---
title: llama-3.1-8b-instruct-fast · Cloudflare Workers AI docs
description: "[Fast version] The Meta Llama 3.1 collection of multilingual large
  language models (LLMs) is a collection of pretrained and instruction tuned
  generative models. The Llama 3.1 instruction tuned text only models are
  optimized for multilingual dialogue use cases and outperform many of the
  available open source and closed chat models on common industry benchmarks."
chatbotDeprioritize: false
source_url:
  html: https://developers.cloudflare.com/workers-ai/models/llama-3.1-8b-instruct-fast/
  md: https://developers.cloudflare.com/workers-ai/models/llama-3.1-8b-instruct-fast/index.md
---

![Meta logo](https://developers.cloudflare.com/_astro/meta.x5nlFKBG.svg)

# llama-3.1-8b-instruct-fast

Text Generation • Meta

@cf/meta/llama-3.1-8b-instruct-fast

\[Fast version] The Meta Llama 3.1 collection of multilingual large language models (LLMs) is a collection of pretrained and instruction tuned generative models. The Llama 3.1 instruction tuned text only models are optimized for multilingual dialogue use cases and outperform many of the available open source and closed chat models on common industry benchmarks.

| Model Info | |
| - | - |
| Context Window[](https://developers.cloudflare.com/workers-ai/glossary/) | 128,000 tokens |
| Terms and License | [link](https://github.com/meta-llama/llama-models/blob/main/models/llama3_1/LICENSE) |

## Playground

Try out this model with Workers AI LLM Playground. It does not require any setup or authentication and an instant way to preview and test a model directly in the browser.

[Launch the LLM Playground](https://playground.ai.cloudflare.com/?model=@cf/meta/llama-3.1-8b-instruct-fast)

## Usage

Worker - Streaming

```ts
export interface Env {
  AI: Ai;
}


export default {
  async fetch(request, env): Promise<Response> {


    const messages = [
      { role: "system", content: "You are a friendly assistant" },
      {
        role: "user",
        content: "What is the origin of the phrase Hello, World",
      },
    ];


    const stream = await env.AI.run("@cf/meta/llama-3.1-8b-instruct-fast", {
      messages,
      stream: true,
    });


    return new Response(stream, {
      headers: { "content-type": "text/event-stream" },
    });
  },
} satisfies ExportedHandler<Env>;
```

Worker

```ts
export interface Env {
  AI: Ai;
}


export default {
  async fetch(request, env): Promise<Response> {


    const messages = [
      { role: "system", content: "You are a friendly assistant" },
      {
        role: "user",
        content: "What is the origin of the phrase Hello, World",
      },
    ];
    const response = await env.AI.run("@cf/meta/llama-3.1-8b-instruct-fast", { messages });


    return Response.json(response);
  },
} satisfies ExportedHandler<Env>;
```

Python

```py
import os
import requests


ACCOUNT_ID = "your-account-id"
AUTH_TOKEN = os.environ.get("CLOUDFLARE_AUTH_TOKEN")


prompt = "Tell me all about PEP-8"
response = requests.post(
  f"https://api.cloudflare.com/client/v4/accounts/{ACCOUNT_ID}/ai/run/@cf/meta/llama-3.1-8b-instruct-fast",
    headers={"Authorization": f"Bearer {AUTH_TOKEN}"},
    json={
      "messages": [
        {"role": "system", "content": "You are a friendly assistant"},
        {"role": "user", "content": prompt}
      ]
    }
)
result = response.json()
print(result)
```

curl

```sh
curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/run/@cf/meta/llama-3.1-8b-instruct-fast \
  -X POST \
  -H "Authorization: Bearer $CLOUDFLARE_AUTH_TOKEN" \
  -d '{ "messages": [{ "role": "system", "content": "You are a friendly assistant" }, { "role": "user", "content": "Why is pizza so good" }]}'
```

OpenAI compatible endpoints

Workers AI also supports OpenAI compatible API endpoints for `/v1/chat/completions` and `/v1/embeddings`. For more details, refer to [Configurations ](https://developers.cloudflare.com/workers-ai/configuration/open-ai-compatibility/).

## Parameters

\* indicates a required field

### Input

* `0` object

  * `frequency_penalty` number min 0 max 2

    Decreases the likelihood of the model repeating the same lines verbatim.

  * `image` one of

    * `0` array

      An array of integers that represent the image data constrained to 8-bit unsigned integer values

      * `items` number

        A value between 0 and 255

    * `1` string

      Binary string representing the image contents.

  * `lora` string

    Name of the LoRA (Low-Rank Adaptation) model to fine-tune the base model.

  * `max_tokens` integer default 256

    The maximum number of tokens to generate in the response.

  * `presence_penalty` number min 0 max 2

    Increases the likelihood of the model introducing new topics.

