> ## Documentation Index
> Fetch the complete documentation index at: https://docs.aihubmix.com/llms.txt
> Use this file to discover all available pages before exploring further.

# LiteLLM

## LiteLLM 概覽

LiteLLM 是由 [BerriAI](https://github.com/BerriAI/litellm) 開發的開源**統一 AI 閘道**。它提供單一標準化介面以呼叫市面上幾乎所有主要 LLM。                           儲存庫:[https://github.com/BerriAI/litellm](https://github.com/BerriAI/litellm)

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每個 LLM 供應商都有自己的 SDK 與 API 格式 — OpenAI、Anthropic、Google 都不一樣。切換模型或同時使用多個模型,意謂著要維護不同的程式碼庫。LiteLLM 解決了這個問題:**寫一次,改一個參數,呼叫任何模型**。

### 兩種使用模式

| 模式               | 說明                              | 適合對象        |
| :--------------- | :------------------------------ | :---------- |
| **Python SDK**   | `pip install litellm`,直接在程式碼中呼叫 | 個人專案、快速原型   |
| **Proxy Server** | 獨立部署的 AI 閘道                     | 團隊共用、企業存取控制 |

### 核心能力

* **統一的 OpenAI 格式**:支援 OpenAI、Anthropic、Gemini、Bedrock、Azure 等 100+ 供應商
* **虛擬 key 管理**:集中管理團隊 API key,不需要暴露原始 key
* **成本追蹤**:依使用者或專案監控 token 用量與花費
* **負載平衡**:跨模型自動分配流量,支援容錯切換
* **高效能**:1,000 RPS 下 P95 延遲約 8ms

***

## 安裝

### 系統需求

Python 3.8+

**macOS**

透過 [Homebrew](https://brew.sh/) 安裝:

```bash theme={null}
brew install python
```

驗證:

```bash theme={null}
python3 --version
```

**Windows**

從 [python.org/downloads](https://www.python.org/downloads/) 下載安裝程式。安裝過程中,請勾選 **「Add Python to PATH」**。

驗證:

```bash theme={null}
python --version
```

**Linux(Ubuntu/Debian)**

```bash theme={null}
sudo apt update
sudo apt install python3 python3-pip
```

### pip

pip 通常與 Python 一同附帶。驗證是否可用:

```bash theme={null}
pip --version
# or
pip3 --version
```

如找不到,請手動安裝:

```bash theme={null}
# Universal method
python3 -m ensurepip --upgrade

# Ubuntu/Debian
sudo apt install python3-pip

# Upgrade to latest
pip install --upgrade pip
```

### 安裝 LiteLLM

環境準備好之後:

```bash theme={null}
python3 -m pip install litellm
```

驗證安裝:

```bash theme={null}
python3 -m pip show litellm
```

### 選用相依套件

某些供應商需要額外的套件:

```bash theme={null}
# AWS Bedrock
pip install litellm[bedrock]

# Google Vertex AI
pip install litellm[vertex]

# All dependencies (not recommended for production)
pip install litellm[all]
```

### 安裝 Proxy Server

如要部署獨立閘道:

```bash theme={null}
pip install 'litellm[proxy]'
```

### Docker(選用)

```bash theme={null}
docker pull ghcr.io/berriai/litellm:main-latest
```

> **建議**:個人開發使用 `pip install litellm`;團隊部署選擇 Proxy + Docker。

***

## 設定 API Key 並進行第一次呼叫

### 取得您的 AiHubMix API Key

前往 [aihubmix.com](https://aihubmix.com) 儀表板並建立 API key。

### 設定環境變數

```bash theme={null}
export AIHUBMIX_API_KEY="your-aihubmix-key"
```

### 第一次呼叫

```python theme={null}
import os
from litellm import completion

response = completion(
    model="openai/gpt-4o-mini",
    api_base="https://aihubmix.com/v1",
    api_key=os.environ.get("AIHUBMIX_API_KEY"),
    messages=[{"role": "user", "content": "Hello, introduce yourself"}]
)

print(response.choices[0].message.content)
```

***

## 基本用法

### 1. 切換模型

AiHubMix 支援所有主流模型。切換只需更改 `model` 參數:

```python theme={null}
import os
from litellm import completion

response = completion(
    model="openai/claude-sonnet-4-6",  # change this
    api_base="https://aihubmix.com/v1",
    api_key=os.environ.get("AIHUBMIX_API_KEY"),
    messages=[{"role": "user", "content": "Hello, introduce yourself"}]
)

print(response.choices[0].message.content)
```

***

### 2. 串流輸出

加上 `stream=True` 即可逐 token 接收輸出:

```python theme={null}
import os
from litellm import completion

response = completion(
    model="openai/claude-sonnet-4-6",
    api_base="https://aihubmix.com/v1",
    api_key=os.environ.get("AIHUBMIX_API_KEY"),
    messages=[{"role": "user", "content": "Explain Python in 100 words"}],
    stream=True
)

for chunk in response:
    print(chunk.choices[0].delta.content or "", end="", flush=True)
print()
```

