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payload

build and debug Payload CMS projects

Covers Backend TypeScript CMS Database

Description

Use when working with Payload projects (payload.config.ts, collections, fields, hooks, access control, Payload API). Use when debugging validation errors, security issues, relationship queries, transactions, or hook behavior.

SKILL.md

Payload Application Development

Payload is a Next.js native CMS with TypeScript-first architecture, providing admin panel, database management, REST/GraphQL APIs, authentication, and file storage.

Quick Reference

TaskSolutionDetails
Auto-generate slugsslugField()FIELDS.md#slug-field-helper
Restrict content by userAccess control with queryACCESS-CONTROL.md#row-level-security-with-complex-queries
Local API user opsuser + overrideAccess: falseQUERIES.md#access-control-in-local-api
Draft/publish workflowversions: { drafts: true }COLLECTIONS.md#versioning--drafts
Computed fieldsvirtual: true with field-level hooks.afterRead returning the valueFIELDS.md#virtual-fields
Conditional fieldsadmin.conditionFIELDS.md#conditional-fields
Custom field validationvalidate functionFIELDS.md#validation
Filter relationship listfilterOptions on fieldFIELDS.md#relationship
Select specific fieldsselect parameterQUERIES.md#field-selection
Auto-set author/datesbeforeChange hookHOOKS.md#collection-hooks
Prevent hook loopsreq.context checkHOOKS.md#context
Cascading deletesbeforeDelete hookHOOKS.md#collection-hooks
Geospatial queriespoint field with near/withinFIELDS.md#point-geolocation
Reverse relationshipsjoin field typeFIELDS.md#join-fields
Next.js revalidationContext control in afterChangeHOOKS.md#nextjs-revalidation-with-context-control
Query by relationshipNested property syntaxQUERIES.md#nested-properties
Complex queriesAND/OR logicQUERIES.md#andor-logic
TransactionsPass req to operationsADAPTERS.md#threading-req-through-operations
Background jobsJobs queue with tasksADVANCED.md#jobs-queue
Custom API routesCollection custom endpointsADVANCED.md#custom-endpoints
Cloud storageStorage adapter pluginsADAPTERS.md#storage-adapters
Multi-languagelocalization config + localized: trueADVANCED.md#localization
Create plugin(options) => (config) => ConfigPLUGIN-DEVELOPMENT.md#plugin-architecture
Plugin package setupPackage structure with SWCPLUGIN-DEVELOPMENT.md#plugin-package-structure
Add fields to collectionMap collections, spread fieldsPLUGIN-DEVELOPMENT.md#adding-fields-to-collections
Plugin hooksPreserve existing hooks in arrayPLUGIN-DEVELOPMENT.md#adding-hooks
Check field typeType guard functionsFIELD-TYPE-GUARDS.md

Quick Start

npx create-payload-app@latest my-app
cd my-app
pnpm dev

Minimal Config

import { buildConfig } from 'payload'
import { mongooseAdapter } from '@payloadcms/db-mongodb'
import { lexicalEditor } from '@payloadcms/richtext-lexical'
import path from 'path'
import { fileURLToPath } from 'url'

const filename = fileURLToPath(import.meta.url)
const dirname = path.dirname(filename)

export default buildConfig({
  admin: {
    user: 'users',
    importMap: {
      baseDir: path.resolve(dirname),
    },
  },
  collections: [Users, Media],
  editor: lexicalEditor(),
  secret: process.env.PAYLOAD_SECRET,
  typescript: {
    outputFile: path.resolve(dirname, 'payload-types.ts'),
  },
  db: mongooseAdapter({
    url: process.env.DATABASE_URL,
  }),
})

Essential Patterns

Defaults & Conventions

Apply these defaults when modeling content unless there's a clear reason not to:

  • Enable drafts/versions by default: versions: { drafts: true }. This is the recommended starting point for any content collection. It auto-injects a _status field (draft / published / changed) — don't add your own status field, it's redundant. Only skip versions for collections that have no publish/draft lifecycle (e.g. internal join tables, settings).
  • Use slugField() for all slugs instead of hand-rolling { name: 'slug', type: 'text', unique: true }. It auto-generates the slug from the title, adds a regenerate toggle, and handles uniqueness/indexing for you. It defaults to generating from a title field — if the collection has no title, pass the source field: slugField({ useAsSlug: 'name' }).
  • position: 'sidebar' is for short, at-a-glance fields — status, category, author, publish date. Avoid it for long fields that need horizontal space to be usable (description, rich text content, long text). Those belong in the main document area.

