7 Best Onyx Alternatives in 2026 (Open Source)
Onyx — Open Source AI Platform - AI Chat with advanced features that works with every LLM. Provides a unified, low-latency internal knowledge representation for agents, replacing iterative MCP searches with instant context fetching.
Short answer
- Closest match to Onyx: LibreChat.
- Most actively developed: Open WebUI (1,515 commits in the last 90 days).
- Fastest growing: Open WebUI (+3,942 GitHub stars in the last 30 days).
- No commit in 6+ months: Open Assistant API.
These 7 open-source tools do the same job. They are ordered by how closely they match Onyx, with live GitHub data so you can see which projects are actively maintained.
| Tool | GitHub stars | Stars / 30d | Last commit |
|---|---|---|---|
| Onyx(original) | 32.3k | +240 | 2026-10-02 |
| LibreChat | 45.2k | +1,618 | 2026-10-01 |
| Open WebUI | 153.8k | +3,942 | 2026-09-21 |
| Open Assistant API | 367 | +1 | 2024-12-14 |
| MaxKB | 22.9k | -30 | 2026-09-28 |
| Casibase | 5.7k | +190 | 2026-10-01 |
| JeecgBoot | 48.1k | +210 | 2026-09-22 |
| Khoj | 37.6k | +225 | 2026-08-02 |
1. LibreChat
Open-source ChatGPT-like interface for multiple AI models, agents, and sandboxed code execution
What sets it apart: Most feature-complete self-hosted ChatGPT alternative — uniquely combines agents, MCP, code interpreter, image gen, and multi-user auth in one package, unlike single-provider UIs
Best for: Organizations wanting a private, self-hosted ChatGPT replacement; Teams needing multi-user AI platform with access control and audit
2. Open WebUI
User-friendly AI Interface (Supports Ollama, OpenAI API, ...)
What sets it apart: Unlike LM Studio (desktop-only, personal use), Open WebUI is a full multi-user platform with RAG, RBAC, SCIM provisioning, 9 vector DBs, and Google Drive/OneDrive integration — the most feature-complete self-hosted ChatGPT alternative
Best for: Teams wanting a self-hosted ChatGPT alternative with full data control and Ollama integration; Organizations needing enterprise-grade AI platform with LDAP/SCIM/SSO and multiple vector DB backends
3. Open Assistant API
Open-source, self-hosted AI assistant API compatible with OpenAI and supporting LLMs, RAG, and tools
What sets it apart: Open-source OpenAI Assistant API compatible service supporting multiple LLMs via One API, with RAG, web search, and local deployment
Best for: self-hosted-openai-assistant-alternative; multi-llm-assistant-apps; enterprise-local-deployment
4. MaxKB
🔥 MaxKB is an open-source platform for building enterprise-grade agents.
What sets it apart: Combines enterprise-grade agent building with comprehensive RAG pipelines and MCP tool-use capabilities in an open-source package.
Best for: Enterprise agent development; Intelligent customer service systems; Corporate internal knowledge bases
5. Casibase
Open-source AI knowledge base and MCP/A2A management platform with admin UI, user management, and SSO
What sets it apart: vs other knowledge base platforms: Enterprise-grade open-source AI Cloud OS with built-in SSO (Casdoor), admin UI, MCP/A2A agent management, and support for 10+ LLM providers out of the box
Best for: Enterprise teams needing a self-hosted AI knowledge base with admin UI; Organizations requiring SSO and user management for AI chatbots; Multi-model AI platform deployment with MCP/A2A support
6. JeecgBoot
AI low-code platform for generating systems, code, forms, and reports with chat and workflow orchestration
What sets it apart: Combines AI-powered natural language programming with enterprise low-code platform specifically for Java system generation and AI agent development.
Best for: Java developers automating repetitive coding tasks; Building enterprise AI applications with low-code; Creating AI agents with workflow orchestration
7. Khoj
Open-source, self-hostable platform for custom AI agents, research, automation, and personal assistance
What sets it apart: Open-source, self-hostable platform that scales from personal on-device AI to enterprise agents with custom knowledge and tools.
Best for: Users wanting self-hosted personal AI agents; Building custom agents for automation and research; Extending capabilities with local or cloud LLMs
FAQ
- What are the best alternatives to Onyx?
- The closest open-source alternatives to Onyx are LibreChat, Open WebUI and Open Assistant API, followed by MaxKB, Casibase and JeecgBoot. They are ranked by how closely they match what Onyx does.
- Which Onyx alternative is the most popular?
- Open WebUI has the most GitHub stars among Onyx alternatives, with 153,800 stars.
- Which Onyx alternative is the most actively maintained?
- By recent activity, Open WebUI (1,515 commits in the last 90 days) is the most actively developed alternative.