What is flutter-expert?

A development guide for building Flutter applications, which use one codebase to target multiple platforms. It covers interface components, app state, native platform connections, performance, testing, and releases.

Use it to design widget architecture, manage state with Riverpod or Bloc, connect to native features, tune performance, test apps, and prepare releases.

It helps developers organise Flutter apps and manage data shared between screens. It also covers the platform-specific and operational work needed to test and ship an app.

flutter-expert — Skill for Claude Code and Codex by johnefemer

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.

Any agent

npx skills add johnefemer/skillfish --skill flutter-expert

Clone the repo

git clone --depth 1 https://github.com/johnefemer/skillfish

Made for: Claude Code, Codex.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/johnefemer/skillfish/flutter-expert/github.svg)](https://agentmods.dev/skills/johnefemer/skillfish/flutter-expert)

Your own site

<a href="https://agentmods.dev/skills/johnefemer/skillfish/flutter-expert"><img src="https://agentmods.dev/badge/skills/johnefemer/skillfish/flutter-expert/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/johnefemer/skillfish/flutter-expert"><img src="https://agentmods.dev/badge/skills/johnefemer/skillfish/flutter-expert.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 874 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 unknown 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.

Model	Per session	Once invoked
Fable 5.1	$0.00000	$0.00874
Opus 5.5	$0.00000	$0.00350
Sonnet 5.5	$0.00000	$0.00175
Haiku 4.5	$0.00000	$0.00087

Measured 2mo ago against content hash a9d9717bd007, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

flutter-expert 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 2mo 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.

skills/flutter-expert/SKILL.md · 78 lines

The source is not reproduced here

No licence file

Read it on GitHub

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.

2mo ago First seen · 78 lines · 0 tokens per session scan A a9d9717bd007

Subscribe to this mod's changes

flutter-expert is a skill published in the GitHub repository johnefemer/skillfish (4 stars, last pushed 4d ago), with no licence file. It costs nothing until one of its globs matches a file; then it loads 874 tokens. 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 2026-09-03.

Mobile Testing

flutter-expert next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
flutter-expertjohnefemer/skillfish	Skill	4	4d ago	none	A	0	Claude Code, Codex
orca-emulator-androidstablyai/orca	Skill	117k	yesterday	MIT	A	102	Claude Code, Codex
glance-canonical-layoutsandroid/skills	Skill	10k	yesterday	Apache-2.0	A	56	Claude Code
android-tombstone-symbolicationdotnet/skills	Skill	5.8k	yesterday	MIT	A	176	Claude Code
dogfoodcallstack/agent-device	Skill	5.3k	yesterday	MIT	A	55	Claude Code
winapp-mauimicrosoft/winappCli	Skill	1.4k	yesterday	MIT	A	68	Claude Code
app_remixrome-os/rome	Skill	889	yesterday	MIT	A	50	Claude Code, Codex