循环 Agent

循环Agent是Blades框架中用于实现循环执行逻辑的重要组件，循环Agent基于条件函数的返回值决定是否继续执行某个任务。这种模式非常适合需要重复处理直到达成目标的场景。 alt text

核心概念

在Blades中实现循环逻辑，可直接使用已经封装好的 NewLoopAgent 函数初始化一个循环Agent，需要传入参数 LoopConfig ,结构如下：

type LoopConfig struct {
    Name          string
    Description   string
    MaxIterations int
    Condition     LoopCondition
    SubAgents     []blades.Agent
}

name : 循环Agent的名称，用于标识和区分不同的循环Agent
description : 循环Agent的描述，用于说明循环Agent的用途和功能
maxIterations : 循环Agent的最大迭代次数，防止无限循环
condition : 循环Agent的终止条件，其参数类型为 LoopCondition ，该结构为函数类型如下，输入参数与Agent的Run函数一致：

type LoopCondition func(ctx context.Context, output *blades.Message) (bool, error)

subAgents : 循环Agent包含的子Agent列表，这些子Agent将按循环执行

运行流程

1. 创建SubAgents

使用 blades.NewAgent 创建多个子Agent，分别制定对应的任务。在此处举例构建一个写作Agent进行写作和一个审阅Agent进行评判。

model := openai.NewModel(os.Getenv("OPENAI_MODEL"), openai.Config{
    APIKey: os.Getenv("OPENAI_API_KEY"),
})
writerAgent, err := blades.NewAgent(
    "WriterAgent",
    blades.WithModel(model),
    blades.WithInstruction(`Draft a short paragraph on climate change.
        {{if .suggestions}}
        **Draft**
        {{.draft}}

        Here are the suggestions to consider:
        {{.suggestions}}
        {{end}}
    `),
    blades.WithOutputKey("draft"),
)
reviewerAgent, err := blades.NewAgent(
    "ReviewerAgent",
    blades.WithModel(model),
    blades.WithInstruction(`Review the draft and suggest improvements.
        If the draft is good, respond with "The draft is good".

        **Draft**
        {{.draft}}
    `),
    blades.WithOutputKey("suggestions"),
)

2. 创建循环Agent

创建循环Agent时应当设置最大循环次数，避免无限循环。此处例子中设置的最大循环次数为3，且设置若出现“good”则终止循环。

loopAgent := flow.NewLoopAgent(flow.LoopConfig{
    Name:          "WritingReviewFlow",
    Description:   "An agent that loops between writing and reviewing until the draft is good.",
    MaxIterations: 3,
    Condition: func(ctx context.Context, output *blades.Message) (bool, error) {
        return !strings.Contains(output.Text(), "good"), nil
    },
    SubAgents: []blades.Agent{
        writerAgent,
        reviewerAgent,
    },
})

3. 运行循环Agent

在此处例子中运行循环Agent时，创建了一个Runner并调用其RunStream方法，传入上下文和输入消息，即可得到一个消息流，遍历该消息流即可获取每个Agent的输出结果。

input := blades.UserMessage("Please write a short paragraph about climate change.")
runner := blades.NewRunner(loopAgent)
stream := runner.RunStream(context.Background(), input)
for message, err := range stream {
    if err != nil {
        log.Fatal(err)
    }
    log.Println(message.Author, message.Text())
}

最佳实践

合理的条件设计: 循环条件应能准确反映任务完成状态，避免永远无法满足的条件
设置合适的最大迭代次数: 根据业务场景设置合理的上限，防止资源浪费
完善的错误处理: 在条件函数和执行任务中都要考虑错误处理，避免因异常导致的无限循环
状态传递优化: 合理利用输入输出参数传递状态信息，确保每次迭代都能基于最新状态进行处理

完整示例

package main

import (
    "context"
    "log"
    "os"
    "strings"

    "github.com/go-kratos/blades"
    "github.com/go-kratos/blades/contrib/openai"
    "github.com/go-kratos/blades/flow"
)

func main() {
    model := openai.NewModel(os.Getenv("OPENAI_MODEL"), openai.Config{
        APIKey: os.Getenv("OPENAI_API_KEY"),
    })
    writerAgent, err := blades.NewAgent(
        "WriterAgent",
        blades.WithModel(model),
        blades.WithInstruction(`Draft a short paragraph on climate change.
            {{if .suggestions}}
            **Draft**
            {{.draft}}

            Here are the suggestions to consider:
            {{.suggestions}}
            {{end}}
        `),
        blades.WithOutputKey("draft"),
    )
    if err != nil {
        log.Fatal(err)
    }
    reviewerAgent, err := blades.NewAgent(
        "ReviewerAgent",
        blades.WithModel(model),
        blades.WithInstruction(`Review the draft and suggest improvements.
            If the draft is good, respond with "The draft is good".

            **Draft**
            {{.draft}}
        `),
        blades.WithOutputKey("suggestions"),
    )
    if err != nil {
        log.Fatal(err)
    }
    loopAgent := flow.NewLoopAgent(flow.LoopConfig{
        Name:          "WritingReviewFlow",
        Description:   "An agent that loops between writing and reviewing until the draft is good.",
        MaxIterations: 3,
        Condition: func(ctx context.Context, output *blades.Message) (bool, error) {
            return !strings.Contains(output.Text(), "good"), nil
        },
        SubAgents: []blades.Agent{
            writerAgent,
            reviewerAgent,
        },
    })
    input := blades.UserMessage("Please write a short paragraph about climate change.")
    runner := blades.NewRunner(loopAgent)
    stream := runner.RunStream(context.Background(), input)
    for message, err := range stream {
        if err != nil {
            log.Fatal(err)
        }
        log.Println(message.Author, message.Text())
    }
}