Borrowing it
Nothing to install: this file belongs to brunobrown/claude-flet-plugin. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/brunobrown/claude-flet-plugin/main/.agents/skills/flet-extension/SKILL.mdgit clone --depth 1 https://github.com/brunobrown/claude-flet-pluginWrote 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.
[](https://agentmods.dev/skills/brunobrown/claude-flet-plugin/flet-extension)<a href="https://agentmods.dev/skills/brunobrown/claude-flet-plugin/flet-extension"><img src="https://agentmods.dev/badge/skills/brunobrown/claude-flet-plugin/flet-extension/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/brunobrown/claude-flet-plugin/flet-extension"><img src="https://agentmods.dev/badge/skills/brunobrown/claude-flet-plugin/flet-extension.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00079 | $0.12276 |
| Opus 5 | $0.00039 | $0.06138 |
| Sonnet 5 | $0.00016 | $0.02455 |
| Haiku 4.5 | $0.00008 | $0.01228 |
Grade A, and why
flet-extension 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 10d 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.
How it starts
The opening of the file, as written. The whole thing — 1,731 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Flet Extension Development — Complete Reference
Flet 0.85.x | Validated against real production extensions (flet-onesignal, flet-vibration, flet-video, flet-audio)
Flet 0.85.x context for extensions
- Companion extensions evolved in lockstep with 0.85.0:
flet-video— Configurable player controls (show/hide play/pause, seek bar, fullscreen, etc.) and an asynctake_screenshot()method on the player controlflet-audio— NewAudioRecorderwith PCM16 streaming and direct upload to backend
- Core APIs your extension may want to integrate with:
page.take_screenshot()/page.take_animation()and the new top-levelScreenshotcontrol (flet.controls.core.screenshot.Screenshot)ft.Routeroutlets — if your extension renders a navigator/host, expose hooks foruse_route_params/use_view_pathinteropft.use_dialog— for UI controls that surface dialogs, prefer this hook over imperativepage.show_dialog
- The deprecated
DragTargetEvent.x/y/offsetproperties (replaced bylocal_position/global_positionin 0.85.0) affect any extension that re-emits or wraps drag targets — update before 0.88.0.
Extension Architecture Overview
Two Extension Types
| Aspect | ft.Service |
ft.LayoutControl |
|---|---|---|
| Has UI | No | Yes |
| Base class (Python) | ft.Service |
ft.LayoutControl |
| Base class (Dart) | FletService |
StatefulWidget |
| Add to app | page.services.append() |
page.add() / controls list |
| Extension handler | createService(control) |
createWidget(control) |
| width/height | No | Yes (inherited) |
| expand | No | Yes (inherited) |
| Examples | Push notifications, audio, geolocation | WebView, video player, map |
When to Use Which
- Service: SDKs that run in background, platform APIs (push, permissions, location, audio)
- UI Control: Widgets that render on screen and occupy visual space (players, maps, charts)
Directory Structure
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 10d ago First seen · 1,731 lines · 79 tokens per session scan A 2a9f8f0cb031
flet-extension is a skill published in the GitHub repository brunobrown/claude-flet-plugin (3 stars, last pushed 4mo ago), licensed MIT. It adds 79 tokens to every session and 12,276 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.
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