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OpenAPI Specification
openapi: 3.2.0
info:
title: BillingEngine Customers API
version: 1.0.0
summary: REST API for customers, invoices and payments of BillingEngine.
description: 'BillingEngine is online invoicing software for freelancers and small businesses in Germany. Every invoice is an e-invoice (ZUGFeRD and XRechnung, EN 16931).
The API is available in the paid plans. Authenticate with the API key from your settings as a bearer token. All requests and responses use JSON; amounts are given in the currency of the record, dates as YYYY-MM-DD. Each key may send 60 requests per minute. New invoices are created as drafts and count towards the monthly invoice maximum of the plan.
Documentation: https://www.billingengine.com/en/api'
termsOfService: https://www.billingengine.com/en/terms_of_service
contact:
name: BillingEngine
url: https://www.billingengine.com/en/contact
license:
name: Proprietary
url: https://www.billingengine.com/en/terms_of_service
servers:
- url: https://www.billingengine.com/api/v1
description: Production
security:
- bearerAuth: []
tags:
- name: Customers
description: Customers of the account.
paths:
/customers:
get:
tags:
- Customers
operationId: listCustomers
summary: List customers
description: All customers, ordered. The query parameter searches company, names and email.
parameters:
- name: query
in: query
schema:
type: string
description: Search company, names and email.
- name: page
in: query
schema:
type: integer
minimum: 1
default: 1
description: Page number.
- name: per_page
in: query
schema:
type: integer
minimum: 1
maximum: 100
default: 25
description: Records per page, at most 100.
responses:
'200':
description: A page of customers.
content:
application/json:
schema:
type: object
required:
- data
- pagination
properties:
data:
type: array
items:
$ref: '#/components/schemas/Customer'
pagination:
$ref: '#/components/schemas/Pagination'
'400':
$ref: '#/components/responses/BadRequest'
'401':
$ref: '#/components/responses/Unauthorized'
'403':
$ref: '#/components/responses/Forbidden'
post:
tags:
- Customers
operationId: createCustomer
summary: Create a customer
description: A new customer needs a company or a last name and an address with line 1, postal code, city and country. The number is assigned automatically.
requestBody:
required: true
content:
application/json:
schema:
$ref: '#/components/schemas/CustomerInput'
responses:
'201':
description: The created customer.
content:
application/json:
schema:
$ref: '#/components/schemas/Customer'
'400':
$ref: '#/components/responses/BadRequest'
'401':
$ref: '#/components/responses/Unauthorized'
'403':
$ref: '#/components/responses/Forbidden'
'422':
$ref: '#/components/responses/Unprocessable'
/customers/{id}:
parameters:
- name: id
in: path
required: true
schema:
type: integer
description: Record id.
get:
tags:
- Customers
operationId: getCustomer
summary: Get a customer
responses:
'200':
description: The customer.
content:
application/json:
schema:
$ref: '#/components/schemas/Customer'
'400':
$ref: '#/components/responses/BadRequest'
'401':
$ref: '#/components/responses/Unauthorized'
'403':
$ref: '#/components/responses/Forbidden'
'404':
$ref: '#/components/responses/NotFound'
patch:
tags:
- Customers
operationId: updateCustomer
summary: Change a customer
description: PUT is accepted as well.
requestBody:
required: true
content:
application/json:
schema:
$ref: '#/components/schemas/CustomerInput'
responses:
'200':
description: The changed customer.
content:
application/json:
schema:
$ref: '#/components/schemas/Customer'
'400':
$ref: '#/components/responses/BadRequest'
'401':
$ref: '#/components/responses/Unauthorized'
'403':
$ref: '#/components/responses/Forbidden'
'404':
$ref: '#/components/responses/NotFound'
'422':
$ref: '#/components/responses/Unprocessable'
components:
responses:
Unprocessable:
description: The record is invalid. The messages explain why.
content:
application/json:
schema:
$ref: '#/components/schemas/Errors'
Unauthorized:
description: Missing or invalid API key.
content:
application/json:
schema:
$ref: '#/components/schemas/Errors'
BadRequest:
description: 'Malformed request: missing parameter, invalid JSON, invalid date or invalid filter.'
content:
application/json:
schema:
$ref: '#/components/schemas/Errors'
NotFound:
description: Record not found.
content:
application/json:
schema:
$ref: '#/components/schemas/Errors'
Forbidden:
description: The API is not available in the Free plan, or the monthly invoice maximum of the plan has been reached.
content:
application/json:
schema:
$ref: '#/components/schemas/Errors'
schemas:
CustomerInput:
type: object
properties:
company:
type: string
first_name:
type: string
last_name:
type: string
email:
type: string
format: email
phone:
type: string
vat_number:
type: string
buyer_reference:
type: string
address_attributes:
$ref: '#/components/schemas/Address'
Customer:
type: object
properties:
id:
type: integer
number:
type:
- string
- integer
- 'null'
name:
type: string
description: Company, or first and last name.
company:
type:
- string
- 'null'
first_name:
type:
- string
- 'null'
last_name:
type:
- string
- 'null'
email:
type:
- string
- 'null'
phone:
type:
- string
- 'null'
vat_number:
type:
- string
- 'null'
buyer_reference:
type:
- string
- 'null'
description: Buyer reference (BT-10), for example a Leitweg-ID.
address:
oneOf:
- $ref: '#/components/schemas/Address'
- type: 'null'
Address:
type: object
properties:
line_1:
type: string
line_2:
type:
- string
- 'null'
postal_code:
type: string
city:
type: string
region:
type:
- string
- 'null'
country:
type: string
description: ISO country code such as DE.
examples:
- DE
Errors:
type: object
required:
- errors
properties:
errors:
type: array
items:
type: string
Pagination:
type: object
required:
- page
- per_page
- pages
- count
properties:
page:
type: integer
per_page:
type: integer
pages:
type: integer
count:
type: integer
securitySchemes:
bearerAuth:
type: http
scheme: bearer
description: 'The API key from the settings of your account, sent as "Authorization: Bearer <key>". Only available in the paid plans.'
externalDocs:
description: API documentation
url: https://www.billingengine.com/en/api