  * `prompt` string required min 1 max 131072

    The input text prompt for the model to generate a response.

  * `raw` boolean

    If true, a chat template is not applied and you must adhere to the specific model's expected formatting.

  * `repetition_penalty` number min 0 max 2

    Penalty for repeated tokens; higher values discourage repetition.

  * `seed` integer min 1 max 9999999999

    Random seed for reproducibility of the generation.

  * `stream` boolean

    If true, the response will be streamed back incrementally using SSE, Server Sent Events.

  * `temperature` number default 0.6 min 0 max 5

    Controls the randomness of the output; higher values produce more random results.

  * `top_k` integer min 1 max 50

    Limits the AI to choose from the top 'k' most probable words. Lower values make responses more focused; higher values introduce more variety and potential surprises.

  * `top_p` number min 0 max 2

    Adjusts the creativity of the AI's responses by controlling how many possible words it considers. Lower values make outputs more predictable; higher values allow for more varied and creative responses.

* `1` object

  * `frequency_penalty` number min 0 max 2

    Decreases the likelihood of the model repeating the same lines verbatim.

  * `functions` array

    * `items` object

      * `code` string required

      * `name` string required

  * `image` one of

    * `0` array

      An array of integers that represent the image data constrained to 8-bit unsigned integer values

      * `items` number

        A value between 0 and 255

    * `1` string

      Binary string representing the image contents.

  * `max_tokens` integer default 256

    The maximum number of tokens to generate in the response.

  * `messages` array required

    An array of message objects representing the conversation history.

    * `items` object

      * `content` string required max 131072

        The content of the message as a string.

      * `role` string required

        The role of the message sender (e.g., 'user', 'assistant', 'system', 'tool').

  * `presence_penalty` number min 0 max 2

    Increases the likelihood of the model introducing new topics.

  * `repetition_penalty` number min 0 max 2

    Penalty for repeated tokens; higher values discourage repetition.

  * `seed` integer min 1 max 9999999999

    Random seed for reproducibility of the generation.

  * `stream` boolean

    If true, the response will be streamed back incrementally.

  * `temperature` number default 0.6 min 0 max 5

    Controls the randomness of the output; higher values produce more random results.

  * `tools` array

    A list of tools available for the assistant to use.

    * `items` one of

      * `0` object

        * `description` string required

          A brief description of what the tool does.

        * `name` string required

          The name of the tool. More descriptive the better.

        * `parameters` object required

          Schema defining the parameters accepted by the tool.

          * `properties` object required

            Definitions of each parameter.

            * `additionalProperties` object

              * `description` string required

                A description of the expected parameter.

              * `type` string required

                The data type of the parameter.

          * `required` array

            List of required parameter names.

            * `items` string

          * `type` string required

            The type of the parameters object (usually 'object').

      * `1` object

        * `function` object required

          Details of the function tool.

          * `description` string required

            A brief description of what the function does.

          * `name` string required

            The name of the function.

          * `parameters` object required

            Schema defining the parameters accepted by the function.

            * `properties` object required

              Definitions of each parameter.

              * `additionalProperties` object

                * `description` string required

                  A description of the expected parameter.

                * `type` string required

                  The data type of the parameter.

            * `required` array

              List of required parameter names.

              * `items` string

            * `type` string required

              The type of the parameters object (usually 'object').

        * `type` string required

          Specifies the type of tool (e.g., 'function').

  * `top_k` integer min 1 max 50

    Limits the AI to choose from the top 'k' most probable words. Lower values make responses more focused; higher values introduce more variety and potential surprises.

  * `top_p` number min 0 max 2

    Controls the creativity of the AI's responses by adjusting how many possible words it considers. Lower values make outputs more predictable; higher values allow for more varied and creative responses.

