> ## Documentation Index
> Fetch the complete documentation index at: https://developers.hubspot.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

---
id: 633621c2-4410-42f6-8b2d-cf0481698b1b
---

# Update an event property

> Update an existing property in a custom event definition.

> [accordion] Supported products

> [accordion] Required Scopes


## OpenAPI

````yaml specs/2026-03/events-manage-event-definitions-v2026-03.json PATCH /events/2026-03/event-definitions/{eventName}/property/{propertyName}
openapi: 3.0.1
info:
  title: Events Manage Event Definitions
  description: Basepom for all HubSpot Projects
  version: 2026-03
  x-hubspot-product-tier-requirements:
    marketing: ENTERPRISE
    sales: ENTERPRISE
    service: ENTERPRISE
    cms: ENTERPRISE
    commerce: ENTERPRISE
    crmHub: ENTERPRISE
    dataHub: ENTERPRISE
servers:
  - url: https://api.hubapi.com
security: []
tags:
  - name: Advanced
  - name: Basic
  - name: Batch
paths:
  /events/2026-03/event-definitions/{eventName}/property/{propertyName}:
    patch:
      tags:
        - Basic
      summary: Update an existing custom event property
      description: Update an existing property in a custom event definition.
      operationId: >-
        patch-/events/2026-03/event-definitions/{eventName}/property/{propertyName}
      parameters:
        - name: eventName
          in: path
          description: >-
            The unique identifier of the event whose property you want to
            update.
          required: true
          style: simple
          explode: false
          schema:
            type: string
        - name: propertyName
          in: path
          description: >-
            The unique identifier of the property to be updated within the
            specified event.
          required: true
          style: simple
          explode: false
          schema:
            type: string
      requestBody:
        content:
          application/json:
            schema:
              $ref: >-
                #/components/schemas/ExternalBehavioralEventPropertyDefinitionPatch
        required: true
      responses:
        '201':
          description: successful operation
          headers:
            Location:
              description: URL of the newly created resource
              style: simple
              explode: false
              schema:
                type: string
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Property'
        default:
          $ref: '#/components/responses/Error'
          description: ''
      security:
        - oauth2:
            - behavioral_events.event_definitions.read_write
components:
  schemas:
    ExternalBehavioralEventPropertyDefinitionPatch:
      type: object
      properties:
        description:
          type: string
          description: >-
            A description of the property that will be shown as help text in
            HubSpot.
        label:
          type: string
          description: Human readable label for the property. Used in HubSpot UI
        options:
          type: array
          description: >-
            A list of available options for the property if it is an
            enumeration. NOTE: This field is only applicable for enumerated
            properties.
          items:
            $ref: '#/components/schemas/OptionInput'
    Property:
      required:
        - description
        - fieldType
        - groupName
        - label
        - name
        - options
        - type
      type: object
      properties:
        archived:
          type: boolean
          description: Indicates whether the property is archived.
        archivedAt:
          type: string
          description: >-
            The date and time when this property was archived, in ISO 8601
            format.
          format: date-time
        calculated:
          type: boolean
          description: Indicates whether the property is calculated.
        calculationFormula:
          type: string
          description: The formula used to calculate the property, if applicable.
        createdAt:
          type: string
          description: >-
            The date and time when this property was created, in ISO 8601
            format.
          format: date-time
        createdUserId:
          type: string
          description: The ID of the user who created this property.
        currencyPropertyName:
          type: string
          description: The name of the currency property associated with this property.
        dataSensitivity:
          type: string
          description: >-
            The sensitivity level of the data. Valid values include
            'non_sensitive', 'sensitive', and 'highly_sensitive'.
          enum:
            - highly_sensitive
            - non_sensitive
            - sensitive
        dateDisplayHint:
          type: string
          description: >-
            A hint for how date values should be displayed. Valid values include
            'absolute', 'absolute_with_relative', 'time_since', and
            'time_until'.
          enum:
            - absolute
            - absolute_with_relative
            - time_since
            - time_until
        description:
          type: string
          description: A description of the property.
        displayOrder:
          type: integer
          description: The order in which this property is displayed.
          format: int32
        externalOptions:
          type: boolean
          description: Indicates whether the property options are external.
        fieldType:
          type: string
          description: The field type of the property.
        formField:
          type: boolean
          description: Indicates whether the property is a form field.
        groupName:
          type: string
          description: The name of the group to which this property belongs.
        hasUniqueValue:
          type: boolean
          description: Indicates whether the property has a unique value.
        hidden:
          type: boolean
          description: Indicates whether the property is hidden.
          example: false
        hubspotDefined:
          type: boolean
          description: Indicates whether the property is defined by HubSpot.
        label:
          type: string
          description: The display label for the property.
        modificationMetadata:
          $ref: '#/components/schemas/PropertyModificationMetadata'
        name:
          type: string
          description: The unique name of the property.
        numberDisplayHint:
          type: string
          description: >-
            A hint for how number values should be displayed. Valid values
            include 'unformatted', 'formatted', 'currency', 'percentage',
            'duration', and 'probability'.
          enum:
            - currency
            - duration
            - formatted
            - percentage
            - probability
            - unformatted
        options:
          type: array
          description: >-
            An array of options available for this property, each defined by a
            label, value, and other attributes.
          items:
            $ref: '#/components/schemas/Option'
        referencedObjectType:
          type: string
          description: The type of object that this property references.
        sensitiveDataCategories:
          type: array
