Creating a FlowApp

This guide walks through creating a complete FlowApp from scratch. We’ll build a Cal.com integration as our example.

Project structure

FlowApps are located in IqraInfrastructure/Managers/FlowApp/Apps/:

Apps/
└── CalCom/
    ├── CalComApp.cs                    # Main app definition
    ├── Actions/
    │   ├── BookMeetingAction.cs        # Action implementation
    │   └── BookMeeting.json            # JSON Schema for action inputs
    ├── Fetchers/
    │   └── GetEventTypesByIdFetcher.cs # Dynamic dropdown data
    └── Models/
        └── CalComModels.cs             # Request/response DTOs

Step 1: Create the main app class

Create a class that implements IFlowApp:

IqraInfrastructure/Managers/FlowApp/Apps/CalCom/CalComApp.cs

using IqraCore.Interfaces.FlowApp;
using IqraCore.Interfaces.Integration;
using Microsoft.Extensions.Logging;

namespace IqraInfrastructure.Managers.FlowApp.Apps.CalCom
{
    public class CalComApp : IFlowApp
    {
        public string AppKey => "cal_com";
        public string Name => "Cal.com";
        public string IconUrl => "https://cal.com/favicon.ico";
        public string? IntegrationType => "cal_com"; // Links to admin dashboard

        private readonly IHttpClientFactory _httpClientFactory;
        private readonly ILogger<CalComApp> _logger;
        private const string BaseUrl = "https://api.cal.com/";

        public IReadOnlyList<IFlowAction> Actions { get; }
        public IReadOnlyList<IFlowDataFetcher> DataFetchers { get; }

        public CalComApp(IHttpClientFactory httpClientFactory, ILogger<CalComApp> logger)
        {
            _httpClientFactory = httpClientFactory;
            _logger = logger;

            // Initialize actions
            Actions = new List<IFlowAction>
            {
                new BookMeetingAction(this),
                new CancelBookingAction(this),
                // ... more actions
            };

            // Initialize fetchers
            DataFetchers = new List<IFlowDataFetcher>
            {
                new GetEventTypesByIdFetcher(this)
            };
        }

        public HttpClient CreateClient()
        {
            var client = _httpClientFactory.CreateClient();
            client.BaseAddress = new Uri(BaseUrl);
            return client;
        }
    }
}

The AppKey must be unique across all FlowApps. Use lowercase snake_case by convention.

Constructor dependencies

You can inject any registered service:

IHttpClientFactory - For making HTTP requests
ILogger<T> - For logging
Custom services from your DI container

Step 2: Define an action

Actions perform the actual work. Create a partial class implementing IFlowAction:

IqraInfrastructure/Managers/FlowApp/Apps/CalCom/Actions/BookMeetingAction.cs

using IqraCore.Entities.FlowApp;
using IqraCore.Interfaces.FlowApp;
using IqraCore.Models.FlowApp.Integration;
using System.Text.Json;

namespace IqraInfrastructure.Managers.FlowApp.Apps.CalCom.Actions
{
    public partial class BookMeetingAction : IFlowAction
    {
        private readonly CalComApp _app;

        public BookMeetingAction(CalComApp app)
        {
            _app = app;
        }

        public string ActionKey => "BookMeeting";
        public string Name => "Book a Meeting";
        public string Description => "Schedules a new booking on Cal.com.";

        public IReadOnlyList<ActionOutputPort> GetOutputPorts()
        {
            return new List<ActionOutputPort>
            {
                new ActionOutputPort { Key = "success", Label = "Success (201)" },
                new ActionOutputPort { Key = "conflict", Label = "Slot Taken (409)" },
                new ActionOutputPort { Key = "error", Label = "Error" }
            };
        }

        public async Task<ActionExecutionResult> ExecuteAsync(
            JsonElement input, 
            BusinessAppIntegrationDecryptedModel integration)
        {
            try
            {
                // 1. Extract credentials
                var apiKey = integration.DecryptedFields["ApiKey"];
                var client = _app.CreateClient();

                // 2. Build request from validated input
                var request = new CreateBookingRequest
                {
                    Start = input.GetProperty("start").GetString(),
                    Attendee = new Attendee
                    {
                        Name = input.GetProperty("attendeeName").GetString(),
                        Email = input.GetProperty("attendeeEmail").GetString(),
                        TimeZone = input.TryGetProperty("attendeeTimeZone", out var tz) 
                            ? tz.GetString() ?? "UTC" 
                            : "UTC"
                    }
                };

