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

# Preview an existing meter

> Dry-run an existing meter against your real usage over the last 7 whole UTC days (today included, future-dated events excluded). Same shape as the unsaved-definition preview; nothing is written.



## OpenAPI

````yaml post /v1/meters/{id}/preview
openapi: 3.0.0
info:
  title: Creem API
  description: >-
    Creem is an all-in-one platform for managing subscriptions and recurring
    revenue, tailored specifically for today's SaaS companies. It enables you to
    boost revenue, enhance customer retention, and scale your operations
    seamlessly.
  version: v1
  contact:
    name: Creem Support
    url: https://creem.io
    email: support@creem.io
  license:
    name: Commercial
    url: https://creem.io/terms
  termsOfService: https://creem.io/terms
servers:
  - url: https://api.creem.io
    description: Production — live API for processing real transactions and data.
    x-speakeasy-server-id: prod
  - url: https://test-api.creem.io
    description: Test — sandbox API for development and testing with no real charges.
    x-speakeasy-server-id: test
security: []
tags: []
externalDocs:
  description: Creem Documentation
  url: https://docs.creem.io
paths:
  /v1/meters/{id}/preview:
    post:
      tags:
        - Meters
      summary: Preview an existing meter
      description: >-
        Dry-run an existing meter against your real usage over the last 7 whole
        UTC days (today included, future-dated events excluded). Same shape as
        the unsaved-definition preview; nothing is written.
      operationId: previewExistingMeter
      parameters:
        - name: id
          required: true
          in: path
          schema:
            type: string
      responses:
        '200':
          description: Preview of the meter
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/MeterPreviewApiResponseDto'
        '400':
          description: Bad Request - Invalid input parameters
        '401':
          description: Unauthorized - Invalid or missing API key
        '404':
          description: Not Found - Resource does not exist
      security:
        - ApiKey: []
components:
  schemas:
    MeterPreviewApiResponseDto:
      type: object
      properties:
        matched_events:
          type: number
          description: Events the meter would count over the preview window
          example: 137
        units:
          type: string
          description: >-
            Aggregated units over the whole window, as a string for BigInt
            safety
          example: '4820'
        distinct_customers:
          type: number
          description: Distinct customers among the matching events
          example: 12
        daily:
          description: The last 7 UTC days (today included), oldest first and zero-filled
          type: array
          items:
            $ref: '#/components/schemas/MeterPreviewDailyApiResponseDto'
      required:
        - matched_events
        - units
        - distinct_customers
        - daily
    MeterPreviewDailyApiResponseDto:
      type: object
      properties:
        date:
          type: string
          description: UTC calendar day
          example: '2026-08-16'
        event_count:
          type: number
          description: Matching events on this day
          example: 42
        value:
          type: string
          description: >-
            The aggregation folded over this day alone, as a string for BigInt
            safety
          example: '1280'
      required:
        - date
        - event_count
        - value
  securitySchemes:
    ApiKey:
      type: apiKey
      in: header
      name: x-api-key
      description: >-
        API key for authentication. You can find your API key in the Creem
        dashboard under Settings > API Keys.

````