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OpenProse

A new kind of language for a new kind of computer.

A long-running AI session is a Turing-complete computer. OpenProse is a programming language for it.

The OpenProse VM

A long-running AI session is a Turing-complete computer. OpenProse is a programming language for it. LLMs are simulators—when given a detailed system description, they don't just describe it, they become it.

1

Simulation Is Implementation

The OpenProse spec describes a VM with enough fidelity that reading it induces simulation. Each session spawns a real subagent, outputs are real artifacts. Simulation with sufficient fidelity is implementation.

2

The Fourth Wall **...**

When you need AI judgment instead of strict execution, break out of structure. The **...** syntax lets you speak directly to the VM—it evaluates conditions semantically.

3

Structure + Flexibility

English is already an agent framework—we're structuring it, not replacing it. Unambiguous control flow where it matters, natural language where you want flexibility.

4

Open Standard, Zero Lock-in

OpenProse runs on any Prose Complete system. It's not a library you're locked into—it's a language specification. Switch platforms anytime; your .prose files work everywhere.

Prose Complete

A System is Prose Complete if it can run a .prose program of arbitrary complexity.

Not all systems are Prose Complete. It's not just the model—it's the model plus the harness. Together, they need to successfully induce the VM: maintain state in context or files, spawn real subagents, and evaluate discretion conditions intelligently.

Sort by
#SystemStatus
1
Claude Code+Opus 4.5
Falls down on long-running programs
Approaching Prose Completevibe
2
Claude Code+Sonnet 4.5
Falls down on long-running programs
Approaching Prose Completevibe
3
Amp+Opus 4.5 / Sonnet 4.5
Under Evaluation
4
OpenCode+Opus 4.5 / Sonnet 4.5
Lacking async subagents—falls down on programs utilizing parallel processing
Not Prose Completeanecdotal
5
OpenCode+Codex
Lacking async subagents—falls down on programs utilizing parallel processing
Not Prose Completeanecdotal
6
Codex CLI+Codex
Lacking subagents—cannot run any Prose utilizing sessions
Not Prose Completeanecdotal
Interestingly, Codex can simulate sessions in the weights—suggesting an alternate approach we will pursue.

Common questions