npm package: @libar-dev/zod-convex-builders
Description: Authentication-aware function builders for Convex with Zod v4
Author: Libar AI
Latest version: 0.1.0

# @libar-dev/zod-convex-builders

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Authentication-aware function builders for Convex with zero-runtime validation using generated PropertyValidators.

## Why This Package?

### Zero-Cast Integration
- ✅ **HTTP actions**: Function pattern eliminates FunctionReference casts
- ✅ **Log payloads**: Fixed `Record<string, unknown>` (no generic needed)
- ✅ **3 generic parameters**: Avoids generic explosion (DataModel, TUserId, TMembership)
- ✅ **50-70% code reduction**: Similar to convex-workflows migration

### Core Features
- **90% Bundle Reduction** - Zero runtime Zod (60-65MB → 10-15MB) via generated PropertyValidators
- **Full Type Safety** - Type-only Zod imports with complete type inference
- **Authentication Builders** - Create auth-aware queries, mutations, actions, AND HTTP endpoints with branded types
- **HTTP Authentication** - Centralized CORS + auth for HTTP actions (zero manual infrastructure, zero casts)
- **Return Validation** - Optional runtime validation for function boundaries
- **Test Utilities** - Helpers for testing functions with VObject return types

## Installation

```bash
npm install @libar-dev/zod-convex-builders zod@^4.1.0
```

**Peer Dependencies:**
- `convex` >=1.30.0 <2.0.0
- `zod` ^4.1.0 (build-time only, zero runtime cost)

**Dependencies:**
- `@libar-dev/zod-convex-core` - Core conversion engine
- `@libar-dev/zod-convex-codecs` - Bidirectional codecs

**Build-Time Tools:**
- `@libar-dev/zod-convex-gen` - Validator generation CLI (REQUIRED for 90% reduction)

## Quick Start

### 1. Define Schema (Build-Time Only)

```typescript
// src/validation-schemas/getUser.ts
import { z } from 'zod';
import { createIdValidators } from '@libar-dev/zod-convex-ids';

const ids = createIdValidators({ user: 'users' } as const);

export const GetUserArgsSchema = z.object({
  userId: ids.userId(),
}).strict();

export type GetUserArgs = z.infer<typeof GetUserArgsSchema>; // REQUIRED
```

### 2. Generate Validators

```bash
npm run generate:validators
# Creates: convex/generatedValidators/getUser.ts
```

### 3. Use in Convex Functions

```typescript
// convex/users.ts
import type { GetUserArgs } from '../src/validation-schemas/getUser';
import { getUserArgsFields } from './generatedValidators/getUser';
import { zQuery } from '@libar-dev/zod-convex-builders';
import { query } from './_generated/server';

export const getUser = zQuery(
  query,
  getUserArgsFields,  // PropertyValidators (NO runtime Zod)
  async (ctx, args: GetUserArgs) => {
    return await ctx.db.get(args.userId);
  }
);
```

**👉 For complete end-to-end guide, see [`examples/withReturns.ts`](./examples/withReturns.ts)**

## Core Features

### Function Wrappers

| Wrapper | Visibility | Use Case |
|---------|-----------|----------|
| `zQuery`, `zMutation`, `zAction` | Public | Client-callable functions |
| `zInternalQuery`, `zInternalMutation`, `zInternalAction` | Internal | Server-only functions |
| `zCustomQuery`, `zCustomMutation`, `zCustomAction` | Configurable | Custom context extension |

### Authentication Builders

Create auth-aware functions with **zero-cast integration**:

```typescript
import { createAuthWrappers } from '@libar-dev/zod-convex-builders';

const authWrappers = createAuthWrappers<DataModel, UserId, Membership>(
  {
    getAuthenticatedUserId: async (ctx) => asUserId(identity.subject),
    getUserMemberships: async (ctx, userId) => getMemberships(ctx, userId),
    workflowUserMarker: asWorkflowUserId('WORKFLOW_USER'),
    isAdminRole: (membership) => membership.role === 'admin',
    // ... more config
  },
  { query, mutation, action }
);

export const zAuthenticatedQuery = authWrappers.zAuthenticatedQuery;
export const zAuthenticatedMutation = authWrappers.zAuthenticatedMutation;
// ... more exports
```

**Available Builders:**
- `zAuthenticatedQuery/Mutation/Action` - Requires authentication
- `zOptionalAuthQuery/Mutation` - Optional authentication
- `zAdminQuery/Mutation` - Admin-only access

