--- title: LLM API — OpenAI Compatible | RunAPI description: Access RunAPI language models through one OpenAI-compatible API endpoint. url: https://runapi.ai/llm.md canonical: https://runapi.ai/llm locale: en site: RunAPI image: https://runapi.ai/assets/opengraph-f702f2b1.png alternates: en: https://runapi.ai/llm zh-CN: https://runapi.ai/zh-CN/llm es: https://runapi.ai/es/llm ja: https://runapi.ai/ja/llm de: https://runapi.ai/de/llm fr: https://runapi.ai/fr/llm pt-BR: https://runapi.ai/pt-BR/llm ko: https://runapi.ai/ko/llm it: https://runapi.ai/it/llm nl: https://runapi.ai/nl/llm pl: https://runapi.ai/pl/llm tr: https://runapi.ai/tr/llm zh-TW: https://runapi.ai/zh-TW/llm zh-HK: https://runapi.ai/zh-HK/llm ar: https://runapi.ai/ar/llm x-default: https://runapi.ai/llm --- > HTML version: https://runapi.ai/llm > Site index for agents: https://runapi.ai/llms.txt # LLM API — OpenAI Compatible Access [Claude](https://runapi.ai/models/claude.md), GPT, [Gemini](https://runapi.ai/models/gemini.md), [DeepSeek](https://runapi.ai/models/deepseek.md), and Grok through one OpenAI-compatible endpoint. /v1/chat/completions, /v1/messages, /v1/responses. [Get API Key](https://runapi.ai/login) [Browse Models](https://runapi.ai/models.md) 67 models · drop-in base_url swap · pay per token | Value | Metric | | --- | --- | | 67 | LLM models | | 15-25% | Below official | | 2 lines | To migrate | ## Multi-Model Comparison Prompt: `Explain quantum computing in one sentence` | Model | Provider | Price | | --- | --- | --- | | Claude/claude-fable-5 (`/v1/messages`) | Anthropic | Input $10.00 / 1M tokens \| Output $50.00 / 1M tokens | | Claude/claude-fable-5-1 (`/v1/messages`) | Anthropic | Input $10.00 / 1M tokens \| Output $50.00 / 1M tokens | | Claude/claude-haiku-4-5-20251001 (`/v1/messages`) | Anthropic | Input $0.60 / 1M tokens \| Output $3.00 / 1M tokens | ## 4 endpoint shapes, one key - **Chat completion** - The OpenAI shape every SDK already speaks. Swap base_url and keep your existing request code. - **Message** - The Messages API shape for system prompts, tool use, and structured content blocks. - **Response** - The stateful shape for multi-turn agent loops with server-side conversation handling. - **Embedding** - Vector embeddings for retrieval, billed per token on the same RunAPI key. ## LLMs on one key | Model | Provider | Price | | --- | --- | --- | | Claude/claude-fable-5 | Anthropic | $10.00 / 1M in | | Claude/claude-fable-5-1 | Anthropic | $10.00 / 1M in | | Claude/claude-haiku-4-5-20251001 | Anthropic | $0.60 / 1M in | | Claude/claude-opus-4-1-20250805 | Anthropic | $9.00 / 1M in | | Claude/claude-opus-4-5-20251101 | Anthropic | $3.00 / 1M in | | Claude/claude-opus-4-6 | Anthropic | $3.00 / 1M in | | Claude/claude-opus-4-7 | Anthropic | $3.00 / 1M in | | Claude/claude-opus-4-8 | Anthropic | $3.00 / 1M in | [View all 67 LLM models](https://runapi.ai/models.md) ## Quickstart ### Call any model with the OpenAI shape #### curl ```bash curl https://runapi.ai/v1/chat/completions \ -H "Authorization: Bearer $RUNAPI_API_KEY" \ -H "Content-Type: application/json" \ -d '{"model":"deepseek-v4-flash","messages":[{"role":"user","content":"Explain the difference between concurrency and parallelism."}]}' ``` #### Response ```json { "id": "chatcmpl-abc123", "object": "chat.completion", "model": "deepseek-v4-flash", "choices": [ { "message": { "role": "assistant", "content": "Hello! How can I help?" }, "finish_reason": "stop" } ], "usage": { "prompt_tokens": 12, "completion_tokens": 8, "total_tokens": 20 } } ``` ## Four Steps to Your First Generation **How it works** 1. **Get Your API Key** - Create one key for your RunAPI account. 2. **Use OpenAI Format** - Send requests through the documented OpenAI-compatible endpoint. 3. **We Route Smartly** - RunAPI selects a supported route for your request. 