Content Type Builder#

The Content Type Builder (CTB) is the admin UI plugin (packages/core/content-type-builder) for defining and editing the schemas of content types and components in Strapi. It operates exclusively in development mode — all edits are staged in client-side Redux state and not written to disk until the user explicitly saves.

The CTB is split across two packages:

Important distinction: Schema files (on disk) define field types and structure. Display configuration — list/edit view layout, field metadata — lives separately in the database, managed by packages/core/content-manager/server/. See the Plugin Configuration and Layout Storage section below.

Client-Side State: DataManager#

All pending schema changes live in a Redux store managed by the DataManager. The central files are:

• DataManagerProvider.tsx — wraps the CTB UI, fetches initial schema data, and exposes saveSchema()
• DataManagerContext.ts — TypeScript interface for context value; declares moveAttribute, saveSchema, and other mutations
• useDataManager.ts — thin useContext wrapper consumed by every CTB component
• reducer.ts — Redux Toolkit slice with full undo/redo (50-step history limit) 1

The state shape holds a working copy (contentTypes, components) alongside the initial copy (initialContentTypes, initialComponents) loaded from the server 2. Each schema and attribute carries an explicit status field: NEW | CHANGED | UNCHANGED | REMOVED.

Key Reducers#

Development mode gate: SortableRow disables drag handles when !isInDevelopmentMode or when the type/attribute status is REMOVED 5.

Drag-and-Drop Attribute Reordering#

The attribute list is rendered in List.tsx, which uses @dnd-kit/core with a verticalListSortingStrategy 6. Each row is a SortableRow wrapping AttributeRow via useSortable from @dnd-kit/sortable.

On DragEnd, the handler calls moveAttribute from useDataManager with the source and destination indices 7. This dispatches the moveAttribute reducer action, which does a splice/insert in the attributes array and marks the parent type as CHANGED 3.

Key behaviours:

• Movement is restricted to the vertical axis via restrictToVerticalAxis modifier 8
• A DragOverlay portal renders the dragged item on top of other content 9
• Both PointerSensor and KeyboardSensor are registered for accessibility 10

Reordering is optimistic and local — the new order is not persisted until the user clicks "Save" and triggers saveSchema().

Saving Schema Changes#

When the user saves, saveSchema() in DataManagerProvider calls stateToRequestData(), which:

1. Filters only schemas with status NEW | CHANGED | REMOVED 11
2. Maps each schema through formatTypeForRequest(), which translates status → action (create / update / delete) and flattens info/options into the root object 12
3. Sends every attribute regardless of individual attribute status — the comment in the source explicitly notes this preserves field order 13
4. Returns tracking event counts for analytics alongside the formatted payload 14

The formatted payload is POSTed to /update-schema 15, a development-mode-only route protected by admin::hasPermissions.

Server-Side Flow#

1. schema.ts controller — validates the payload via validateUpdateSchema(), sets internals.isUpdating = true to block concurrent saves, and delegates to the schema service 16
2. schema.ts service — creates new types first, then updates existing ones, writes schema files to disk, and emits EventHub events for create / update / delete lifecycle hooks 17
3. Server reload — strapi.reload() is called after the file write, restarting the Strapi process to pick up the new schema files 18

Plugin Configuration and Layout Storage (Content Manager)#

Schema files (on disk) define field types and constraints. Display configuration — list/edit view layout, field metadata, settings — is stored separately in the database via Strapi's strapi::core-store entity under the key prefix plugin_content_manager_configuration_ 19.

Store Layer (store.ts)#

packages/core/content-manager/server/src/services/utils/store.ts is the low-level utility:

• getModelConfiguration(key) — reads from the core store and merges with EMPTY_CONFIG ({ settings:{}, metadatas:{}, layouts:{ list:[], edit:[] } }) 20
• getModelConfigurations(keys[]) — batch loads multiple configs in one DB query using $in 21
• setModelConfiguration(key, value) — merges partial updates into the stored record and skips writes when the config is unchanged 22
• deleteKey(key) — hard-deletes from strapi::core-store 23

Configuration Service (configuration.ts)#

packages/core/content-manager/server/src/services/configuration.ts is a factory that wraps storeUtils and adds:

• A prefix (e.g. content_types or components) namespacing keys as {prefix}::{uid} 24
• syncConfigurations() — on each server start, compares stored UIDs against currently registered schemas and automatically creates, updates, or deletes configuration records to keep them in sync 25

Content Types Service (content-types.ts)#

packages/core/content-manager/server/src/services/content-types.ts is the public API consumed by controllers:

• findConfiguration(contentType) — retrieves the stored config for a UID 26
• updateConfiguration(contentType, newConfiguration) — persists admin-edited layout changes 27
• syncConfigurations() — delegates to the configuration service for startup sync 28

The prefix for content types is 'content_types'; for components it is 'components' (defined when createConfigurationService is called for each service) 29.