Overview
Rig is a Rust framework for building LLM-powered applications. It provides modular abstractions for tool-calling agents, reasoning workflows, and retrieval-augmented generation (RAG). Unlike the other Rust projects in this section, Rig is a general-purpose agent framework rather than a coding-specific tool — but it provides the foundational building blocks for building one.
| Attribute | Value |
|---|---|
| Language / Stack | Rust + Tokio |
| GitHub | github.com/0xplaygrounds/rig |
| License | MIT |
| Closest Match | Rust agent framework (like LangChain for Rust) |
| Maturity | Active development |
Key Features
- Modular tool system — Define tools as Rust structs with auto-generated JSON schemas.
- Multi-provider LLM support — OpenAI, Anthropic, Cohere, and local models via Ollama.
- Agent workflows — Compose agents with explicit reasoning steps and tool orchestration.
- RAG support — Vector stores, embeddings, and retrieval pipelines.
- Type-safe — Leverages Rust's type system for compile-time tool validation.
Architecture
Rig follows a builder-pattern architecture where agents are composed from "providers" (LLM backends), "tools" (functions the agent can call), and "pipelines" (multi-step workflows). It is designed to be embedded in larger Rust applications rather than run as a standalone service. The framework handles LLM communication, tool schema generation, and response parsing, leaving the orchestration logic to the application developer.
Strengths
- Type safety — Rust's type system catches tool schema mismatches at compile time.
- Modularity — Composable building blocks let you build exactly the agent you need.
- Performance — Rust-native with async Tokio for high-throughput agent workloads.
- Multi-provider — Not locked to a single LLM vendor.
- Active development — Regular releases and growing community.
Gaps vs Open SWE
- General-purpose — Not designed specifically for coding agents; no built-in file editing tools.
- No sandbox — No built-in execution isolation.
- No GitHub/Slack — No platform integrations included.
- Library, not platform — You build the service layer yourself.
Relevance to xCoder
Rig is our primary reference for Rust agent framework design. If we build a Rust-native agent runtime (separate from our TypeScript driver), Rig provides the tool-calling and LLM abstraction layers. Its type-safe tool system is something we may emulate in our own Rust execution substrate. We consider Rig the "LangChain for Rust" and track its evolution closely.
Research note