ByteDance Open Sources Eino: Golang LLM Development Framework

ByteDance announced today that after more than six months of internal use and iteration, Eino, a comprehensive Golang-based LLM application development framework, has been officially open-sourced under CloudWeGo.

Quick Introduction to Eino

Eino is built on clear “component” definitions and provides powerful process “orchestration” capabilities, covering the entire development lifecycle, aimed at helping developers create the most sophisticated LLM applications in the shortest time possible.

Have you ever felt this way: wanting to add LLM capabilities to your application but not knowing where to start in this relatively new field; wanting to stay at the forefront of research and apply the latest industry achievements, but finding that your application development framework hasn’t been updated for months; trying to understand Python code in your project and needing to repeatedly check the context to determine a variable or parameter type.

Eino’s Unique Advantages

Software applications based on large language models are in a rapid development phase, with new technologies, ideas, and practices constantly emerging. An excellent LLM application development framework needs to both encapsulate the “unchanging” universal core elements in the field and enable agile horizontal and vertical expansion based on the latest developments.

Currently mainstream frameworks like LangChain and LlamaIndex are based on Python. While they can quickly implement diverse functionalities by leveraging Python’s rich ecosystem, they also inherit the issues of “weak type checking” and “high long-term maintenance costs” that come with Python as a dynamic language. As LLM applications rapidly enter large-scale online operation, the high reliability and high maintainability achieved through Golang as a strongly-typed language are becoming increasingly valuable.

LLM application development is a relatively new field, sometimes requiring a trial-and-error approach where practice validates understanding. Leveraging ByteDance’s high-frequency applications like Douyin and DouBao, with their diverse scenarios, rapid iteration, and massive feedback, Eino has unique advantages in practice-driven design.

Stable Core

• Provides stable component definitions: each component type as an interface with comprehensive, stable definitions
• Supports universal foundation capabilities: including streaming programming capabilities, callback capabilities, and option extension capabilities
• Provides fixed data flow and process orchestration paradigms: Chain (directed acyclic graphs), Graph (directed graphs or DAGs), Workflow (DAGs with field mapping capabilities)

Agile Extension

• Supports horizontal component extension: e.g., ChatModel can be extended to support OpenAI, Gemini, Claude implementations
• Supports Lambda types: custom functions can be declared as Lambda types for orchestration
• Provides specific orchestration paradigms: such as ReAct Agent, Host Multi-Agent, and other best practice encapsulations

High Reliability and Easy Maintenance

• Strong type system: fully utilizes Golang’s strong typing features for type checking
• Modular design: core library and component implementations are separate go modules with minimized dependencies
• Clear layered design: each layer has clear responsibilities and functional cohesion

Tool Ecosystem

• Provides three auxiliary tools: chain tracing, debugging, and visualization
• Built-in tracing callback, integrated with Langfuse platform
• Supports IDE plugins and UI drag-and-drop development

Project Open Source Links:

• cloudwego/eino
• cloudwego/eino-ext