Churnkey Billing Contacts API

Billing-contact management for Failed Payment Recovery.

Operations 2

POST /api/events/customer-update/set-users Set billing contacts for a customer #
POST /api/events/customer-update/set-users/bulk Set billing contacts for many customers #

Work with this as data

Every API here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for apis

7 MCP tools reach this
  • find_apisBrowse and filter every API in the catalog.
  • get_api_artifactsOne API's artifacts, grouped by type.
  • get_openapiThe primary OpenAPI for this API.
  • find_similar_apisAPIs that look like this one.
  • apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
  • resolveTurn a domain, URL or GitHub org into the provider it belongs to.
  • find_cohortsEvery scored population of providers in the catalog.
All 92 tools →

Call it yourself

curl for this page
This API
curl "https://apis.io/api/v1/apis/churnkey-billing-contacts-api"
All apis
curl "https://apis.io/api/v1/apis?limit=25"

Discovery needs no key. Ratings and market analysis are Pro.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

A second provider on the same verified email joins the account you already have.

OpenAPI Specification

churnkey-billing-contacts-api-openapi.yml Raw ↑
openapi: 3.2.0
info:
  title: Churnkey Billing Contacts API
  description: 'REST surface for Churnkey, retention and growth infrastructure for subscription companies. This document covers Churnkey''s server-to-server REST endpoints: the Data API (Cancel Flow sessions and aggregations, plus GDPR data-subject requests) under https://api.churnkey.co/v1/data, and the Event/Customer API (event tracking, customer updates, and billing-contact management for Failed Payment Recovery) under https://api.churnkey.co/v1/api. All requests are authenticated with an App ID header (x-ck-app) and an API key header. The Data API uses a Data API key (x-ck-api-key from Settings > Account); the event and billing-contact endpoints use a Churnkey API key. Churnkey''s personalized Cancel Flows are delivered client-side via a JavaScript SDK authorized with a server-computed HMAC-SHA256 authHash and are not modeled as REST paths here. Endpoint paths and parameters below reflect Churnkey''s public documentation as of the review date; request and response schemas are honestly modeled where the docs do not publish a full schema.'
  version: '1.0'
  contact:
    name: Churnkey
    url: https://churnkey.co
servers:
- url: https://api.churnkey.co/v1
  description: Churnkey production API
security:
- apiKeyAuth: []
  appIdAuth: []
tags:
- name: Billing Contacts
  description: Billing-contact management for Failed Payment Recovery.
paths:
  /api/events/customer-update/set-users:
    post:
      operationId: setBillingUsers
      tags:
      - Billing Contacts
      summary: Set billing contacts for a customer
      description: Attaches one or more users to a customer and flags which are billing admins. Billing admins receive Failed Payment Recovery (dunning) communications.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/SetUsersInput'
      responses:
        '200':
          description: The billing contacts were set.
          content:
            application/json:
              schema:
                type: object
                properties:
                  success:
                    type: boolean
        '401':
          $ref: '#/components/responses/Unauthorized'
  /api/events/customer-update/set-users/bulk:
    post:
      operationId: setBillingUsersBulk
      tags:
      - Billing Contacts
      summary: Set billing contacts for many customers
      description: Bulk variant of set-users - each array item uses the same structure as the single update.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: array
              items:
                $ref: '#/components/schemas/SetUsersInput'
      responses:
        '200':
          description: The billing contacts were set.
          content:
            application/json:
              schema:
                type: object
                properties:
                  success:
                    type: boolean
        '401':
          $ref: '#/components/responses/Unauthorized'
components:
  schemas:
    BillingUser:
      type: object
      required:
      - userId
      - data
      properties:
        userId:
          type: string
          description: Internal user identifier.
        data:
          type: object
          required:
          - email
          - name
          - billingAdmin
          properties:
            email:
              type: string
              format: email
            name:
              type: string
            phone:
              type: string
            billingAdmin:
              type: boolean
              description: When true, this user receives Payment Recovery emails.
          additionalProperties: true
    Error:
      type: object
      properties:
        error:
          type: object
          properties:
            code:
              type: string
            message:
              type: string
    SetUsersInput:
      type: object
      required:
      - customerId
      - users
      properties:
        customerId:
          type: string
          description: Payment-provider customer ID (for example a Stripe customer ID).
        users:
          type: array
          items:
            $ref: '#/components/schemas/BillingUser'
  responses:
    Unauthorized:
      description: Missing or invalid API key / App ID headers.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  securitySchemes:
    apiKeyAuth:
      type: apiKey
      in: header
      name: x-ck-api-key
      description: Churnkey API key. The Data API (/v1/data) uses the Data API key from Settings > Account; the event and billing-contact endpoints (/v1/api) use a Churnkey API key.
    appIdAuth:
      type: apiKey
      in: header
      name: x-ck-app
      description: Churnkey Application ID (App ID) from Settings.