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Gemini 3.1 Flash Lite

Text Generation • Google • Proxied

Google's lightest and most cost-efficient Gemini model for high-throughput tasks.

Model Info
Context Window ↗1,000,000 tokens
Terms and Licenselink ↗
More informationlink ↗
PricingView pricing in the Cloudflare dashboard ↗

Usage

TypeScript
const response = await env.AI.run(
  'google/gemini-3.1-flash-lite',
  {
    contents: [
      {
        role: 'user',
        parts: [
          {
            text: 'What are the three laws of thermodynamics?',
          },
        ],
      },
    ],
  },
  {
    gateway: { id: 'default' },
  }
)
console.log(response)
The three laws of thermodynamics (plus the "zeroth" law, which was defined later but is foundational) describe how energy moves and transforms within physical systems.

Here is a breakdown of the laws:

### 0. The Zeroth Law (The Law of Equilibrium)
**"If two systems are each in thermal equilibrium with a third system, they are in thermal equilibrium with each other."**
*   **What it means:** This law essentially defines the concept of **temperature**. It allows us to use thermometers; if a thermometer reads the same temperature when placed in two different containers of water, we know the water in both containers is at the same temperature, even if they aren't touching.

### 1. The First Law (The Law of Conservation of Energy)
**"Energy cannot be created or destroyed, only transformed from one form to another."**
*   **What it means:** The total energy of an isolated system remains constant. You can change energy from heat to work (or vice versa), but you cannot get "something for nothing." If you put a certain amount of energy into a system, you will get that same amount back out in some form (like heat or motion), unless some is lost to the environment.

### 2. The Second Law (The Law of Entropy)
**"The entropy of an isolated system will always increase over time; it can never decrease."**
*   **What it means:** This law introduces the concept of **entropy**, which is often described as a measure of disorder or randomness. It states that energy naturally spreads out and becomes less useful over time. Heat will always flow spontaneously from a hot object to a cold object, never the other way around. This is why perpetual motion machines are impossible and why time feels like it has a "direction" (the arrow of time).

### 3. The Third Law (The Law of Absolute Zero)
**"As the temperature of a system approaches absolute zero (0 Kelvin), the entropy of a perfect crystal approaches zero."**
*   **What it means:** It is impossible to reach absolute zero through any finite number of physical processes. As a system gets colder, its particles lose energy and move less, eventually reaching a state of minimum possible motion and perfect order (a perfect crystal structure). Because you can never extract all the energy from a system, you can never reach absolute zero.

***

### Summary
*   **0th Law:** You have to play by the rules of temperature (equilibrium).
*   **1st Law:** You can't win (you can't create energy).
*   **2nd Law:** You can't even break even (you always lose some energy to entropy).
*   **3rd Law:** You can't get out of the game (you can't reach absolute zero).

Examples

With System Instruction — Using a system instruction to set context
TypeScript
const response = await env.AI.run(
  'google/gemini-3.1-flash-lite',
  {
    contents: [
      {
        role: 'user',
        parts: [
          {
            text: 'How do I read a JSON file in Python?',
          },
        ],
      },
    ],
    systemInstruction: {
      parts: [
        {
          text: 'You are a helpful coding assistant specializing in Python.',
        },
      ],
    },
    generationConfig: {
      temperature: 0.3,
    },
  },
  {
    gateway: { id: 'default' },
  }
)
console.log(response)
To read a JSON file in Python, you use the built-in `json` module.

Here is the standard way to do it:

### 1. The Basic Approach
Use the `open()` function to open the file and `json.load()` to parse it into a Python dictionary or list.

```python
import json

# Open the file
with open('data.json', 'r') as file:
    data = json.load(file)

# Now 'data' is a Python dictionary or list
print(data)
```

### Key details:
*   **`with open(...)`**: This is a "context manager." It is best practice because it ensures the file is automatically closed after you are done reading it, even if an error occurs.
*   **`json.load()`**: This function takes the file object and converts the JSON data into the corresponding Python object (e.g., `{}` becomes a `dict`, `[]` becomes a `list`, `true` becomes `True`).

