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

# Upsert Request Property

> Create or update a property of a specific request.

<Warning>
  <strong>For users in the European Union:</strong> Please use `eu.api.helicone.ai` instead of
  `api.helicone.ai`.
</Warning>


## OpenAPI

````yaml put /v1/request/{requestId}/property
openapi: 3.0.0
info:
  title: helicone-api
  version: 1.0.0
  license:
    name: MIT
  contact: {}
servers:
  - url: https://api.helicone.ai/
  - url: http://localhost:8585/
security: []
paths:
  /v1/request/{requestId}/property:
    put:
      tags:
        - Request
      operationId: PutProperty
      parameters:
        - in: path
          name: requestId
          required: true
          schema:
            type: string
      requestBody:
        required: true
        content:
          application/json:
            schema:
              properties:
                value:
                  type: string
                key:
                  type: string
              required:
                - value
                - key
              type: object
      responses:
        '200':
          description: Ok
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Result_null.string_'
      security:
        - api_key: []
components:
  schemas:
    Result_null.string_:
      anyOf:
        - $ref: '#/components/schemas/ResultSuccess_null_'
        - $ref: '#/components/schemas/ResultError_string_'
    ResultSuccess_null_:
      properties:
        data:
          type: number
          enum:
            - null
          nullable: true
        error:
          type: number
          enum:
            - null
          nullable: true
      required:
        - data
        - error
      type: object
      additionalProperties: false
    ResultError_string_:
      properties:
        data:
          type: number
          enum:
            - null
          nullable: true
        error:
          type: string
      required:
        - data
        - error
      type: object
      additionalProperties: false
  securitySchemes:
    api_key:
      type: apiKey
      name: Authorization
      in: header
      description: 'Bearer token authentication. Format: ''Bearer YOUR_API_KEY'''

````