> ## Documentation Index > Fetch the complete documentation index at: https://docs.geogen.io/llms.txt > Use this file to discover all available pages before exploring further. # Create Domain Group > Create a domain group that merges analytics for multiple entities representing the same brand. Entity references in `primaryEntity` and `entities` may be either: - an `entityId` returned by `GET /v1/entities` (a tracking ID for an entity in this workspace), or - an entity UUID returned as `entityUuid` by `GET /v1/competitors` (any entity in the system). At least 2 entities are required, and `primaryEntity` must be included in the `entities` array. Each entity may belong to at most one group at a time. Additional non-primary entities count toward your workspace entity limit. ## OpenAPI ````yaml post /domain-groups openapi: 3.1.0 info: title: Geogen API description: >- API for accessing LLM visibility data, managing entities, and tracking AI mentions. version: 1.0.0 servers: - url: https://api.geogen.io/v1 description: Production server security: - bearerAuth: [] paths: /domain-groups: post: tags: - Domain Groups summary: Create Domain Group description: >- Create a domain group that merges analytics for multiple entities representing the same brand. Entity references in `primaryEntity` and `entities` may be either: - an `entityId` returned by `GET /v1/entities` (a tracking ID for an entity in this workspace), or - an entity UUID returned as `entityUuid` by `GET /v1/competitors` (any entity in the system). At least 2 entities are required, and `primaryEntity` must be included in the `entities` array. Each entity may belong to at most one group at a time. Additional non-primary entities count toward your workspace entity limit. operationId: createDomainGroup requestBody: required: true content: application/json: schema: type: object required: - primaryEntity - entities properties: name: type: string description: >- Display name for the group. Defaults to the primary entity's name when omitted. primaryEntity: type: string description: >- The primary entity reference (entityId or entity UUID). Its name/favicon represent the group in the UI. entities: type: array minItems: 2 items: type: string description: >- Array of 2+ entity references (entityIds or entity UUIDs). Must include the primary entity. entityId: type: string description: >- Optional. When provided, scopes the group to this entity tracking. Only analytics generated under this tracking will be merged. examples: merge_brand_domains: summary: Merge two workspace entities value: name: Acme primaryEntity: j5712abc34def56ghij7890klmn entities: - j5712abc34def56ghij7890klmn - j97def56ghij7890klmn5712abc merge_with_competitor_uuid: summary: Merge with a competitor entity UUID description: >- Mix workspace tracking IDs and entity UUIDs from /v1/competitors. value: primaryEntity: j5712abc34def56ghij7890klmn entities: - j5712abc34def56ghij7890klmn - 550e8400-e29b-41d4-a716-446655440000 responses: '201': description: Domain group created successfully. content: application/json: schema: type: object properties: success: type: boolean data: $ref: '#/components/schemas/DomainGroup' message: type: string '400': description: >- Bad request — validation failed, fewer than 2 entities, primary not included, entity overlap with another group, or workspace entity limit exceeded. content: application/json: schema: $ref: '#/components/schemas/Error' '401': description: Unauthorized content: application/json: schema: $ref: '#/components/schemas/Error' '404': description: Referenced `entityId` not found in this workspace. content: application/json: schema: $ref: '#/components/schemas/Error' '429': description: >- Rate limit exceeded — either the global write limit or the per-workspace domain-group change limit (5 changes per week). content: application/json: schema: type: object properties: error: type: string retryAfter: type: number components: schemas: DomainGroup: type: object description: >- A group of entities that represent the same brand. Analytics for grouped entities are merged across all pages and responses. properties: id: type: string description: Domain group ID. name: type: string description: Display name for the group. primaryEntityUuid: type: string description: UUID of the entity whose name and favicon represent the group. entityTrackingId: type: string nullable: true description: >- Optional entity-tracking scope. When set, the group only applies to analytics generated under this specific tracking. entities: type: array description: >- Entities included in the group. The entity with `isPrimary=true` represents the group. items: $ref: '#/components/schemas/DomainGroupEntity' createdAt: type: number description: Creation timestamp (ms). updatedAt: type: number description: Last update timestamp (ms). Error: type: object properties: error: type: string description: Error message DomainGroupEntity: type: object description: A single entity inside a domain group, enriched with display data. properties: entityId: type: string nullable: true description: >- Tracking ID for the entity in this workspace (null when the entity is not tracked here, e.g. a competitor). entityUuid: type: string description: Stable, system-wide entity UUID. name: type: string nullable: true description: Entity display name. target: type: string nullable: true description: Entity domain or term. faviconUrl: type: string nullable: true description: Favicon URL for the entity, if known. isPrimary: type: boolean description: >- Whether this entity is the group's primary entity (its name/favicon represent the group). inWorkspace: type: boolean description: Whether this entity is tracked in the current workspace. securitySchemes: bearerAuth: type: http scheme: bearer description: 'API key authentication. Format: Bearer wsk_your_api_key' ````