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 thoughtbot/rails-consultant --skill prior-artgit clone --depth 1 https://github.com/thoughtbot/rails-consultantWrote 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/thoughtbot/rails-consultant/prior-art)<a href="https://agentmods.dev/skills/thoughtbot/rails-consultant/prior-art"><img src="https://agentmods.dev/badge/skills/thoughtbot/rails-consultant/prior-art/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/thoughtbot/rails-consultant/prior-art"><img src="https://agentmods.dev/badge/skills/thoughtbot/rails-consultant/prior-art.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 | $0.00036 | $0.00853 |
| Opus 5.5 | $0.00014 | $0.00341 |
| Sonnet 5.5 | $0.00007 | $0.00171 |
| Haiku 4.5 | $0.00004 | $0.00085 |
Grade A, and why
prior-art 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 1mo 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 — 73 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Behavior
Research how this codebase handles $ARGUMENTS. Explore the codebase thoroughly and report what you find.
Step 1: Search Broadly
Cast a wide net across the codebase. Use multiple search strategies:
- Grep for keywords — search for terms related to the concern (e.g. for error reporting:
error,exception,rescue,Sentry,Bugsnag,notify,report) - Check common Rails locations — initializers, middleware, concerns, base classes, config files, lib/
- Check the Gemfile — are there gems related to this concern? What do they tell you about the approach?
- Check application-level base classes —
ApplicationController,ApplicationRecord,ApplicationJob— these often set patterns that everything inherits - Check for dedicated directories or files — service objects, concerns, lib/ modules that handle this concern
Don't stop at the first result. The goal is to find every place this concern is handled — the consistent pattern and the exceptions.
Step 2: Check Git History
For the key files involved in this concern:
git log --oneline -10 <file>to see recent changesgit log --all --oneline --grep="<keyword>"to find commits related to the concern- Look for: when the pattern was established, whether it's evolved, any recent changes or migrations from one approach to another
Git history reveals whether a pattern is settled or in flux — critical context before you build on top of it.
Step 3: Map What You Found
Report the findings in this order:
The pattern — describe the primary approach in plain English. One paragraph. "This codebase handles X by doing Y." If there's a clear convention, name it. If there are multiple approaches, name each.
Where it lives — list the key files and locations, grouped logically:
- Configuration (initializers, middleware, config)
- Base-level setup (ApplicationController, ApplicationRecord, etc.)
- Implementation files (services, concerns, models, specific controllers)
- Tests (how is this concern tested?)
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.
- 1mo ago First seen · 73 lines · 36 tokens per session scan A afebd194c2f5
prior-art is a skill published in the GitHub repository thoughtbot/rails-consultant (27 stars, last pushed 1mo ago), licensed MIT. It adds 36 tokens to every session and 853 once invoked, about $0.0001 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.
Other skills, from other repositories
elixir-way
Map mechanisms from any language or framework (Rails, Django, PHP, Node, Go, JVM, .NET, others) to idiomatic Elixir. Use when a rewrite or port needs verdicts, targets, guarantee checks or a translationese review.
review
Review Elixir/Phoenix changes before committing — bugs, security, Ecto, LiveView, and Oban anti-patterns, via parallel specialist agents. Use when asked to review changes, a component, a diff, or a PR.
audit
Project health audit and health check — architecture, performance, tests, dependencies, code quality. Use when assessing overall project health, before releases, or after refactors.
pr-review
Address feedback left on a GitHub pull request: fetch unresolved review threads, make agreed Elixir/Phoenix code fixes, reply, and resolve. Use for a PR URL/number or reviewer comments. NOT for pre-PR review, findings triage, or CI monitoring.
start
Start or resume an Elixir rewrite of an app in any language (Rails, Django, PHP, Node, Go, Java, .NET, others) and show its status. Use when someone wants to port, migrate or rewrite an app into Elixir/Phoenix.
boundaries
Analyze Phoenix context boundaries and module coupling via mix xref. Use when checking cross-context calls, validating dependencies, before splitting modules, or reviewing architecture.