# OpenProse

> OpenProse is an open-source operating system for reliable long-running AI agents. Instead of scripting brittle prompt chains, developers write structured Markdown contracts - *.prose.md files - that declare the world state an agent should maintain. A reactive runtime figures out the work needed to get there, and the same program runs unchanged across Claude Code, Codex, OpenCode, and Amp. Founded in 2026 by Dan Barrett and backed by Y Combinator's Spring 2026 batch.

- **Founded:** 2026
- **Headquarters:** San Francisco, California, United States
- **Founders:** Dan Barrett (Founder & CEO)
- **Team size:** 3
- **Products:** OpenProse language & spec, Reactor runtime, Forme dependency injection, Prose interpreter / harness interface, Managed Cloud (early access)
- **Notable:** Reached 1.7k+ GitHub stars with 132 forks and 260+ commits in its first year, Backed by Y Combinator (Spring 2026 batch), Shipped a framework-agnostic language that runs unchanged across Claude Code, Codex, OpenCode, and Amp

## Products & services

- **OpenProse language & spec** — An open-source, MIT-licensed declarative language for standing AI work. Programs are *.prose.md files that declare responsibilities with Goal, Requires, Maintains, Continuity, and Strategies sections instead of scripting instructions.
- **Reactor runtime** — The recommended reactive runtime (@openprose/reactor, @openprose/reactor-cli) that watches for changes and re-renders only affected nodes when fingerprints move, with memoized execution that skips work when inputs are unchanged.
- **Forme dependency injection** — A wiring system that automatically constructs dependency graphs by matching responsibility contracts semantically, so components connect by contract rather than manual glue.
- **Prose interpreter / harness interface** — An abstract host interface that turns any harness - Claude Code, Codex, OpenCode, Amp - into an OpenProse VM, so a single program runs unchanged across platforms.
- **Managed Cloud (early access)** — A hosted offering for scheduled execution, event triggers, and durable traces with signed receipt ledgers for accountability and debugging.

## Achievements

- Reached 1.7k+ GitHub stars with 132 forks and 260+ commits in its first year
- Backed by Y Combinator (Spring 2026 batch)
- Shipped a framework-agnostic language that runs unchanged across Claude Code, Codex, OpenCode, and Amp
- Featured in Kent Beck's newsletter 'Genie Lessons from Genie Sessions: Prose as a Programming Language' (May 2026)

## Latest updates

- **2026-05** — Featured in Kent Beck's newsletter examining prose as a programming language.
- **2026-03** — Raised a seed round as part of Y Combinator's Spring 2026 batch.
- **2026-06** — Reactor runtime and CLI published to npm (@openprose/reactor, @openprose/reactor-cli); GitHub project passed 1.7k stars.

## Links

- Website: https://prose.md
- LinkedIn: https://www.linkedin.com/company/openprose
- Twitter/X: https://x.com/irl_danB
- GitHub: https://github.com/openprose/prose

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Profile page: https://yespress.io/openprose-yc-p26
Published by YesPress — https://yespress.io
Last updated: 2026-07-30