Inngest + Next.js Patterns
Templates and conventions for building event-driven, durable background work on Inngest from a Next.js App Router project. The skill enforces the conventions Inngest's own docs use (decentralized eventType() schemas, kebab-case stable function IDs, idempotent steps) so that retries, replays, and concurrency controls actually do what they advertise.
When to Apply
Read this skill when you are:
- Setting up Inngest in a Next.js app for the first time (client + route handler + first function)
- Adding a new background job, webhook handler, or scheduled task to a Next.js app
- Defining a new domain event that other functions will trigger on
- Orchestrating multi-step work that must survive process restarts (durable workflows, sagas)
- Reviewing existing Inngest code for event naming, step idempotency, or stable function IDs
- Migrating from
setTimeout/ a queue library / a cron service to Inngest's durable execution model
How to Use
- First time in this codebase? Read
references/conventions.mdbefore writing anything. The conventions explain why event names take a specific shape, why function IDs must be stable, and why everystep.runmust be idempotent — once you understand the reasoning, the templates make sense. - Pick a template from the catalog below based on what you're creating.
- Render it by substituting the documented parameters. Each template has a parameter table at the top of its file.
- Wire it up: new functions must be added to
src/inngest/functions/index.ts(the registry the route handler reads). The conventions doc shows the registry pattern.
Available Templates
| Template | Output Path | Use When |
|---|---|---|
| client.ts.template | src/inngest/client.ts | One-time setup: create the singleton Inngest client. Generate once per app. |
| route-handler.ts.template | src/app/api/inngest/route.ts | One-time setup: the App Router endpoint Inngest hits to invoke your functions. Generate once per app. |
| event.ts.template | src/inngest/events/{domain}.ts | Defining a new typed event (with Zod schema) that producers send and functions consume. |
| function.ts.template | src/inngest/functions/{name}.ts | Standard event-triggered durable function with steps. Parameterized retries, concurrency, throttle, debounce, cancelOn, onFailure. |
| function-cron.ts.template | src/inngest/functions/{name}.ts | Scheduled function — runs on a cron expression (with timezone). Optionally also accepts a manual event trigger for ad-hoc invocation. |
| function-fan-out.ts.template | src/inngest/functions/{name}.ts | Orchestrator that receives one event and fans out work — via step.sendEvent (fire-and-forget) or Promise.all(step.invoke(...)) (wait for results). |
Quick Reference
- Event name shape:
domain/entity.verb_past— e.g.,app/user.created,shop/order.placed,billing/invoice.paid. The conventions doc has the full rule. - Function
id: stable kebab-case, never rename it after deploy — Inngest uses it as the durable state key. - Step
id: descriptive kebab-case, also durable; changing one re-runs that step on replay. - Idempotency: every
step.runmust be safely retryable. If it calls a third-party API that mutates state, pass an idempotency key. - Dev server:
npx inngest-cli@latest dev, then UI at http://localhost:8288. SetINNGEST_DEV=1in.env.localto point the SDK at it.
Project Layout Assumption
Templates assume a src/ directory with App Router:
src/
├── app/api/inngest/route.ts # generated by route-handler template
└── inngest/
├── client.ts # generated by client template
├── events/ # one file per domain (events.shop.ts, events.user.ts)
│ └── {domain}.ts # generated by event template
└── functions/
├── index.ts # registry: re-exports all functions as an array
└── {name}.ts # generated by function/cron/fan-out templates
If your project uses a different layout (no src/, or Pages Router), override the output paths in config.json. The conventions doc explains the trade-offs.
Setup
config.json controls path overrides. On first use, check whether its fields are filled in — if not, ask the user before generating (project root differs from the default assumption).
Related Skills
vercel:ai-sdk— if your Inngest functions invoke LLMs, the AI SDK gives you streaming + provider abstraction; pair them withstep.runfor retry safety.vercel:vercel-functions— Inngest'sserve()adapter for Next.js runs as a Vercel Serverless Function by default; the AI SDK skill has notes on Fluid Compute and timeout extension for long agent runs.