---

### 2. Handling Errors (Best Practice)
If the file might not exist or the JSON might be malformed, it is good practice to add error handling:

```python
import json

try:
    with open('data.json', 'r') as file:
        data = json.load(file)
except FileNotFoundError:
    print("The file was not found.")
except json.JSONDecodeError:
    print("The file contains invalid JSON.")
```

---

### 3. What if you have a JSON string instead of a file?
If you already have the JSON data stored in a variable (as a string) rather than in a file, use `json.loads()` (the "s" stands for "string"):

```python
import json

json_string = '{"name": "Alice", "age": 30}'
data = json.loads(json_string)

print(data["name"])  # Output: Alice
```

### Summary:
*   Use **`json.load(file_object)`** to read from a **file**.
*   Use **`json.loads(string)`** to read from a **string**.
Multi-turn Conversation — Continuing a conversation with context
TypeScript
const response = await env.AI.run(
  'google/gemini-3.1-flash-lite',
  {
    contents: [
      {
        role: 'user',
        parts: [
          {
            text: 'I need help planning a road trip from San Francisco to Los Angeles.',
          },
        ],
      },
      {
        role: 'model',
        parts: [
          {
            text: "I'd be happy to help! The drive is about 380 miles and takes roughly 5-6 hours. Would you like suggestions for scenic routes or interesting stops along the way?",
          },
        ],
      },
      {
        role: 'user',
        parts: [
          {
            text: 'Yes, what are some good places to stop?',
          },
        ],
      },
    ],
    generationConfig: {
      maxOutputTokens: 500,
    },
  },
  {
    gateway: { id: 'default' },
  }
)
console.log(response)
{
  "candidates": [
    {
      "content": {
        "role": "model"
      },
      "finishReason": "MAX_TOKENS"
    }
  ],
  "usageMetadata": {
    "promptTokenCount": 64,
    "candidatesTokenCount": 496,
    "totalTokenCount": 560,
    "trafficType": "ON_DEMAND",
    "promptTokensDetails": [
      {
        "modality": "TEXT",
        "tokenCount": 64
      }
    ],
    "candidatesTokensDetails": [
      {
        "modality": "TEXT",
        "tokenCount": 496
      }
    ]
  },
  "modelVersion": "gemini-3.1-flash-lite-preview",
  "createTime": "2026-04-17T05:56:34.641767Z",
  "responseId": "ksvhaeeVJ6CIq8YPzKOY8Qk",
  "gatewayMetadata": {
    "keySource": "Unified"
  }
}
Creative Writing — Higher temperature for creative output
TypeScript
const response = await env.AI.run(
  'google/gemini-3.1-flash-lite',
  {
    contents: [
      {
        role: 'user',
        parts: [
          {
            text: 'Write a short story opening about a detective finding an unusual clue.',
          },
        ],
      },
    ],
    generationConfig: {
      temperature: 0.8,
      maxOutputTokens: 300,
    },
  },
  {
    gateway: { id: 'default' },
  }
)
console.log(response)
The rain drummed a frantic rhythm against the windowpane of the derelict apartment, but Detective Elias Thorne didn’t hear it. He was staring at the center of the dust-choked rug, where the victim had supposedly spent his final moments.

There was no blood. There were no shell casings. There was only a single, perfectly preserved sprig of lavender resting on the floorboards.

Thorne knelt, his knees popping in the silence, and pulled a pair of latex gloves from his pocket. As he leaned in, the scent hit him—not the stale, metallic smell of death he had expected, but a sharp, clinical floral aroma that felt entirely out of place in a room smelling of rot and damp wallpaper. 

He reached out with his tweezers to bag the evidence, but stopped cold. The lavender wasn't just lying on the wood; it was pulsing. A faint, rhythmic bioluminescence ebbed from the petals, casting a soft, rhythmic violet glow against the floorboards. It was breathing in sync with his own heartbeat.

Thorne pulled his hand back, his pulse quickening. He had been a homicide detective for twenty years, and he knew that dead men didn't leave behind flowers that remembered how to live.

Parameters

toolConfig

API Schemas (Raw)

Input
Output