**👉 For complete authentication setup, see [`examples/README.md`](./examples/README.md#authentication-patterns)**

### HTTP Authentication Wrappers

Create auth-aware HTTP actions with **centralized CORS** and **zero infrastructure code**:

```typescript
import { createHttpAuthWrappers } from '@libar-dev/zod-convex-builders';
import { httpAction } from './_generated/server';
import { internal } from './_generated/api';

const httpAuthWrappers = createHttpAuthWrappers<DataModel, UserId, Membership>(
  {
    getUserIdFromIdentity: (subject) => asUserId(subject),

    // Function pattern (NOT FunctionReference) - consumer writes wrapper
    getUserMemberships: async (ctx, userId) => {
      return await ctx.runQuery(internal.auth.getMemberships, { userId });
    },

    verifyEntityAccess: async (ctx, userId, entityId) => {
      return await ctx.runQuery(internal.auth.checkEntityAccess, { userId, entityId });
    },

    cors: {
      clientOrigin: process.env.CLIENT_ORIGIN,
      fallbackOrigin: 'http://localhost:3000',
    },
    log: {
      info: (_ctx, data) => console.log(data),
      error: (_ctx, data) => console.error(data),
    },
  },
  httpAction
);

export const { httpAuthenticatedAction } = httpAuthWrappers;

// Usage - ZERO authentication/CORS code in handler!
export const streamAiMessage = httpAuthenticatedAction({
  handler: async (ctx, request) => {
    // ctx.userId is UserId (typed, authenticated)
    // ctx.memberships is Membership[] (typed)
    // CORS headers added automatically
    // ZERO casts!

    const body = await request.json();
    // ... business logic only
    return new Response(JSON.stringify({ success: true }));
  }
});
```

**Available Builders:**
- `httpAuthenticatedAction` - Requires authentication, returns 401 if not authenticated
- `httpOptionalAuthAction` - Optional authentication (userId/memberships null if not authenticated)
- `httpAdminAction` - Admin-only access, returns 403 if not admin

**Key Benefits:**
- ✅ **Zero manual authentication** - Wrapper handles identity verification
- ✅ **Automatic CORS headers** - Centralized configuration
- ✅ **Typed contexts** - Branded UserId and Membership types flow automatically
- ✅ **Optional authorization** - `ctx.verifyEntityAccess(entityId)` helper
- ✅ **Response-based errors** - 401/403 responses, not exceptions
- ✅ **Zero casts** - Function pattern eliminates all type casts

### Why Function Pattern Instead of FunctionReference?

**Design Decision**: HTTP wrappers use function pattern (not FunctionReference) for zero-cast integration.

**Reason**: HTTP actions cannot access `ctx.db` directly. Auth wrappers have a unique requirement that workflows don't: **wrappers must call these functions internally with generic-typed arguments and preserve perfect type flow**.

#### Pattern Comparison

| Aspect | FunctionReference Pattern | Function Pattern (Used Here) |
|--------|--------------------------|------------------------------|
| **Wrapper Casts** | 3 casts to `any` required | **0 casts** ✅ |
| **Consumer Code** | Simple (direct reference) | One-time wrapper (~3 lines) |
| **Type Safety** | ⚠️ Casts break type safety | ✅ Full inference chain |
| **Pattern Alignment** | ✅ Framework-native type | ✅ Zero-cast goal (broader principle) |
| **Use Case** | Pass reference to engine | Wrapper **calls** function directly |

#### Key Insight: Context Matters

The Convex-Native pattern recommends FunctionReference as a concrete framework type. However, auth wrappers differ from workflows:

**Workflows** (where FunctionReference works):
- Pass FunctionReference to **engine** (engine handles calls)
- No type preservation needed
- FunctionReference pattern is perfect

**Auth Wrappers** (why function pattern is needed):
- Wrapper **calls** function directly with generic-typed `TUserId`
- Must preserve `TUserId` → `TMembership[]` type flow
- FunctionReference requires casts that defeat zero-cast goal

**Consumer writes one-time wrapper:**
```typescript
getUserMemberships: async (ctx, userId) => {
  return await ctx.runQuery(internal.auth.getMemberships, { userId });
}
// ✅ Zero casts! Types flow automatically: TUserId → TMembership[]
```

**Trade-off Analysis:**
- **FunctionReference**: Simple config (direct reference) but 3 casts in wrapper internals
- **Function Pattern**: One-time wrapper (~3 lines per function) but **zero casts everywhere**

**Decision**: Function pattern prioritizes the **broader Convex-Native goal** (zero-cast integration, perfect type flow) over strict framework type usage. This is a pragmatic deviation that serves the pattern's core principle.

