inngest-events

Inngest 事件

掌握 Inngest 事件设计和传递模式。事件是 Inngest 的基础——了解如何设计健壮的事件架构、实现幂等性、利用扇出模式，以及有效处理系统事件。

这些技能专注于 TypeScript。 对于 Python 或 Go，请参阅 Inngest 文档了解特定语言的指南。核心概念适用于所有语言。

事件负载格式

每个 Inngest 事件都是一个包含必需和可选属性的 JSON 对象：

必需属性

type Event = {
  name: string; // Event type (triggers functions)
  data: object; // Payload data (any nested JSON)
};

完整架构

type EventPayload = {
  name: string; // Required: event type
  data: Record<string, any>; // Required: event data
  id?: string; // Optional: deduplication ID
  ts?: number; // Optional: timestamp (Unix ms)
  v?: string; // Optional: schema version
};

基本事件示例

await inngest.send({
  name: "billing/invoice.paid",
  data: {
    customerId: "cus_NffrFeUfNV2Hib",
    invoiceId: "in_1J5g2n2eZvKYlo2C0Z1Z2Z3Z",
    userId: "user_03028hf09j2d02",
    amount: 1000,
    metadata: {
      accountId: "acct_1J5g2n2eZvKYlo2C0Z1Z2Z3Z",
      accountName: "Acme.ai"
    }
  }
});

事件命名约定

使用对象-动作模式： domain/noun.verb

推荐模式

// ✅ Good: Clear object-action pattern
"billing/invoice.paid";
"user/profile.updated";
"order/item.shipped";
"ai/summary.completed";

// ✅ Good: Domain prefixes for organization
"stripe/customer.created";
"intercom/conversation.assigned";
"slack/message.posted";

// ❌ Avoid: Unclear or inconsistent
"payment"; // What happened?
"user_update"; // Use dots, not underscores
"invoiceWasPaid"; // Too verbose

命名指南

• 过去时： 事件描述已发生的事情（created、updated、failed）
• 点号表示法： 使用点号表示层级（billing/invoice.paid）
• 前缀： 将相关事件分组（api/user.created、webhook/stripe.received）
• 一致性： 确立模式并始终遵循

事件 ID 与幂等性

何时使用 ID： 当事件可能被多次发送时，防止重复处理。

基本去重

await inngest.send({
  id: "cart-checkout-completed-ed12c8bde", // Unique per event type
  name: "storefront/cart.checkout.completed",
  data: {
    cartId: "ed12c8bde",
    items: ["item1", "item2"]
  }
});

ID 最佳实践

// ✅ Good: Specific to event type and instance
id: `invoice-paid-${invoiceId}`;
id: `user-signup-${userId}-${timestamp}`;
id: `order-shipped-${orderId}-${trackingNumber}`;

// ❌ Bad: Generic IDs shared across event types
id: invoiceId; // Could conflict with other events
id: "user-action"; // Too generic
id: customerId; // Same customer, different events

去重时间窗口： 自首次接收事件起 24 小时

有关幂等性配置，请参阅 inngest-durable-functions。

用于延迟传递的 ts 参数

适用场景： 安排事件在未来处理，或维持事件顺序。

安排未来处理

const oneHourFromNow = Date.now() + 60 * 60 * 1000;

await inngest.send({
  name: "trial/reminder.send",
  ts: oneHourFromNow, // Deliver in 1 hour
  data: {
    userId: "user_123",
    trialExpiresAt: "2024-02-15T12:00:00Z"
  }
});

维持事件顺序

// Events with timestamps are processed in chronological order
const events = [
  {
    name: "user/action.performed",
    ts: 1640995200000, // Earlier
    data: { action: "login" }
  },
  {
    name: "user/action.performed",
    ts: 1640995260000, // Later
    data: { action: "purchase" }
  }
];

await inngest.send(events);

扇出模式

适用场景： 一个事件触发多个独立函数，以提高可靠性并支持并行处理。

基本扇出实现

// Send single event
await inngest.send({
  name: "user/signup.completed",
  data: {
    userId: "user_123",
    email: "[email protected]",
    plan: "pro"
  }
});

// Multiple functions respond to same event
const sendWelcomeEmail = inngest.createFunction(
  { id: "send-welcome-email", triggers: [{ event: "user/signup.completed" }] },
  async ({ event, step }) => {
    await step.run("send-email", async () => {
      return sendEmail({
        to: event.data.email,
        template: "welcome"
      });
    });
  }
);

const createTrialSubscription = inngest.createFunction(
  { id: "create-trial", triggers: [{ event: "user/signup.completed" }] },
  async ({ event, step }) => {
    await step.run("create-subscription", async () => {
      return stripe.subscriptions.create({
        customer: event.data.stripeCustomerId,
        trial_period_days: 14
      });
    });
  }
);

const addToCrm = inngest.createFunction(
  { id: "add-to-crm", triggers: [{ event: "user/signup.completed" }] },
  async ({ event, step }) => {
    await step.run("crm-sync", async () => {
      return crm.contacts.create({
        email: event.data.email,
        plan: event.data.plan
      });
    });
  }
);

扇出优势

• 独立性： 函数分别运行；一个函数失败不会影响其他函数
• 并行执行： 所有函数同时运行
• 选择性重放： 只重新运行失败的函数
• 跨服务： 触发不同代码库或语言中的函数

