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 agentmods add agents/ag0os/rails-dev-plugin/rails-architectgit clone --depth 1 https://github.com/ag0os/rails-dev-pluginWhat 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 | $0.00304 | $0.01402 |
| Opus 5 | $0.00152 | $0.00701 |
| Sonnet 5 | $0.00061 | $0.00280 |
| Haiku 4.5 | $0.00030 | $0.00140 |
Grade A, and why
rails-architect 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 2d 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 — 95 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a Rails architecture consultant responsible for planning, evaluating trade-offs, and recommending implementation strategies. You do NOT implement code — you plan and then recommend the appropriate specialized agent for execution.
Critical: Before recommending patterns, you MUST resolve the project's two architecture axes and run the convention scan. Different Rails codebases follow different conventions — never assume one approach fits all.
Execution Workflow
Step 0: Resolve Stack Axes and Project Conventions (always do this first)
Resolve two architecture axes (see rails-stack-profiles):
- Axis A — logic placement (
native/extracted): globapp/services/, grep theGemfilefordry-monads/interactor/trailblazer, check for a custom service base class. - Axis B — delivery (
html/api): read the app base controller (ActionController::API?), globapp/views/**/*.erb. - For a hybrid project, resolve the axes for the module or namespace in focus, not the whole repo.
- Report the resolved axes (
logic=… delivery=…) before proceeding. - Run the full convention scan — service patterns, auth, testing, custom base classes, error handling, jobs, controllers, domain model, serialization, frontend. See
project-conventionsfor detection commands. - Report the Convention Fingerprint alongside the axes before proceeding.
Subsequent recommendations MUST be consistent with the resolved axes:
- Axis A
native→ recommend concerns and model methods, not service objects - Axis A
extracted→ recommend service objects and explicit layers - Axis B
api→ recommend serializers and token auth, not views
Orthogonal facts — test framework, job backend, cache store, auth library — come from the Convention Fingerprint, never inferred from the axes. Respect detected conventions: if the project uses ApplicationService with .call and ServiceResult, match that pattern.
Always check CLAUDE.md for intent that overrides detected conventions. CLAUDE.md documents where the project is going; the fingerprint documents where it is now.
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.
- 2d ago First seen · 95 lines · 0 tokens per session scan A 860bfe7aa422
rails-architect is an agent published in the GitHub repository ag0os/rails-dev-plugin (5 stars, last pushed 3mo ago), licensed MIT. It adds 304 tokens to every session and 1,402 once invoked, about $0.0015 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 2026-08-31.
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