Basic Collection

import type { CollectionConfig } from 'payload'
import { slugField } from 'payload'

export const Posts: CollectionConfig = {
  slug: 'posts',
  admin: {
    useAsTitle: 'title',
    // _status (from versions.drafts) shows the draft/published state — no custom status field needed
    defaultColumns: ['title', 'author', '_status', 'createdAt'],
  },
  versions: {
    drafts: true,
  },
  fields: [
    { name: 'title', type: 'text', required: true },
    slugField(), // auto-generates from `title`, unique + indexed, sidebar position
    { name: 'content', type: 'richText' }, // long field — stays in the main area, not the sidebar
    // short, at-a-glance field — good sidebar candidate
    { name: 'author', type: 'relationship', relationTo: 'users', admin: { position: 'sidebar' } },
  ],
  timestamps: true,
}

For more collection patterns (auth, upload, drafts, live preview), see COLLECTIONS.md.

Common Fields

// Text field
{ name: 'title', type: 'text', required: true }

// Relationship
{ name: 'author', type: 'relationship', relationTo: 'users', required: true }

// Rich text
{ name: 'content', type: 'richText', required: true }

// Slug — use the helper instead of a hand-rolled text field
slugField()

// Select (for genuine taxonomy — NOT publish state; use versions.drafts + _status for that)
{ name: 'category', type: 'select', options: ['news', 'tutorial', 'opinion'] }

// Upload
{ name: 'image', type: 'upload', relationTo: 'media' }

For all field types (array, blocks, point, join, virtual, conditional, etc.), see FIELDS.md.

Hook Example

Hooks live at one of two levels and they are not interchangeable. Collection hooks receive { doc, data, req, operation, ... } and act on the whole document. Field hooks live inside an individual field's hooks object, receive { value, siblingData, ... }, and return the new value for that field. Computed/virtual fields, per-field formatters, and per-field access masking are field hooks; cross-field business logic is a collection hook.

// Collection-level: business logic across the document
export const Posts: CollectionConfig = {
  slug: 'posts',
  hooks: {
    beforeChange: [
      async ({ data, operation }) => {
        if (operation === 'create') {
          data.slug = slugify(data.title)
        }
        return data
      },
    ],
  },
  fields: [{ name: 'title', type: 'text' }],
}

// Field-level: compute / format a single field's value (virtual fields use this)
export const Users: CollectionConfig = {
  slug: 'users',
  fields: [
    { name: 'firstName', type: 'text' },
    { name: 'lastName', type: 'text' },
    {
      name: 'fullName',
      type: 'text',
      virtual: true,
      hooks: {
        afterRead: [({ siblingData }) => `${siblingData.firstName} ${siblingData.lastName}`],
      },
    },
  ],
}

When asked to "compute a field" or "populate a field's value in a hook", use a field-level hook on that field — never a collection-level afterRead that mutates doc.

For all hook patterns, see HOOKS.md. For access control, see ACCESS-CONTROL.md.

Access Control with Type Safety

import type { Access } from 'payload'
import type { User } from '@/payload-types'

// Type-safe access control
export const adminOnly: Access = ({ req }) => {
  const user = req.user as User
  return user?.roles?.includes('admin') || false
}

// Row-level access control
export const ownPostsOnly: Access = ({ req }) => {
  const user = req.user as User
  if (!user) return false
  if (user.roles?.includes('admin')) return true

  return {
    author: { equals: user.id },
  }
}

Query Example

// Local API
const posts = await payload.find({
  collection: 'posts',
  where: {
    status: { equals: 'published' },
    'author.name': { contains: 'john' },
  },
  depth: 2,
  limit: 10,
  sort: '-createdAt',
})

// Query with populated relationships
const post = await payload.findByID({
  collection: 'posts',
  id: '123',
  depth: 2, // Populates relationships (default is 2)
})
// Returns: { author: { id: "user123", name: "John" } }

// Without depth, relationships return IDs only
const post = await payload.findByID({
  collection: 'posts',
  id: '123',
  depth: 0,
})
// Returns: { author: "user123" }

For all query operators and REST/GraphQL examples, see QUERIES.md.

