Agent Skills: TanStack Form v1 Core Features

Also covers array/nested fields with dot notation, listeners for side effects (onMount/onChange/onBlur with debouncing), linked/cross-field validation, reactivity via useStore selectors, the Reset API, SSR/hydration (TanStack Start), devtools, and React Native patterns. This is the React skill for TanStack Form — for the Next.js Server Actions-specific variant see nextjs-tanstack-form, and for SOLID file-organization rules see solid-react. </objective>

TanStack Form v1 Core Features

Agent Workflow (MANDATORY)

Before ANY implementation, spawn 3 agents in parallel, one Agent call each with a name:

1. fuse-ai-pilot:explore-codebase - Analyze existing form components and validation patterns
2. fuse-ai-pilot:research-expert - Verify latest TanStack Form v1 docs via Context7/Exa
3. mcp__context7__query-docs - Check Zod validation and React 19 Server Actions patterns

After implementation, run fuse-ai-pilot:sniper for validation.

MANDATORY: SOLID Principles

ALWAYS apply SOLID principles from solid-react skill.

→ See ../solid-react/SKILL.md for complete rules

Key Rules:

• Source files stay within FUSE_SOLID_MAX_LINES and split by responsibility when cohesion drops
• Interfaces in modules/[feature]/src/interfaces/
• JSDoc mandatory on all exports
• No business logic in components

Core Hooks

| Hook | Purpose | Guide | |------|---------|-------| | useForm() | Initialize form with validation | references/tanstack-form-basics.md | | useField() | Subscribe to individual field | references/tanstack-form-basics.md | | form.Field | Render prop component for fields | references/tanstack-form-basics.md | | form.Subscribe | Watch form state changes | references/tanstack-form-basics.md |

→ See references/tanstack-form-basics.md for detailed usage

Validation Adapters

TanStack Form v1 (@tanstack/react-form 1.33.x) supports Standard Schema natively — pass the schema itself to validators (onChange: userSchema). No adapter: validatorAdapter and @tanstack/zod-form-adapter (last release 0.42.1, pre-v1, Zod 3 only) are removed/obsolete.

| Library | Usage | Min version | Bundle Size | |---------|-------|-------------|-------------| | Zod | validators: { onChange: schema } | 3.24.0 | ~12KB | | Yup | validators: { onChange: schema } | 1.7.0 | ~40KB | | Valibot | validators: { onChange: schema } | 1.0.0 | ~6KB |

→ See references/zod-validation.md for Zod patterns → See references/yup-valibot.md for alternatives

Key Features

Async Validation

Server-side checks with debouncing and loading states. → See references/async-validation.md

Server Actions (React 19)

Integration with useActionState and progressive enhancement. → See references/server-actions.md

Arrays & Nested Fields

Dynamic field arrays and dot notation for nested objects. → See references/arrays-nested.md

TypeScript Integration

Full type inference from Zod schemas and defaultValues. → See references/typescript.md

shadcn/ui Integration

Field wrapper components with shadcn styling. → See references/shadcn-integration.md

Listeners (Side Effects)

onMount, onChange, onBlur, onSubmit with debouncing. → See references/listeners.md

Linked Fields

Cross-field validation and dependent dropdowns. → See references/linked-fields.md

Reactivity & Performance

useStore selectors and granular subscriptions. → See references/reactivity.md

Reset API

Form and field reset with custom values. → See references/reset-api.md

SSR & Hydration

TanStack Start integration and server state merge. → See references/ssr-hydration.md

Devtools

Debug form state with @tanstack/react-form-devtools. → See references/devtools.md

React Native

Mobile-specific patterns with TextInput. → See references/react-native.md

Standard Schema

ArkType and Effect Schema support. → See references/standard-schema.md

Templates

| Template | Use Case | |----------|----------| | templates/basic-form.md | Login/signup with Zod | | templates/multi-step-form.md | Wizard with step validation | | templates/dynamic-fields.md | Add/remove field arrays | | templates/file-upload-form.md | File input with preview | | templates/server-action-form.md | React 19 Server Actions | | templates/optimistic-form.md | useOptimistic integration | | templates/nested-form.md | Dot notation nested fields | | templates/search-form.md | Debounced search | | templates/conditional-fields.md | Show/hide based on values | | templates/form-composition.md | Reusable field components | | templates/listeners-form.md | Side effects & auto-save | | templates/linked-fields-form.md | Cross-field validation | | templates/reactivity-form.md | Performance optimization | | templates/reset-form.md | Form/field reset patterns | | templates/ssr-form.md | SSR & hydration | | templates/devtools-form.md | Devtools integration | | templates/react-native-form.md | React Native forms |

Best Practices

1. Validation: Use Zod/Yup/Valibot, NOT custom regex
2. Async: Debounce server validation (300-500ms)
3. Errors: Display field.state.meta.errors
4. Nested: Use dot notation (address.street)
5. Arrays: Use mode="array" with pushValue/removeValue
6. TypeScript: Infer types with z.infer<typeof schema>

Forbidden (Anti-Patterns)

• ❌ useState for form state → use useForm()
• ❌ Regex validation → use Zod/Yup/Valibot
• ❌ No debounce on async → use onChangeAsyncDebounceMs
• ❌ Validation in components → move to schema
• ❌ Direct onChange → use field.handleChange
• ❌ No TypeScript types → use z.infer<typeof schema>