**Benefits:**
- ✅ **Zero casts** (vs 3 casts with FunctionReference pattern)
- ✅ **Consistent with query/mutation wrappers** pattern (same function approach)
- ✅ **Type-safe at all boundaries** - complete inference chain
- ✅ **Consumer controls integration layer** - explicit wrapper code

**👉 For HTTP action patterns, see [`examples/README.md`](./examples/README.md#http-authentication-patterns)**

### Return Type Validation

Add runtime validation to function boundaries:

```typescript
export const getUser = zQuery(
  query,
  getUserArgsFields,
  async (ctx, args) => {
    return await ctx.db.get(args.userId);
  },
  {
    returns: v.union(v.object(userDocFields), v.null()),  // Runtime validation
  }
);
```

**👉 For return validators guide, see [`examples/withReturns.ts`](./examples/withReturns.ts)**

### Test Utilities

Handle VObject types in tests:

```typescript
import { unwrapForTest, isNonNull, extractPage } from '@libar-dev/zod-convex-builders/testUtils';

// Option 1: Type annotation (recommended)
const result = (await mutation(...)) as MessageCreationResult;

// Option 2: Unwrap helper
const result = unwrapForTest<MessageCreationResult>(await mutation(...));

// Nullable results
if (isNonNull(result)) {
  expect(result.name).toBe('John');
}

// Pagination
const items = extractPage(paginatedResult);
```

**Available Utilities:**
- `unwrapForTest<T>()` - Unwrap VObject types
- `unwrapAsyncForTest<T>()` - Async unwrap
- `isNonNull<T>()` - Type guard for nullable
- `extractPage<T>()` - Extract pagination array
- `isDiscriminatedAs()` - Type guard for unions

**👉 For complete testing patterns, see [`examples/testPatterns.ts`](./examples/testPatterns.ts)**

### Branded Types

Type-safe branded types for domain modeling:

```typescript
import {
  type UserId,
  type WorkflowUserId,
  asUserId,
  asWorkflowUserId,
  isWorkflowUserId,
} from '@libar-dev/zod-convex-builders';

const userId = asUserId('user_123');
const workflowId = asWorkflowUserId('WORKFLOW_USER');

if (isWorkflowUserId(ctx.userId)) {
  // Handle workflow context
}
```

## Examples & Resources

### Complete Guides

| File | Description | Lines |
|------|-------------|-------|
| [`examples/withReturns.ts`](./examples/withReturns.ts) | Complete end-to-end flow from schema → validator → function → test | 397 |
| [`examples/testPatterns.ts`](./examples/testPatterns.ts) | 7 comprehensive testing patterns for all return types | 519 |
| [`examples/commonTypes.ts`](./examples/commonTypes.ts) | Reusable schema library (pagination, results, CRUD, etc.) | 438 |
| [`examples/README.md`](./examples/README.md) | Navigation guide and troubleshooting | 323 |

### Quick Navigation

**New to the package?**
1. Read [`examples/withReturns.ts`](./examples/withReturns.ts) for complete understanding
2. Reference [`examples/README.md`](./examples/README.md) for common scenarios

**Writing tests?**
→ See [`examples/testPatterns.ts`](./examples/testPatterns.ts) for all 7 testing patterns

**Building schemas?**
→ See [`examples/commonTypes.ts`](./examples/commonTypes.ts) for reusable patterns

**Migrating from v0.0.x?**
→ See [Migration from Runtime Zod](#migration-from-runtime-zod) below + [`examples/README.md`](./examples/README.md)

**Troubleshooting?**
→ See [`examples/README.md#troubleshooting`](./examples/README.md#troubleshooting)

## API Reference

### Function Wrappers

```typescript
import {
  zQuery,
  zInternalQuery,
  zMutation,
  zInternalMutation,
  zAction,
  zInternalAction,
} from '@libar-dev/zod-convex-builders';

// Usage: zQuery(builder, argsFields, handler, options?)
export const getUser = zQuery(query, getUserArgsFields, async (ctx, args) => {
  return await ctx.db.get(args.userId);
});
```

