Open Source • Apache 2.0 License

The Agent Programming Language

Define Agents. Compile to Any Language.

A declarative language for building AI agents. Write once, compile to TypeScript, Python, or Go.

SageSyn introduces the Agent Programming Language (.sag) - a clean, YAML-like syntax for defining intelligent agents. With LSP support for VSCode, Vim, and Neovim, plus native constructs for MCP, A2A, and AG-UI protocols, agents become first-class citizens in your development workflow.

Think:TypeScript is to JavaScript as .sag is to agent SDKs

Our Mission

To establish a universal language for defining intelligent agents - one that compiles to any target, integrates with any model, and speaks every protocol.

Core Pillars

  • Declarative language for agent definition
  • Multi-target compilation (TS, Python, Go)
  • LSP support for intelligent editing
  • Protocol primitives (MCP, A2A, AG-UI)
  • Visual IDE for workflow design

What is SageSyn?

Understanding what we are—and what we're not

SageSyn IS

  • A programming language for defining AI agents (.sag files)
  • A multi-target compiler (TypeScript, Python, Go)
  • An LSP server for intelligent editing
  • A visual IDE for designing agent workflows
  • Protocol-native (MCP, A2A, AG-UI as language constructs)
  • An open source project (Apache 2.0)

SageSyn is NOT

  • Yet another agent framework
  • A hosted service or SaaS platform
  • Tied to a single LLM provider
  • A no-code / low-code platform
  • A chatbot or conversational interface
  • A replacement for understanding agents

Core Principles

The foundational values that guide everything we build

Declarative Syntax

Define agents in clean, readable YAML-like syntax. Focus on what your agent does, not the boilerplate. The language handles the complexity.

Multi-Target Compilation

Write once, compile to TypeScript, Python, or Go. Your agent definitions become production-ready code in any language your team uses.

LSP-Powered Editing

Full Language Server Protocol support. Get autocompletion, hover docs, diagnostics, and refactoring in VSCode, Vim, Neovim, and any LSP-compatible editor.

Protocol Primitives

MCP, A2A, and AG-UI are first-class language constructs. Define tool connections, agent discovery, and UI streaming as native syntax, not afterthoughts.

Model Agnostic

Work with any LLM provider—Claude, GPT-4, Gemini, Llama, or your own models. The language abstracts the provider, your agents stay portable.

Open Source Core

Apache 2.0 licensed compiler, LSP server, and runtime. Build on SageSyn, contribute back, and shape the future of agent development.

Core Capabilities

Everything you need to build, test, and deploy intelligent agents

Agent Programming Language

A declarative, YAML-like language purpose-built for defining intelligent agents.

  • Clean, readable syntax for agent definition
  • Native workflow constructs (perceive, reason, execute, respond)
  • Protocol primitives (MCP servers, A2A discovery, AG-UI events)
  • Type-safe tool definitions
  • Structured model configuration

Multi-Target Compiler

Compile .sag files to production-ready code in any language.

  • TypeScript target with full type safety
  • Python target for ML/AI ecosystems
  • Go target for high-performance systems
  • Optimized code generation
  • Source maps for debugging

Language Server Protocol

First-class editor support for an intelligent development experience.

  • Autocompletion for agents, tools, protocols
  • Hover documentation and type information
  • Real-time diagnostics and error reporting
  • Go-to-definition and find references
  • Refactoring support (rename, extract)

Visual Agent Canvas

Design and visualize agent workflows with an intuitive node-based interface.

  • Drag-and-drop workflow design
  • Visual representation of .sag files
  • Real-time execution visualization
  • Context window inspector
  • Integrated execution logs

Protocol Native

Built with first-class support for emerging agent protocols

MCP

Model Context Protocol

Connect agents to external tools, databases, and services through native syntax. MCP servers become typed dependencies in your .sag file.

A2A

Agent-to-Agent Protocol

Build multi-agent systems where agents declare their capabilities and discover each other through the language itself.

AG-UI

Agent-User Interface Protocol

Define how your agent communicates with user interfaces - streaming responses, state updates, and interactive elements.

Built with Modern Technology

A carefully selected stack optimized for performance, developer experience, and cross-platform compatibility

language

Agent Language Spec

compiler

Rust

lspServer

Rust

targets

TypeScriptPythonGo

visualIde

Tauri + React

Code Editor

Monaco Editor

Apache 2.0 Licensed

Open Source at Heart

SageSyn is built in the open. Join our growing community of developers, contributors, and agent builders.

Join the Community

GitHub Discussions
Discord Community
Weekly Office Hours

Ways to Contribute

languageSpec
compiler
lspServer
runtimes
Documentation