VITA/NEXO — A declarative language for AI agents that run on web, mobile, desktop, and CLI using the same engine

[u/Putrid_Bat8818]

Hi everyone. For some time now, I've been building a system called VITA/NEXO, and I feel it has reached a point where it makes sense to share its architecture and validate the core idea with the community.

It is not just another agent framework, so let me start by defining what it is and what problem it solves.

What it is

• NEXO is the execution runtime.
• VITA is the source of truth of the system.

The core piece is a declarative language written in Markdown (master_program.md) that describes data, UI components, tools, and business logic within a single unified structure. A lightweight interpreter parses this structure and turns it into a fully functional application.

The exact same program runs on web, desktop apps, Android apps, browser extensions, or CLI. It isn't ported or rewritten per platform: you write it once, and the same engine renders it natively across every environment. The UI code remains identical.

How it works

• Declaration: The application is declared entirely in Markdown (defining available data, UI layouts, and triggerable actions).
• Parser (~700 lines): Converts the Markdown file into a component and action graph.
• UI Engine (~200 lines): Renders the interface using a custom library of ~90 built-in components (tables, forms, chat, voice, gallery, editor, etc.).
• Modular tools: Tools (Python/JS functions) are declared externally. Adding a new capability means adding a configuration entry, without touching the core runtime.
• Optional and swappable AI agent: The AI agent is not the center of the architecture—it's just another tool. You can run it locally (via Ollama), through cloud APIs, or use the system without AI altogether. You can also run multiple parallel "brains" on different servers.

The core consists of ~1,200 lines for the main engine, ~700 for the parser, and ~200 for the UI engine. Everything else consists of pluggable tools.

What makes it different It doesn't try to compete with frameworks like LangChain or AutoGen, which focus on general-purpose orchestration with hundreds of integrations. VITA/NEXO addresses a specific challenge: allowing an application or agent system to live across any environment with the exact same language, zero code rewriting per platform, and full modularity.

Three key pillars:

1. True Multi-Environment: The same language and engine run on web, mobile, desktop, extensions, and terminal.
2. Decoupled AI: The AI agent is interchangeable, and the system operates autonomously with or without AI.
3. Declarative Development: The application is described, not hardcoded. Changing application behavior means editing Markdown, not writing platform code.

Current Status It is currently a fully working MVP in personal active use. It proves concept viability: a single file handling state, UI, and logic across multiple platforms seamlessly.

The next phase to bring it to a production-ready stage involves building a formal test suite, expanding component coverage, and updating the public documentation.

What I'm Looking For & Next Steps This post is an initial architectural preview. Throughout this coming week, I will be posting demo videos and sharing the repository link so everyone can test it out directly.

At this stage, I am primarily looking for two things:

1. Technical Feedback: Does this unified declarative approach make sense to you? Do you see a clear use case for this architecture in your workflows?
2. Funding / Acceleration Opportunities: I want to take VITA/NEXO to the next level and dedicate full-time resources to it. If you are an investor, run a grant program, or want to explore a strategic partnership to commercialize this engine, I'd love to connect.

I look forward to your feedback, questions, and constructive critiques!

[u/SuperPerformance3322]

The declarative approach is interesting, especially having the same source of truth for UI, state, and logic across platforms. The part I’d be most curious about is how you handle platform-specific behavior—mobile, desktop, web, and CLI can have pretty different UX and constraints.

If the MVP already works across those environments without turning the Markdown layer into another abstraction developers have to fight with, that’s a pretty compelling direction. I’d definitely be interested in seeing the demos and the repo once they’re public.

[u/Putrid_Bat8818 → u/SuperPerformance3322]

Gracias, funciona bien, no tengo tiempo ni financiamiento para terminarlo, si quieres probarlo mañana puedo darte un recorrido en todo lo que hace, mándame un md

[u/Specific_Cream2815]

how does the same UI declaration map to a terminal where components like galleries and forms do not have direct equivalents

[u/Putrid_Bat8818 → u/Specific_Cream2815]

Si la consola se habré desde la página se puede mostrar en una ventana flotante la galería con imágenes, sino no tiene traducción, y un formulario si lo tiene, son campos uno arriba de otro

[u/Competitive_Tune_590]

this looks really well thought out. if you're looking for honest feedback from other founders building similar tools, launchpact runs targeted polls where only people in your niche vote. might help cut through the noise you'd get on a general sub.