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ワークフローエージェントの呼び出し

ワークフローからエージェントを呼び出す

この例では、指定された天気条件に合わせてアクティビティを提案するAIエージェントを呼び出し、ワークフローのステップ内で実行するワークフローの作成方法を説明します。

セットアップ

npm install @ai-sdk/openai @mastra/core

プランニングエージェントの定義

場所とそれに対応する天候条件をもとに活動を計画するために、LLMコールを活用するプランニングエージェントを定義します。

agents/planning-agent.ts
import { Agent } from "@mastra/core/agent"; import { openai } from "@ai-sdk/openai"; const llm = openai("gpt-4o"); // Create a new agent for activity planning const planningAgent = new Agent({ name: "planningAgent", model: llm, instructions: ` You are a local activities and travel expert who excels at weather-based planning. Analyze the weather data and provide practical activity recommendations. 📅 [Day, Month Date, Year] ═══════════════════════════ 🌡️ WEATHER SUMMARY • Conditions: [brief description] • Temperature: [X°C/Y°F to A°C/B°F] • Precipitation: [X% chance] 🌅 MORNING ACTIVITIES Outdoor: • [Activity Name] - [Brief description including specific location/route] Best timing: [specific time range] Note: [relevant weather consideration] 🌞 AFTERNOON ACTIVITIES Outdoor: • [Activity Name] - [Brief description including specific location/route] Best timing: [specific time range] Note: [relevant weather consideration] 🏠 INDOOR ALTERNATIVES • [Activity Name] - [Brief description including specific venue] Ideal for: [weather condition that would trigger this alternative] ⚠️ SPECIAL CONSIDERATIONS • [Any relevant weather warnings, UV index, wind conditions, etc.] Guidelines: - Suggest 2-3 time-specific outdoor activities per day - Include 1-2 indoor backup options - For precipitation >50%, lead with indoor activities - All activities must be specific to the location - Include specific venues, trails, or locations - Consider activity intensity based on temperature - Keep descriptions concise but informative Maintain this exact formatting for consistency, using the emoji and section headers as shown. `, }); export { planningAgent };

アクティビティ計画ワークフローの定義

アクティビティ計画ワークフローを2つのステップで定義します。1つ目はネットワークコールで天気を取得し、2つ目はplanning agentを使ってアクティビティを計画します。

workflows/agent-workflow.ts
import { createWorkflow, createStep } from "@mastra/core/workflows"; import { z } from "zod"; // Helper function to convert numeric weather codes to human-readable descriptions function getWeatherCondition(code: number): string { const conditions: Record<number, string> = { 0: "Clear sky", 1: "Mainly clear", 2: "Partly cloudy", 3: "Overcast", 45: "Foggy", 48: "Depositing rime fog", 51: "Light drizzle", 53: "Moderate drizzle", 55: "Dense drizzle", 61: "Slight rain", 63: "Moderate rain", 65: "Heavy rain", 71: "Slight snow fall", 73: "Moderate snow fall", 75: "Heavy snow fall", 95: "Thunderstorm", }; return conditions[code] || "Unknown"; } const forecastSchema = z.object({ date: z.string(), maxTemp: z.number(), minTemp: z.number(), precipitationChance: z.number(), condition: z.string(), location: z.string(), });

ステップ1: 指定した都市の天気データを取得するステップを作成

workflows/agent-workflow.ts
const fetchWeather = createStep({ id: "fetch-weather", description: "Fetches weather forecast for a given city", inputSchema: z.object({ city: z.string(), }), outputSchema: forecastSchema, execute: async ({ inputData }) => { if (!inputData) { throw new Error("Trigger data not found"); } // First API call: Convert city name to latitude and longitude const geocodingUrl = `https://geocoding-api.open-meteo.com/v1/search?name=${encodeURIComponent(inputData.city)}&count=1`; const geocodingResponse = await fetch(geocodingUrl); const geocodingData = (await geocodingResponse.json()) as { results: { latitude: number; longitude: number; name: string }[]; }; if (!geocodingData.results?.[0]) { throw new Error(`Location '${inputData.city}' not found`); } const { latitude, longitude, name } = geocodingData.results[0]; // Second API call: Get weather data using coordinates const weatherUrl = `https://api.open-meteo.com/v1/forecast?latitude=${latitude}&longitude=${longitude}&current=precipitation,weathercode&timezone=auto,&hourly=precipitation_probability,temperature_2m`; const response = await fetch(weatherUrl); const data = (await response.json()) as { current: { time: string; precipitation: number; weathercode: number; }; hourly: { precipitation_probability: number[]; temperature_2m: number[]; }; }; const forecast = { date: new Date().toISOString(), maxTemp: Math.max(...data.hourly.temperature_2m), minTemp: Math.min(...data.hourly.temperature_2m), condition: getWeatherCondition(data.current.weathercode), location: name, precipitationChance: data.hourly.precipitation_probability.reduce( (acc, curr) => Math.max(acc, curr), 0, ), }; return forecast; }, });

ステップ2: agentを使ってアクティビティの提案を生成するステップを作成

workflows/agent-workflow.ts
const planActivities = createStep({ id: "plan-activities", description: "Suggests activities based on weather conditions", inputSchema: forecastSchema, outputSchema: z.object({ activities: z.string(), }), execute: async ({ inputData, mastra }) => { const forecast = inputData; if (!forecast) { throw new Error("Forecast data not found"); } const prompt = `Based on the following weather forecast for ${forecast.location}, suggest appropriate activities: ${JSON.stringify(forecast, null, 2)} `; const agent = mastra?.getAgent("planningAgent"); if (!agent) { throw new Error("Planning agent not found"); } const response = await agent.stream([ { role: "user", content: prompt, }, ]); let activitiesText = ""; for await (const chunk of response.textStream) { process.stdout.write(chunk); activitiesText += chunk; } return { activities: activitiesText, }; }, }); const activityPlanningWorkflow = createWorkflow({ steps: [fetchWeather, planActivities], id: "activity-planning-step1-single-day", inputSchema: z.object({ city: z.string().describe("The city to get the weather for"), }), outputSchema: z.object({ activities: z.string(), }), }) .then(fetchWeather) .then(planActivities); activityPlanningWorkflow.commit(); export { activityPlanningWorkflow };

MastraクラスにAgentとWorkflowインスタンスを登録する

planning agentとactivity planning workflowをmastraインスタンスに登録します。 これは、activity planning workflow内でplanning agentへのアクセスを可能にするために重要です。

index.ts
import { Mastra } from "@mastra/core/mastra"; import { createLogger } from "@mastra/core/logger"; import { activityPlanningWorkflow } from "./workflows/agent-workflow"; import { planningAgent } from "./agents/planning-agent"; // Create a new Mastra instance and register components const mastra = new Mastra({ workflows: { activityPlanningWorkflow, }, agents: { planningAgent, }, logger: createLogger({ name: "Mastra", level: "info", }), }); export { mastra };

アクティビティ計画ワークフローを実行する

ここでは、mastra インスタンスからアクティビティ計画ワークフローを取得し、実行を作成して、必要な inputData を使ってその実行を開始します。

exec.ts
import { mastra } from "./"; const workflow = mastra.getWorkflow("activityPlanningWorkflow"); const run = workflow.createRun(); // Start the workflow with New York as the city input const result = await run.start({ inputData: { city: "New York" } }); console.dir(result, { depth: null });