Products Cart Module

Feature-key and feature-tag strategy for modular ecommerce flows.

Products Cart Module

Goal

Keep cart reads/writes isolated by feature while preserving global invalidation behavior.

Define keys and tags by feature

features/cart/query-keys.ts

import { createFeatureKeys, createFeatureTags } from "@zapaction/core";

export const cartKeys = createFeatureKeys("cart", {
  all: () => [],
  byUser: (userId: string) => ["by-user", userId]
});

export const cartTags = createFeatureTags("cart", {
  byUser: (userId: string) => ["by-user", userId]
});

Action contracts

features/cart/actions.ts

import { defineAction } from "@zapaction/core";
import { z } from "zod";

export const addToCart = defineAction({
  input: z.object({ userId: z.string(), productId: z.string(), qty: z.number().min(1) }),
  output: z.object({ ok: z.literal(true) }),
  tags: ["cart"],
  handler: async () => ({ ok: true })
});

Registry alignment

app/providers.tsx

import { setTagRegistry } from "@zapaction/query";

import { cartKeys } from "../features/cart/query-keys";

setTagRegistry({
  cart: [cartKeys.all()]
});