Tanstack Comprehensive

Complete guide to Tanstack Start, Router, and Query patterns for full-stack type-safe applications.

Overview

This skill covers the complete Tanstack ecosystem used in this project:

• Tanstack Router - File-based routing with type-safe navigation
• Tanstack Query - Data fetching, caching, and state management
• Tanstack Start - Server-side rendering and data loading
• tRPC Integration - Type-safe API calls

When to Apply

Reference these guidelines when:

• Creating or modifying routes
• Implementing data fetching (client or server-side)
• Working with loaders, queries, or mutations
• Handling navigation or URL parameters
• Integrating forms with server operations
• Optimizing data loading patterns

Quick Reference

Critical Patterns

File-Based Routing:

• Pages: dashboard/index.tsx → /dashboard
• Layouts: _authenticated.tsx → Wraps child routes
• Dynamic: users/$id.tsx → /users/123

Data Loading (Recommended Pattern):

// loader + pendingComponent + useSuspenseQuery
export const Route = createFileRoute('/page')({
  loader: async ({ context }) => {
    await context.queryClient.ensureQueryData(
      context.trpc.myData.queryOptions()
    );
  },
  pendingComponent: MySkeleton,
  component: MyPage,
});

function MyPage() {
  const trpc = useTrpc();
  const { data } = useSuspenseQuery(trpc.myData.queryOptions());
  return <div>{data.name}</div>;
}

tRPC Integration:

// ✅ CORRECT
const { data } = useQuery(trpc.organizations.getCurrent.queryOptions());

// ❌ WRONG - This method doesn't exist
const { data } = trpc.organizations.getCurrent.useQuery();

Navigation:

<Link to="/users/$id" params={{ id: '123' }}>User</Link>

Search Params (Avoid Re-renders):

// ✅ Read on demand
const router = useRouter();
const ref = router.latestLocation.search.ref;

// ❌ Subscribes to all changes
const search = useSearch({ from: '__root__' });
const ref = search.ref;

Architecture

workspace (Tanstack Start)
  ↓ tRPC client
api-trpc (Hono + tRPC)
  ↓ Drizzle ORM
Database (PostgreSQL)

Key Principle: Never access database directly. Always use tRPC procedures.

References

Complete documentation with examples:

• references/routing.md - File-based routing, navigation, params, loaders, authentication
• references/data-fetching.md - Queries, mutations, tRPC integration, SSR patterns, Mastra queries
• references/server-functions.md - Server-side operations, tRPC from workspace, error handling

To find specific patterns:

grep -l "loader" references/*.md
grep -l "useSuspenseQuery" references/*.md
grep -l "search params" references/*.md

Core Concepts

1. Routing Patterns

File Structure Determines URLs:

• index.tsx → Route root (e.g., /dashboard)
• _layout.tsx → Layout wrapper (doesn't affect URL)
• $param.tsx → Dynamic segment
• Nested folders → Nested routes

Type-Safe Navigation:

// Link component
<Link to="/users/$id" params={{ id }}>User</Link>

// Programmatic
const navigate = useNavigate();
navigate({ to: '/dashboard', search: { tab: 'overview' } });

// In component
const { id } = Route.useParams(); // Type-safe
const { tab } = Route.useSearch(); // Type-safe

2. Data Loading Patterns

Recommended: loader + pendingComponent + useSuspenseQuery

Why this pattern?

• Skeleton shows immediately (no blank screen)
• No duplicate queries (loader preloads, component reads cache)
• Simpler component code (data always available)
• Better UX (immediate visual feedback)

export const Route = createFileRoute('/dashboard')({
  loader: async ({ context }) => {
    // Preload all data in parallel
    await Promise.all([
      context.queryClient.ensureQueryData(
        context.trpc.organizations.getCurrent.queryOptions()
      ),
      context.queryClient.ensureQueryData(
        context.trpc.members.list.queryOptions()
      ),
    ]);
  },
  pendingComponent: DashboardSkeleton,
  component: DashboardPage,
});

function DashboardPage() {
  const trpc = useTrpc();
  // Data guaranteed - no loading checks needed
  const { data: org } = useSuspenseQuery(
    trpc.organizations.getCurrent.queryOptions()
  );
  const { data: members } = useSuspenseQuery(
    trpc.members.list.queryOptions()
  );

  return <div>{org.name} - {members.length} members</div>;
}

Anti-Pattern: useQuery + manual loading check

// ❌ DON'T DO THIS
function MyPage() {
  const { data, isLoading } = useQuery(...);

  if (isLoading || !data) {
    return <MySkeleton />; // Causes blank screen flash
  }

  return <div>{data.name}</div>;
}

3. tRPC Integration

CRITICAL: The project uses createTRPCOptionsProxy which provides factory functions, NOT hooks.

Correct Usage:

import { useQuery, useMutation } from '@tanstack/react-query';
import { trpc } from '@/trpc';

// Queries
const { data } = useQuery(
  trpc.organizations.getCurrent.queryOptions()
);

// With params
const { data } = useQuery(
  trpc.users.getById.queryOptions({ id: '123' })
);

// Mutations
const mutation = useMutation(
  trpc.organizations.update.mutationOptions()
);

mutation.mutate({ name: 'New Name' });

Query Invalidation:

import { useQueryClient } from '@tanstack/react-query';

const queryClient = useQueryClient();

// Invalidate specific query
queryClient.invalidateQueries({
  queryKey: [['organizations', 'getCurrent']],
});

// Invalidate all organization queries
queryClient.invalidateQueries({
  queryKey: [['organizations']],
});

4. Search Params Optimization

Problem: useSearch() subscribes to ALL search param changes, causing unnecessary re-renders.

