Rollbacks

If charging an order still fails after retries, release its inventory reservation or choose another payment path. Catch the failed step.run() error and put the fallback or compensation in its own step.

Add a compensating step

This TypeScript v4 example reserves inventory, tries to charge an order, and releases the reservation if charging still fails. The three called functions represent your application's integrations. It uses the inngest client from the Quick start.

export const fulfillOrder = inngest.createFunction(
  {
    id: "fulfill-order",
    triggers: { event: "shop/order.placed" },
  },
  async ({ event, step }) => {
    const orderId = event.data.orderId;
    const reservationId = await step.run("reserve-inventory", () =>
      reserveInventory(orderId)
    );

    try {
      await step.run("charge-order", () => chargeOrder(orderId));
    } catch (error) {
      await step.run("release-inventory", () =>
        releaseInventory(reservationId)
      );
      throw error;
    }
  }
);

Inngest retries charge-order before the catch block runs. If it still fails, release-inventory is its own durable, retriable step. Rethrowing the error leaves the function failed after compensation; returning instead would let the function continue. Give reservation, charge, and release operations stable IDs so each can be called again safely.

Choose recovery or compensation

• Fallback. Call another service in a new step, then continue when its result satisfies the workflow.
• Compensation. Undo a completed external action in a new step, such as releasing a reservation. This is a business action, not an automatic transaction rollback.
• Ignore a noncritical failure. Catch the failed step and record the outcome so the function can continue intentionally. Catch only a step whose failure you can handle. An unhandled failed step makes the function fail. A function-level Failure handlers runs after the function has exhausted retries; it serves a different purpose from local recovery.