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}¤t=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 });