ChatModel - arkbot

A Volcengine Ark Bot implementation for Eino that implements the ToolCallingChatModel interface. This enables seamless integration with Eino’s LLM capabilities for enhanced natural language processing and generation.

Features

  • Implements github.com/cloudwego/eino/components/model.ToolCallingChatModel
  • Easy integration with Eino’s model system
  • Configurable model parameters
  • Support for chat completion
  • Support for streaming responses
  • Custom response parsing support
  • Flexible model configuration

Installation

go get github.com/cloudwego/eino-ext/components/model/arkbot@latest

Quick Start

Here’s a quick example of how to use the Ark Bot:


package main

import (
	"context"
	"encoding/json"
	"log"
	"os"

	"github.com/cloudwego/eino/schema"

	"github.com/cloudwego/eino-ext/components/model/arkbot"
)

func main() {
	ctx := context.Background()

	// Get ARK_API_KEY and ARK_MODEL_ID: https://www.volcengine.com/docs/82379/1399008
	chatModel, err := arkbot.NewChatModel(ctx, &arkbot.Config{
		APIKey: os.Getenv("ARK_API_KEY"),
		Model:  os.Getenv("ARK_MODEL_ID"),
	})

	if err != nil {
		log.Fatalf("NewChatModel failed, err=%v", err)
	}

	inMsgs := []*schema.Message{
		{
			Role:    schema.User,
			Content: "What's the weather in Beijing?",
		},
	}

	msg, err := chatModel.Generate(ctx, inMsgs)
	if err != nil {
		log.Fatalf("Generate failed, err=%v", err)
	}

	log.Printf("generate output: \n")
	log.Printf("  request_id: %s\n", arkbot.GetArkRequestID(msg))
	if bu, ok := arkbot.GetBotUsage(msg); ok {
		bbu, _ := json.Marshal(bu)
		log.Printf("  bot_usage: %s\n", string(bbu))
	}
	if ref, ok := arkbot.GetBotChatResultReference(msg); ok {
		bRef, _ := json.Marshal(ref)
		log.Printf("  bot_chat_result_reference: %s\n", bRef)
	}
	respBody, _ := json.MarshalIndent(msg, "  ", "  ")
	log.Printf("  body: %s\n", string(respBody))
}

Configuration

The model can be configured using the arkbot.Config struct:

    
    type Config struct {
    // Timeout specifies the maximum duration to wait for API responses
    // If HTTPClient is set, Timeout will not be used.
    // Optional. Default: 10 minutes
    Timeout *time.Duration `json:"timeout"`
    
    // HTTPClient specifies the client to send HTTP requests.
    // If HTTPClient is set, Timeout will not be used.
    // Optional. Default &http.Client{Timeout: Timeout}
    HTTPClient *http.Client `json:"http_client"`
    
    // RetryTimes specifies the number of retry attempts for failed API calls
    // Optional. Default: 2
    RetryTimes *int `json:"retry_times"`
    
    // BaseURL specifies the base URL for Ark service
    // Optional. Default: "https://ark.cn-beijing.volces.com/api/v3"
    BaseURL string `json:"base_url"`
    // Region specifies the region where Ark service is located
    // Optional. Default: "cn-beijing"
    Region string `json:"region"`
    
    // The following three fields are about authentication - either APIKey or AccessKey/SecretKey pair is required
    // For authentication details, see: https://www.volcengine.com/docs/82379/1298459
    // APIKey takes precedence if both are provided
    APIKey    string `json:"api_key"`
    AccessKey string `json:"access_key"`
    SecretKey string `json:"secret_key"`
    
    // The following fields correspond to Ark's chat completion API parameters
    // Ref: https://www.volcengine.com/docs/82379/1298454
    
    // Model specifies the ID of endpoint on ark platform
    // Required
    Model string `json:"model"`
    
    // MaxTokens limits the maximum number of tokens that can be generated in the chat completion.
    // Optional. Default: 4096
    MaxTokens *int `json:"max_tokens,omitempty"`
    
    // Temperature specifies what sampling temperature to use
    // Generally recommend altering this or TopP but not both
    // Range: 0.0 to 1.0. Higher values make output more random
    // Optional. Default: 1.0
    Temperature *float32 `json:"temperature,omitempty"`
    
    // TopP controls diversity via nucleus sampling
    // Generally recommend altering this or Temperature but not both
    // Range: 0.0 to 1.0. Lower values make output more focused
    // Optional. Default: 0.7
    TopP *float32 `json:"top_p,omitempty"`
    
    // Stop sequences where the API will stop generating further tokens
    // Optional. Example: []string{"\n", "User:"}
    Stop []string `json:"stop,omitempty"`
    
    // FrequencyPenalty prevents repetition by penalizing tokens based on frequency
    // Range: -2.0 to 2.0. Positive values decrease likelihood of repetition
    // Optional. Default: 0
    FrequencyPenalty *float32 `json:"frequency_penalty,omitempty"`
    
