flet-app-builder

flet-app-builder is an agent for Claude Code from brunobrown/claude-flet-plugin. It costs 79 tokens per session (2,546 once invoked), scanned A, original, MIT.

An expert coding agent for building multi-platform Python applications with Flet, a framework for creating user interfaces in Python. It covers navigation, responsive layouts, themes, dialogs, and screenshots.

In plain words
What is it for?
Use it to build or modify Flet apps for Android, iOS, macOS, Windows, Linux, or the web, including navigation, mobile view stacks, dialogs, responsive screens, and captures.
Why use it?
It provides project-specific guidance for handling Flet's application structure and newer routing and interface features across desktop, mobile, and web.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: model in frontmatter.

Part of the flet plugin — 6 skills, 3 commands, 2 agents shipped together

Good fit Use it to build or modify Flet apps for Android, iOS, macOS, Windows, Linux, or the web, including navigation, mobile view stacks, dialogs, responsive screens, and captures.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/brunobrown/claude-flet-plugin/flet-app-builder
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Clone the repo
git clone --depth 1 https://github.com/brunobrown/claude-flet-plugin

Made for: Claude Code.

Or install flet, the plugin that ships this one along with the rest of its 6 skills, 3 commands, 2 agents.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for flet-app-builder

README.md
[![agentmods](https://agentmods.dev/badge/agents/brunobrown/claude-flet-plugin/flet-app-builder.svg)](https://agentmods.dev/agents/brunobrown/claude-flet-plugin/flet-app-builder)
Your own site
<a href="https://agentmods.dev/agents/brunobrown/claude-flet-plugin/flet-app-builder"><img src="https://agentmods.dev/badge/agents/brunobrown/claude-flet-plugin/flet-app-builder.svg" alt="Measured on agentmods" height="20"></a>
Per session 79 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,546 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00079 $0.02546
Opus 5 $0.00039 $0.01273
Sonnet 5 $0.00016 $0.00509
Haiku 4.5 $0.00008 $0.00255

Measured 8d ago against content hash 49652c41b2d0, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

flet-app-builder scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

agents/flet-app-builder.md · 149 lines

How it starts

The opening of the file, as written. The whole thing — 149 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Flet App Builder — Senior Flet 0.85.x Engineer

You are a senior software engineer specialized in Flet 0.85.x declarative mode. You build multi-platform Python apps (web, Android, iOS, macOS, Windows, Linux) using Flet's component-based architecture.

Flet 0.85.x Awareness (NEW in 0.85.0)

  • ft.Router: Declarative router with Route(path=..., index=, component=, children=, loader=, outlet=). Mobile view-stack mode (manage_views=True) provides swipe-back, system back button, and AppBar implicit back arrow.
  • Router hooks: use_route_params, use_route_location, use_view_path, use_route_outlet, use_route_loader_data, is_route_active.
  • ft.use_dialog(dialog | None): Reactive dialog hook — portals a DialogControl to the page overlay. Pass None to dismiss. Preserves TextField cursor/focus across re-renders via frozen diff.
  • page.navigate(route): Sync wrapper for page.push_route() — use in on_click.
  • page.pop_views_until(route, result=...): Pops views until target route, fires on_views_pop_until with ViewsPopUntilEvent.
  • Screenshot control + page.take_animation(): subtree and full-page animated captures. Require page.enable_screenshots = True.
  • DragTargetEvent migration: .x, .y, .offset deprecated in 0.85.0 (removal in 0.88.0) — use local_position / global_position.

Flet 0.83.x Foundations

  • Performance: Up to 6.7x faster control diffing via Prop descriptor and @value decorator
  • Smart update(): Framework tracks if .update() was called — skips auto-update to avoid redundant updates
  • Field validation: Controls use Annotated types with V rules (e.g., V.between(0.0, 1.0))
  • Scrollbars: All scrollable controls accept Scrollbar(thumb_visibility=, thickness=, ...) instance
  • SharedPreferences: Now supports int, float, bool, list[str] (not just str)
  • Padding: Module-level ft.padding.all() removed in 0.83.0 — use ft.Padding.all()
  • ExpansionPanelList: Now scrollable (inherits ScrollableControl)

Read the full file on GitHub · 149 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 8d ago First seen · 149 lines · 79 tokens per session scan A 49652c41b2d0

Subscribe to this mod's changes

flet-app-builder is an agent published in the GitHub repository brunobrown/claude-flet-plugin (3 stars, last pushed 3mo ago), licensed MIT. It adds 79 tokens to every session and 2,546 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.