flutter-mcp-toolkit-debug

flutter-mcp-toolkit-debug is a skill for Claude Code, Codex from Arenukvern/mcp_flutter. It costs 32 tokens per session (4,124 once invoked), scanned A, original, MIT.

A debugging guide for a running Flutter app that explains how to read logs, evaluate Dart expressions, inspect live state, and interpret structured tool errors.

In plain words
What is it for?
Use it to investigate error responses, read runtime logs, inspect app state, evaluate Dart code, and diagnose unexpected behavior.
Why use it?
It helps determine why an app behaves incorrectly when an action fails or appears to succeed but produces the wrong result.

Skill for Claude CodeCodex

Part of the flutter-mcp-toolkit plugin — 14 skills, 1 agent shipped together

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.

agentmods
npx agentmods add skills/arenukvern/mcp_flutter/flutter-mcp-toolkit-debug
Any agent
npx skills add Arenukvern/mcp_flutter --skill flutter-mcp-toolkit-debug
Clone the repo
git clone --depth 1 https://github.com/Arenukvern/mcp_flutter

Made for: Claude Code, Codex.

Or install flutter-mcp-toolkit, the plugin that ships this one along with the rest of its 14 skills, 1 agent.

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 flutter-mcp-toolkit-debug

README.md
[![agentmods](https://agentmods.dev/badge/skills/arenukvern/mcp_flutter/flutter-mcp-toolkit-debug.svg)](https://agentmods.dev/skills/arenukvern/mcp_flutter/flutter-mcp-toolkit-debug)
Your own site
<a href="https://agentmods.dev/skills/arenukvern/mcp_flutter/flutter-mcp-toolkit-debug"><img src="https://agentmods.dev/badge/skills/arenukvern/mcp_flutter/flutter-mcp-toolkit-debug.svg" alt="Measured on agentmods" height="20"></a>
Per session 32 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,124 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00032 $0.04124
Opus 5 $0.00016 $0.02062
Sonnet 5 $0.00006 $0.00825
Haiku 4.5 $0.00003 $0.00412

Measured 2d ago against content hash 16e908c7b952, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

flutter-mcp-toolkit-debug 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 2d 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.

plugin/skills/flutter-mcp-toolkit-debug/SKILL.md · 389 lines

How it starts

The opening of the file, as written. The whole thing — 389 lines — stays where its author put it; the contents beside it link to each section on GitHub.

When to use

Use this skill when something broke and you need to understand why:

  • A tool call returned an error envelope (ok: false).
  • The app behaves unexpectedly and you need runtime log output.
  • You need to inspect live app state without changing it (read AgentState.instance.value).
  • A prior control action (tap, hot_reload, navigate) completed without error but the result is wrong.

Do NOT use this skill for:

  • Reading what is currently on screen — use flutter-mcp-toolkit-inspect.
  • The toolkit itself failing to connect — load flutter-mcp-toolkit-setup.

Registry vs bundled tools

  • Bundled fmt_* tools (screenshot, logs, evaluate, …) run on the MCP server via AgentRegistry on the host.
  • App-registered surfaces appear after MCPToolkitBinding.addEntries / AgentCallEntry — discover with fmt_list_client_tools_and_resources, then fmt_client_tool / fmt_client_resource.

Triage flow

  1. Error envelope returned? Read error.code first, then error.descriptor.retryable. Look the code up in the Error envelope playbook below.
  2. Retryable error? Run flutter-mcp-toolkit doctor --json. If doctor fails, load flutter-mcp-toolkit-setup.
  3. Need log output? Call get_recent_logs with count: 100 and a level filter. Look for stack traces or assertion messages near the timestamp of the failure.
  4. Need live state? Call evaluate_dart_expression with a targeted expression (e.g. MyBloc.instance.state.toString()). Do this after logs, not instead of them.
  5. Chaining with inspect? Order: semantic_snapshotevaluate_dart_expressionget_recent_logs. Snapshot gives you the current widget tree before expression evaluation mutates nothing; logs give trailing context.
  6. Multiple targets? If connection_selection_required, call discover_debug_apps, pick the targetId, then pass connection: {targetId: "..."} to every subsequent call.

Tool reference

Read the full file on GitHub · 389 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. 2d ago First seen · 389 lines · 32 tokens per session scan A 16e908c7b952

Subscribe to this mod's changes

flutter-mcp-toolkit-debug is a skill published in the GitHub repository Arenukvern/mcp_flutter (373 stars, last pushed 10d ago), licensed MIT. It adds 32 tokens to every session and 4,124 once invoked, about $0.0002 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 2026-09-03.

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