4. **Stream Responses** - Receive streamed output when the selected endpoint supports SSE. ## Why Developers Choose RunAPI ### One Key, All Models Stop juggling API keys. One integration gives you access to 230+ models across all providers. ### 15-25% Cost Savings Our volume agreements with providers mean lower prices than going direct. No markup on top. ### Automatic Failover If a provider goes down, we route to the next best option. Your app stays up. ### OpenAI-Compatible Drop-in replacement for OpenAI SDK. Change one line of code to access any model. ### Real-Time Billing Pay only for what you use. Per-request pricing with no minimums. Track costs per model, per project. ### Data Privacy Our Privacy Policy explains how request data and generated content are processed and retained. ### Explore ## More AI APIs - [Video API](https://runapi.ai/models.md?modality=video) - Generate, edit, and upscale video with 80 models [Learn more](https://runapi.ai/models.md?modality=video) - [Image API](https://runapi.ai/models.md?modality=image) - Create and transform images with 49 models [Learn more](https://runapi.ai/models.md?modality=image) - [Music API](https://runapi.ai/models.md?modality=audio_music) - Compose original tracks with AI [Learn more](https://runapi.ai/models.md?modality=audio_music) - [Audio API](https://runapi.ai/models.md?modality=audio_music) - Text-to-speech with 31 models [Learn more](https://runapi.ai/models.md?modality=audio_music) ## What teams build with it **Coding Agents** Route planning to Opus and edits to a cheap model, on one key with one invoice. **RAG Pipelines** Embeddings and generation on the same endpoint, so retrieval and answering share a budget. **Content Generation** Fan out drafts across models and keep the best, without signing five provider contracts. **Multi-model Comparison** A/B the same prompt across Claude, GPT, and Gemini by changing one string. ## RunAPI vs alternatives | Feature | RunAPI | OpenRouter | Direct API | | --- | --- | --- | --- | | LLM models | 66 | 300+ | 1 provider | | Other modalities | Video, Image, Music, Audio | No | Per provider | | Pricing | 15-25% below official | Market rate | Official rate | | Native Messages API | Yes | No | Yes | | Unified credits | Yes | Yes | No | | MCP server + CLI | Yes | No | No | ## LLM API questions ### How do I migrate from an OpenAI-compatible client? Point the client at the documented RunAPI base URL and use your RunAPI key. Keep the request shape supported by the selected endpoint. ### Is streaming supported? Streaming is available when the selected model and endpoint expose a streaming response. ### Do tool calls work? Tool calling is available on models and endpoint shapes that declare tool support in their runtime contract. ### How are tokens billed? Input and output rates are listed in the model catalog. Usage is billed from the token counts reported for the request. ### Which endpoint should I use? Choose the endpoint shape that matches your existing client and the capabilities required by your request. ### What if a route is unavailable? The API returns the request status through its documented response contract so your application can retry or choose another supported model. ## Swap two lines, keep your code 67 models behind the OpenAI shape you already ship. Start free, no credit card required. - [Get API Key](https://runapi.ai/login) - [Read the Docs](https://runapi.ai/docs/guides) --- ## More from RunAPI - [Home](https://runapi.ai/.md) ### Product - [Model Catalog](https://runapi.ai/models.md) - [Pricing](https://runapi.ai/pricing.md) - [Providers](https://runapi.ai/models#all-models) ### Developers - [Documentation](https://runapi.ai/docs/guides) - [SDKs](https://runapi.ai/sdk.md) - [CLI](https://runapi.ai/cli.md) - [MCP Server](https://runapi.ai/mcp.md) ### Guides - [Claude Code vs Cursor](https://runapi.ai/claude-code-vs-cursor.md) - [Cursor API Setup](https://runapi.ai/cursor-api-setup.md) - [RunAPI vs OpenRouter](https://runapi.ai/openrouter-alternative.md) ### Company - [Enterprise](https://runapi.ai/contact.md) - [Contact](https://runapi.ai/contact.md) ### Legal - [Terms](https://runapi.ai/terms.md) - [Privacy](https://runapi.ai/privacy.md) - [Site index for agents](https://runapi.ai/llms.txt) Contact: contact@runapi.ai ## Structured data ```json [ { "@context": "https://schema.org", "inLanguage": "en", "@type": "WebSite", "name": "RunAPI", "url": "https://runapi.ai/", "potentialAction": { "@type": "SearchAction", "target": { "@type": "EntryPoint", "urlTemplate": "https://runapi.ai/models?q={search_term_string}" }, "query-input": "required name=search_term_string" } }, { "@context": "https://schema.org", "inLanguage": "en", "@type": "Organization", "name": "RunAPI", "url": "https://runapi.ai/", "logo": { "@type": "ImageObject", "url": "https://runapi.ai/icon.svg" }, "sameAs": [ "https://github.com/runapi-ai" ] } ] ```