### Authentication Wrappers Factory

```typescript
import { createAuthWrappers } from '@libar-dev/zod-convex-builders';

const wrappers = createAuthWrappers<DataModel, UserId, Membership>(
  config,
  { query, mutation, action }
);

// Returns:
// - zAuthenticatedQuery, zAuthenticatedMutation, zAuthenticatedAction
// - zOptionalAuthQuery, zOptionalAuthMutation
// - zAdminQuery, zAdminMutation (if isAdminRole provided)
```

### HTTP Authentication Wrappers Factory

```typescript
import { createHttpAuthWrappers } from '@libar-dev/zod-convex-builders';

const httpWrappers = createHttpAuthWrappers<DataModel, UserId, Membership>(
  {
    getUserIdFromIdentity: (subject) => asUserId(subject),

    // Function pattern for zero-cast integration
    getUserMemberships: async (ctx, userId) => {
      return await ctx.runQuery(internal.auth.getMemberships, { userId });
    },

    verifyEntityAccess: async (ctx, userId, entityId) => {
      return await ctx.runQuery(internal.auth.checkEntityAccess, { userId, entityId });
    },

    cors: {
      clientOrigin: process.env.CLIENT_ORIGIN,
      fallbackOrigin: 'http://localhost:3000',
    },
    log: {
      info: (_ctx, data) => console.log(data),
      error: (_ctx, data) => console.error(data),
    },
  },
  httpAction
);

// Returns:
// - httpAuthenticatedAction - Requires authentication
// - httpOptionalAuthAction - Optional authentication
// - httpAdminAction - Admin-only (if isAdminRole provided)
```

### Custom Function Integration

```typescript
import { zCustomQuery, zCustomMutation, zCustomAction, NoOp } from '@libar-dev/zod-convex-builders';

export const zq = zCustomQuery(query, NoOp);
export const zm = zCustomMutation(mutation, NoOp);
```

### Test Utilities (TEST CODE ONLY)

```typescript
import {
  unwrapForTest,
  unwrapAsyncForTest,
  isNonNull,
  extractPage,
  isDiscriminatedAs,
} from '@libar-dev/zod-convex-builders/testUtils';
```

### Branded Types

```typescript
import {
  type UserId,
  type WorkflowUserId,
  type MembershipId,
  type AnyUserId,
  asUserId,
  asWorkflowUserId,
  asMembershipId,
  isWorkflowUserId,
} from '@libar-dev/zod-convex-builders';
```

## Memory Optimization

**PropertyValidators-Only Pattern** achieves massive bundle reduction:

- **Before**: ~60-65MB bundle (runtime Zod validation)
- **After**: ~10-15MB bundle (generated PropertyValidators)
- **Reduction**: 75-83% decrease in memory usage

### How It Works

1. Define Zod schemas in `src/validation-schemas/` (outside Convex bundle)
2. Run `npm run generate:validators` to create PropertyValidators
3. Import type-only Zod (`import type { z }`) in Convex functions
4. Use generated validators (`getUserArgsFields`) at runtime

**Result**: Zero runtime Zod, full type safety maintained.

### Verify Bundle Reduction

```bash
# Build and check bundle size
npx convex dev --once --debug-bundle-path
ls -lh .convex/bundle/  # Expected: ~10-15MB

# Compare with runtime Zod (before migration)
du -sh .convex/bundle/  # Should show 75-83% reduction
```

**Tested environment**: 56+ table schemas, 100+ functions, production Convex app

## Migration from Runtime Zod

**If upgrading from v0.0.x** (runtime Zod pattern):

### Before (v0.0.x - DEPRECATED)

```typescript
import { z } from 'zod';  // Runtime import ❌
import { zQuery } from '@libar-dev/zod-convex-builders';

export const getUser = zQuery(
  query,
  z.object({ userId: z.string() }),  // Runtime Zod ❌
  async (ctx, args) => { /* ... */ }
);
```

### After (v0.1.0+ - REQUIRED)

```typescript
// 1. Move schema to src/validation-schemas/getUser.ts
export const GetUserArgsSchema = z.object({ userId: ids.userId() }).strict();
export type GetUserArgs = z.infer<typeof GetUserArgsSchema>; // ✅ REQUIRED

// 2. Generate: npm run generate:validators

// 3. Use PropertyValidators
import type { GetUserArgs } from '../src/validation-schemas/getUser';  // ✅ Type-only
import { getUserArgsFields } from './generatedValidators/getUser';  // ✅ Generated

export const getUser = zQuery(query, getUserArgsFields, async (ctx, args: GetUserArgs) => {
  return await ctx.db.get(args.userId);
});
```

