Nfon address API

The address API from Nfon — 1 operation(s) for address.

Operations 1

GET /address/onkz/{countrycode}/{postalcode}/{city}/{street} Lookup ONKZ for an address #

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/nfon-address-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

nfon-address-api-openapi.yml Raw ↑
openapi: 3.2.0
info:
  description: APIs for managing PBX configuration, tenants, operators, licenses, and related resources
  title: PBX Configuration Address API
  version: 2026.07.20
servers:
- url: /configuration/v1
tags:
- name: address
paths:
  /address/onkz/{countrycode}/{postalcode}/{city}/{street}:
    get:
      summary: Lookup ONKZ for an address
      tags:
      - address
      description: Geocodes the given address via OpenStreetMap Nominatim and determines the German ONKZ (Ortsnetzkennzahl / area code). Only German addresses (countrycode=de) are supported.
      operationId: lookupAddressOnkz
      security:
      - OAuth2:
        - bss.license-manage
      responses:
        '200':
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AddressOnkzResponse'
          headers:
            X-Request-Id:
              schema:
                format: uuid
                type: string
              description: Unique request identifier
          description: ONKZ found
        '502':
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AddressOnkzResponse'
          headers:
            X-Request-Id:
              schema:
                format: uuid
                type: string
              description: Unique request identifier
          description: Geocoding service unavailable
        '400':
          content:
            application/json:
              examples:
                example:
                  value:
                    request_id: 550e8400-e29b-41d4-a716-446655440000
                    message: Invalid request parameters
                    code: validation_error
                  summary: Validation error
              schema:
                $ref: '#/components/schemas/AddressOnkzResponse'
          headers:
            X-Request-Id:
              schema:
                format: uuid
                type: string
              description: Unique request identifier
          description: Validation error
        '404':
          content:
            application/json:
              examples:
                example:
                  value:
                    request_id: 550e8400-e29b-41d4-a716-446655440000
                    message: The requested resource was not found
                    code: not_found
                  summary: Not found
              schema:
                $ref: '#/components/schemas/AddressOnkzResponse'
          headers:
            X-Request-Id:
              schema:
                format: uuid
                type: string
              description: Unique request identifier
          description: Address or ONKZ not found
components:
  schemas:
    AddressCoordinates:
      properties:
        longitude:
          type: number
          description: Longitude in WGS84
          format: double
          example: '11.57549'
        latitude:
          type: number
          description: Latitude in WGS84
          format: double
          example: '48.137154'
      type: object
      description: AddressCoordinates holds latitude and longitude.
    AddressStatus:
      properties:
        detail:
          type: string
          description: Human-readable status message
          example: ONKZ found
        code:
          type: integer
          description: Status code (200=found, 400=validation error, 404=not found, 500=server error)
          example: '200'
      type: object
      required:
      - code
      - detail
      description: AddressStatus holds the status of the lookup.
    AddressOnkzResponse:
      properties:
        status:
          $ref: '#/components/schemas/AddressStatus'
        address:
          $ref: '#/components/schemas/AddressDetail'
        onkz:
          type:
          - string
          - 'null'
          description: German area code (Ortsnetzkennzahl), null if not found
          example: 089
        coordinates:
          $ref: '#/components/schemas/AddressCoordinates'
      type: object
      required:
      - status
      description: AddressOnkzResponse represents the response for an address ONKZ lookup.
    AddressDetail:
      properties:
        country:
          type: string
          description: Country name
          example: Deutschland
        country_code:
          type: string
          description: ISO country code
          example: de
        house_number:
          type: string
          description: House number
          example: '1'
        postcode:
          type: string
          description: Postal code
          example: '80331'
        street:
          type: string
          description: Street name
          example: Marienplatz
        city:
          type: string
          description: City name
          example: München
      type: object
      description: AddressDetail holds the resolved address fields.
  securitySchemes:
    jwt:
      scheme: bearer
      bearerFormat: JWT
      type: http