> ## Documentation Index > Fetch the complete documentation index at: https://docs.dados.rio/llms.txt > Use this file to discover all available pages before exploring further. # List group members > List all members of a specific group with their membership details. **Authorization**: Users can view members of groups they have permission to access. Permissions are checked via Cerbos policies. **Member Information**: Returns each member's CPF, display name (if available), join timestamp, and who added them to the group. **Use Cases**: - View team composition - Audit group membership - Administrative oversight - Access control verification **Sorting**: Members are returned sorted by join date (newest first). ## OpenAPI ````yaml https://raw.githubusercontent.com/prefeitura-rio/heimdall/main/docs/api/openapi.json get /api/v1/groups/{group_name}/members openapi: 3.1.0 info: title: Heimdall Admin Service description: >- # Heimdall Admin Service API A comprehensive admin service for user and group management with authorization powered by Cerbos. ## Features - **User Management**: Automatic user creation from JWT tokens with role-based access control - **Group Management**: Create, manage, and assign users to groups with hierarchical permissions - **Role Management**: Define and assign roles to users and groups - **Mapping Management**: Configure API endpoint to action mappings for authorization - **Action Management**: Define available actions for fine-grained permission control - **Cerbos Integration**: Policy-based authorization with external Cerbos service - **Audit Logging**: Comprehensive audit trail for all administrative operations - **Redis Caching**: High-performance caching for frequently accessed data version: 1.0.0 servers: - url: https://services.pref.rio/heimdall-admin description: Production server - url: https://services.staging.app.dados.rio/heimdall-admin description: Staging server security: [] tags: - name: health description: Service health and readiness checks - name: users description: >- User management operations. Users are automatically created from JWT tokens. - name: groups description: >- Group management operations. Groups organize users and can have roles assigned. - name: memberships description: Group membership management. Assign and remove users from groups. - name: roles description: >- Role management operations. Roles define permissions that can be assigned to users or groups. - name: actions description: >- Action management operations. Actions define the granular permissions available in the system. - name: mappings description: >- API endpoint to action mapping configuration. Maps HTTP endpoints to authorization actions. paths: /api/v1/groups/{group_name}/members: get: tags: - memberships summary: List group members description: >- List all members of a specific group with their membership details. **Authorization**: Users can view members of groups they have permission to access. Permissions are checked via Cerbos policies. **Member Information**: Returns each member's CPF, display name (if available), join timestamp, and who added them to the group. **Use Cases**: - View team composition - Audit group membership - Administrative oversight - Access control verification **Sorting**: Members are returned sorted by join date (newest first). operationId: list_group_members_api_v1_groups__group_name__members_get parameters: - name: group_name in: path required: true schema: type: string title: Group Name responses: '200': description: List of group members retrieved successfully content: application/json: schema: type: array items: $ref: '#/components/schemas/GroupMemberResponse' title: >- Response List Group Members Api V1 Groups Group Name Members Get example: - subject: '12345678901' display_name: João Silva joined_at: '2024-01-15T10:30:00Z' added_by: '98765432109' - subject: '23456789012' display_name: Maria Santos joined_at: '2024-01-10T09:15:00Z' added_by: '98765432109' '401': description: Unauthorized - Invalid or missing JWT token content: application/json: example: detail: Could not validate credentials '403': description: Forbidden - Insufficient permissions to view group members content: application/json: example: detail: >- Permission denied to view members of group 'engineering_team:backend' '404': description: Group not found content: application/json: example: detail: Group 'unknown-group' not found '422': description: Validation Error content: application/json: schema: $ref: '#/components/schemas/HTTPValidationError' '500': description: Internal server error content: application/json: example: detail: 'Failed to retrieve group members: Database connection error' security: - HTTPBearer: [] components: schemas: GroupMemberResponse: properties: subject: type: string title: Subject description: User's CPF (Brazilian tax ID) example: '12345678901' display_name: anyOf: - type: string - type: 'null' title: Display Name description: User's display name if available example: João Silva joined_at: type: string title: Joined At description: ISO timestamp when the user joined the group example: '2024-01-15T10:30:00Z' added_by: anyOf: - type: string - type: 'null' title: Added By description: CPF of the user who added this member example: '98765432109' type: object required: - subject - joined_at title: GroupMemberResponse description: Response model for a group member. example: added_by: '98765432109' display_name: João Silva joined_at: '2024-01-15T10:30:00Z' subject: '12345678901' HTTPValidationError: properties: detail: items: $ref: '#/components/schemas/ValidationError' type: array title: Detail type: object title: HTTPValidationError ValidationError: properties: loc: items: anyOf: - type: string - type: integer type: array title: Location msg: type: string title: Message type: type: string title: Error Type type: object required: - loc - msg - type title: ValidationError securitySchemes: HTTPBearer: type: http scheme: bearer ````