使用 Google Agent Development Kit 和 A2A 构建跨语言多智能体团队

英文标题：Build Cross-Language Multi-Agent Team with Google’s Agent Development Kit and A2A

本文演示如何用 Python 提取智能体与 Go 合规验证智能体，通过 Agent2Agent (A2A) 协议和 Google Agent Development Kit (ADK) 协同完成合同合规检查。核心架构包括跨语言智能体协作、RemoteA2aAgent 抽象以及流水线编排，展示生产环境中不同技术栈智能体无缝集成的模式。文中提供完整代码与开源应用，为开发者提供了构建稳健、可审计的分布式 AI 系统的方法。

11.7 KB 357.9 KB 241.1 KB 403.4 KB 116.0 KB 851.7 KB 64.8 KB 12.8 KB 496.8 KB 112.2 KB

// go-compliance-agent/internal/agentcard/card.go
func GetCard() AgentCard {
	agentURL := os.Getenv("AGENT_URL")
	if agentURL == "" {
		agentURL = "http://localhost:8888"
	}

	return AgentCard{
		Name:        "Security Compliance Validator",
		Description: "基于 Go 的验证引擎，根据公司合规政策规则检查供应商合同。",
		Version:     "1.0.0",
		SupportedInterfaces: []AgentInterface{
			{
				URL:             agentURL,
				ProtocolBinding: "JSONRPC",
				ProtocolVersion: "1.0",
			},
		},
		Capabilities: Capabilities{
			ExtendedAgentCard: false,
		},
		DefaultInputModes:  []string{"application/json"},
		DefaultOutputModes: []string{"application/json"},
		Skills: []Skill{
			{
				ID:          "contract_compliance_check",
				Name:        "合同合规检查",
				Description: "根据公司政策规则验证提取的合同字段。",
				Tags:        []string{"合规", "合同", "验证"},
				Examples: []string{
					"检查此合同是否存在合规违规",
					"根据政策验证供应商协议条款",
				},
			},
		},
	}
}

class ComplianceStep(str, Enum):
    INGESTED = "INGESTED"                     # 合同已上传，等待提取
    EXTRACTED = "EXTRACTED"                    # 字段已被 Gemini 解析
    COMPLIANCE_PENDING = "COMPLIANCE_PENDING"  # 已发送至 Go 智能体，等待结果
    COMPLIANCE_COMPLETE = "COMPLIANCE_COMPLETE"# Go 智能体返回判定结果
    MANUAL_REVIEW = "MANUAL_REVIEW"           # 超时或错误，路由至人工处理
    REVIEW_READY = "REVIEW_READY"             # 报告已生成，发现违规项
    APPROVED = "APPROVED"                      # 所有检查通过

# python-extraction-agent/app/agent.py
from google.adk.agents import Agent, SequentialAgent
from google.adk.agents.remote_a2a_agent import RemoteA2aAgent
from google.adk.models import Gemini


# 子智能体 1: 使用 LLM 推理进行接收和提取详情
extractor_agent = Agent(
   name="extractor_agent",
   model=Gemini(model="gemini-3.5-flash"),
   instruction="你是一个法律数据提取智能体。提取合同字段：金额、承包商、日期、保险……",
   tools=[read_contract_text, save_extracted_fields, classify_risk_level]
)

# 子智能体 2: 包装为本地智能体的 Go A2A 合规服务
compliance_agent = RemoteA2aAgent(
   name="compliance_agent",
   agent_card=GO_AGENT_CARD_URL,
   description="根据公司政策验证提取的合同字段。"
)

# 子智能体 3: 生成最终的审计摘要报告
report_agent = Agent(
   name="report_agent",
   model=Gemini(model="gemini-3.5-flash"),
   instruction="生成最终的合规报告和 Markdown 摘要。",
   tools=[generate_summary_report]
)

# 协调器: 按顺序将它们串联
root_agent = SequentialAgent(
   name="contract_compliance_coordinator",
    description="按顺序编排合同解析、A2A 合规验证和最终报告生成。",
   sub_agents=[extractor_agent, compliance_agent, report_agent],
)

// 简化伪代码——完整实现见 GitHub 仓库


func HandleJSONRPC(w http.ResponseWriter, r *http.Request) {
    var req JSONRPCRequest
    json.NewDecoder(r.Body).Decode(&req)