### Output

* `0` object

  * `response` string

    The generated text response from the model

  * `tool_calls` array

    An array of tool calls requests made during the response generation

    * `items` object

      * `arguments` object

        The arguments passed to be passed to the tool call request

      * `name` string

        The name of the tool to be called

* `1` string

## API Schemas

The following schemas are based on JSON Schema

* Input

  ```json
  {
      "oneOf": [
          {
              "properties": {
                  "frequency_penalty": {
                      "description": "Decreases the likelihood of the model repeating the same lines verbatim.",
                      "maximum": 2,
                      "minimum": 0,
                      "type": "number"
                  },
                  "image": {
                      "oneOf": [
                          {
                              "description": "An array of integers that represent the image data constrained to 8-bit unsigned integer values",
                              "items": {
                                  "description": "A value between 0 and 255",
                                  "type": "number"
                              },
                              "type": "array"
                          },
                          {
                              "description": "Binary string representing the image contents.",
                              "format": "binary",
                              "type": "string"
                          }
                      ]
                  },
                  "lora": {
                      "description": "Name of the LoRA (Low-Rank Adaptation) model to fine-tune the base model.",
                      "type": "string"
                  },
                  "max_tokens": {
                      "default": 256,
                      "description": "The maximum number of tokens to generate in the response.",
                      "type": "integer"
                  },
                  "presence_penalty": {
                      "description": "Increases the likelihood of the model introducing new topics.",
                      "maximum": 2,
                      "minimum": 0,
                      "type": "number"
                  },
                  "prompt": {
                      "description": "The input text prompt for the model to generate a response.",
                      "maxLength": 131072,
                      "minLength": 1,
                      "type": "string"
                  },
                  "raw": {
                      "default": false,
                      "description": "If true, a chat template is not applied and you must adhere to the specific model's expected formatting.",
                      "type": "boolean"
                  },
                  "repetition_penalty": {
                      "description": "Penalty for repeated tokens; higher values discourage repetition.",
                      "maximum": 2,
                      "minimum": 0,
                      "type": "number"
                  },
                  "seed": {
                      "description": "Random seed for reproducibility of the generation.",
                      "maximum": 9999999999,
                      "minimum": 1,
                      "type": "integer"
                  },
                  "stream": {
                      "default": false,
                      "description": "If true, the response will be streamed back incrementally using SSE, Server Sent Events.",
                      "type": "boolean"
                  },
                  "temperature": {
                      "default": 0.6,
                      "description": "Controls the randomness of the output; higher values produce more random results.",
                      "maximum": 5,
                      "minimum": 0,
                      "type": "number"
                  },
                  "top_k": {
                      "description": "Limits the AI to choose from the top 'k' most probable words. Lower values make responses more focused; higher values introduce more variety and potential surprises.",
                      "maximum": 50,
                      "minimum": 1,
                      "type": "integer"
                  },
                  "top_p": {
                      "description": "Adjusts the creativity of the AI's responses by controlling how many possible words it considers. Lower values make outputs more predictable; higher values allow for more varied and creative responses.",
                      "maximum": 2,
                      "minimum": 0,
                      "type": "number"
                  }
              },
              "required": [
                  "prompt"
              ],
              "title": "Prompt"
          },
          {
              "properties": {
                  "frequency_penalty": {
                      "description": "Decreases the likelihood of the model repeating the same lines verbatim.",
                      "maximum": 2,
                      "minimum": 0,
                      "type": "number"
                  },
                  "functions": {
                      "items": {
                          "properties": {
                              "code": {
                                  "type": "string"
                              },
                              "name": {
                                  "type": "string"
                              }
                          },
                          "required": [
                              "name",
                              "code"
                          ],
                          "type": "object"
                      },
                      "type": "array"
                  },
                  "image": {
                      "oneOf": [
                          {
                              "description": "An array of integers that represent the image data constrained to 8-bit unsigned integer values",
                              "items": {
                                  "description": "A value between 0 and 255",
                                  "type": "number"
                              },
                              "type": "array"
                          },
                          {
                              "description": "Binary string representing the image contents.",
                              "format": "binary",
                              "type": "string"
                          }
                      ]
                  },
                  "max_tokens": {
                      "default": 256,
                      "description": "The maximum number of tokens to generate in the response.",
                      "type": "integer"
                  },
                  "messages": {
                      "description": "An array of message objects representing the conversation history.",
                      "items": {
                          "properties": {
                              "content": {
                                  "description": "The content of the message as a string.",
                                  "maxLength": 131072,
                                  "type": "string"
                              },
                              "role": {
                                  "description": "The role of the message sender (e.g., 'user', 'assistant', 'system', 'tool').",
                                  "type": "string"
                              }
                          },
                          "required": [
                              "role",
                              "content"
                          ],
                          "type": "object"
                      },
                      "type": "array"
                  },
                  "presence_penalty": {
                      "description": "Increases the likelihood of the model introducing new topics.",
                      "maximum": 2,
                      "minimum": 0,
                      "type": "number"
                  },
                  "repetition_penalty": {
                      "description": "Penalty for repeated tokens; higher values discourage repetition.",
                      "maximum": 2,
                      "minimum": 0,
                      "type": "number"
                  },
                  "seed": {
                      "description": "Random seed for reproducibility of the generation.",
                      "maximum": 9999999999,
                      "minimum": 1,
                      "type": "integer"
                  },
                  "stream": {
                      "default": false,
                      "description": "If true, the response will be streamed back incrementally.",
                      "type": "boolean"
                  },
                  "temperature": {
                      "default": 0.6,
                      "description": "Controls the randomness of the output; higher values produce more random results.",
                      "maximum": 5,
                      "minimum": 0,
                      "type": "number"
                  },
                  "tools": {
                      "description": "A list of tools available for the assistant to use.",
                      "items": {
                          "oneOf": [
                              {
                                  "properties": {
                                      "description": {
                                          "description": "A brief description of what the tool does.",
                                          "type": "string"
                                      },
                                      "name": {
                                          "description": "The name of the tool. More descriptive the better.",
                                          "type": "string"
                                      },
                                      "parameters": {
                                          "description": "Schema defining the parameters accepted by the tool.",
                                          "properties": {