                // 3. Make API call
                var httpRequest = new HttpRequestMessage(HttpMethod.Post, "/v2/bookings");
                httpRequest.Content = new StringContent(
                    JsonSerializer.Serialize(request), 
                    System.Text.Encoding.UTF8, 
                    "application/json"
                );
                httpRequest.Headers.Add("Authorization", $"Bearer {apiKey}");
                httpRequest.Headers.Add("cal-api-version", "2024-08-13");
                
                var response = await client.SendAsync(httpRequest);
                var responseContent = await response.Content.ReadAsStringAsync();

                // 4. Handle different outcomes
                if (response.IsSuccessStatusCode)
                {
                    var result = JsonSerializer.Deserialize<CalComResponse<BookingResponseData>>(responseContent);
                    return ActionExecutionResult.SuccessPort("success", result?.Data);
                }

                if (response.StatusCode == HttpStatusCode.Conflict)
                {
                    return ActionExecutionResult.SuccessPort(
                        "conflict", 
                        new { message = "Time slot is no longer available." }
                    );
                }

                return ActionExecutionResult.Failure(
                    "API_ERROR", 
                    $"Cal.com Error: {response.StatusCode} - {responseContent}"
                );
            }
            catch (Exception ex)
            {
                return ActionExecutionResult.Failure("EXCEPTION", ex.Message);
            }
        }
    }
}

Always mark action classes as partial - the GetInputSchemaJson() method is auto-generated by the FlowAppSchemaGenerator.

Output ports

Output ports define the possible execution paths:

IqraInfrastructure/Managers/FlowApp/Apps/CalCom/Actions/BookMeetingAction.cs:24-32

public IReadOnlyList<ActionOutputPort> GetOutputPorts()
{
    return new List<ActionOutputPort>
    {
        new ActionOutputPort { Key = "success", Label = "Success (201)" },
        new ActionOutputPort { Key = "conflict", Label = "Slot Taken (409)" },
        new ActionOutputPort { Key = "error", Label = "Error" }
    };
}

success: API call succeeded
conflict: Specific error case (slot unavailable)
error: Generic failure (handled automatically by ActionExecutionResult.Failure)

Step 3: Create the JSON schema

Create a schema file with the same base name as your action (e.g., BookMeetingAction.cs → BookMeeting.json):

IqraInfrastructure/Managers/FlowApp/Apps/CalCom/Actions/BookMeeting.json

{
  "type": "object",
  "title": "Book a Meeting",
  "required": ["start", "attendeeName", "attendeeEmail"],
  "properties": {
    "start": {
      "type": "string",
      "title": "Start Time",
      "description": "ISO 8601 Date string (e.g. 2024-01-01T10:00:00Z)"
    },
    "attendeeName": {
      "type": "string",
      "title": "Attendee Name"
    },
    "attendeeEmail": {
      "type": "string",
      "title": "Attendee Email"
    },
    "attendeeTimeZone": {
      "type": "string",
      "title": "Attendee TimeZone",
      "default": "UTC"
    },
    "notes": {
      "type": "string",
      "title": "Additional Notes"
    }
  },
  "oneOf": [
    {
      "title": "By Event ID",
      "required": ["eventTypeId"],
      "properties": {
        "eventTypeId": {
          "type": "integer",
          "title": "Event Type ID",
          "x-fetcher": "GetEventTypesById"
        }
      }
    },
    {
      "title": "By User & Slug",
      "required": ["username", "eventTypeSlug"],
      "properties": {
        "username": {
          "type": "string",
          "title": "Username"
        },
        "eventTypeSlug": {
          "type": "string",
          "title": "Event Type Slug"
        }
      }
    }
  ]
}

The x-fetcher property links a field to a data fetcher for dynamic dropdowns. See Schema Definition for details.

Step 4: Create a data fetcher

Data fetchers populate dynamic dropdowns:

IqraInfrastructure/Managers/FlowApp/Apps/CalCom/Fetchers/GetEventTypesByIdFetcher.cs

using IqraCore.Entities.FlowApp;
using IqraCore.Interfaces.FlowApp;
using IqraCore.Models.FlowApp.Integration;
using System.Net.Http.Json;
using System.Text.Json;

namespace IqraInfrastructure.Managers.FlowApp.Apps.CalCom.Fetchers
{
    public class GetEventTypesByIdFetcher : IFlowDataFetcher
    {
        private readonly CalComApp _app;
        
        public GetEventTypesByIdFetcher(CalComApp app) { _app = app; }

        public string FetcherKey => "GetEventTypesById";

        public async Task<List<DynamicOption>> FetchOptionsAsync(
            BusinessAppIntegrationDecryptedModel? integration, 
            JsonElement context)
        {
            if (integration == null) return new();

            try
            {
                var apiKey = integration.DecryptedFields["ApiKey"];
                var client = _app.CreateClient();

                var httpRequest = new HttpRequestMessage(HttpMethod.Get, "/v2/event-types");
                httpRequest.Headers.Add("Authorization", $"Bearer {apiKey}");
                httpRequest.Headers.Add("cal-api-version", "2024-06-14");
                
                var response = await client.SendAsync(httpRequest);
                if (!response.IsSuccessStatusCode) return new();

                var result = await response.Content.ReadFromJsonAsync<CalComResponse<List<EventTypeDto>>>();

                return result?.Data?.Select(e => new DynamicOption
                {
                    Label = $"{e.Title} ({e.Length}m)",
                    Value = e.Id,
                    Description = $"ID: {e.Id}"
                }).ToList() ?? new();
            }
            catch { return new(); }
        }
    }
}

