to say back in time, so you stay quiet. Contexa is a real-time conversation copilot for that moment. Contexa listens to a browser tab (Zoom, Meet, or a webinar), your microphone, or a recording, and streams the audio straight from the browser to AssemblyAI. Universal-3.5 Pro Realtime transcribes English, Japanese, and mixed-language speech with speaker labels, and Indonesian is routed to Whisper Streaming. Product names and technical terms from your documents are sent as keyterms, updated mid-stream when you add a document, so the transcript spells them right. Every finished turn is translated into Indonesian, English, or Japanese, and questions meant for you are detected. Contexa then searches your own documents (PDF, DOCX, Markdown, web pages, or a whole GitHub repository) with hybrid keyword and semantic retrieval, and drafts an answer in your language plus a ready-to-say version in the speaker's language. It cites the passages it used and says so when your documents don't cover the question. A Pop out window keeps the answer on top of your meeting. When you stop, Contexa writes a recap and saves the session to a history you can search by meaning, across languages. Contexa is built on AssemblyAI's Realtime Speech-to-Text API with its own orchestration: temporary streaming tokens keep the API key out of the browser, end-of-turn detection drives the pipeline, and every stream is terminated cleanly. On the deployed app, translations appear 1.0-1.7 s after a speaker finishes and grounded answers 1.5-1.9 s after a question is detected. Contexa is for students, professionals, and founders who have good ideas but join conversations in a second language. It is live on Vercel and Railway, and open source (MIT).