KPN Application Keys API

openapi: 3.2.0
info:
  title: Webhook Signing Keys - KPN Application Keys API
  description: 'When KPN delivers a webhook to your endpoint, signing keys are to know the request genuinely

    came from KPN and wasn''t tampered with in transit.


    KPN signs every outbound webhook payload using HMAC-SHA256 and includes the signature

    in a header. You store a shared secret on your side, compute the

    expected signature over the incoming request body, and compare it to the header value.

    If they match, the payload is genuine. This API lets you create and manage those

    shared secrets.


    **How signing keys work**


    You can set a signing key at three levels — Organization, Team, or Application. When

    KPN delivers a webhook, it picks the active key starting at the most specific level

    (Application), falling back to Team, then Organization. KPN automatically provisions

    an organization-level key on your first webhook delivery if you haven''t created one.


    Each key moves through a simple lifecycle:


    - **staged** — created but not yet in use. Lets you set up your receiver before switching over.

    - **active** — the key currently used to sign all outgoing webhook deliveries.

    - **retiring** — being phased out after a newer key was activated. Kept alive long enough for any already-sent webhooks to be verified.

    - **retired** — fully decommissioned. Safe to delete.


    **Rotating keys without downtime**


    You can switch to a new signing key at any time without missing a delivery:


    1. Create a new key with `staged: true` — your current active key keeps signing.

    2. Call `/reveal` to get the new key''s plaintext secret and configure your receiver to accept both keys.

    3. Activate the new key — the previously active key moves to retiring automatically.

    4. Once you''re confident all in-flight deliveries have been verified, retire then delete the old key.


    **Verifying payloads on your end**


    When a webhook arrives, check the header. It contains an HMAC-SHA256

    hex digest of the raw request body, signed with your active key secret. On your side,

    recompute that digest over the raw body bytes using your stored secret and compare the

    two values with a constant-time comparison — this prevents timing attacks. If the values

    don''t match, reject the request.


    **Authentication**


    You need an OAuth 2.0 Bearer token to call these endpoints. You must add **WebhookConfigs-SigningKeys-KPN** product to your project. Exchange your **Client ID**

    and **Client Secret** (available in the [KPN API Store](https://developer.kpn.com)) for

    an access token, then pass it as `Authorization: Bearer <token>` on every request.

    Tokens expire, so build in a refresh before expiry.


    **Need help?**


    - [KPN Developer Portal](https://developer.kpn.com)

    - [Getting Started with KPN APIs](https://developer.kpn.com/getting-started)

    - [API Support](https://developer.kpn.com/support)

    '
  version: 4.0.0
  contact:
    name: API Support
    email: api_developer@kpn.com
    url: https://developer.kpn.com/support
  termsOfService: https://developer.kpn.com/legal
servers:
- description: SwaggerHub API Auto Mocking
  url: https://virtserver.swaggerhub.com/kpn/webhook-signing-key-management-kpn/4.0.0
- url: https://api-prd.kpn.com/webhookconfigs-kpn
  description: Production
security:
- OAuth2: []
tags:
- name: Application Keys
  description: 'Signing keys at application scope. Highest precedence — overrides both team and

    org keys for deliveries belonging to this specific application.

    '
paths:
  /applications/keys:
    post:
      operationId: createApplicationSigningKey
      tags:
      - Application Keys
      summary: Create application signing key
      description: "Creates a new signing key at application scope.\n\n- `staged: false` (default) — key becomes **active** immediately; any previously\n  active application key is moved to **retiring** automatically.\n- `staged: true` — key is created as **staged**; activate it later.\n"
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/SigningKeyCreateRequest'
            examples:
              activeKey:
                summary: Create and immediately activate
                value:
                  secret: my-shared-secret-at-least-32-chars-long
              stagedKey:
                summary: Create in staged state
                value:
                  secret: my-shared-secret-at-least-32-chars-long
                  staged: true
      responses:
        '201':
          description: Created
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SigningKeyResponse'
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '403':
          $ref: '#/components/responses/Forbidden'
        '500':
          $ref: '#/components/responses/InternalServerError'
    get:
      operationId: listApplicationSigningKeys
      tags:
      - Application Keys
      summary: List application signing keys
      description: Lists all signing keys at application scope.
      parameters:
      - $ref: '#/components/parameters/StatusFilter'
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/SigningKeyResponse'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '403':
          $ref: '#/components/responses/Forbidden'
        '500':
          $ref: '#/components/responses/InternalServerError'
  /applications/keys/reveal:
    get:
      operationId: revealApplicationSigningKeySecret
      tags:
      - Application Keys
      summary: Reveal active application signing key secret
      description: Returns the decrypted plaintext secret for the currently active application signing key.
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SigningKeyRevealResponse'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '403':
          $ref: '#/components/responses/Forbidden'
        '404':
          description: No active signing key found for your application.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ApiErrorResponse'
        '500':
          $ref: '#/components/responses/InternalServerError'
  /applications/keys/{key_id}/activate:
    post:
      operationId: activateApplicationSigningKey
      tags:
      - Application Keys
      summary: Activate a staged application signing key
      description: 'Transitions the key from `staged` to `active`.

        Any currently `active` application key is automatically moved to `retiring`.