The context parameter contains the current form state, allowing dependent fetchers:

// Fetch event types only for the selected username
if (context.TryGetProperty("username", out var username))
{
    var user = username.GetString();
    // Fetch event types for specific user
}

Step 5: Build and test

Build the project

The FlowAppSchemaGenerator runs at build time and generates the GetInputSchemaJson() method:

Generated code

public partial class BookMeetingAction
{
    public string GetInputSchemaJson()
    {
        return "{\"type\":\"object\",\"title\":\"Book a Meeting\",...}";
    }
}

Verify discovery

Check the logs on startup:

Initialized 1 Flow Apps.

If your app isn’t discovered, verify:

Class implements IFlowApp
Class is not abstract or an interface
Class is in the same assembly as FlowAppManager

Test in the UI

Configure credentials in the admin dashboard
Create a new agent script
Add your FlowApp action to the flow
Fill in the form and test execution

Public apps (no authentication)

For apps that don’t require credentials:

public class UtilityApp : IFlowApp
{
    public string AppKey => "utility";
    public string Name => "Utility Functions";
    public string IconUrl => "/icons/utility.svg";
    public string? IntegrationType => null; // No integration required
    
    // ...
}

Set RequiresIntegration = false in your actions:

public class GetCountriesAction : IFlowAction
{
    public bool RequiresIntegration => false;
    
    public async Task<ActionExecutionResult> ExecuteAsync(
        JsonElement input, 
        BusinessAppIntegrationDecryptedModel? integration)
    {
        // integration will be null
        // Fetch data from public API
    }
}

Best practices

Use descriptive action and fetcher keys

Good: BookMeeting, GetEventTypes, SendEmail
Bad: Action1, Fetch, DoStuff

Keys appear in logs and error messages.

Define meaningful output ports

Use specific ports for common error cases:

new ActionOutputPort { Key = "conflict", Label = "Slot Already Booked" },
new ActionOutputPort { Key = "not_found", Label = "Event Type Not Found" },
new ActionOutputPort { Key = "rate_limit", Label = "Rate Limit Exceeded" }

This allows agents to handle errors gracefully.

Return structured data in results

Include relevant data in the result for downstream nodes:

return ActionExecutionResult.SuccessPort("success", new {
    bookingId = result.Id,
    confirmationUrl = result.Url,
    startTime = result.StartTime
});

Handle rate limits and retries

Implement retry logic with exponential backoff:

if (response.StatusCode == HttpStatusCode.TooManyRequests)
{
    var retryAfter = response.Headers.RetryAfter?.Delta ?? TimeSpan.FromSeconds(60);
    return ActionExecutionResult.Failure(
        "RATE_LIMIT", 
        $"Rate limited. Retry after {retryAfter.TotalSeconds}s"
    );
}

Log errors with context

Use structured logging:

_logger.LogError(
    ex, 
    "Failed to book meeting for {Email} at {StartTime}", 
    attendeeEmail, 
    startTime
);

Next steps

Schema definition

Learn advanced schema features like conditional fields, dynamic fetchers, and custom validation

FlowApp System

API Reference

Advanced

Creating a FlowApp

Project structure

Step 1: Create the main app class

Constructor dependencies

Step 2: Define an action

Output ports

Step 3: Create the JSON schema

Step 4: Create a data fetcher

Step 5: Build and test

Public apps (no authentication)

Best practices

Next steps

Schema definition

Build docs developers (and LLMs) love

FlowApp System

API Reference

Advanced

​Project structure

​Step 1: Create the main app class

​Constructor dependencies

​Step 2: Define an action

​Output ports

​Step 3: Create the JSON schema

​Step 4: Create a data fetcher

​Step 5: Build and test

​Public apps (no authentication)

​Best practices

​Next steps

Schema definition

Build docs developers (and LLMs) love

Project structure

Step 1: Create the main app class

Constructor dependencies

Step 2: Define an action

Output ports

Step 3: Create the JSON schema

Step 4: Create a data fetcher

Step 5: Build and test

Public apps (no authentication)

Best practices

Next steps