> ## 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.

# Update an event property

> Update a specific property of a behavioral event definition in your HubSpot account. This operation allows you to modify the details of an existing property associated with a given event. Use this endpoint to keep your event properties up-to-date with the latest information.

> [accordion] Supported products

> [accordion] Required Scopes


## OpenAPI

````yaml specs/2026-09/events-manage-event-definitions-v2026-09.json PATCH /events/2026-09/event-definitions/{eventName}/property/{propertyName}
openapi: 3.0.1
info:
  title: Events Manage Event Definitions
  description: Basepom for all HubSpot Projects
  version: 2026-09
  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
paths:
  /events/2026-09/event-definitions/{eventName}/property/{propertyName}:
    patch:
      tags:
        - Basic
      summary: Update property
      description: >-
        Update a specific property of a behavioral event definition in your
        HubSpot account. This operation allows you to modify the details of an
        existing property associated with a given event. Use this endpoint to
        keep your event properties up-to-date with the latest information.
      operationId: >-
        patch-/events/2026-09/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 name 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.
        displayOrder:
          type: integer
          description: >-
            For not hidden properties, indicates the order to display the
            property on the record's activity timeline (ex: displayOrder: 0 is
            at the top).
          format: int32
        hidden:
          type: boolean
          description: >-
            Controls whether or not this property is displayed on the record's
            activity timeline.
        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's value, 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, with valid values including
            'non_sensitive', 'sensitive', and 'highly_sensitive'.
          enum:
            - highly_sensitive
            - non_sensitive
            - sensitive
        dateDisplayHint:
          type: string
          description: >-
            A hint for displaying date properties, with valid values including
            '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 relative to other
            properties.
          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 displaying number properties, with valid values including
            '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, applicable if the
            property supports multiple values.
          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.
          items:
            type: string
        showCurrencySymbol:
          type: boolean
          description: Indicates whether a currency symbol is shown for the property.
        textDisplayHint:
          type: string
          description: >-
            A hint for displaying text properties, with valid values including
            '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 string providing additional information about 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 view.
        label:
          type: string
          description: A string representing the display label for the option.
        value:
          type: string
          description: A string representing the unique value associated with the option.
    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 whether the definition of the property is
            read-only.
        readOnlyOptions:
          type: boolean
          description: >-
            A boolean indicating whether the options of the property are
            read-only.
        readOnlyValue:
          type: boolean
          description: A boolean indicating whether the value of the property is read-only.
    Option:
      required:
        - hidden
        - label
        - value
      type: object
      properties:
        description:
          type: string
          description: A detailed description of the option, providing additional context.
        displayOrder:
          type: integer
          description: >-
            An integer that determines the order in which the option appears
            relative to other options.
          format: int32
        hidden:
          type: boolean
          description: A boolean indicating whether the option is hidden from users.
        label:
          type: string
          description: The display name of the option, shown to users.
        value:
          type: string
          description: >-
            The internal value associated with the option, used in data
            processing.
      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, represented as an object with
            additional properties.
          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, represented as an array of
            ErrorDetail objects.
          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. This is a string
            property.
        context:
          type: object
          additionalProperties:
            type: array
            items:
              type: string
          description: >-
            Context about the error condition, represented as an object where
            each key is a context name and each value is an array of strings
            providing additional details.
          example: '{missingScopes=[scope1, scope2]}'
        in:
          type: string
          description: >-
            The name of the field or parameter in which the error was found.
            This is a string property.
        message:
          type: string
          description: >-
            A human readable message describing the error along with remediation
            steps where appropriate. This is a required string property.
        subCategory:
          type: string
          description: >-
            A specific category that contains more specific detail about the
            error. This is a string property.
      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: ''

````