    // 从 A2A 消息中提取合同详情
    var details compliance.ContractDetails
    extractContractFromMessage(req.Params, &details)

    // 运行确定性策略检查
    result := compliance.CheckCompliance(details, policy)

    // 以 JSON-RPC 响应的形式返回判定结果
    writeJSONRPCResult(w, req.ID, result)
}

// go-compliance-agent/internal/agentcard/card.go
func GetCard() AgentCard {
	agentURL := os.Getenv("AGENT_URL")
	if agentURL == "" {
		agentURL = "http://localhost:8888"
	}

	return AgentCard{
		Name:        "Security Compliance Validator",
		Description: "Go-based validation engine that checks vendor contracts against corporate compliance policy rules.",
		Version:     "1.0.0",
		SupportedInterfaces: []AgentInterface{
			{
				URL:             agentURL,
				ProtocolBinding: "JSONRPC",
				ProtocolVersion: "1.0",
			},
		},
		Capabilities: Capabilities{
			ExtendedAgentCard: false,
		},
		DefaultInputModes:  []string{"application/json"},
		DefaultOutputModes: []string{"application/json"},
		Skills: []Skill{
			{
				ID:          "contract_compliance_check",
				Name:        "Contract Compliance Check",
				Description: "Validates extracted contract fields against corporate policy rules.",
				Tags:        []string{"compliance", "contract", "validation"},
				Examples: []string{
					"Check this contract for compliance violations",
					"Validate vendor agreement terms against policy",
				},
			},
		},
	}
}

class ComplianceStep(str, Enum):
    INGESTED = "INGESTED"                     # Contract uploaded, awaiting extraction
    EXTRACTED = "EXTRACTED"                    # Fields parsed by Gemini
    COMPLIANCE_PENDING = "COMPLIANCE_PENDING"  # Sent to Go agent, awaiting result
    COMPLIANCE_COMPLETE = "COMPLIANCE_COMPLETE"# Go agent returned verdict
    MANUAL_REVIEW = "MANUAL_REVIEW"           # Timeout or error, routed to human
    REVIEW_READY = "REVIEW_READY"             # Report generated, violations found
    APPROVED = "APPROVED"                      # All checks passed

# python-extraction-agent/app/agent.py
from google.adk.agents import Agent, SequentialAgent
from google.adk.agents.remote_a2a_agent import RemoteA2aAgent
from google.adk.models import Gemini


# Sub-Agent 1: Ingests & extracts details using LLM reasoning
extractor_agent = Agent(
   name="extractor_agent",
   model=Gemini(model="gemini-3.5-flash"),
   instruction="You are a Legal Data Extraction Agent. Extract contract fields: value, contractor, dates, insurance...",
   tools=[read_contract_text, save_extracted_fields, classify_risk_level]
)

# Sub-Agent 2: Go A2A Compliance Service wrapped as a local agent
compliance_agent = RemoteA2aAgent(
   name="compliance_agent",
   agent_card=GO_AGENT_CARD_URL,
   description="Validates extracted contract fields against corporate policies."
)

# Sub-Agent 3: Generates the final audit summary report
report_agent = Agent(
   name="report_agent",
   model=Gemini(model="gemini-3.5-flash"),
   instruction="Generate the final compliance report and Markdown summary.",
   tools=[generate_summary_report]
)

# Coordinator: Chains them together sequentially
root_agent = SequentialAgent(
   name="contract_compliance_coordinator",
    description="Orchestrates contract parsing, A2A compliance validation, and final reporting in sequence.",
   sub_agents=[extractor_agent, compliance_agent, report_agent],
)

// Simplified pseudo-code — see GitHub repository for full implementation


func HandleJSONRPC(w http.ResponseWriter, r *http.Request) {
    var req JSONRPCRequest
    json.NewDecoder(r.Body).Decode(&req)

    // Extract contract details from the A2A message
    var details compliance.ContractDetails
    extractContractFromMessage(req.Params, &details)

    // Run deterministic policy checks
    result := compliance.CheckCompliance(details, policy)

    // Return verdict as a JSON-RPC response
    writeJSONRPCResult(w, req.ID, result)
}