> ## Documentation Index > Fetch the complete documentation index at: https://www.stratus.run/docs/llms.txt > Use this file to discover all available pages before exploring further. # Introduction > The Agent Reliability Layer Stratus X1 Stratus X1 ## What is Stratus X1? STRATUS X1 is a **predictive world model** that enables AI agents to reason and plan before acting. Unlike traditional LLMs that generate actions token-by-token, Stratus gives agents the ability to: Encode current state into embedding space Simulate multiple possible futures Choose the path most likely to succeed The result: **2.1×** higher task success rates, **68%** fewer tokens, **54%** better accuracy. ## Quick Start Get started with Stratus in minutes. Get your API key and make your first request in under 5 minutes. ## Key Features Drop-in replacement for OpenAI's API. Change one line of code and get world model prediction. Predict complete action sequences and validate plans before execution with `/v1/rollout`. Works with any LLM as the execution engine — GPT-4o, Claude, DeepSeek, Llama, Gemini, Grok, Mistral, Qwen, and 40+ more providers via OpenRouter. Designed specifically for agentic workflows — web navigation, task automation, multi-step reasoning. Benchmarked on WebArena and HotpotQA. Significant lift across all major LLMs. Fast enough to fit in any agent loop. Predict futures without slowing down execution. ## Why Agents Need World Models **Traditional LLMs** (not Stratus) struggle with multi-step tasks because they: * **Don't plan ahead** — Generate one token at a time (greedy decoding) * **Can't predict outcomes** — No internal model of how actions affect state * **Lack foresight** — Commit to paths without evaluating consequences **Stratus X1 solves this** by learning a predictive world model in embedding space. Agents can now simulate futures before acting, dramatically improving success rates. **The World Model Layer** Stratus sits between your agent and the LLM, predicting state transitions in latent space. It enables zero-shot planning in novel situations by learning the dynamics of how actions change the world. ## Explore the Docs Understand how Stratus works and when to use it. Complete API documentation and examples. API keys, rate limits, and security. Navigate the dashboard and manage your account. Pricing, packages, and billing management.