***

### 3. 多輪對話

在 `messages` 清單中傳入對話歷史,讓模型記住上下文:

```python theme={null}
import os
from litellm import completion

messages = [
    {"role": "user", "content": "My name is Alex"},
    {"role": "assistant", "content": "Hello, Alex!"},
    {"role": "user", "content": "What is my name?"}
]

response = completion(
    model="openai/claude-sonnet-4-6",
    api_base="https://aihubmix.com/v1",
    api_key=os.environ.get("AIHUBMIX_API_KEY"),
    messages=messages
)

print(response.choices[0].message.content)
```

***

### 4. 非同步呼叫

同時傳送多個請求而無需逐一等待:

```python theme={null}
import os
import asyncio
from litellm import acompletion

async def ask(question):
    response = await acompletion(
        model="openai/claude-sonnet-4-6",
        api_base="https://aihubmix.com/v1",
        api_key=os.environ.get("AIHUBMIX_API_KEY"),
        messages=[{"role": "user", "content": question}]
    )
    return response.choices[0].message.content

async def main():
    questions = [
        "What color is an apple?",
        "What color is the sky?",
        "What color is grass?"
    ]
    results = await asyncio.gather(*[ask(q) for q in questions])
    for q, r in zip(questions, results):
        print(f"Q: {q}")
        print(f"A: {r}")
        print()

asyncio.run(main())
```

***

### 5. 逾時與重試

避免請求因網路問題而懸停或失敗:

```python theme={null}
import os
from litellm import completion

response = completion(
    model="openai/claude-sonnet-4-6",
    api_base="https://aihubmix.com/v1",
    api_key=os.environ.get("AIHUBMIX_API_KEY"),
    messages=[{"role": "user", "content": "Hello"}],
    timeout=10,      # raise an error after 10 seconds
    num_retries=3    # retry up to 3 times on failure
)

print(response.choices[0].message.content)
```

> `timeout` 以秒為單位。`num_retries` 建議設為 2-3;過高的值會拖慢回應速度。

***

### 6. Token 使用量與成本追蹤

每次回應都包含 token 使用資料:

```python theme={null}
import os
from litellm import completion

response = completion(
    model="openai/claude-sonnet-4-6",
    api_base="https://aihubmix.com/v1",
    api_key=os.environ.get("AIHUBMIX_API_KEY"),
    messages=[{"role": "user", "content": "Explain Python in 100 words"}]
)

print(response.choices[0].message.content)
print()
print("Token usage:")
print(f"  Input:  {response.usage.prompt_tokens}")
print(f"  Output: {response.usage.completion_tokens}")
print(f"  Total:  {response.usage.total_tokens}")
```

追蹤每次呼叫的成本:

```python theme={null}
import os
from litellm import completion, completion_cost

response = completion(
    model="openai/claude-sonnet-4-6",
    api_base="https://aihubmix.com/v1",
    api_key=os.environ.get("AIHUBMIX_API_KEY"),
    messages=[{"role": "user", "content": "Explain Python in 100 words"}]
)

cost = completion_cost(completion_response=response)
print(f"Cost: ${cost:.6f}")
```

***

### 7. 負載平衡與容錯切換

設定多個模型可自動分配流量,並在其中之一失敗時切換到備援:

```python theme={null}
import os
from litellm import Router

router = Router(
    model_list=[
        {
            "model_name": "my-model",
            "litellm_params": {
                "model": "openai/claude-sonnet-4-6",
                "api_base": "https://aihubmix.com/v1",
                "api_key": os.environ.get("AIHUBMIX_API_KEY"),
            }
        },
        {
            "model_name": "my-model",
            "litellm_params": {
                "model": "openai/gpt-4o",
                "api_base": "https://aihubmix.com/v1",
                "api_key": os.environ.get("AIHUBMIX_API_KEY"),
            }
        }
    ]
)

response = router.completion(
    model="my-model",
    messages=[{"role": "user", "content": "Hello"}]
)

print(response.choices[0].message.content)
```

> 兩個模型共用同一個 `model_name`。LiteLLM 會在它們之間輪詢,並在其中之一傳回錯誤時自動容錯切換。

***

### 8. 部署 Proxy Server

Proxy Server 是獨立的閘道。團隊成員透過它路由所有請求,而無需自己的 API key。

**安裝**

```bash theme={null}
python3 -m pip install 'litellm[proxy]'
```

**建立 config.yaml**

```yaml theme={null}
model_list:
  - model_name: gpt-4o
    litellm_params:
      model: openai/gpt-4o
      api_base: https://aihubmix.com/v1
      api_key: os.environ/AIHUBMIX_API_KEY

  - model_name: claude-sonnet
    litellm_params:
      model: openai/claude-sonnet-4-6
      api_base: https://aihubmix.com/v1
      api_key: os.environ/AIHUBMIX_API_KEY

  - model_name: gemini-flash
    litellm_params:
      model: openai/gemini-2.0-flash
      api_base: https://aihubmix.com/v1
      api_key: os.environ/AIHUBMIX_API_KEY
```