    // LogitBias modifies likelihood of specific tokens appearing in completion
    // Optional. Map token IDs to bias values from -100 to 100
    LogitBias map[string]int `json:"logit_bias,omitempty"`
    
    // PresencePenalty prevents repetition by penalizing tokens based on presence
    // Range: -2.0 to 2.0. Positive values increase likelihood of new topics
    // Optional. Default: 0
    PresencePenalty *float32 `json:"presence_penalty,omitempty"`
    
    // CustomHeader the http header passed to model when requesting model
    CustomHeader map[string]string `json:"custom_header"`
    
    // LogProbs specifies whether to return log probabilities of the output tokens.
    LogProbs bool `json:"log_probs"`
    
    // TopLogProbs specifies the number of most likely tokens to return at each token position, each with an associated log probability.
    TopLogProbs int `json:"top_log_probs"`
    
    // ResponseFormat specifies the format that the model must output.
    ResponseFormat *ResponseFormat `json:"response_format,omitempty"`
    }

Request Options

The Ark model supports various request options to customize the behavior of API calls. Here are the available options:

// WithCustomHeader sets custom headers for a single request
// the headers will override all the headers given in ChatModelConfig.CustomHeader
func WithCustomHeader(m map[string]string) model.Option {}

examples

generate


package main

import (
	"context"
	"encoding/json"
	"log"
	"os"

	"github.com/cloudwego/eino/schema"

	"github.com/cloudwego/eino-ext/components/model/arkbot"
)

func main() {
	ctx := context.Background()

	// Get ARK_API_KEY and ARK_MODEL_ID: https://www.volcengine.com/docs/82379/1399008
	chatModel, err := arkbot.NewChatModel(ctx, &arkbot.Config{
		APIKey: os.Getenv("ARK_API_KEY"),
		Model:  os.Getenv("ARK_MODEL_ID"),
	})

	if err != nil {
		log.Fatalf("NewChatModel failed, err=%v", err)
	}

	inMsgs := []*schema.Message{
		{
			Role:    schema.User,
			Content: "What's the weather in Beijing?",
		},
	}

	msg, err := chatModel.Generate(ctx, inMsgs)
	if err != nil {
		log.Fatalf("Generate failed, err=%v", err)
	}

	log.Printf("generate output: \n")
	log.Printf("  request_id: %s\n", arkbot.GetArkRequestID(msg))
	if bu, ok := arkbot.GetBotUsage(msg); ok {
		bbu, _ := json.Marshal(bu)
		log.Printf("  bot_usage: %s\n", string(bbu))
	}
	if ref, ok := arkbot.GetBotChatResultReference(msg); ok {
		bRef, _ := json.Marshal(ref)
		log.Printf("  bot_chat_result_reference: %s\n", bRef)
	}
	respBody, _ := json.MarshalIndent(msg, "  ", "  ")
	log.Printf("  body: %s\n", string(respBody))
}

stream


package main

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"os"

	"github.com/cloudwego/eino/schema"

	"github.com/cloudwego/eino-ext/components/model/arkbot"
)

func main() {
	ctx := context.Background()

	// Get ARK_API_KEY and ARK_MODEL_ID: https://www.volcengine.com/docs/82379/1399008
	chatModel, err := arkbot.NewChatModel(ctx, &arkbot.Config{
		APIKey: os.Getenv("ARK_API_KEY"),
		Model:  os.Getenv("ARK_MODEL_ID"),
	})
	if err != nil {
		log.Printf("NewChatModel failed, err=%v", err)
		return
	}

	streamMsgs, err := chatModel.Stream(ctx, []*schema.Message{
		{
			Role:    schema.User,
			Content: "What's the weather in Beijing?",
		},
	})

	if err != nil {
		log.Printf("Generate failed, err=%v", err)
		return
	}

	defer streamMsgs.Close() // do not forget to close the stream

	msgs := make([]*schema.Message, 0)

	log.Printf("stream output:")
	for {
		msg, err := streamMsgs.Recv()
		if err == io.EOF {
			break
		}
		msgs = append(msgs, msg)
		if err != nil {
			log.Printf("\nstream.Recv failed, err=%v", err)
			return
		}
		fmt.Print(msg.Content)
	}

	msg, err := schema.ConcatMessages(msgs)
	if err != nil {
		log.Printf("ConcatMessages failed, err=%v", err)
		return
	}

	log.Printf("generate output: \n")
	log.Printf("  request_id: %s\n", arkbot.GetArkRequestID(msg))
	if bu, ok := arkbot.GetBotUsage(msg); ok {
		bbu, _ := json.Marshal(bu)
		log.Printf("  bot_usage: %s\n", string(bbu))
	}
	if ref, ok := arkbot.GetBotChatResultReference(msg); ok {
		bRef, _ := json.Marshal(ref)
		log.Printf("  bot_chat_result_reference: %s\n", bRef)
	}
	respBody, _ := json.MarshalIndent(msg, "  ", "  ")
	log.Printf("  body: %s\n", string(respBody))
}

For More Details


最后修改 October 22, 2025 : doc(Eino): add chatmodel docs (#1446) (4d2c2e5)