local-fake-api

A simple async local mock API without backend.

✅ Designed for prototyping or fast iterations

✅ REST-style responses

✅ Supports IndexedDB or LocalStorage

✅ Simulate an async API effortlessly

Installation

npm install local-fake-api

CRUD API

Factory

createApi<T>(tableName: string): Api<T>

Creates a table-scoped API instance that uses tableName as:

• IndexedDB: object store name

• LocalStorage: key name

• Returns: CRUD methods for type T with REST-style responses.

Methods

All methods return a REST-style response:

interface ApiResponse<T = unknown> {
  data?: T; // the result data
  success: boolean; // true if operation succeeded
  message?: string; // optional error message
}

list(filter?: Partial<Record<string, unknown>>): Promise<ApiResponse<{ data: T[]; total: number,success: boolean }>>

Fetch all stored items (optionally filtered).

• data: T[]
• total: total items count
• success: true if operation succeeds

Example:

const res = await api.list({ done: true });
if (res.success) {
  console.log(res.data?.data, res.data?.total);
}

get(id: string, keyName?: keyof T): Promise<ApiResponse<T | null>>

Fetch a single item by id (or other key).

create(item: Omit<T, "id">): Promise<ApiResponse<T>>

Create a new item (auto-generates id).

update(id: string, updates: Partial<Omit<T, "id">>, keyName?: keyof T): Promise<ApiResponse<T | null>>

Update specific fields of an item by id.

delete(id: string, keyName?: keyof T): Promise<ApiResponse<void>>

Delete an item by id.

clearAll(filter?: Partial<Record<string, unknown>>): Promise<ApiResponse<void>>

Clear all items (optionally filter items to keep).

Example

type Todo = { id: string; text: string; done: boolean };
type Note = { id: string; title: string; content: string };

const todoApi = createApi<Todo>("todos");
const noteApi = createApi<Note>("notes");

async function run() {
  console.log("\n=== TODOS ===");
  await todoApi.clearAll();
  const newTodo = await todoApi.create({ text: "Buy milk", done: false });
  console.log("Added todo:", newTodo);
  console.log("All todos:", await todoApi.list());
  const updatedTodo = await todoApi.update(newTodo.data!.id, { done: true });
  console.log("Updated todo:", updatedTodo);
  await todoApi.delete(newTodo.data!.id);
  console.log("Todo deleted. Remaining todos:", await todoApi.list());

  console.log("\n=== NOTES ===");
  await noteApi.clearAll();
  const newNote = await noteApi.add({
    title: "Meeting Notes",
    content: "Discuss project roadmap.",
  });
  console.log("Added note:", newNo