> ## Documentation Index > Fetch the complete documentation index at: https://docs.aiinsurance.io/llms.txt > Use this file to discover all available pages before exploring further. # Update Custom Object > Updates a custom object's data fields. The request body must include a `data` object — this is a **full replacement** of the object's field data, not a merge. Include all fields you want the object to have after the update. **Relationship fields are not accepted in `data`** — use the dedicated relationship management endpoints instead. **Required permission:** `company.fmv1_custom_object:update` ## OpenAPI ````yaml /openapi/generated-external-api.yaml put /api/v1/external/companies/{companyId}/custom-objects/{objectType}/{objectId} openapi: 3.0.3 info: title: AI Insurance External API description: External API for AI Insurance platform version: 1.0.0 contact: email: support@aiinsurance.io servers: - url: https://app.aiinsurance.io description: Production security: - ApiKeyAuth: [] paths: /api/v1/external/companies/{companyId}/custom-objects/{objectType}/{objectId}: put: tags: - Field Model Custom Objects summary: Update Custom Object description: > Updates a custom object's data fields. The request body must include a `data` object — this is a **full replacement** of the object's field data, not a merge. Include all fields you want the object to have after the update. **Relationship fields are not accepted in `data`** — use the dedicated relationship management endpoints instead. **Required permission:** `company.fmv1_custom_object:update` operationId: updateCustomObject parameters: - $ref: '#/components/parameters/companyId' - $ref: '#/components/parameters/objectType' - $ref: '#/components/parameters/objectId' requestBody: required: true content: application/json: schema: type: object required: - data properties: data: type: object additionalProperties: true description: Field values keyed by referenceId (full replacement) examples: update: summary: Update vehicle fields value: data: vehicleMake: Toyota vehicleModel: Camry year: 2025 vin: 1HGBH41JXMN109186 color: Blue responses: '200': description: Custom object updated successfully content: application/json: schema: $ref: '#/components/schemas/CustomObject' examples: success: summary: Updated vehicle value: id: 550e8400-e29b-41d4-a716-446655440020 companyId: 550e8400-e29b-41d4-a716-446655440000 type: vehicle displayName: Toyota Camry data: vehicleMake: Toyota vehicleModel: Camry year: 2025 vin: 1HGBH41JXMN109186 color: Blue relationships: ownerExposure: 550e8400-e29b-41d4-a716-446655440200 createdAt: '2026-01-15T10:30:00.000Z' updatedAt: '2026-01-20T14:00:00.000Z' createdBy: google-oauth2|123456789 updatedBy: google-oauth2|987654321 '400': description: Bad Request - Validation error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: relationshipField: summary: Relationship field in data value: error: code: VALIDATION_ERROR message: >- Field 'ownerExposure' is a relationship field and cannot be set in data. Use the relationship management endpoints instead. '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/Forbidden' '404': description: Custom object not found content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: notFound: summary: Custom object not found value: error: code: NOT_FOUND message: Custom object not found '500': $ref: '#/components/responses/InternalServerError' components: parameters: companyId: name: companyId in: path required: true schema: type: string format: uuid description: Company identifier objectType: name: objectType in: path required: true schema: type: string description: >- Custom object type in snake_case format (e.g., `vehicle`, `building_info`) objectId: name: objectId in: path required: true schema: type: string format: uuid description: Custom object identifier schemas: CustomObject: type: object description: | A custom object entity. The `data` field contains regular field values and the `relationships` field contains IDs of related entities keyed by field reference ID. required: - id - companyId - type - displayName - data - relationships properties: id: type: string format: uuid description: Custom object identifier companyId: type: string format: uuid description: Company identifier type: type: string description: The object type in snake_case format displayName: type: string description: Computed display name based on the type's display name expression data: type: object additionalProperties: true description: > Dynamic field data for the custom object. Keys are field `referenceId`s defined in the company's field configuration. Only includes regular (non-relationship) fields. relationships: type: object additionalProperties: true description: > Relationship data keyed by field `referenceId`. Values are either a single UUID string (for single-cardinality relationships) or an array of UUID strings (for multi-cardinality relationships). createdAt: type: string format: date-time nullable: true description: When the custom object was created updatedAt: type: string format: date-time nullable: true description: When the custom object was last updated createdBy: type: string nullable: true description: User ID who created the custom object updatedBy: type: string nullable: true description: User ID who last updated the custom object ErrorResponse: type: object description: Standard error response for all external API endpoints required: - error properties: error: type: object required: - code - message properties: code: type: string description: Machine-readable error code example: VALIDATION_ERROR message: type: string description: Human-readable error message example: 'submissionId: Required field is missing' details: type: array description: Additional details for validation errors (field-level errors) items: type: object properties: field: type: string description: The field that caused the error example: submissionId message: type: string description: Description of the field error example: Required field is missing responses: Unauthorized: description: Unauthorized - Invalid or missing API key content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: missingApiKey: summary: Missing API key value: error: code: UNAUTHORIZED message: Authorization header is required bearerTokenNotAllowed: summary: Bearer token used instead of API key value: error: code: UNAUTHORIZED message: External API endpoints require API key authentication Forbidden: description: Forbidden - Insufficient permissions content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: insufficientPermissions: summary: Insufficient permissions value: error: code: FORBIDDEN message: Insufficient permissions to perform this action InternalServerError: description: Internal Server Error - Unexpected error occurred content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: internalError: summary: Unexpected server error value: error: code: INTERNAL_ERROR message: An unexpected error occurred. Please try again later. securitySchemes: ApiKeyAuth: type: apiKey in: header name: Authorization description: >- API key authentication. Include your API key in the Authorization header. ````