added sample client with sample autogenerated client code

as per Visual Studio Extension

src/BreCalClient/App.xaml

@@ -0,0 +1,9 @@
+<Application x:Class="BreCalClient.App"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:local="clr-namespace:BreCalClient"
+             StartupUri="MainWindow.xaml">
+    <Application.Resources>
+         
+    </Application.Resources>
+</Application>

src/BreCalClient/App.xaml.cs

@@ -0,0 +1,17 @@
+using System;
+using System.Collections.Generic;
+using System.Configuration;
+using System.Data;
+using System.Linq;
+using System.Threading.Tasks;
+using System.Windows;
+
+namespace BreCalClient
+{
+    /// <summary>
+    /// Interaction logic for App.xaml
+    /// </summary>
+    public partial class App : Application
+    {
+    }
+}

src/BreCalClient/AssemblyInfo.cs

@@ -0,0 +1,10 @@
+using System.Windows;
+
+[assembly: ThemeInfo(
+    ResourceDictionaryLocation.None, //where theme specific resource dictionaries are located
+                                     //(used if a resource is not found in the page,
+                                     // or application resource dictionaries)
+    ResourceDictionaryLocation.SourceAssembly //where the generic resource dictionary is located
+                                              //(used if a resource is not found in the page,
+                                              // app, or any theme specific resource dictionaries)
+)]

src/BreCalClient/BreCalClient.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>WinExe</OutputType>
+    <TargetFramework>net6.0-windows</TargetFramework>
+    <Nullable>enable</Nullable>
+    <UseWPF>true</UseWPF>
+  </PropertyGroup>
+
+</Project>

src/BreCalClient/BreCalClient.sln

@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.5.33627.172
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "BreCalClient", "BreCalClient.csproj", "{FA9E0A87-FBFB-4F2B-B5FA-46DE2E5E4BCB}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{FA9E0A87-FBFB-4F2B-B5FA-46DE2E5E4BCB}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{FA9E0A87-FBFB-4F2B-B5FA-46DE2E5E4BCB}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{FA9E0A87-FBFB-4F2B-B5FA-46DE2E5E4BCB}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{FA9E0A87-FBFB-4F2B-B5FA-46DE2E5E4BCB}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {CBF797A4-0CAF-4F01-B0D5-708702165337}
+	EndGlobalSection
+EndGlobal

src/BreCalClient/MainWindow.xaml

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+<Window x:Class="BreCalClient.MainWindow"
+        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+        xmlns:local="clr-namespace:BreCalClient"
+        mc:Ignorable="d"
+        Title="MainWindow" Height="450" Width="800">
+    <Grid>
+
+    </Grid>
+</Window>

src/BreCalClient/MainWindow.xaml.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Data;
+using System.Windows.Documents;
+using System.Windows.Input;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+using System.Windows.Navigation;
+using System.Windows.Shapes;
+
+namespace BreCalClient
+{
+    /// <summary>
+    /// Interaction logic for MainWindow.xaml
+    /// </summary>
+    public partial class MainWindow : Window
+    {
+        public MainWindow()
+        {
+            InitializeComponent();
+        }
+    }
+}

