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OpenProse is building open-source infrastructure for long-running AI work: a declarative language plus a reactive harness/runtime for reliable agent workflows.
OpenProse is a Y Combinator company in the Spring 2026 batch. Its directory entry describes it as: An open-source operating system for reliable long-running agents. The founder listed is Dan Barrett (Founder/CEO) (Y Combinator directory entry, May 19, 2026).
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New accelerator entry · 2026-05-19 · the record
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OpenProse is building open-source infrastructure for long-running AI work: a declarative language plus a reactive harness/runtime for reliable agent workflows.
Read from the page's own HTML and response headers on 10 September 2026, at https://prose.md/. Each badge matched a string the site serves about itself — hover one to see which. Nothing here is a traffic, ranking or revenue figure: those cannot be read off a page and are not claimed.
Checked away from the directory entry. What is below does not come from the company's Y Combinator page.
Declare standing AI jobs as Markdown contracts. A deterministic harness runs only what changed, and signs a receipt for every decision.
The title and description the site itself served, answering 200. Not a cached copy and not the company's directory entry — what was live when we asked.
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Example from a real report (our sample on Target): “The Q2 2026 earnings report, published August 19, 2026, showed adjusted EPS of $2.46 against an expected $2.33” Source: CNBC
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Sourced from the company's Y Combinator directory entry, and from the company's own site, read directly on 2026-09-06 (prose.md).
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