Active Storage Validations is a Ruby gem for adding validation rules to files attached through Rails Active Storage. Rails developers use it to check whether uploaded images, videos, audio files, PDFs, and other attachments meet requirements such as type, size, dimensions, duration, or quantity.
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.
git clone --depth 1 https://github.com/igorkasyanchuk/active_storage_validationsWrote 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/rules/igorkasyanchuk/active_storage_validations/spec-analyzers)<a href="https://agentmods.dev/rules/igorkasyanchuk/active_storage_validations/spec-analyzers"><img src="https://agentmods.dev/badge/rules/igorkasyanchuk/active_storage_validations/spec-analyzers/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/rules/igorkasyanchuk/active_storage_validations/spec-analyzers"><img src="https://agentmods.dev/badge/rules/igorkasyanchuk/active_storage_validations/spec-analyzers.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 | $0.00000 | $0.00301 |
| Opus 5.5 | $0.00000 | $0.00120 |
| Sonnet 5.5 | $0.00000 | $0.00060 |
| Haiku 4.5 | $0.00000 | $0.00030 |
Grade A, and why
spec-analyzers 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.
What it actually says
Analyzer specs
- Follow shared conventions in
spec.mdc(namedsubject,describe/context,described_class). - Boot via
rails_helper;AnalyzerHelpersis auto-included forspec/analyzers. - Gate processor-specific examples with metadata
image_processor: :vips/:mini_magick(filtered inrails_helperwhenIMAGE_PROCESSORis set). Do not useskipfor matrix gating — that reports pending in CI. Keepskiponly for capability checks (missing gem / API). - Stub external commands with RSpec mocks (
allow/allow_any_instance_of), not Minitest.stub/stub_any_instance. - Timeouts fail closed (empty metadata / validation errors) and may emit
timeout.active_storage_validations— assert that per analyzer underdescribe "timeouts"(usetimed_out_command_resultfromAnalyzerHelpers). Keep process-group /run_commandmechanics incommandable_spec.rb. - Metadata is cached on blobs as string keys
asv_*viaASVBlobMetadatable; blobs are treated as immutable once keys exist. - Prefer shared examples
"returns the right metadata for any attachable"and"works fine with 2 pages pdf"when applicable.
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 · 16 lines · 0 tokens per session scan A 3c5ac1665cc7
spec-analyzers is a cursor rule published in the GitHub repository igorkasyanchuk/active_storage_validations (1,193 stars, last pushed 2d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 301 tokens. 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.
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