        '
      parameters:
      - $ref: '#/components/parameters/KeyId'
      responses:
        '200':
          description: Activated
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SigningKeyResponse'
        '400':
          description: Key is not in staged state.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ApiErrorResponse'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '403':
          $ref: '#/components/responses/Forbidden'
        '404':
          $ref: '#/components/responses/NotFound'
        '500':
          $ref: '#/components/responses/InternalServerError'
  /applications/keys/{key_id}/retire:
    post:
      operationId: retireApplicationSigningKey
      tags:
      - Application Keys
      summary: Retire a retiring application signing key
      description: Transitions the key from `retiring` to `retired`. Only keys in `retiring` state can be retired.
      parameters:
      - $ref: '#/components/parameters/KeyId'
      responses:
        '200':
          description: Retired
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SigningKeyResponse'
        '400':
          description: Key is not in retiring state.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ApiErrorResponse'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '403':
          $ref: '#/components/responses/Forbidden'
        '404':
          $ref: '#/components/responses/NotFound'
        '500':
          $ref: '#/components/responses/InternalServerError'
  /applications/keys/{key_id}:
    delete:
      operationId: deleteApplicationSigningKey
      tags:
      - Application Keys
      summary: Delete a retired application signing key
      description: Permanently deletes the key record. Only keys in `retired` state can be deleted.
      parameters:
      - $ref: '#/components/parameters/KeyId'
      responses:
        '204':
          description: Deleted
        '400':
          description: Key is not in retired state.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ApiErrorResponse'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '403':
          $ref: '#/components/responses/Forbidden'
        '404':
          $ref: '#/components/responses/NotFound'
        '500':
          $ref: '#/components/responses/InternalServerError'
components:
  responses:
    BadRequest:
      description: Bad request — check your request body for missing or invalid fields.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ApiErrorResponse'
          example:
            errorResponse:
              code: '400'
              message: Bad Request
              info: https://developer.kpn.com/documentation-webhook-signing-keys
    NotFound:
      description: Not found — the requested key does not exist.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ApiErrorResponse'
          example:
            errorResponse:
              code: '404'
              message: Not Found
              info: https://developer.kpn.com/documentation-webhook-signing-keys
    InternalServerError:
      description: Internal server error.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ApiErrorResponse'
          example:
            errorResponse:
              code: '500'
              message: Internal Server Error
              info: https://developer.kpn.com/support
    Unauthorized:
      description: Unauthorized — missing or invalid Bearer token.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ApiErrorResponse'
          example:
            errorResponse:
              code: '401'
              message: Unauthorized
              info: https://developer.kpn.com/getting-started
    Forbidden:
      description: Forbidden — your token does not have permission to access this resource.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ApiErrorResponse'
          example:
            errorResponse:
              code: '403'
              message: Forbidden
              info: https://developer.kpn.com/support
  schemas:
    SigningKeyCreateRequest:
      type: object
      required:
      - secret
      properties:
        key_id:
          type: string
          maxLength: 128
          description: 'Optional custom identifier for this key. If omitted, a `wk_`-prefixed ID is

            generated automatically (e.g. `wk_2C6EDCDFDFD944F3A75D0D36`).

            '
        secret:
          type: string
          minLength: 1
          maxLength: 4096
          description: 'The shared secret used for HMAC-SHA256 signing of outbound webhook payloads.

            Configure your webhook receiver with this value to verify incoming signatures.

            **This value is never returned after creation** — use the `/reveal` endpoint

            to retrieve it for the currently active key.

            '
        staged:
          type: boolean
          default: false
          description: '`false` (default) — key becomes active immediately; any previously active key

            at the same scope is moved to retiring automatically.


            `true` — key is created in staged state. Use this for zero-downtime rotation:

            update your receiver first, then activate the key.

            '
    SigningKeyResponse:
      type: object
      description: Signing key metadata. Does not include the secret value.
      properties:
        key_id:
          type: string
          example: wk_2C6EDCDFDFD944F3A75D0D36
        status:
          type: string
          enum:
          - staged
          - active
          - retiring
          - retired
          description: Current lifecycle state of the key.
        created_at:
          type: string
          format: date-time
        updated_at:
          type: string
          format: date-time
    SigningKeyRevealResponse:
      type: object
      description: 'Contains the decrypted plaintext secret for the active signing key.

        **Treat this like a password** — do not log or expose it.

        '
      properties:
        key_id:
          type: string
          example: wk_2C6EDCDFDFD944F3A75D0D36
        secret:
          type: string
          description: Plaintext HMAC-SHA256 shared secret. Configure your receiver with this value.
        status:
          type: string
          enum:
          - active
        created_at:
          type: string
          format: date-time
        updated_at:
          type: string
          format: date-time
    ApiErrorResponse:
      type: object
      properties:
        errorResponse:
          type: object
          properties:
            code:
              type: string
              description: HTTP status code as a string.
              example: '400'
            message:
              type: string
              description: Human-readable error message.
            info:
              type: string
              description: URL to relevant documentation or support page.
  parameters:
    StatusFilter:
      in: query
      name: status
      required: false
      description: Filter keys by lifecycle status.
      schema:
        type: string
        enum:
        - STAGED
        - ACTIVE
        - RETIRING
        - RETIRED
    KeyId:
      in: path
      name: key_id
      required: true
      schema:
        type: string
      description: The `key_id` returned by the create or list endpoint.
      example: wk_2C6EDCDFDFD944F3A75D0D36
  securitySchemes:
    OAuth2:
      type: oauth2
      flows:
        clientCredentials:
          tokenUrl: https://api-prd.kpn.com/oauth/client_credential/accesstoken?grant_type=client_credentials
          scopes: {}