Vellum
Vellum is a glass-box agentic ICD-10 coder.
Core trick
Rejects any code whose quoted evidence is not a substring of the discharge note, using a model-free, network-free check.
Description
Vellum is a glass-box agentic ICD-10 coder. Five Claude Opus roles read a hospital discharge summary, resolve each finding to a current code through live terminology tools, challenge one another, and sign off a chart. What makes it a product rather than a black box is that every code carries a receipt: the sentence the model quoted, and a deterministic verdict, with no model and no network, on whether that sentence exists in the note. The motivating finding is that a fluent model sometimes invents its citation, quoting a sentence that was never written, and a more capable model makes the fabrication more convincing. A code whose citation cannot be found is never accepted on the system's own authority. I evaluated it in two stages. On ninety real inpatient notes, self-hosted open models hallucinate most of their codes, and even with retrieval plateau near 0.16 exact F1. On four identical synthetic notes, the deployed pipeline reaches 0.93 to the best open configuration's 0.57, and it is the only one that grounds every code and fabricates none. The limits are stated as plainly as the numbers.
README excerpt
<div align="center"> <img src="docs/images/bird.gif" alt="Vellum" width="120" /> # Vellum ### Coding you can prove. **An auditable agentic ICD-10 autocoder whose work you can prove, and the moment it cannot.** Five Claude Opus roles read a hospital discharge summary and propose the billable codes. Four model-free, network-free engines then prove or refuse every one of them. The point of difference is that Vellum catches the model inventing its own evidence: when the model quotes a sentence that is not in the record, a substring check with no model and no network finds it and holds the code back. <p> <img src="docs/images/icons/python.svg" alt="Python" height="34" /> <img src="docs/images/icons/fastapi.svg" alt="FastAPI" height="34" /> <img src="docs/images/icons/react.svg" alt="React" height="34" /> <img src="docs/images/icons/typescript.svg" alt="TypeScript" height="34" /> <img src="docs/images/icons/tailwindcss.svg" alt="Tailwind CSS" height="34" /> <img src="docs/images/icons/vite.svg" alt="Vite" height="34" /> <img src="docs/images/icons/sqlite.svg" alt="SQLite" height="34" /> <img src="docs/images/icons/pnpm.svg" alt="pnpm" height="34" /> <img src="docs/images/icons/built-with-claude.svg" alt="Built with Claude" height="34" /> </p> **[▶ Watch the three-minute demo](https://www.youtube.com/watch?v=FBezih99aBI)** · Built with Claude: Life Sciences (Builder tra