Ivy Create App

ivy-create-app

Create an ad hoc Ivy app with any combination of views.

Pre-flight: Read Learnings

If the file .ivy/learnings/ivy-create-app.md exists in the project directory, read it first and apply any lessons learned from previous runs of this skill.

Reference Files

Read these before implementing:

• references/AGENTS.md -- Ivy framework API reference (widgets, hooks, layouts, inputs, colors)
• references/ChatApp.cs -- streaming chat app with IChatClient, ImmutableArray messages
• references/OpenAIConnection.cs -- IConnection implementation for external services
• references/DesignGuidelines.md -- layout patterns, spacing, UX interaction rules

Workflow

This skill guides you through creating custom Ivy applications:

1. Plan - Understand the user's request and design the app structure
2. Review - Present the plan for user approval (accept / request changes / cancel)
3. Implement - Generate all app files following reference patterns

Step 1: Plan the App

If the app requires data from a database, use ivy cli explain connections/{ConnectionName} to get the connection schema first.

If the user's prompt includes a .wsdl URL or mentions SOAP/WSDL, the app MUST use a SOAP connection (IConnection) rather than hardcoding HTTP calls. Any external service access must go through an IConnection implementation.

Analysis

• Determine what views and components the app needs.
• Multiple entities = multiple apps. If the request involves distinct data entities (e.g., Contacts, Deals, Activities), plan a separate app for each entity rather than combining them into tabs within a single app. A Dashboard app may reference data from multiple entities, but each entity's CRUD/management screen should be its own app.
• TabsLayout is for showing different views or aspects of the same data (e.g., chart vs. table view, settings categories, wizard steps) -- not for combining unrelated entity screens.
• Choose a Lucide icon for the app (PascalCase, e.g. ShoppingBag, LayoutDashboard, FileText, Users).

Plan Format

# Plan

## Create App: [AppName]

**Connection**: `[ConnectionName or "None"]`
**App Attribute**: `[App(icon: Icons.[LucideIcon])]`
**Note**: The `group` parameter defaults to `["Apps"]` at runtime. Only specify `group` explicitly when assigning the app to a different group (e.g., `group: ["Tools"]`, `group: ["Settings"]`).
**Layout**: `[Blades / Dashboard / Custom]`
**Chrome**: `[UseAppShell / UseDefaultApp]`
**Files**: `Apps\[AppName]App.cs`
**Namespace**: `{ProjectNamespace}.Apps`

[Description of the app entry point and layout.]

### Create View: [ViewName]

**Files**: `Apps\[AppFolder]\[ViewName].cs`
**Namespace**: `{ProjectNamespace}.Apps.[AppFolder]`

[Description of what this view does, what data it shows, what interactions it supports.]

Chrome Decision

• If the app has only one app class and no multi-app navigation needs, set Chrome to UseDefaultApp. This skips the sidebar.
• If the app has multiple app classes or the user explicitly wants sidebar navigation, set Chrome to UseAppShell.
• Include a ### Update Program.cs section at the end of the plan.

Data File Ordering

If the plan includes files with large static datasets (lookup tables, seed data, icon/emoji lists, etc.):

• These files should be created last, after all UI and logic files.
• Prefer programmatic generation or embedded resources over inlined literals.

Present the plan to the user and ask them to Accept, Request Changes, or Cancel.

Step 2: Handle Changes

If the user requests changes, apply them to the plan and present the updated plan again.

Step 3: Implement

Once approved, implement all app files.

Namespace Conventions

• App files ([AppName]App.cs): namespace {ProjectNamespace}.Apps;
• View files: namespace {ProjectNamespace}.Apps.[AppFolder];

Required Using Directives

Every generated .cs file must include explicit using statements. Do NOT rely on global usings.

Connection usings (when using a database connection):

• using {ProjectNamespace}.Connections.{ConnectionName}; -- for context factory
• using {ProjectNamespace}.Connections.{ConnectionName}.Models; -- for entity classes (only if project uses a Models subfolder)
• using Microsoft.EntityFrameworkCore; -- for LINQ extensions

Common Ivy usings by view type:

App Entry Point

Use [App(icon: Icons.[Icon], group: ["Apps"])] attribute. The icon and group are parameters inside the [App(...)] attribute -- they are NOT separate attributes.

