Apps similar to GPT Index include Sim Studio, which is free and open source. Other options are Cactus, LangChain, SimplAI and Platos. In total there are nine Large Language Model (LLM) Tools like GPT Index for Windows, self-hosting, Mac, Linux and the web.
Sim Studio is a powerful platform for building, testing, and optimizing agentic workflows. It provides developers with intuitive tools to design sophisticated agent-based applications through a visual interface.
United Kingdom
LangChain is a framework for developing applications powered by language models. We believe that the most powerful and differentiated applications will not only call out to a language model, but will also be:
SimplAI is an enterprise-grade platform that helps organizations transform into AI-native enterprises. It enables the rapid creation, deployment, and monitoring of intelligent AI agents while automating complex workflows—securely, scalably, and reliably.
United States
Build, ship, and operate AI agents on infrastructure you own. Apache 2.0. Self-hostable in one docker compose up.
India
Teammately is The AI AI-Engineer - the AI Agent for AI Engineers that autonomously builds AI Products, Models and Agents based on LLM, prompt, RAG and ML.
United Kingdom
Dedoctive provides auditable AI for defensible decisions - it grounds outputs in trusted evidence, provides full source-level provenance, and governs workflows with human-in-the-loop guardrails.