Getting Payload Instance

// In API routes (Next.js)
import { getPayload } from 'payload'
import config from '@payload-config'

export async function GET() {
  const payload = await getPayload({ config })

  const posts = await payload.find({
    collection: 'posts',
  })

  return Response.json(posts)
}

// In Server Components
import { getPayload } from 'payload'
import config from '@payload-config'

export default async function Page() {
  const payload = await getPayload({ config })
  const { docs } = await payload.find({ collection: 'posts' })

  return <div>{docs.map(post => <h1 key={post.id}>{post.title}</h1>)}</div>
}

Security Pitfalls

1. Local API Access Control (CRITICAL)

By default, Local API operations bypass ALL access control, even when passing a user.

// ❌ SECURITY BUG: Passes user but ignores their permissions
await payload.find({
  collection: 'posts',
  user: someUser, // Access control is BYPASSED!
})

// ✅ SECURE: Actually enforces the user's permissions
await payload.find({
  collection: 'posts',
  user: someUser,
  overrideAccess: false, // REQUIRED for access control
})

When to use each:

  • overrideAccess: true (default) - Server-side operations you trust (cron jobs, system tasks)
  • overrideAccess: false - When operating on behalf of a user (API routes, webhooks)

See QUERIES.md#access-control-in-local-api.

2. Transaction Failures in Hooks

Nested operations in hooks without req break transaction atomicity.

// ❌ DATA CORRUPTION RISK: Separate transaction
hooks: {
  afterChange: [
    async ({ doc, req }) => {
      await req.payload.create({
        collection: 'audit-log',
        data: { docId: doc.id },
        // Missing req - runs in separate transaction!
      })
    },
  ]
}

// ✅ ATOMIC: Same transaction
hooks: {
  afterChange: [
    async ({ doc, req }) => {
      await req.payload.create({
        collection: 'audit-log',
        data: { docId: doc.id },
        req, // Maintains atomicity
      })
    },
  ]
}

See ADAPTERS.md#threading-req-through-operations.

3. Infinite Hook Loops

Hooks triggering operations that trigger the same hooks create infinite loops.

// ❌ INFINITE LOOP
hooks: {
  afterChange: [
    async ({ doc, req }) => {
      await req.payload.update({
        collection: 'posts',
        id: doc.id,
        data: { views: doc.views + 1 },
        req,
      }) // Triggers afterChange again!
    },
  ]
}

// ✅ SAFE: Use context flag
hooks: {
  afterChange: [
    async ({ doc, req, context }) => {
      if (context.skipHooks) return

      await req.payload.update({
        collection: 'posts',
        id: doc.id,
        data: { views: doc.views + 1 },
        context: { skipHooks: true },
        req,
      })
    },
  ]
}

See HOOKS.md#context.

Project Structure

src/
├── app/
│   ├── (frontend)/
│   │   └── page.tsx
│   └── (payload)/
│       └── admin/[[...segments]]/page.tsx
├── collections/
│   ├── Posts.ts
│   ├── Media.ts
│   └── Users.ts
├── globals/
│   └── Header.ts
├── components/
│   └── CustomField.tsx
├── hooks/
│   └── slugify.ts
└── payload.config.ts

Building & Type Generation

Payload generates payload-types.ts for you — you rarely need to run generate:types by hand.

