ListenUp

Inspiration

What it does

How we built it

Challenges we ran into

Accomplishments that we're proud of

What we learned

What's next for ListenUp

Inspiration

Transcripts are usually treated as terminal documents even though people need them to become decisions, captions, searchable records, and follow-up work.

What it does

ListenUp is a private-first transcript studio for owned audio, video, direct media, and pasted captions. It combines speaker-aware transcription, cleanup, editing, search, history, playback, and TXT/SRT/VTT exports. For Build Week, one GPT-5.6 action converts a transcript into a structured brief with summary, themes, action items, exact quotes, chapters, follow-up questions, and a plain-language version.

How we built it

The product uses Next.js, React, TypeScript, Prisma, SQLite, OpenAI transcription, and the Responses API. GPT-5.6 output is typed and Zod-validated. Requests use store:false, cap transcript length, require sessions for private text, and enforce separate member and demo limits. Direct media URLs are checked against unsafe destinations and redirects.

Challenges and learning

Codex recovered and audited a mixed existing codebase, preserved the working transcript workflow, implemented structured briefs, protected the public demo, repaired standalone build tracing, ran static and runtime checks, captured responsive evidence, deployed the Sites showcase, and generated the verified demo package. The public judge sample is synthetic and labels fallback output truthfully rather than exposing an unmetered model endpoint.

Accomplishments

The independently runnable public repository includes sample data, setup, the GPT-5.6 structured-output reference, and a public showcase. Lint, TypeScript, a 31-route production build, route protection, responsive QA, and secret scans passed.

Built With

• next.js