### Migration Checklist

- [ ] Move Zod schemas from `convex/` to `src/validation-schemas/`
- [ ] Add type alias exports to all schemas (`export type`)
- [ ] Run `npm run generate:validators`
- [ ] Update functions to use generated validators
- [ ] Change `import { z }` → `import type { z }` in Convex files
- [ ] Verify bundle: Should be ~10-15MB (down from 60-65MB)

**👉 For complete migration guide, see [`examples/README.md`](./examples/README.md)**

## Convex-Native Pattern

This package uses **optional generic parameters with defaults** for zero-cast integration:

```typescript
export interface AuthConfig<
  DataModel extends GenericDataModel,
  TUserId extends string = string,      // ✅ Default: backward compatible
  TMembership = unknown                   // ✅ Flexible default
>
```

**Convex-Native Pattern**: Limited to 3 type parameters maximum:
- `DataModel` (Convex GenericDataModel)
- `TUserId` (User ID type, default: string)
- `TMembership` (Membership type, default: unknown)

**Note**: Previous versions had 4 parameters (including TLogPayload), but this was removed to avoid generic explosion. Log payloads now use fixed `Record<string, unknown>` type.

**Benefits**:
- ✅ **Zero casts** - Types flow from factory config through all consumers
- ✅ **Centralized config** - Configure once, use everywhere
- ✅ **Backward compatible** - Defaults work for existing code
- ✅ **Type safety** - Full branded type support with IntelliSense
- ✅ **50-70% code reduction** - Function pattern eliminates wrapper overhead

## Development

### Building from Source

```bash
# Monorepo development
npm run build:packages  # Builds all packages

# Standalone development
npm run build  # Uses committed validators
```

### Modifying Schemas

```bash
# After editing src/schemas/
npm run generate:validators
git add src/generatedValidators/
npm run build
```

**Published Package**: Ships with pre-built `dist/` - no build step required.

## Performance

### Validation Overhead

- **Validation happens once** at function boundary
- **Return validation is optional** - use when needed
- **Codecs are cached** - no repeated parsing
- **Type inference is compile-time** - zero runtime overhead

### PropertyValidators Performance

**PropertyValidators Path** (RECOMMENDED):
- Zero Zod parsing - validators passed directly to Convex runtime
- Single validation - Convex validates once at function entry
- No codec conversion - args passed through without transformation
- **Result**: 75-83% memory reduction (60-65MB → 10-15MB)

### Validation Strength

PropertyValidators provide **complete validation guarantees**:
- Structural validation (types, IDs, nested objects)
- Business rules (email format, string length, refinements)

**Key Insight**: PropertyValidators use Convex's optimized validator system, generated from Zod schemas. Business rules preserved during generation.

## Visibility Preservation

The builders correctly preserve Convex's visibility type system:

```typescript
// Public - appears in api.queries
export const myPublicQuery = zAuthenticatedQuery({ ... });

// Internal - appears in api.internal.queries only
export const myInternalQuery = zInternalAuthenticatedQuery({ ... });
```

**Runtime properties**:
```typescript
myPublicQuery.isPublic === true;
myInternalQuery.isInternal === true;
```

## Related Packages

- [`@libar-dev/zod-convex-gen`](https://www.npmjs.com/package/@libar-dev/zod-convex-gen) - Generate Convex validators (REQUIRED for 90% reduction)
- [`@libar-dev/zod-convex-core`](https://www.npmjs.com/package/@libar-dev/zod-convex-core) - Core conversion engine
- [`@libar-dev/zod-convex-ids`](https://www.npmjs.com/package/@libar-dev/zod-convex-ids) - Type-safe ID validation
- [`@libar-dev/zod-convex-codecs`](https://www.npmjs.com/package/@libar-dev/zod-convex-codecs) - Bidirectional codecs
- [`@libar-dev/zod-convex-tables`](https://www.npmjs.com/package/@libar-dev/zod-convex-tables) - Table utilities

## License

MIT License - See [LICENSE](./LICENSE) file for details.

Copyright (c) 2025 Libar AI