# OpenRouter — Unified LLM API with Smart Routing

> Single API endpoint for 200+ LLM models with automatic fallbacks, price comparison, and usage tracking. Route to the cheapest or fastest model that fits your needs. 3,000+ stars.

## Install

Save in your project root:

## Quick Use

```bash
# Works with any OpenAI SDK — just change the base URL
export OPENROUTER_API_KEY=sk-or-...
```

```python
from openai import OpenAI

client = OpenAI(
    base_url="https://openrouter.ai/api/v1",
    api_key="sk-or-..."
)

response = client.chat.completions.create(
    model="anthropic/claude-sonnet-4-20250514",
    messages=[{"role": "user", "content": "Hello!"}]
)
```

Get your free API key at [openrouter.ai](https://openrouter.ai/keys).

---

## Intro

OpenRouter is a unified API gateway for 200+ LLM models from every major provider with 3,000+ GitHub stars. One API key, one endpoint, access to Claude, GPT-4, Gemini, Llama, Mistral, and hundreds more. It offers automatic fallbacks, real-time price comparison, and usage dashboards — letting you route requests to the cheapest or fastest model that meets your requirements. Best for developers who want multi-model access without managing 10 different API keys. Works with: any OpenAI-compatible client, LangChain, LiteLLM, Cursor, Continue. Setup time: under 1 minute.

---

## Key Features

### 200+ Models, One API Key

| Provider | Example Models |
|----------|---------------|
| Anthropic | Claude Opus 4, Sonnet 4, Haiku |
| OpenAI | GPT-4o, GPT-4, o1 |
| Google | Gemini 2.5 Pro, Flash |
| Meta | Llama 3.1 70B, 405B |
| Mistral | Mistral Large, Codestral |
| Open-source | DeepSeek, Qwen, Phi |

### Smart Routing

```python
# Auto-select the cheapest model that passes your requirements
response = client.chat.completions.create(
    model="openrouter/auto",  # Smart routing
    messages=[...],
    route="lowest-cost"  # or "lowest-latency"
)
```

### Fallback Chains

```python
# If primary model is down, auto-fallback
response = client.chat.completions.create(
    model="anthropic/claude-sonnet-4-20250514",
    extra_body={
        "fallbacks": ["openai/gpt-4o", "google/gemini-pro"]
    },
    messages=[...]
)
```

### Price Comparison
Real-time pricing dashboard shows cost per million tokens:

| Model | Input $/M | Output $/M |
|-------|-----------|------------|
| Claude Sonnet | $3.00 | $15.00 |
| GPT-4o | $2.50 | $10.00 |
| Llama 3.1 70B | $0.60 | $0.60 |
| Gemini Flash | $0.075 | $0.30 |

### Usage Dashboard
Track spending, requests, and token usage per model, per day, per API key.

### Use with Popular Tools

**Cursor:**
Settings > Models > OpenAI Base URL: `https://openrouter.ai/api/v1`

**Continue:**
```json
{"models": [{"provider": "openrouter", "model": "anthropic/claude-sonnet-4-20250514"}]}
```

### Key Stats
- 3,000+ GitHub stars
- 200+ LLM models
- OpenAI-compatible API
- Smart routing and fallbacks
- Real-time price comparison

### FAQ

**Q: What is OpenRouter?**
A: OpenRouter is a unified API gateway for 200+ LLM models with one API key, automatic fallbacks, price comparison, and smart routing.

**Q: Is OpenRouter free?**
A: Free tier with limited credits. Pay-as-you-go with no markup on many models.

**Q: How does pricing compare to direct API access?**
A: Most models are at or near provider pricing. Some open-source models are free.

---

## Source & Thanks

> Created by [OpenRouter](https://github.com/OpenRouterTeam). Licensed under MIT.
>
> [openrouter](https://openrouter.ai) — ⭐ 3,000+

Thanks for making multi-model LLM access simple.

---

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## 快速使用

```python
from openai import OpenAI
client = OpenAI(base_url="https://openrouter.ai/api/v1", api_key="sk-or-...")
response = client.chat.completions.create(
    model="anthropic/claude-sonnet-4-20250514", messages=[{"role": "user", "content": "你好"}]
)
```

---

## 简介

OpenRouter 是一个统一 API 网关，GitHub 3,000+ stars。一个 API Key 访问 200+ LLM 模型，支持自动降级、实时价格比较和智能路由。适合需要多模型访问而不想管理多个 API 密钥的开发者。

---

## 来源与感谢

> Created by [OpenRouter](https://github.com/OpenRouterTeam). Licensed under MIT.
>
> [openrouter](https://openrouter.ai) — ⭐ 3,000+

---
Source: https://tokrepo.com/en/workflows/283d7316-11a4-447b-8151-95b0f5124cbb
Author: AI Open Source