                                              "properties": {
                                                  "additionalProperties": {
                                                      "properties": {
                                                          "description": {
                                                              "description": "A description of the expected parameter.",
                                                              "type": "string"
                                                          },
                                                          "type": {
                                                              "description": "The data type of the parameter.",
                                                              "type": "string"
                                                          }
                                                      },
                                                      "required": [
                                                          "type",
                                                          "description"
                                                      ],
                                                      "type": "object"
                                                  },
                                                  "description": "Definitions of each parameter.",
                                                  "type": "object"
                                              },
                                              "required": {
                                                  "description": "List of required parameter names.",
                                                  "items": {
                                                      "type": "string"
                                                  },
                                                  "type": "array"
                                              },
                                              "type": {
                                                  "description": "The type of the parameters object (usually 'object').",
                                                  "type": "string"
                                              }
                                          },
                                          "required": [
                                              "type",
                                              "properties"
                                          ],
                                          "type": "object"
                                      }
                                  },
                                  "required": [
                                      "name",
                                      "description",
                                      "parameters"
                                  ]
                              },
                              {
                                  "properties": {
                                      "function": {
                                          "description": "Details of the function tool.",
                                          "properties": {
                                              "description": {
                                                  "description": "A brief description of what the function does.",
                                                  "type": "string"
                                              },
                                              "name": {
                                                  "description": "The name of the function.",
                                                  "type": "string"
                                              },
                                              "parameters": {
                                                  "description": "Schema defining the parameters accepted by the function.",
                                                  "properties": {
                                                      "properties": {
                                                          "additionalProperties": {
                                                              "properties": {
                                                                  "description": {
                                                                      "description": "A description of the expected parameter.",
                                                                      "type": "string"
                                                                  },
                                                                  "type": {
                                                                      "description": "The data type of the parameter.",
                                                                      "type": "string"
                                                                  }
                                                              },
                                                              "required": [
                                                                  "type",
                                                                  "description"
                                                              ],
                                                              "type": "object"
                                                          },
                                                          "description": "Definitions of each parameter.",
                                                          "type": "object"
                                                      },
                                                      "required": {
                                                          "description": "List of required parameter names.",
                                                          "items": {
                                                              "type": "string"
                                                          },
                                                          "type": "array"
                                                      },
                                                      "type": {
                                                          "description": "The type of the parameters object (usually 'object').",
                                                          "type": "string"
                                                      }
                                                  },
                                                  "required": [
                                                      "type",
                                                      "properties"
                                                  ],
                                                  "type": "object"
                                              }
                                          },
                                          "required": [
                                              "name",
                                              "description",
                                              "parameters"
                                          ],
                                          "type": "object"
                                      },
                                      "type": {
                                          "description": "Specifies the type of tool (e.g., 'function').",
                                          "type": "string"
                                      }
                                  },
                                  "required": [
                                      "type",
                                      "function"
                                  ]
                              }
                          ],
                          "type": "object"
                      },
                      "type": "array"
                  },
                  "top_k": {
                      "description": "Limits the AI to choose from the top 'k' most probable words. Lower values make responses more focused; higher values introduce more variety and potential surprises.",
                      "maximum": 50,
                      "minimum": 1,
                      "type": "integer"
                  },
                  "top_p": {
                      "description": "Controls the creativity of the AI's responses by adjusting how many possible words it considers. Lower values make outputs more predictable; higher values allow for more varied and creative responses.",
                      "maximum": 2,
                      "minimum": 0,
                      "type": "number"
                  }
              },
              "required": [
                  "messages"
              ],
              "title": "Messages"
          }
      ],
      "type": "object"
  }
  ```

* Output

  ```json
  {
      "oneOf": [
          {
              "contentType": "application/json",
              "properties": {
                  "response": {
                      "description": "The generated text response from the model",
                      "type": "string"
                  },
                  "tool_calls": {
                      "description": "An array of tool calls requests made during the response generation",
                      "items": {
                          "properties": {
                              "arguments": {
                                  "description": "The arguments passed to be passed to the tool call request",
                                  "type": "object"
                              },
                              "name": {
                                  "description": "The name of the tool to be called",
                                  "type": "string"
                              }
                          },
                          "type": "object"
                      },
                      "type": "array"
                  }
              },
              "type": "object"
          },
          {
              "contentType": "text/event-stream",
              "format": "binary",
              "type": "string"
          }
      ]
  }
  ```
