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.
npx skills add Arenukvern/mcp_flutter --skill flutter-mcp-toolkit-maintain-webgit clone --depth 1 https://github.com/Arenukvern/mcp_flutterWrote 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/arenukvern/mcp_flutter/flutter-mcp-toolkit-maintain-web)<a href="https://agentmods.dev/skills/arenukvern/mcp_flutter/flutter-mcp-toolkit-maintain-web"><img src="https://agentmods.dev/badge/skills/arenukvern/mcp_flutter/flutter-mcp-toolkit-maintain-web/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/arenukvern/mcp_flutter/flutter-mcp-toolkit-maintain-web"><img src="https://agentmods.dev/badge/skills/arenukvern/mcp_flutter/flutter-mcp-toolkit-maintain-web.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00088 | $0.01978 |
| Opus 5.5 | $0.00035 | $0.00791 |
| Sonnet 5.5 | $0.00018 | $0.00396 |
| Haiku 4.5 | $0.00009 | $0.00198 |
Grade A, and why
flutter-mcp-toolkit-maintain-web 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 7d 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 — 161 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Maintain Web (Chrome + WebMCP)
Dogfood app: showcase/flutter_test_app. Canonical platform doc: showcase/flutter_test_app/INTENTCALL_PLATFORM.md.
WebMCP vs VM MCP
| Path | Proves |
|---|---|
VM extensions + fmt_* tools |
MCP toolkit dogfood (always) |
navigator.modelContext / document.modelContext |
True WebMCP (Chrome flags / --web-browser-flag) |
ADR: decisions/0008_web_agent_invoke_js_only.mdx — JS fetch('/agent/invoke') 404 by design; Dart invokeDirect works when modelContext exists.
JIT vs AOT web: which driving tier
VM extensions (fmt_*, the toolkit) require the Dart VM service — they
exist on JIT web (DDC via flutter run). An AOT web build
(flutter build web) has no VM service: drive it through the CDP
tier instead — flutter_mcp_harness's WebBuildTarget/FlutterWebCdp
(this repo, ADR-0018) over the browser-level primitives
(universal-automation-family ADR-0045). For typed app intents on AOT
web, publish window.__mcpActions handlers (plain JS interop, AOT-safe)
— the CDP driver's InvokeAction dispatches to them; projecting the
toolkit's tool catalog onto that registry is the tracked bridge.
Launch (repeatable WebMCP)
make web-showcase
# WS_URI from .showcase/web_app.log (re-grep after hot reload)
grep -Eo 'ws://127\.0\.0\.1:[0-9]+/[A-Za-z0-9_=-]+/ws' .showcase/web_app.log | tail -1
dart run mcp_server_dart/bin/flutter_mcp_toolkit.dart webmcp chrome-args
dart run mcp_server_dart/bin/flutter_mcp_toolkit.dart webmcp verify --web-port 8080
Stop: make showcase-stop.
Do not rely on chrome://flags alone across machines — use CLI flags / make web-showcase / VS Code launch args.
VS Code / Cursor launch
Use config showcase/flutter_test_app Chrome + WebMCP in .vscode/launch.json:
--web-browser-flag=--user-data-dir=${workspaceFolder}/.showcase/chrome-webmcp-profile— persistent profile sochrome://flagssurvive stop/start (Flutter default is a temp profile every run).--web-browser-flag=--enable-features=WebMCPTesting,WebModelContext,DevToolsWebMCPSupport--web-browser-flag=--enable-experimental-web-platform-features
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.
- 7d ago Changed · +12 lines 5d917d84b3c7
- 23d ago Changed · +71 lines · +14 tokens per session 628d6f9f625f
- 1mo ago First seen · 78 lines · 74 tokens per session scan A 6f4f30bd39c5
flutter-mcp-toolkit-maintain-web is a skill published in the GitHub repository Arenukvern/mcp_flutter (392 stars, last pushed 7d ago), licensed MIT. It adds 88 tokens to every session and 1,978 once invoked, about $0.0004 per session on Opus 5.5. 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 2026-09-03.
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