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 ariaramin/flutter-skills --skill flutter-concurrency-memory-performancegit clone --depth 1 https://github.com/ariaramin/flutter-skillsWrote 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/ariaramin/flutter-skills/flutter-concurrency-memory-performance)<a href="https://agentmods.dev/skills/ariaramin/flutter-skills/flutter-concurrency-memory-performance"><img src="https://agentmods.dev/badge/skills/ariaramin/flutter-skills/flutter-concurrency-memory-performance/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/ariaramin/flutter-skills/flutter-concurrency-memory-performance"><img src="https://agentmods.dev/badge/skills/ariaramin/flutter-skills/flutter-concurrency-memory-performance.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 | $0.00140 | $0.03741 |
| Opus 5.5 | $0.00056 | $0.01496 |
| Sonnet 5.5 | $0.00028 | $0.00748 |
| Haiku 4.5 | $0.00014 | $0.00374 |
Grade A, and why
flutter-concurrency-memory-performance 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.
How it starts
The opening of the file, as written. The whole thing — 457 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Flutter Concurrency, Memory & Performance
Improve measurable behavior while preserving product semantics. Understand the execution model before introducing concurrency, ownership before diagnosing leaks, and the real bottleneck before optimizing code.
Operating stance
Apply these rules throughout the task:
- Measure before optimizing. Establish a reproducible scenario and baseline before claiming improvement.
- Treat
asyncas asynchronous coordination, not automatic CPU parallelism. - Keep latency-sensitive root-isolate work short; synchronous CPU inside an
asyncfunction still blocks that isolate. - Use asynchronous APIs for ordinary I/O. Introduce isolates for measured CPU/blocking work, not merely because an operation takes time.
- Include isolate startup, initialization, transfer, queueing, memory, and shutdown in the cost model.
- Never create one isolate per tiny task or blindly size a pool from
Platform.numberOfProcessors. - Bound producer/consumer systems: worker queues, retries, caches, pending requests, event streams, and background jobs need an overload policy unless naturally bounded.
- Use cancellation when the underlying operation supports it; otherwise invalidate stale work/results. A
Futurehas no generic cancellation contract. - Use
mountedonly for UI lifetime validity. Use request IDs, generations, cancellation, or serialization for logical concurrency correctness. - Diagnose memory by ownership and reachability. Ordinary Dart objects are garbage collected; leaks are usually unintended retained references.
- Separate Dart heap from external/native/image/raster/GPU/RSS growth before choosing a fix.
- Release scarce/native resources deterministically. Finalizers are fallback safety, not normal lifecycle management.
- Optimize algorithms and duplicate work before syntax/allocation micro-tuning.
- Profile production-representative builds and representative devices. Debug timing is not shipping evidence.
- Use actual display/frame timing rather than a universal 16 ms rule; 90/120 Hz devices have tighter deadlines.
- Keep Web behavior separate from Dart Native: Dart isolates are Native-only, and Flutter
computedoes not create Dart parallelism on Web. - Treat mobile OS background execution as a platform scheduling problem, not an isolate-lifetime feature.
- Do not perform an unrelated architecture/state-management rewrite for a localized performance problem.
What ships with it
7 files 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.
- 8d ago First seen · 457 lines · 140 tokens per session scan A bbe461755dcc
flutter-concurrency-memory-performance is a skill published in the GitHub repository ariaramin/flutter-skills (6 stars, last pushed 8d ago), licensed MIT. It adds 140 tokens to every session and 3,741 once invoked, about $0.0006 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 2026-10-11.
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