  • During development: typescript.autoGenerate defaults to true, so the dev server regenerates types automatically whenever your config changes. Don't run generate:types manually while the dev server is running — it's redundant.
  • During builds: payload build generates the import map and types before running next build. Prefer it over calling next build directly so neither is ever stale. Pass --no-types to skip type generation.
  • Manual generation (payload generate:types) is an escape hatch — only when neither the dev server nor a build is in the loop (e.g. a one-off script, or CI before a step that doesn't run payload build).
// payload.config.ts
export default buildConfig({
  typescript: {
    outputFile: path.resolve(dirname, 'payload-types.ts'),
    // autoGenerate defaults to true — types regenerate in dev automatically
  },
})

// Usage
import type { Post, User } from '@/payload-types'

Common Gotchas

  1. Local API bypasses access control unless you pass overrideAccess: false
  2. Missing req in nested operations breaks transaction atomicity
  3. Hook loops — operations in hooks can re-trigger the same hooks; use req.context flags
  4. Field-level access returns boolean only, no query constraints
  5. Relationship depth defaults to 2; set depth: 0 for IDs only
  6. Draft status_status field is auto-injected when drafts are enabled
  7. Types regenerate automatically in dev (autoGenerate) and during payload build — avoid running generate:types manually
  8. MongoDB transactions require replica set configuration
  9. SQLite transactions are disabled by default; enable with transactionOptions: {}
  10. Point fields are not supported in SQLite

Best Practices

Content Modeling

  • Enable versions: { drafts: true } by default on content collections; rely on the auto-injected _status field rather than adding a custom status field
  • Use slugField() for slugs instead of hand-rolling a unique text field
  • Reserve position: 'sidebar' for short, at-a-glance fields (status, category, author, date); keep long fields (description, rich text) in the main area

Security

  • Default to restrictive access, gradually add permissions
  • Use overrideAccess: false when passing user to Local API
  • Field-level access only returns boolean (no query constraints)
  • Never trust client-provided data
  • Use saveToJWT: true for roles to avoid database lookups

Performance

  • Index frequently queried fields
  • Use select to limit returned fields
  • Set maxDepth on relationships to prevent over-fetching
  • Prefer query constraints over async operations in access control
  • Cache expensive operations in req.context

Data Integrity

  • Always pass req to nested operations in hooks
  • Use context flags to prevent infinite hook loops
  • Enable transactions for MongoDB (requires replica set) and Postgres
  • Use beforeValidate for data formatting
  • Use beforeChange for business logic

Type Safety

  • Let dev (autoGenerate) and payload build generate types; run generate:types manually only when neither is running
  • Import types from generated payload-types.ts
  • Type your user object: import type { User } from '@/payload-types'
  • Use field type guards for runtime type checking
  • When extracting any Payload value into a named constant — a collection, field, hook, access function, plugin, etc. — annotate it with the matching Payload type (CollectionConfig, Field, CollectionBeforeChangeHook, Access, Plugin, …) or use satisfies <Type>. Without an annotation, string properties like type: 'text' widen to string and discriminated unions (Field, CollectionConfig) fail to resolve. Inline literals get this for free via contextual typing; extracted constants do not.

Organization

  • Keep collections in separate files
  • Extract access control to access/ directory
  • Extract hooks to hooks/ directory
  • Use reusable field factories for common patterns
  • Document complex access control with comments

Reference Documentation

  • FIELDS.md - All field types, validation, admin options
  • FIELD-TYPE-GUARDS.md - Type guards for runtime field type checking and narrowing
  • COLLECTIONS.md - Collection configs, auth, upload, drafts, live preview
  • HOOKS.md - Collection hooks, field hooks, context patterns
  • ACCESS-CONTROL.md - Collection, field, global access control, RBAC, multi-tenant
  • ACCESS-CONTROL-ADVANCED.md - Context-aware, time-based, subscription-based access, factory functions, templates
  • QUERIES.md - Query operators, Local/REST/GraphQL APIs
  • ENDPOINTS.md - Custom API endpoints: authentication, helpers, request/response patterns
  • ADAPTERS.md - Database, storage, email adapters, transactions
  • ADVANCED.md - Authentication, jobs, endpoints, components, plugins, localization
  • PLUGIN-DEVELOPMENT.md - Plugin architecture, monorepo structure, patterns, best practices

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