Quaderno

Quaderno Contacts API

Customers and vendors.

Documentation GitHub OpenAPI

Business capability

Customer Data Management BC-420.10

Operations 5

GET /contacts.json List contacts #

POST /contacts.json Create a contact #

GET /contacts/{id}.json Retrieve a contact #

PUT /contacts/{id}.json Update a contact #

DELETE /contacts/{id}.json Delete a contact #

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/quaderno-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.

GitHub Google LinkedIn

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

OpenAPI Specification

openapi: 3.2.0
info:
  title: Quaderno Contacts API
  description: The Quaderno API is a REST API for tax compliance, invoicing, and sales tax / VAT automation.
  version: '1.0'
  contact:
    name: Quaderno
    url: https://developers.quaderno.io
  license:
    name: Proprietary
    url: https://quaderno.io/terms/
servers:
- url: https://{account}.quadernoapp.com/api
  description: Production (account-scoped)
  variables:
    account:
      default: ACCOUNT_NAME
      description: Your Quaderno account subdomain.
security:
- basicAuth: []
tags:
- name: Contacts
  description: Customers and vendors.
paths:
  /contacts.json:
    get:
      operationId: listContacts
      tags:
      - Contacts
      summary: List contacts
      description: Lists contacts (customers and vendors), with optional filtering and pagination.
      parameters:
      - $ref: '#/components/parameters/Page'
      - name: q
        in: query
        required: false
        description: Full-text search across contact fields.
        schema:
          type: string
      responses:
        '200':
          description: A list of contacts.
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/Contact'
        '401':
          $ref: '#/components/responses/Unauthorized'
    post:
      operationId: createContact
      tags:
      - Contacts
      summary: Create a contact
      description: Creates a new contact.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/ContactInput'
      responses:
        '201':
          description: The created contact.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Contact'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '422':
          $ref: '#/components/responses/ValidationError'
  /contacts/{id}.json:
    parameters:
    - $ref: '#/components/parameters/Id'
    get:
      operationId: getContact
      tags:
      - Contacts
      summary: Retrieve a contact
      responses:
        '200':
          description: The requested contact.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Contact'
        '404':
          $ref: '#/components/responses/NotFound'
    put:
      operationId: updateContact
      tags:
      - Contacts
      summary: Update a contact
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/ContactInput'
      responses:
        '200':
          description: The updated contact.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Contact'
        '404':
          $ref: '#/components/responses/NotFound'
        '422':
          $ref: '#/components/responses/ValidationError'
    delete:
      operationId: deleteContact
      tags:
      - Contacts
      summary: Delete a contact
      responses:
        '204':
          description: The contact was deleted.
        '404':
          $ref: '#/components/responses/NotFound'
components:
  responses:
    Unauthorized:
      description: Missing or invalid API key.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    NotFound:
      description: The requested resource was not found.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    ValidationError:
      description: The request payload failed validation.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  schemas:
    Contact:
      allOf:
      - $ref: '#/components/schemas/ContactInput'
      - type: object
        properties:
          id:
            type: string
          full_name:
            type: string
          created_at:
            type: integer
    ContactInput:
      type: object
      required:
      - kind
      properties:
        kind:
          type: string
          enum:
          - company
          - person
          description: Whether the contact is a company or a person.
        first_name:
          type: string
        last_name:
          type: string
        contact_name:
          type: string
        street_line_1:
          type: string
        city:
          type: string
        postal_code:
          type: string
        region:
          type: string
        country:
          type: string
          description: ISO 3166-1 alpha-2 country code.
        email:
          type: string
        tax_id:
          type: string
    Error:
      type: object
      properties:
        error:
          type: string
        errors:
          type: object
          additionalProperties: true
  parameters:
    Id:
      name: id
      in: path
      required: true
      description: The unique ID of the resource.
      schema:
        type: string
    Page:
      name: page
      in: query
      required: false
      description: Page number for paginated results (25 records per page).
      schema:
        type: integer
        default: 1
  securitySchemes:
    basicAuth:
      type: http
      scheme: basic
      description: HTTP Basic Authentication. Use your private API key as the username; the password can be any value. API keys are managed in the Quaderno account settings.