instantdb

instantdb

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# Install this skill:
npx skills add instantdb/skills --skill "instantdb"

Install specific skill from multi-skill repository

# Description

Build complete, functional apps with InstantDB as the backend. Use when creating React/vanilla JS or expo applications. Triggers on requests for building apps.

# SKILL.md


name: instantdb
description: Build complete, functional apps with InstantDB as the backend. Use when creating React/vanilla JS or expo applications. Triggers on requests for building apps.


Act as a world-class senior frontend engineer with deep expertise in InstantDB
and UI/UX design. Your primary goal is to generate complete and functional apps
with excellent visual asthetics using InstantDB as the backend.

About InstantDB aka Instant

Instant is a client-side database (Modern Firebase) with built-in queries, transactions, auth, permissions, storage, real-time, and offline support.

Instant SDKs

Instant provides client-side JS SDKs and an admin SDK:

  • @instantdb/core --- vanilla JS
  • @instantdb/react --- React
  • @instantdb/react-native --- React Native / Expo
  • @instantdb/admin --- backend scripts / servers

When installing, always check what package manager the project uses (npm, pnpm,
bun) first and then install the latest version of the Instant SDK. If working in
React use Next and Tailwind unless specified otherwise.

Managing Instant Apps

Prerequisites

Look for instant.schema.ts and instant.perms.ts. These define the schema and permissions.
Look for an app id and admin token in .env or another env file.

If schema/perm files exist but the app id/admin token are missing, ask the user where to find them or whether to create a new app.

To create a new app:

npx instant-cli init-without-files --title <APP_NAME>

This outputs an app id and admin token. Store them in an env file.

If you get an error related to not being logged in tell the user to:

  • Sign up for free or log in at https://instantdb.com
  • Then run npx instant-cli login to authenticate the CLI
  • Then re-run the init command

If you have an app id/admin token but no schema/perm files, pull them:

npx instant-cli pull --yes

Schema changes

Edit instant.schema.ts, then push:

npx instant-cli push schema --yes

New fields = additions; missing fields = deletions.

To rename fields:

npx instant-cli push schema --rename 'posts.author:posts.creator stores.owner:stores.manager' --yes

Permission changes

Edit instant.perms.ts, then push:

npx instant-cli push perms --yes

CRITICAL Query Guidelines

CRITICAL: When using React make sure to follow the rules of hooks. Remember, you can't have hooks show up conditionally.

CRITICAL: You MUST index any field you want to filter or order by in the schema. If you do not, you will get an error when you try to filter or order by it.

Here is how ordering works:

Ordering:        order: { field: 'asc' | 'desc' }

Example:         $: { order: { dueDate: 'asc' } }

Notes:           - Field must be indexed + typed in schema
                 - Cannot order by nested attributes (e.g. 'owner.name')

CRITICAL: Here is a concise summary of the where operator map which defines all the filtering options you can use with InstantDB queries to narrow results based on field values, comparisons, arrays, text patterns, and logical conditions.

Equality:        { field: value }

Inequality:      { field: { $ne: value } }

Null checks:     { field: { $isNull: true | false } }

Comparison:      $gt, $lt, $gte, $lte   (indexed + typed fields only)

Sets:            { field: { $in: [v1, v2] } }

Substring:       { field: { $like: 'Get%' } }      // case-sensitive
                  { field: { $ilike: '%get%' } }   // case-insensitive

Logic:           and: [ {...}, {...} ]
                  or:  [ {...}, {...} ]

Nested fields:   'relation.field': value

CRITICAL: The operator map above is the full set of where filters Instant
supports right now. There is no $exists, $nin, or $regex. And $like and
$ilike are what you use for startsWith / endsWith / includes.

CRITICAL: Pagination keys (limit, offset, first, after, last, before) only work on top-level namespaces. DO NOT use them on nested relations or else you will get an error.

CRITICAL: If you are unsure how something works in InstantDB you fetch the relevant urls in the documentation to learn more.

CRITICAL Permission Guidelines

Below are some CRITICAL guidelines for writing permissions in InstantDB.

data.ref

  • Use data.ref("<path.to.attr>") for linked attributes.
  • Always returns a list.
  • Must end with an attribute.

Correct

auth.id in data.ref('post.author.id') // auth.id in list of author ids
data.ref('owner.id') == [] // there is no owner

Errors

auth.id in data.post.author.id
auth.id in data.ref('author')
data.ref('admins.id') == auth.id
auth.id == data.ref('owner.id')
data.ref('owner.id') == null
data.ref('owner.id').length > 0

auth.ref

  • Same as data.ref but path must start with $user.
  • Returns a list.

Correct

'admin' in auth.ref('$user.role.type')
auth.ref('$user.role.type')[0] == 'admin'

Errors

auth.ref('role.type')
auth.ref('$user.role.type') == 'admin'

Unsupported

newData.ref('x')
data.ref(someVar + '.members.id')

$users Permissions

  • Default view permission is auth.id == data.id
  • Default create, update, and delete permissions is false
  • Can override view and update
  • Cannot override create or delete

$files Permissions

  • Default permissions are all false. Override as needed to allow access.
  • data.ref does not work for $files permissions.
  • Use data.path.startsWith(...) or data.path.endsWith(...) to write
    path-based rules.

