Orbit Rust SDK

A complete Rust rewrite of OpenCode — the open-source AI coding agent.

We're rebuilding OpenCode from the ground up in 100% Rust for better performance, lower memory footprint, and a truly native experience.

Note: This is the open-source backend SDK derived from OpenCode. Orbit (our Unified Development Environment) is a separate, proprietary product that uses this SDK.

Why Rust?

Aspect	TypeScript/Bun	Rust
Memory	~200-500MB runtime	~20-50MB
Startup	1-3 seconds	<100ms
Binary Size	Node/Bun runtime required	Single static binary
Native Integration	FFI overhead	Zero-cost Tauri integration
Concurrency	Event loop limitations	True parallelism with async/await

By rewriting in Rust, we get:

• Instant startup — no runtime initialization
• Minimal memory — critical for running alongside heavy IDEs
• Native Tauri integration — seamless desktop app without IPC overhead
• Single binary distribution — no dependencies, no node_modules
• True concurrency — parallel tool execution without blocking

What is Orbit SDK?

Orbit Rust SDK is an open-source AI agent backend that handles:

• LLM provider communication — Anthropic, OpenAI, Google, AWS Bedrock, local models
• Tool execution — bash, file operations, code analysis
• Session management — conversation state and context
• Real-time streaming — event handling and SSE
• OAuth authentication — Claude Pro, ChatGPT Plus, GitHub Copilot

Comparison

Feature	Orbit SDK	Claude Agent SDK	Codex CLI	OpenCode
Language	Rust	Python/TypeScript	TypeScript	TypeScript
Memory Usage	~20-50MB	~200-400MB	~150-300MB	~200-500MB
Startup Time	<100ms	1-2s	1-2s	1-3s
Binary Distribution	Single static binary	Runtime required	Runtime required	Runtime required
Provider Agnostic	✅ All major providers	❌ Anthropic only	❌ OpenAI only	✅ All major providers
Open Source	✅ MIT	❌ Proprietary	✅ Apache 2.0	✅ MIT
Tool Execution	✅ Parallel	✅ Sequential	✅ Sequential	✅ Sequential

Installation

Once released, install via cargo:

cargo install orbit-sdk

Or add to your Cargo.toml:

[dependencies]
orbit-sdk = "0.1"

Quick Start

use orbit_sdk::{Agent, Provider};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Initialize with your preferred provider
    let agent = Agent::builder()
        .provider(Provider::Anthropic)
        .model("claude-sonnet-4-20250514")
        .build()?;

    // Send a message
    let response = agent
        .chat("Help me refactor this function")
        .await?;

    println!("{}", response);
    Ok(())
}

Supported Providers

Provider	Status	Models
Anthropic	✅	Claude 4, Claude 3.5, Claude 3
OpenAI	✅	GPT-4o, GPT-4, o1, o3
Google	✅	Gemini 2.0, Gemini 1.5
AWS Bedrock	✅	Claude, Titan, Llama
Ollama	✅	Any local model
OpenRouter	✅	100+ models

Architecture

orbit-sdk/
├── orbit-core/         # Foundation utilities (IDs, locks, filesystem)
├── orbit-bus/          # Event pub/sub system
├── orbit-storage/      # JSON file storage
├── orbit-config/       # Configuration management
├── orbit-provider/     # AI provider adapters
├── orbit-session/      # Session management
├── orbit-tools/        # Agent tools (bash, file ops, LSP)
├── orbit-mcp/          # Model Context Protocol client
└── orbit-server/       # HTTP API with SSE

Built-in Tools

Tool	Description
bash	Execute shell commands with streaming output
read	Read files with line number support
write	Create new files
edit	Apply precise edits to existing files
glob	Find files by pattern
grep	Search file contents with regex
lsp	Language Server Protocol integration
mcp	Model Context Protocol servers

Configuration

Create orbit.toml in your project root:

[provider]
default = "anthropic"
model = "claude-sonnet-4-20250514"

[tools]
bash = { enabled = true, timeout = 120 }
read = { enabled = true }
write = { enabled = true }
edit = { enabled = true }

[permissions]
auto_approve = ["read", "glob", "grep"]
require_approval = ["bash", "write", "edit"]

Or use environment variables:

export ANTHROPIC_API_KEY="sk-ant-..."
export OPENAI_API_KEY="sk-..."
export ORBIT_MODEL="claude-sonnet-4-20250514"

Contributing

We welcome contributions! Whether you're:

• Porting TypeScript to Rust — Pick a module and start converting
• Adding features — New tools, providers, or improvements
• Fixing bugs — In either the TS or Rust codebase
• Improving docs — Better examples, guides, and explanations

This SDK is free and open source. Use it, fork it, build on it.

Acknowledgments

Special thanks to OpenCode and Anomaly (SST) for building the original open-source AI coding agent.

OpenCode proved that a fully open-source, provider-agnostic AI agent could rival proprietary solutions. We're taking their excellent work and rebuilding it in Rust to push performance even further.

License

MIT License

Copyright (c) 2025 Recursive Labs Copyright (c) 2024-2025 SST/OpenCode (Original Work)

See LICENSE for details.

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