Borrowing it
Nothing to install: this file belongs to cesarferreira/stax. 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/cesarferreira/stax/main/.claude/skills/stax-dev/SKILL.mdgit clone --depth 1 https://github.com/cesarferreira/staxWrote 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/cesarferreira/stax/stax-dev)<a href="https://agentmods.dev/skills/cesarferreira/stax/stax-dev"><img src="https://agentmods.dev/badge/skills/cesarferreira/stax/stax-dev.svg" alt="Measured on agentmods" 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 | $0.00131 | $0.00995 |
| Opus 5 | $0.00066 | $0.00498 |
| Sonnet 5 | $0.00026 | $0.00199 |
| Haiku 4.5 | $0.00013 | $0.00100 |
Grade A, and why
stax-dev 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 6d 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 — 140 lines — stays where its author put it; the contents beside it link to each section on GitHub.
stax-dev — Development Harness
Execution mode: Sub-agent pipeline — planner → implementer → verifier
Phase 0: Context Check
Before dispatching any agents, check for prior plan output:
ls .claude/plans/stax-plan.md 2>/dev/null
- If the file exists and the user's request is a follow-up ("fix the error", "retry", "it failed"), skip Phase 1 and use the existing plan.
- Otherwise: start fresh. If
.claude/plans/stax-plan.mdexists from a different task, note this to the user.
Phase 1: Plan
Dispatch the planner. Pass the user's full request verbatim plus the project root path.
Agent(
subagent_type: "stax-planner",
model: "opus",
prompt: "
Project root: /Users/cesarferreira/code/github/stax
Request: <user's full request verbatim>
Produce a complete implementation plan following your output format.
Read patterns.md at .claude/skills/stax-dev/references/patterns.md first.
"
)
Save the plan text to .claude/plans/stax-plan.md (create the directory if needed).
Show the plan summary to the user before proceeding to Phase 2.
Phase 2: Implement
Dispatch the implementer with the full plan:
Agent(
subagent_type: "stax-implementer",
model: "sonnet",
prompt: "
Project root: /Users/cesarferreira/code/github/stax
Execute this implementation plan exactly:
---
<full plan content>
---
Read patterns.md at .claude/skills/stax-dev/references/patterns.md first.
Read each file before editing. Do not run build or tests.
Output the CHANGED/CREATED summary at the end.
"
)
Phase 3: Verify
Dispatch the verifier:
Agent(
subagent_type: "stax-verifier",
model: "opus",
prompt: "
Project root: /Users/cesarferreira/code/github/stax
Verify the changes just implemented. Run cargo check, clippy, fmt --check,
then targeted tests with this filter: <Verification Steps from plan>.
Report all results per your reporting format.
"
)
Phase 4: Fix Loop (if verifier reports failures)
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.
- 6d ago First seen · 140 lines · 131 tokens per session scan A 5974931e1d1e
stax-dev is a skill published in the GitHub repository cesarferreira/stax (123 stars, last pushed today), licensed MIT. It adds 131 tokens to every session and 995 once invoked, about $0.0007 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 2026-08-30.
Other skills, from other repositories
dart-run-static-analysis
Execute dart analyze to identify warnings and errors, and use dart fix --apply to automatically resolve mechanical lint issues. Use during development to ensure code quality and before committing changes.
agents-sdk-dotnet-debugging
Use when troubleshooting an agent built with the Microsoft Agents SDK (Microsoft.Agents.Hosting.AspNetCore and related packages) in C# / .NET. Trigger on any of these symptoms: build or C# compile errors, crashes on startup, 401 or auth errors on incoming requests, the bot not responding to messages, appsettings.json…
golang-error-handling
Idiomatic Golang error handling — creation, wrapping with %w, errors.Is/As, errors.Join, custom error types, sentinel errors, panic/recover, the single handling rule, structured logging with slog, HTTP request logging middleware, and samber/oops for production errors. Built to make logs usable at scale with log…
triaging-merge-queue-failures
Decision procedure for a PR that failed or was removed from the Trunk merge queue: classify the kick (superseded by a newer commit, not mergeable, a gate that failed on a cancelled run, real failure, one-off flake, or repo-wide flaky/infra issue) and take the matching action (wait, hold and fix, requeue once, or…
comet-github-issue-fix
在隔离范围内，通过所属 Native 或 Classic workflow、匹配风险的测试、生成 Runtime 检查和谨慎交付，实施已确认的 Comet GitHub Issue 或 review 阻塞项。用户明确要求修复已验证的 Issue 或 PR 问题时使用。.
memory-optimization
Optimize Python code for reduced memory usage and improved memory efficiency. Use when asked to reduce memory footprint, fix memory leaks, optimize data structures for memory, handle large datasets efficiently, or diagnose memory issues. Covers object sizing, generator patterns, efficient data structures, and memory…