Solution: Read search params on-demand using router.latestLocation.

// ✅ CORRECT - No re-renders
import { useRouter } from '@tanstack/react-router';

function ShareButton({ chatId }: Props) {
  const router = useRouter();

  const handleShare = () => {
    const ref = router.latestLocation.search.ref;
    shareChat(chatId, { ref });
  };

  return <button onClick={handleShare}>Share</button>;
}

// ❌ WRONG - Re-renders on every search param change
import { useSearch } from '@tanstack/react-router';

function ShareButton({ chatId }: Props) {
  const search = useSearch({ from: '__root__' });

  const handleShare = () => {
    const ref = search.ref;
    shareChat(chatId, { ref });
  };

  return <button onClick={handleShare}>Share</button>;
}

5. Route Loaders

Pre-load data before navigation:

export const Route = createFileRoute('/_authenticated/dashboard')({
  loader: async ({ context }) => {
    // Blocks navigation until data loaded
    await context.queryClient.ensureQueryData(
      context.trpc.organizations.getCurrent.queryOptions()
    );
  },
  pendingComponent: DashboardSkeleton,
  component: DashboardPage,
});

6. Protected Routes

import { createFileRoute, redirect } from '@tanstack/react-router';

export const Route = createFileRoute('/_authenticated')({
  beforeLoad: async ({ context }) => {
    const session = await getSession(context);

    if (!session) {
      throw redirect({
        to: '/sign-in',
        search: { redirect: location.href },
      });
    }
  },
});

7. Mastra Queries

For AI chat data (messages, threads), use query functions instead of tRPC:

// src/lib/mastra-queries.ts
export const threadMessagesQueryOptions = (threadId: string) => ({
  queryKey: ['mastra', 'messages', threadId] as const,
  queryFn: async () => {
    const client = createMastraClient();
    const { messages } = await client.listThreadMessages(threadId, {
      agentId: 'retripAgent',
    });
    return toAISdkV5Messages(messages);
  },
});

// In component
const { data: messages } = useSuspenseQuery(
  threadMessagesQueryOptions(threadId)
);

Best Practices

✅ Do:

Routing:

• Use file-based routing for all pages
• Leverage type-safe params and search
• Use Link component for navigation
• Protect routes with beforeLoad
• Validate search params with Zod

Data Fetching:

• Use ensureQueryData in loaders with pendingComponent
• Use useSuspenseQuery for loader-prefetched data
• Use queryOptions() with TanStack Query hooks
• Invalidate queries after mutations
• Handle errors gracefully

Performance:

• Read search params on-demand (not reactively)
• Preload routes before navigation
• Load data in parallel with Promise.all()
• Use optimistic updates for instant feedback

❌ Don't:

Routing:

• Mix file-based and programmatic routing
• Use plain <a> tags for internal navigation
• Skip search param validation
• Create deeply nested layouts unnecessarily

Data Fetching:

• Use non-existent .useQuery() method on trpc object
• Use useQuery + manual if (!data) checks for loader data
• Forget pendingComponent when using loaders
• Skip error handling
• Query database directly from workspace
• Use any types

Performance:

• Subscribe to all search params when you only need one
• Skip route preloading on hover/focus
• Load data sequentially when it could be parallel

Common Patterns

Mutation with Invalidation

const queryClient = useQueryClient();

const mutation = useMutation({
  ...trpc.organizations.update.mutationOptions(),
  onSuccess: () => {
    queryClient.invalidateQueries({
      queryKey: [['organizations', 'getCurrent']],
    });
    toast.success('Updated successfully');
  },
});

Optimistic Updates

const mutation = useMutation({
  ...trpc.apiKeys.delete.mutationOptions(),
  onMutate: async (deletedId) => {
    await queryClient.cancelQueries({
      queryKey: [['apiKeys', 'list']],
    });

    const previous = queryClient.getQueryData([['apiKeys', 'list']]);

    queryClient.setQueryData([['apiKeys', 'list']], (old: any) =>
      old?.filter((key: any) => key.id !== deletedId)
    );

    return { previous };
  },
  onError: (err, deletedId, context) => {
    queryClient.setQueryData([['apiKeys', 'list']], context?.previous);
  },
});

Dependent Queries

const { data: user } = useQuery(
  trpc.users.getById.queryOptions({ id: userId })
);

const { data: posts } = useQuery({
  ...trpc.posts.list.queryOptions({ authorId: user?.id }),
  enabled: !!user,
});

Route Preloading

import { Link, useRouter } from '@tanstack/react-router';

function Navigation() {
  const router = useRouter();

  return (
    <Link
      to="/dashboard"
      onMouseEnter={() => router.preloadRoute('/dashboard')}
      onFocus={() => router.preloadRoute('/dashboard')}
    >
      Dashboard
    </Link>
  );
}

Related Skills

• react-best-practices - Performance optimization patterns
• form-patterns - Form handling with React Hook Form

Version: 1.0.0 Last updated: 2026-01-14