Field-level Permissions

Restrict access to specific fields while keeping the entity public:

{
  "$users": {
    "allow": {
      "view": "true"
    },
    "fields": {
      "email": "auth.id == data.id"
    }
  }
}

Notes:

  • Field rules override entity-level view for that field
  • Useful for hiding sensitive data (emails, phone numbers) on public entities

Best Practices

Pass schema when initializing Instant

Always pass schema when initializing Instant to get type safety for queries and transactions

import schema from '@/instant.schema`

// On client
import { init } from '@instantdb/react'; // or your relevant Instant SDK
const clientDb = init({ appId, schema });

// On backend
import { init } from '@instantdb/admin';
const adminDb = init({ appId, adminToken, schema });

Use id() to generate ids

Always use id() to generate ids for new entities

import { id } from '@instantdb/react'; // or your relevant Instant SDK
import { clientDb } from '@/lib/clientDb
clientDb.transact(clientDb.tx.todos[id()].create({ title: 'New Todo' }));

Use Instant utility types for data models

Always use Instant utility types to type data models

import { AppSchema } from '@/instant.schema';

type Todo = InstaQLEntity<AppSchema, 'todos'>; // todo from clientDb.useQuery({ todos: {} })
type PostsWithProfile = InstaQLEntity<
  AppSchema,
  'posts',
  { author: { avatar: {} } }
>; // post from clientDb.useQuery({ posts: { author: { avatar: {} } } })

Use db.useAuth or db.subscribeAuth for auth state

import { clientDb } from '@/lib/clientDb';

// For react/react-native apps use db.useAuth
function App() {
  const { isLoading, user, error } = clientDb.useAuth();
  if (isLoading) { return null; }
  if (error) { return <Error message={error.message /}></div>; }
  if (user) { return <Main />; }
  return <Login />;
}

// For vanilla JS apps use db.subscribeAuth
function App() {
  renderLoading();
  db.subscribeAuth((auth) => {
    if (auth.error) { renderAuthError(auth.error.message); }
    else if (auth.user) { renderLoggedInPage(auth.user); }
    else { renderSignInPage(); }
  });
}

Ad-hoc queries & transactions

Use @instantdb/admin to run ad-hoc queries and transactions on the backend.
Here is an example schema for a chat app along with seed and reset scripts.

// instant.schema.ts
const _schema = i.schema({
  entities: {
    $users: i.entity({
      email: i.string().unique().indexed().optional(),
    }),
    profiles: i.entity({
      displayName: i.string(),
    }),
    channels: i.entity({
      name: i.string().indexed(),
    }),
    messages: i.entity({
      content: i.string(),
      timestamp: i.number().indexed(),
    }),
  },
  links: {
    userProfile: {
      forward: { on: "profiles", has: "one", label: "user", onDelete: "cascade" }, // IMPORTANT: `cascade` can only be used in a has-one link
      reverse: { on: "$users", has: "one", label: "profile" },
    },
    authorMessages: {
      forward: { on: "messages", has: "one", label: "author", onDelete: "cascade" },
      reverse: { on: "profiles", has: "many", label: "messages", },
    },
    channelMessages: {
      forward: { on: "messages", has: "one", label: "channel", onDelete: "cascade" },
      reverse: { on: "channels", has: "many", label: "messages" },
    },
  },
});

// scripts/seed.ts
import { id } from "@instantdb/admin";
import { adminDb } from "@/lib/adminDb";

const users: Record<string, User> = { ... }
const channels: Record<string, Channel> = { ... }
const mockMessages: Message[] = [ ... ]

function seed() {
  console.log("Seeding db...");
  const userTxs = Object.values(users).map(u => adminDb.tx.$users[u.id].create({}));
  const profileTxs = Object.values(users).map(u => adminDb.tx.profiles[u.id].create({ displayName: u.displayName }).link({ user: u.id }));
  const channelTxs = Object.values(channels).map(c => adminDb.tx.channels[c.id].create({ name: c.name }))
  const messageTxs = mockMessages.map(m => {
    const messageId = id();
    return adminDb.tx.messages[messageId].create({
      content: m.content,
      timestamp: m.timestamp,
    })
      .link({ author: users[m.author].id })
      .link({ channel: channels[m.channel].id });
  })

  adminDb.transact([...userTxs, ...profileTxs, ...channelTxs, ...messageTxs]);
}

seed();

// scripts/reset.ts
import { adminDb } from "@/lib/adminDb";

async function reset() {
  console.log("Resetting database...");
  const { $users, channels } = await adminDb.query({ $users: {}, channels: {} });

  // Deleting all users will cascade delete profiles and messages
  const userTxs = $users.map(user => adminDb.tx.$users[user.id].delete());

  const channelTxs = channels.map(channel => adminDb.tx.channels[channel.id].delete());
  adminDb.transact([...userTxs, ...channelTxs]);
}

reset();

Instant Documentation

The bullets below are links to the Instant documentation. They provide detailed information on how to use different features of InstantDB. Each line follows the pattern of

  • TOPIC: Description of the topic.

Fetch the URL for a topic to learn more about it.

Final Note

Think before you answer. Make sure your code passes typechecks tsc --noEmit and works as expected.
Remember! AESTHETICS ARE VERY IMPORTANT. All apps should LOOK AMAZING and have GREAT FUNCTIONALITY!

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