OpenProse
OpenProse is a YC Spring 2026 (P26) company. Based in San Francisco, CA, USA; Remote. Team of 3.
About OpenProse
Summary
OpenProse builds open-source infrastructure for long-running AI agents: a declarative, Markdown-based language and a reactive runtime that let developers specify agent behavior as composable, reusable contracts rather than brittle prompts. The product targets engineers and teams that orchestrate multi-step AI workflows, replacing ad-hoc prompt engineering and fragile context management with structured, version-controlled requirements that agents execute reliably.
Go-to-market
Developers adopt the tooling through a self-serve, open-source model with a hosted "Try it" entry point on the website, lowering the barrier to first use without a sales motion.
From the Y Combinator listing
An open-source operating system for reliable long-running agents
OpenProse is building open-source infrastructure for long-running AI work: a declarative language plus a reactive harness/runtime for reliable agent workflows.
Facts
- B2B / B2B -> Engineering, Product and Design
- San Francisco, CA, USA; Remote
- 3
- Active
- Early
Founders (1)
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