Borrowing it
Nothing to install: this file belongs to matteing/opal. 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/matteing/opal/main/.claude/skills/elixir-cyclic-deps/SKILL.mdgit clone --depth 1 https://github.com/matteing/opalWrote 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/matteing/opal/elixir-cyclic-deps)<a href="https://agentmods.dev/skills/matteing/opal/elixir-cyclic-deps"><img src="https://agentmods.dev/badge/skills/matteing/opal/elixir-cyclic-deps/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/matteing/opal/elixir-cyclic-deps"><img src="https://agentmods.dev/badge/skills/matteing/opal/elixir-cyclic-deps.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Prompt Injection · line 55 Large whitespace padding was detected (a block of blank lines or a long run of spaces). This can push injected instructions below or to the right of the visible area so a human reviewer never sees them while the agent still reads them. Manual review of the hidden content is recommended.Fix: Remove the large whitespace padding (blank-line blocks or long space runs) and review any content hidden below or to the right of it. Keep skill files compact and reviewable so no instructions can be
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 | $0.00065 | $0.01023 |
| Opus 5.5 | $0.00026 | $0.00409 |
| Sonnet 5.5 | $0.00013 | $0.00205 |
| Haiku 4.5 | $0.00006 | $0.00102 |
Grade A, and why
elixir-cyclic-deps 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.
How it starts
The opening of the file, as written. The whole thing — 82 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Elixir Cyclic Dependencies
When to Use
Apply this skill only when the user explicitly asks to check or remove cyclic dependencies (e.g. "check for cycles", "remove cyclic dependencies", "fix xref cycles").
Prerequisite: Elixir Version
Cycle detection is correct only on Elixir 1.19 or higher. Before running any cycle checks:
- Verify version:
elixir -vor inside the project runmix run -e 'IO.inspect(System.version())'. - If the version is below 1.19, stop and inform the user that upgrading to Elixir 1.19+ is required for reliable cycle detection.
Detecting Cycles
Run both commands from the project root. Start with a relaxed threshold, then tighten:
mix xref graph --format cycles --label compile-connected --fail-above 3
mix xref graph --format cycles --label compile --fail-above 3
- compile-connected: cycles in the compile-time dependency graph (modules that compile in a cycle).
- compile: same graph, different label; both should be run.
- --fail-above N: exit code fails when cycle count is above N. Use
3initially, goal is 0.
To list cycles without failing (for inspection), omit --fail-above or set it high:
mix xref graph --format cycles --label compile-connected
mix xref graph --format cycles --label compile
Goal: reach --fail-above 0 for both commands (no cycles).
Workflow
- Check Elixir version (must be ≥ 1.19).
- Establish baseline: run both xref commands with
--fail-above 3(or current project setting). Note cycle count and which modules appear in cycles. - Inspect cycles: run without
--fail-aboveto see full cycle output; identify the smallest set of edges (module A → module B) that, if removed, break cycles. - Plan minimal changeset:
- Prefer breaking a single dependency (e.g. move shared code to a new module both can depend on) over large refactors.
- Helper modules are allowed if they yield the smallest change: extract shared logic into a new module that the cycle participants depend on, so the cycle is broken.
- Avoid duplication; follow existing repository guidelines (e.g. AGENTS.md, .cursor rules) and prior patterns in the codebase.
- Implement: make the chosen change, then re-run both xref commands with
--fail-above 0(or gradually lower from 3 → 0). - Verify:
mix compile --warnings-as-errors, tests, and any project lint (e.g.mix lintormix cyclecheckif defined).
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 · 82 lines · 65 tokens per session scan A 7dfa7784b5f0
elixir-cyclic-deps is a skill published in the GitHub repository matteing/opal (62 stars, last pushed 2mo ago), licensed MIT. It adds 65 tokens to every session and 1,023 once invoked, about $0.0003 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 2026-08-30.
elixir-cyclic-deps compared with skills from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| elixir-cyclic-depsmatteing/opal | Skill | 62 | 2mo ago | MIT | A | 65 | Claude Code |
| systematic-debuggingdamianvtran/local-operator | Skill | 229 | yesterday | MIT | A | 45 | Claude Code, Codex |
| error-handlingmetarhia/metaskills | Skill | 60 | 7d ago | MIT | A | 70 | Claude Code, Codex |
| tracelet-instrumentjnMetaCode/skillet | Skill | 2 | 1mo ago | MIT | A | 51 | Claude Code, Codex |
| systematic-debuggingjnMetaCode/skillet | Skill | 2 | 1mo ago | MIT | A | 43 | Claude Code, Codex |
| golang-lintalexastrum/skl | Skill | 10 | 4mo ago | MIT | A | 100 | Claude Code |
| golang-troubleshootingalexastrum/skl | Skill | 10 | 4mo ago | MIT | A | 130 | Claude Code |