Agents Flex
Agents Flex is a lightweight Java framework for AI agent development, inspired by LangChain and LlamaIndex.
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What is Agents Flex?
Agents Flex is a lightweight, high-performance Java framework for AI agent development, inspired by LangChain and LlamaIndex. It simplifies AI application development by providing unified API encapsulation and rich components for building conversational AI, tool orchestration, and agent workflows on the JVM.
Agents Flex pricing
Pricing model: Freemium
Agents-Flex is 100% free and open source under the Apache 2.0 License. There is no paid tier, subscription, or commercial pricing. The framework is available on GitHub (https://github.com/agents-flex/agents-flex) and Gitee (https://gitee.com/agents-flex/agents-flex) for free download and use. Users only pay for external LLM API calls to providers like OpenAI, GiteeAI, SiliconFlow, or their self-hosted models. No credit card required, no enterprise plans, no usage limits from the framework itself.
Agents Flex pros
- Requires only JDK 8+ (vs JDK 17+ for Spring-AI)
- Works with any Java framework, not Spring-dependent
- Two-line code implementation for chat functionality
- Function Calling requires only a few lines of code
- Superior agent orchestration capabilities compared to Spring-AI and LangChain4j
- Better support for domestic Chinese LLMs and Embedding models
- Native Model Context Protocol (MCP) support
- Built-in Text2SQL and natural language database querying
- AI Skills for reusable agent capability encapsulation
- Supports both synchronous and stream (Stream) APIs
- Complete RAG pipeline with Loader, Parser, Splitter components
- Multiple vector database integrations with custom extension support
- Rich Prompt Frameworks (FEW-SHOT, CRISPE, BROKE, ICIO)
- Built-in image, audio, and video generation capabilities
- Open source under Apache 2.0 license, free forever
- HTTP, SSE, WS protocols for self-hosted model integration
- MessageMemory and ContextMemory for multi-turn conversation management
- Easy custom Embedding algorithm extension through interface implementation
Agents Flex cons
- Java-only framework (not available for Python or other languages)
- Primarily documented in Chinese, limited English documentation
- No official commercial support or enterprise plans
- Relatively new framework with smaller community than LangChain
- Some features still marked as 'planned' requiring PR contributions
- Requires API keys from LLM providers (not free model access)
- Limited third-party tutorials and learning resources compared to established frameworks
- No built-in GUI or low-code interface (code-only development)
Frequently asked questions about Agents Flex
What is Agents-Flex?
Agents-Flex is a lightweight, high-performance Java AI agent development framework designed to simplify AI application development. It provides unified API encapsulation for major LLM vendors (OpenAI, Qwen, DeepSeek, Moonshot, Ollama, etc.), supports cross-service provider compatibility, portability, and orchestration, and works with any Java framework without requiring Spring.
What LLMs does Agents-Flex support?
Agents-Flex supports market mainstream LLMs including ChatGPT, Ollama-deployed models, Spark (Xinghuo), Qwen (Tongyi Qianwen), ChatGLM (Zhipu), OpenAI, GiteeAI models (stable-diffusion-3-medium, FLUX.1-schnell, stable-diffusion-xl-base-1.0, Kolors), and SiliconFlow models (Flux.1-schnell, Stable Diffusion 3/XL/2.1/Turbo variants). It also supports custom model integration through HTTP, SSE, and WS protocols.
What Java version is required?
Agents-Flex requires JDK 8+, which is more accessible than Spring-AI's JDK 17+ requirement. This makes it easier to integrate into existing Java projects that may not have upgraded to newer JDK versions.
Does Agents-Flex work without Spring?
Yes, Agents-Flex is not Spring-dependent and can be used with any Java framework. However, it does provide spring-boot-starter support for users who prefer or need Spring Boot integration.
How do I implement Function Calling?
Function Calling in Agents-Flex requires only a few lines of code using annotations. You define a method with @FunctionDef for the function name and description, @FunctionParam for parameters, then create a FunctionPrompt with your query and the utility class. The LLM will automatically detect and call the function, returning results in just a few code lines.
What is the RAG support in Agents-Flex?
Agents-Flex provides complete RAG (Retrieval-Augmented Generation) support with three main components: Loader (for loading data from web, local files, databases), Parser (for parsing different data types), and Splitter (for document chunking). It includes multiple vector database integrations (Redis, Milvus, ElasticSearch) and Embedding implementations with custom extension interfaces for semantic retrieval.
Can I generate images with Agents-Flex?
Yes, Agents-Flex has built-in AI image generation capabilities supporting OpenAI, Stability, GiteeAI (stable-diffusion-3-medium, FLUX.1-schnell, stable-diffusion-xl-base-1.0, Kolors), and SiliconFlow (Flux.1-schnell, Stable Diffusion 3/XL/2.1/Turbo variants). You create an ImageModel with API configuration, build a GenerateImageRequest with prompt and size, then call generate() and save images to files.
What Prompt Frameworks are available?
Agents-Flex provides rich Prompt Framework support including FEW-SHOT, CRISPE, BROKE, and ICIO frameworks. You can also customize your own unique Prompt Templates with dynamic variable placeholders using PromptTemplate.of() with formatting support for objects, maps, and other data types.
How do I handle multi-turn conversations?
Agents-Flex provides MessageMemory and ContextMemory components for flexible management of multi-turn conversation history and session state. SimplePrompt is used for one-time chat scenarios, while MemoryPrompt is designed for multi-turn conversations. Both support custom extension to meet complex scenario requirements.
Where can I get Agents-Flex and is it free?
Agents-Flex is open source under Apache 2.0 License and completely free. It's available on GitHub at https://github.com/agents-flex/agents-flex and Gitee at https://gitee.com/agents-flex/agents-flex. No paid tiers, subscriptions, or commercial licensing required. You only pay for external LLM API provider costs.