src/BreCalClient/Swagger.yaml

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+openapi: '3.0.0'
+info:
+  version: '1.0.0'
+  title: 'Bremen calling API'
+  description: Administer DEBRE ship calls, times and notifications
+  termsOfService: "https://www.bsmd.de/" # url to terms page
+  contact:
+    name: "Bremen calling API"
+    url: "https://www.textbausteine.net"
+    email: "info@textbausteine.net"
+  license:
+    name: "Use at your own risk"
+    url: "https://www.bsmd.de/license"
+
+servers:
+  # tutorial: https://idratherbewriting.com/learnapidoc/pubapis_openapi_step3_servers_object.html
+  - url : "https://puls200.dyn-dns.org:8088/brecal/api"
+    description: "Test server self-hosted by yours truly"
+
+paths:
+  # tutorial: https://idratherbewriting.com/learnapidoc/pubapis_openapi_step4_paths_object.html
+  /verify:    
+    get:
+      summary: Returns a session key if successful
+      responses:
+        200:
+          description: Successful response
+          content:
+            application/json:
+              schema:
+                title: Session key
+                type: string
+        400:
+          $ref: '#/components/responses/400'
+        403:
+          $ref: '#/components/responses/403'
+        500:
+          $ref: '#/components/responses/500'
+        503:
+          $ref: '#/components/responses/503' 
+
+  /shipcalls:
+    get:
+      summary: Gets a list of ship calls
+      parameters:
+        - name: participant_id          
+          in: query
+          required: true
+          description: "**Id of participant**. *Example: 2*. Id of participant entity requesting ship calls"
+          schema:
+            type: integer
+      responses:
+        200:
+          description: ship call list
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/shipcalls'
+        400:
+          $ref: '#/components/responses/400'
+        401:
+          $ref: '#/components/responses/401'
+        500:
+          $ref: '#/components/responses/500'
+        503:
+          $ref: '#/components/responses/503'
+    post:
+      summary: Create a new ship call
+      requestBody:
+        description: Creates a new ship call. **Do not** provide id parameter.
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/shipcall'
+      responses:
+        400:
+          $ref: '#/components/responses/400'
+        401:
+          $ref: '#/components/responses/401'
+        500:
+          $ref: '#/components/responses/500'
+        503:
+          $ref: '#/components/responses/503'
+
+    put:
+      summary: Updates a ship call
+      requestBody:
+        description: Creates a new ship call. The id parameter is **required**.
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/shipcall'
+      responses:
+        400:
+          $ref: '#/components/responses/400'
+        401:
+          $ref: '#/components/responses/401'
+        500:
+          $ref: '#/components/responses/500'
+        503:
+          $ref: '#/components/responses/503'
+
+  /ships:
+    get:
+      summary: gets a list of registered shipcalls
+      responses:
+        200:
+          description: list of ships
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ship_list'
+        400:
+          $ref: '#/components/responses/400'
+        401:
+          $ref: '#/components/responses/401'
+        500:
+          $ref: '#/components/responses/500'
+        503:
+          $ref: '#/components/responses/503'
+
+  /participant:
+    get:
+      summary: gets a particular participant entry corresponding to user id
+      parameters:
+        - name: user_id
+          in: query
+          required: true
+          description: "**Id of user**. *Example: 2*. User id returned by verify call."
+          schema:
+            type: integer
+      responses:
+        200:
+          description: ship call list
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/participant'
+        400:
+          $ref: '#/components/responses/400'
+        401:
+          $ref: '#/components/responses/401'
+        500:
+          $ref: '#/components/responses/500'
+        503:
+          $ref: '#/components/responses/503'     
+
+  /times:
+    get:
+      summary: Get all recorded times for a a ship call
+      parameters:
+        - name: shipcall_id
+          in: query
+          description: "**Id**. *Example: 42*. Id of referenced ship call."
+          schema:
+            type: integer
+      responses:
+        200:
+          description: list of recorded times
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/times_list'        
+        400:
+          $ref: '#/components/responses/400'
+        401:
+          $ref: '#/components/responses/401'
+        500:
+          $ref: '#/components/responses/500'
+        503:
+          $ref: '#/components/responses/503'
+
+    post:
+      summary: Create a new times entry for a ship call
+      requestBody:
+        description: Times entry that will be added to the ship call. **Do not** provide id parameter.
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/times'
+      responses:
+        400:
+          $ref: '#/components/responses/400'
+        401:
+          $ref: '#/components/responses/401'
+        500:
+          $ref: '#/components/responses/500'
+        503:
+          $ref: '#/components/responses/503'
+
+    put:
+      summary: Update a times entry for a ship call
+      requestBody:
+        description: Times entry that will be added to the ship call. The id parameter is **required**.
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/times'
+      responses:
+        400:
+          $ref: '#/components/responses/400'
+        401:
+          $ref: '#/components/responses/401'
+        500:
+          $ref: '#/components/responses/500'
+        503:
+          $ref: '#/components/responses/503'
+
+    delete:
+      summary: Delete a times entry for a ship call.
+      parameters:
+        - name: id
+          in: query
+          required: true          
+          schema:
+            $ref: '#/components/schemas/timesId'
+      responses:
+        400:
+          $ref: '#/components/responses/400'
+        401:
+          $ref: '#/components/responses/401'
+        500:
+          $ref: '#/components/responses/500'
+        503:
+          $ref: '#/components/responses/503'
+
+  /notifications:
+    get:
+      summary: Gets a list of notifications pursuant to a specified participant and ship call
+      parameters:
+        - name: participant_id
+          in: query
+          required: true
+          description: "**Id of participant**. *Example: 2*. Id returned through loading of participant"
+          schema:
+            type: integer
+        - name: shipcall_id
+          in: query
+          required: true
+          description: "**Id of ship call**. *Example: 52*. Id given in ship call list"
+          schema:
+            $ref: '#/components/schemas/shipcallId'
+      responses:
+        200:
+          description: notification list
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/notification'
+        400:
+          $ref: '#/components/responses/400'
+        401:
+          $ref: '#/components/responses/401'
+        500:
+          $ref: '#/components/responses/500'
+        503:
+          $ref: '#/components/responses/503'
+  /berths:
+    get:
+      summary: Gets a list of all berths registered
+      responses:
+        200:
+          description: list of berths
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/berth_list'
+        400:
+          $ref: '#/components/responses/400'
+        401:
+          $ref: '#/components/responses/401'
+        500:
+          $ref: '#/components/responses/500'
+        503:
+          $ref: '#/components/responses/503'
+components:
+  schemas:
+    timesId:
+      description: The unique identifier for a times entry
+      type: integer
+    shipcallId:
+      description: The unique identifier of a ship call
+      type: integer
+    shipcall:
+      type: object
+      required:
+        - id
+        - ship_id
+        - type      
+        - eta
+        - voyage
+        - etd
+      properties:
+        id:
+          $ref: '#/components/schemas/shipcallId'
+        
+        type:
+          type: string
+          enum:
+            - incoming
+            - outgoing
+            - shifting          
+            
+        description:
+          type: string
+
+    shipcalls:
+      type: array
+      items:
+        $ref: '#/components/schemas/shipcall'
+
+    times:
+      type: object
+      description: the id parameter needs to be missing on POST and to be present on PUT (Update) calls, otherwise a 400 response will be generated
+      required:        
+        - shipcall_id
+        - participant_id
+      properties:
+        id:
+          type: integer
+        start_planned:
+          type: string
+          format: date-time
+        end_planned:
+          type: string
+          format: date-time
+        duration_planned:
+          type: integer
+        start_actual:
+          type: string
+          format: date-time
+        end_actual:
+          type: string
+          format: date-time
+        shipcall_id:
+          type: integer
+        participant_id:
+          type: integer
+      
+    times_list:
+      type: array
+      items:
+        $ref: '#/components/schemas/times'
+      
+    berth:
+      type: object
+      description: Ship berth used for a ship call
+      properties:
+        id:
+          type: integer
+        name1:
+          type: string
+        name2:
+          type: string
+
+    berth_list:
+      type: array
+      items:
+        $ref: '#/components/schemas/berth'
+
+    ship:
+      type: object
+      description: a ship
+      properties:
+        id:
+          type: integer
+        name:
+          type: string
+        imo:
+          type: integer
+        callsign:
+          type: string
+        length:
+          type: number
+          format: float          
+        width:
+          type: number
+          format: float
+        created:
+          type: string
+          format: date-time
+        modified:
+          type: string
+          format: date-time
+
+    ship_list:
+      type: array
+      items:
+        $ref: '#/components/schemas/ship'
+
+    notification:
+      type: object
+      description: a notification created by the engine if a times entry violates a rule
+      properties:
+        id:
+          type: integer
+        times_id:
+          type: integer
+        participant_id:
+          type: integer
+        notification_type:
+          type: string
+          enum: [undefined, email, push]
+        timestamp:
+          type: string
+          format: date-time
+        acknowledged:
+          type: boolean
+      
+    notification_list:
+      type: array
+      items:
+        $ref: '#/components/schemas/notification'
+
+    participant:
+      type: object
+      description: A organisational entity that participates in Bremen Calling
+      properties:
+        id:
+          type: integer
+        name:
+          type: string
+        street:
+          type: string
+        postal code:
+          type: string
+        city: 
+          type: string
+
+    Error:
+      type: object
+      required:
+        - message
+      properties:
+        message:
+          description: A human readable error message
+          type: string
+
+  securitySchemes:
+    ApiKey:
+      type: apiKey
+      in: header
+      name: X-Api-Key
+  responses:
+    400:
+      description: Invalid input
+      content:
+        application/json:
+          schema:
+            $ref: '#/components/schemas/Error'
+    401:
+      description: Not authorized
+      content:
+        application/json:
+          schema:
+            $ref: '#/components/schemas/Error'
+    403:
+      description: Forbidden
+      content:
+        application/json:
+          schema:
+            $ref: '#/components/schemas/Error'
+    500:
+      description: Unexpected error
+      content:
+        application/json:
+          schema:
+            $ref: '#/components/schemas/Error'
+    503:
+      description: Not available
+      content:
+        application/json:
+          schema:
+            $ref: '#/components/schemas/Error'
+
+security:
+  - ApiKey: []
+externalDocs:
+  url: http://textbausteine.net/
+  description: Extra documentation and conditions for Bremen Calling