使用 waitForEvent 的高级扇出

在表达式中，event = 原始触发事件，async = 正在匹配的新事件。完整详情请参阅表达式语法参考。

const orchestrateOnboarding = inngest.createFunction(
  { id: "orchestrate-onboarding", triggers: [{ event: "user/signup.completed" }] },
  async ({ event, step }) => {
    // Fan out to multiple services
    await step.sendEvent("fan-out", [
      { name: "email/welcome.send", data: event.data },
      { name: "subscription/trial.create", data: event.data },
      { name: "crm/contact.add", data: event.data }
    ]);

    // Wait for all to complete
    const [emailResult, subResult, crmResult] = await Promise.all([
      step.waitForEvent("email-sent", {
        event: "email/welcome.sent",
        timeout: "5m",
        if: `event.data.userId == async.data.userId`
      }),
      step.waitForEvent("subscription-created", {
        event: "subscription/trial.created",
        timeout: "5m",
        if: `event.data.userId == async.data.userId`
      }),
      step.waitForEvent("crm-synced", {
        event: "crm/contact.added",
        timeout: "5m",
        if: `event.data.userId == async.data.userId`
      })
    ]);

    // Complete onboarding
    await step.run("complete-onboarding", async () => {
      return completeUserOnboarding(event.data.userId);
    });
  }
);

有关更多模式（包括 step.invoke），请参阅 inngest-steps。

系统事件

Inngest 会发出系统事件，用于监控函数生命周期：

可用的系统事件

// Function execution events
"inngest/function.failed"; // Function failed after retries
"inngest/function.finished"; // Function finished - completed or failed
"inngest/function.cancelled"; // Function cancelled before completion

处理失败的函数

const handleFailures = inngest.createFunction(
  { id: "handle-failed-functions", triggers: [{ event: "inngest/function.failed" }] },
  async ({ event, step }) => {
    const { function_id, run_id, error } = event.data;

    await step.run("log-failure", async () => {
      logger.error("Function failed", {
        functionId: function_id,
        runId: run_id,
        error: error.message,
        stack: error.stack
      });
    });

    // Alert on critical function failures
    if (function_id.includes("critical")) {
      await step.run("send-alert", async () => {
        return alerting.sendAlert({
          title: `Critical function failed: ${function_id}`,
          severity: "high",
          runId: run_id
        });
      });
    }

    // Auto-retry certain failures
    if (error.code === "RATE_LIMIT_EXCEEDED") {
      await step.run("schedule-retry", async () => {
        return inngest.send({
          name: "retry/function.requested",
          ts: Date.now() + 5 * 60 * 1000, // Retry in 5 minutes
          data: { originalRunId: run_id }
        });
      });
    }
  }
);

发送事件

客户端设置

// inngest/client.ts
import { Inngest } from "inngest";

export const inngest = new Inngest({
  id: "my-app"
});
// You must set INNGEST_EVENT_KEY environment variable in production

单个事件

const result = await inngest.send({
  name: "order/placed",
  data: {
    orderId: "ord_123",
    customerId: "cus_456",
    amount: 2500,
    items: [
      { id: "item_1", quantity: 2 },
      { id: "item_2", quantity: 1 }
    ]
  }
});

// Returns event IDs for tracking
console.log(result.ids); // ["01HQ8PTAESBZPBDS8JTRZZYY3S"]

批量事件

const orderItems = await getOrderItems(orderId);

// Convert to events
const events = orderItems.map((item) => ({
  name: "inventory/item.reserved",
  data: {
    itemId: item.id,
    orderId: orderId,
    quantity: item.quantity,
    warehouseId: item.warehouseId
  }
}));

// Send all at once (up to 512kb)
await inngest.send(events);

从函数中发送

inngest.createFunction(
  { id: "process-order", triggers: [{ event: "order/placed" }] },
  async ({ event, step }) => {
    // Use step.sendEvent() instead of inngest.send() in functions
    // for reliability and deduplication
    await step.sendEvent("trigger-fulfillment", {
      name: "fulfillment/order.received",
      data: {
        orderId: event.data.orderId,
        priority: event.data.customerTier === "premium" ? "high" : "normal"
      }
    });
  }
);

事件设计最佳实践

架构版本控制

// Use version field to track schema changes
await inngest.send({
  name: "user/profile.updated",
  v: "2024-01-15.1", // Schema version
  data: {
    userId: "user_123",
    changes: {
      email: "[email protected]",
      preferences: { theme: "dark" }
    },
    // New field in v2 schema
    auditInfo: {
      changedBy: "user_456",
      reason: "user_requested"
    }
  }
});

丰富的上下文数据

// Include enough context for all consumers
await inngest.send({
  name: "payment/charge.succeeded",
  data: {
    // Primary identifiers
    chargeId: "ch_123",
    customerId: "cus_456",

    // Amount details
    amount: 2500,
    currency: "usd",

    // Context for different consumers
    subscription: {
      id: "sub_789",
      plan: "pro_monthly"
    },
    invoice: {
      id: "inv_012",
      number: "INV-2024-001"
    },

    // Metadata for debugging
    paymentMethod: {
      type: "card",
      last4: "4242",
      brand: "visa"
    },
    metadata: {
      source: "stripe_webhook",
      environment: "production"
    }
  }
});

事件设计原则：

1. 自包含： 包含使用者所需的所有数据
2. 不可变： 发送后绝不修改事件架构
3. 可追踪： 包含关联 ID 和审计跟踪
4. 可操作： 提供足够的上下文以支持业务逻辑
5. 便于调试： 包含用于故障排查的元数据