Event payloads and schemas

Send an event such as billing/invoice.paid with the invoice ID that downstream functions need. Keep its name and payload stable so you can change the sender and consumer independently.

Example event

{
  "name": "billing/invoice.paid",
  "data": {
    "invoiceId": "inv_123",
    "customerId": "cus_456"
  },
  "v": "2026-12-01.AA"
}

Required fields

• name selects matching event triggers
• data is a JSON object passed to each run, and describes the event that occurred

Optional fields

• id gives the event a sender-defined deduplication key.
• ts records an event timestamp in Unix milliseconds. A future timestamp can schedule when event-triggered functions start.
• v identifies a payload version.

Use Agent Evals for sessions and outcome scores. Keep sensitive values out of event data unless you have chosen a suitable data protection strategy such as using encryption via middleware.

Name events for facts

Prefer a domain and a past-tense action such as account/user.created. Use one convention across apps. Avoid names that describe which function should run, because more than one function may use the same event.

Define a TypeScript v4 schema

import { eventType, Inngest } from "inngest";
import { z } from "zod";

const inngest = new Inngest({ id: "billing-app" });

export const invoicePaid = eventType("billing/invoice.paid", {
  schema: z.object({
    invoiceId: z.string(),
    customerId: z.string(),
  }),
});

await inngest.send(invoicePaid.create({
  invoiceId: "inv_123",
  customerId: "cus_456",
}));

The event type can also appear in a function's triggers array and in step.waitForEvent(). A runtime schema validates event data. Use staticSchema() when only TypeScript checking is required.

Change a payload safely

Keep existing fields stable for deployed consumers. Add fields when consumers can ignore them. If you must change the meaning or shape of a field, version the event and plan the sender and consumer rollout together. See Versioning for changing code while runs remain active.