          description: >-
            An array of categories indicating the sensitivity of the data
            contained in the property.
          items:
            type: string
        showCurrencySymbol:
          type: boolean
          description: Indicates whether a currency symbol is shown for the property.
        textDisplayHint:
          type: string
          description: >-
            A hint for how text values should be displayed. Valid values include
            'unformatted_single_line', 'multi_line', 'email', 'phone_number',
            'domain_name', 'ip_address', 'physical_address', and 'postal_code'.
          enum:
            - domain_name
            - email
            - ip_address
            - multi_line
            - phone_number
            - physical_address
            - postal_code
            - unformatted_single_line
        type:
          type: string
          description: The data type of the property.
        updatedAt:
          type: string
          description: >-
            The date and time when this property was last updated, in ISO 8601
            format.
          format: date-time
        updatedUserId:
          type: string
          description: The ID of the user who last updated this property.
      description: A HubSpot property
    OptionInput:
      required:
        - displayOrder
        - hidden
        - label
        - value
      type: object
      properties:
        description:
          type: string
          description: A description of the option, represented as a string.
        displayOrder:
          type: integer
          description: >-
            An integer indicating the order in which the option should be
            displayed.
          format: int32
        hidden:
          type: boolean
          description: A boolean indicating whether the option is hidden.
        label:
          type: string
          description: The label of the option, represented as a string.
        value:
          type: string
          description: The value associated with the option, represented as a string.
    PropertyModificationMetadata:
      required:
        - archivable
        - readOnlyDefinition
        - readOnlyValue
      type: object
      properties:
        archivable:
          type: boolean
          description: A boolean indicating whether the property can be archived.
        readOnlyDefinition:
          type: boolean
          description: A boolean indicating if the property's definition is read-only.
        readOnlyOptions:
          type: boolean
          description: A boolean indicating if the options for the property are read-only.
        readOnlyValue:
          type: boolean
          description: A boolean indicating if the property's value is read-only.
    Option:
      required:
        - hidden
        - label
        - value
      type: object
      properties:
        description:
          type: string
          description: A string providing a description of the option.
        displayOrder:
          type: integer
          description: >-
            An integer indicating the order in which the option should be
            displayed relative to other options.
          format: int32
        hidden:
          type: boolean
          description: >-
            A boolean indicating whether the option is hidden from the user
            interface.
        label:
          type: string
          description: A string representing the display label of the option.
        value:
          type: string
          description: A string representing the internal value of the option.
      description: A HubSpot property option
    Error:
      required:
        - category
        - correlationId
        - message
      type: object
      properties:
        category:
          type: string
          description: The error category
        context:
          type: object
          additionalProperties:
            type: array
            items:
              type: string
          description: Context about the error condition
          example: >-
            {invalidPropertyName=[propertyValue], missingScopes=[scope1,
            scope2]}
        correlationId:
          type: string
          description: >-
            A unique identifier for the request. Include this value with any
            error reports or support tickets
          format: uuid
          example: aeb5f871-7f07-4993-9211-075dc63e7cbf
        errors:
          type: array
          description: further information about the error
          items:
            $ref: '#/components/schemas/ErrorDetail'
        links:
          type: object
          additionalProperties:
            type: string
          description: >-
            A map of link names to associated URIs containing documentation
            about the error or recommended remediation steps
        message:
          type: string
          description: >-
            A human readable message describing the error along with remediation
            steps where appropriate
          example: An error occurred
        subCategory:
          type: string
          description: >-
            A specific category that contains more specific detail about the
            error
      description: >-
        Represents an error response returned by the API when an operation
        fails. This component is used in various endpoints to provide detailed
        information about the error encountered.
      example:
        message: Invalid input (details will vary based on the error)
        correlationId: aeb5f871-7f07-4993-9211-075dc63e7cbf
        category: VALIDATION_ERROR
        links:
          knowledge-base: https://www.hubspot.com/products/service/knowledge-base
    ErrorDetail:
      required:
        - message
      type: object
      properties:
        code:
          type: string
          description: The status code associated with the error detail
        context:
          type: object
          additionalProperties:
            type: array
            items:
              type: string
          description: Context about the error condition
          example: '{missingScopes=[scope1, scope2]}'
        in:
          type: string
          description: The name of the field or parameter in which the error was found.
        message:
          type: string
          description: >-
            A human readable message describing the error along with remediation
            steps where appropriate
        subCategory:
          type: string
          description: >-
            A specific category that contains more specific detail about the
            error
      description: >-
        Represents detailed information about an error that occurred in the API.
        This component is used to provide additional context and specifics about
        errors, typically as part of an error response.
  responses:
    Error:
      description: An error occurred.
      content:
        '*/*':
          schema:
            $ref: '#/components/schemas/Error'
  securitySchemes:
    oauth2:
      type: oauth2
      flows:
        authorizationCode:
          authorizationUrl: https://app.hubspot.com/oauth/authorize
          tokenUrl: https://api.hubapi.com/oauth/v1/token
          scopes:
            analytics.behavioral_events.send: ''
            behavioral_events.event_definitions.read_write: ''

````