Common Hallucinations -- Do NOT Use:

• [Icon("...")] -- NOT a valid Ivy attribute
• [Group("...")] -- NOT a valid Ivy attribute
• [Description("...")] -- NOT a valid Ivy attribute
• All metadata belongs as named parameters on the single [App(...)] attribute

App Attribute - Group Parameter

The [App] attribute's group parameter is nullable and has a runtime default value of ["Apps"].

• Omit the group parameter when using the default "Apps" group
• Explicitly specify group only for non-default groups
• CRITICAL: When a specification explicitly defines a non-default group value, you MUST include it in the implementation

Program.cs Chrome Configuration

• If UseDefaultApp: Open Program.cs and remove the server.UseAppShell(...) line entirely, then add server.UseDefaultApp(typeof(AppClassName));. Do NOT keep both.
• If UseAppShell: Ensure server.UseAppShell(new AppShellSettings().DefaultApp<AppClassName>().UseTabs(preventDuplicates: true)); is present.
• Follow the approved plan exactly.

Critical Code Rules

• Use modern C# features: file-scoped namespaces, primary constructors, collection expressions.
• Write UI, logic, and app entry-point files before any data/seed files.
• If a file will contain >50 static records, prefer programmatic generation or embedded JSON resources over inline C# arrays.

When NOT to Use Html Widget

• Do NOT use the Html widget to build interactive canvases, drawing surfaces, or diagram editors. The Html widget renders static HTML -- it cannot handle click/drag events on individual elements within the HTML.
• Simple HTML usage for display purposes is fine.
• If the user needs interactive canvas, drawing, or diagram functionality, recommend using the /ivy-create-external-widget skill to create a React-based external widget instead.

Pattern Sources

• Use ONLY the reference documents in the references/ folder and documentation endpoints for API patterns and code examples.
• Do NOT read existing app files in the project's Apps/ directory for patterns.

After Implementation

After writing all files, summarize what was created and verify the build succeeds.

Reference: Design Guidelines

Page Layout

Centered Max-Width (default):

return Layout.TopCenter()
    | (Layout.Vertical().Width(Size.Full().Max(200)).Margin(10)
        | content);

• Always use Layout.TopCenter() -- without it, content hugs left edge.

Full Center (rare):

return Layout.Center()
    | (Layout.Vertical().Gap(2) | urlInput | submitButton);

Reserve for truly minimal UIs (login, empty state, single action).

Full-Width Panels (editor + preview):

return Layout.TopCenter()
    | (Layout.Vertical().Width(Size.Full().Max(300)).Margin(10)
        | Text.H1("Title")
        | (Layout.Horizontal().Gap(6)
            | (Layout.Vertical().Width(Size.Full()) | leftPanel)
            | (Layout.Vertical().Width(Size.Full()) | rightPanel)));

Visual Hierarchy & Spacing

• Use new Separator() between major sections
• Gap default is 4 -- do NOT add .Gap(4)
• Padding is rarely needed

Inputs & Validation

Use .WithField().Label() -- never call .Label() directly:

nameState.ToTextInput().WithField().Label("Name");

MetricView for KPIs

new MetricView("Sales", Icons.DollarSign,
    ctx => ctx.UseQuery("sales", () => Task.FromResult(new MetricRecord("$84.3K", 0.21, 0.21, "$400K"))))

UX Interaction

• Toast after actions: client.Toast($"{item.Name} added!");
• Confirm destructive actions: Use .WithConfirm()
• Empty states: Show guidance toward first action, not blank area

Post-run: Evaluate and Improve

After completing the task:

1. Evaluate: Did the build succeed? Were there compilation errors, unexpected behavior, or manual corrections needed during this run?
2. Update learnings: If anything required correction or was surprising, append a concise entry to .ivy/learnings/ivy-create-app.md (create the file and .ivy/learnings/ directory if they don't exist). Each entry should note: the date, what went wrong, why, and what to do differently next time.
3. Skip if clean: If everything succeeded without issues, do not update the learnings file.