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

# Start a subscription's meter



## OpenAPI

````yaml /openapi.json post /v1/subscriptions/{id}/start
openapi: 3.1.0
info:
  title: Elapse API
  version: '2026-09-06'
  description: >-
    Per-second billing. Authenticate with your secret key as a bearer token.
    Every amount is a decimal string in USD.
servers:
  - url: http://localhost:4000
security: []
tags:
  - name: Products
    description: Something billed at a rate per second.
  - name: Checkout
    description: Hosted pages a subscriber is sent to.
  - name: Subscriptions
    description: A running meter for one customer on one product.
  - name: Customers
    description: Subscribers, created by Checkout.
  - name: Invoices
    description: One settlement of accrued dollars for a period.
paths:
  /v1/subscriptions/{id}/start:
    post:
      tags:
        - Subscriptions
      summary: Start a subscription's meter
      operationId: subscriptions.start
      parameters:
        - schema:
            type: string
          required: true
          name: id
          in: path
      responses:
        '202':
          description: >-
            Start submitted on chain. Only for products created with
            `start_mode: "merchant"`; the object stays `incomplete` until
            `subscription.updated` arrives, and `pending_tx` is the relayer's
            transaction.
          content:
            application/json:
              schema:
                allOf:
                  - $ref: '#/components/schemas/Subscription'
                  - type: object
                    properties:
                      pending_tx:
                        type: string
                    required:
                      - pending_tx
        '400':
          description: Invalid request.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '401':
          description: Missing or invalid API key.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '404':
          description: No such object in this mode.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
      security:
        - bearerAuth: []
components:
  schemas:
    Subscription:
      type: object
      properties:
        id:
          type: string
          example: sub_7Hq2mV9kLp3RxT
        object:
          type: string
          enum:
            - subscription
        status:
          type: string
          enum:
            - incomplete
            - active
            - paused
            - canceled
        product:
          type: string
        customer:
          type: string
        checkout_session:
          type: string
          nullable: true
        manage_url:
          type: string
          description: >-
            Where the subscriber manages all their meters (FR-API-140b). Your
            app shows this meter with @elapse/react.
          example: https://elapse.finance/account
        rate_usd_per_second:
          type: string
        started_at:
          type: integer
          nullable: true
        paused_at:
          type: integer
          nullable: true
        paused_seconds:
          type: integer
        canceled_at:
          type: integer
          nullable: true
        ended_reason:
          type: string
          nullable: true
          enum:
            - canceled
            - cap_reached
            - null
        max_duration_seconds:
          type: integer
        max_escrow_usd:
          type: string
        funded_usd:
          type: string
        settled_usd:
          type: string
        seconds_elapsed:
          type: integer
        stream_address:
          type: string
          nullable: true
        chain_id:
          type: integer
        currency:
          type: string
          enum:
            - ausd
        livemode:
          type: boolean
        created:
          type: integer
        product_name:
          type: string
        customer_email:
          type: string
          nullable: true
      required:
        - id
        - object
        - status
        - product
        - customer
        - checkout_session
        - manage_url
        - rate_usd_per_second
        - started_at
        - paused_at
        - paused_seconds
        - canceled_at
        - ended_reason
        - max_duration_seconds
        - max_escrow_usd
        - funded_usd
        - settled_usd
        - seconds_elapsed
        - stream_address
        - chain_id
        - currency
        - livemode
        - created
        - product_name
        - customer_email
    Error:
      type: object
      required:
        - error
      properties:
        error:
          type: object
          required:
            - type
            - message
          properties:
            type:
              type: string
              enum:
                - api_error
                - authentication_error
                - invalid_request_error
                - rate_limit_error
                - idempotency_error
                - not_found
            message:
              type: string
            code:
              type: string
              description: Machine-readable reason, when there is one.
            param:
              type: string
              description: The request field at fault, when there is one.
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: >-
        Your secret key: `sk_test_…` for test mode, `sk_live_…` for live.
        Server-side only.

````