**啟動伺服器**

```bash theme={null}
litellm --config config.yaml --port 4000
```

啟動成功會顯示:

```text theme={null}
LiteLLM: Proxy running on http://0.0.0.0:4000
```

**呼叫本機伺服器**

```python theme={null}
import os
from litellm import completion

response = completion(
    model="gpt-4o",
    api_base="http://localhost:4000",
    api_key="any-string",
    messages=[{"role": "user", "content": "Hello"}]
)

print(response.choices[0].message.content)
```

> 此處的 `api_key` 可以是任意字串。真實的 AiHubMix key 由 Proxy 管理。

***

### 9. 虛擬 Key 管理

虛擬 key 讓您可以為不同團隊成員或專案指派獨立的 key,在不暴露真實 AiHubMix key 的情況下控制存取與用量。

**前置需求:啟動 PostgreSQL 執行個體**

```bash theme={null}
docker run -d \
  --name litellm-db \
  -e POSTGRES_USER=litellm \
  -e POSTGRES_PASSWORD=litellm \
  -e POSTGRES_DB=litellm \
  -p 5432:5432 \
  postgres
```

**更新 config.yaml**

```yaml theme={null}
model_list:
  - model_name: gpt-4o
    litellm_params:
      model: openai/gpt-4o
      api_base: https://aihubmix.com/v1
      api_key: os.environ/AIHUBMIX_API_KEY

  - model_name: claude-sonnet
    litellm_params:
      model: openai/claude-sonnet-4-6
      api_base: https://aihubmix.com/v1
      api_key: os.environ/AIHUBMIX_API_KEY

general_settings:
  master_key: sk-my-master-key
  database_url: postgresql://litellm:litellm@localhost:5432/litellm
```

**重新啟動伺服器**

```bash theme={null}
litellm --config config.yaml --port 4000
```

**建立虛擬 key**

```bash theme={null}
curl -X POST http://localhost:4000/key/generate \
  -H "Authorization: Bearer sk-my-master-key" \
  -H "Content-Type: application/json" \
  -d '{
    "key_alias": "team-a",
    "max_budget": 10,
    "models": ["gpt-4o", "claude-sonnet"]
  }'
```

回應中的 `key` 欄位就是虛擬 key,例如 `sk-xxxxxx`。

**使用虛擬 key**

```python theme={null}
from litellm import completion

response = completion(
    model="claude-sonnet",
    api_base="http://localhost:4000",
    api_key="sk-xxxxxx",
    messages=[{"role": "user", "content": "Hello"}]
)

print(response.choices[0].message.content)
```

**檢視使用情況**

```bash theme={null}
curl http://localhost:4000/key/info \
  -H "Authorization: Bearer sk-my-master-key" \
  -H "Content-Type: application/json" \
  -d '{"key": "sk-xxxxxx"}'
```

> 每個虛擬 key 都支援獨立的模型限制、預算上限與到期時間 — 非常適合多成員的團隊工作流程。

***

## 實戰範例:多模型比較

同時將相同問題傳送至多個模型,並比較輸出品質、速度與 token 用量。

**設定 API Key**

```bash theme={null}
export AIHUBMIX_API_KEY="your-key"
```

**執行比較**

```python theme={null}
import os
import time
import asyncio
from litellm import acompletion

MODELS = [
    "gpt-5.5",
    "claude-opus-4-7",
    "deepseek-v4-flash",
    "coding-glm-5.1-free",
]

QUESTION = "If you could give a programmer only one piece of advice, what would it be?"

async def ask_model(model, question):
    start = time.time()
    try:
        response = await acompletion(
            model=f"openai/{model}",
            api_base="https://aihubmix.com/v1",
            api_key=os.environ.get("AIHUBMIX_API_KEY"),
            messages=[{"role": "user", "content": question}]
        )
        return {
            "model": model,
            "answer": response.choices[0].message.content.strip(),
            "tokens": response.usage.total_tokens,
            "time": round(time.time() - start, 2),
            "error": None
        }
    except Exception as e:
        return {
            "model": model,
            "answer": None,
            "tokens": 0,
            "time": round(time.time() - start, 2),
            "error": str(e)
        }

async def main():
    print(f"Question: {QUESTION}")
    print("=" * 60)
    tasks = [ask_model(m, QUESTION) for m in MODELS]
    results = await asyncio.gather(*tasks)
    for r in results:
        print(f"\nModel: {r['model']}")
        print(f"Time: {r['time']}s  |  Tokens: {r['tokens']}")
        print("-" * 40)
        if r["error"]:
            print(f"Error: {r['error']}")
        else:
            print(r["answer"])
    print("\n" + "=" * 60)
    print(f"{'Model':<30} {'Time':>8} {'Tokens':>8}")
    print("-" * 50)
    for r in sorted(results, key=lambda x: x["time"]):
        status = f"{r['time']}s" if not r["error"] else "failed"
        print(f"{r['model']:<30} {status:>8} {r['tokens']:>8}")

asyncio.run(main())
```

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最後更新:2026 年 4 月 29 日
