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 ccarvalho-eng/codex-elixir-phoenix --skill elixir-phoenix-boundariesgit clone --depth 1 https://github.com/ccarvalho-eng/codex-elixir-phoenixWrote 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/ccarvalho-eng/codex-elixir-phoenix/elixir-phoenix-boundaries)<a href="https://agentmods.dev/skills/ccarvalho-eng/codex-elixir-phoenix/elixir-phoenix-boundaries"><img src="https://agentmods.dev/badge/skills/ccarvalho-eng/codex-elixir-phoenix/elixir-phoenix-boundaries/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/ccarvalho-eng/codex-elixir-phoenix/elixir-phoenix-boundaries"><img src="https://agentmods.dev/badge/skills/ccarvalho-eng/codex-elixir-phoenix/elixir-phoenix-boundaries.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 | $0.00020 | $0.01138 |
| Opus 5.5 | $0.00008 | $0.00455 |
| Sonnet 5.5 | $0.00004 | $0.00228 |
| Haiku 4.5 | $0.00002 | $0.00114 |
Grade A, and why
elixir-phoenix-boundaries 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.
This is a copy
88% identical to boundaries — 28 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 138 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Phoenix Context Boundary Validation
Analyze module dependencies to ensure clean context separation and proper architectural boundaries.
Usage
`elixir-phoenix-boundaries` # Check for violations
`elixir-phoenix-boundaries` --assess # Score context health (0-100)
`elixir-phoenix-boundaries` --fix # Suggest fixes for violations
--assess Mode: Context Health Score
Evaluate overall boundary health with a quantified score.
Metrics Calculated
| Metric | Healthy Range | Red Flag | Weight |
|---|---|---|---|
| Modules per context | 3-15 | >20 or <2 | 20% |
| Public API surface | 5-30 funcs | >40 funcs | 15% |
| Fan-out (contexts called) | 1-4 | >6 | 20% |
| Fan-in (called by contexts) | 1-6 | >10 | 15% |
| Circular dependencies | 0 | >0 | 15% |
| Boundary violations | 0 | >0 | 15% |
Commands for Assessment
Use rg --files to count .ex files per context directory under lib/my_app/*/.
Use rg to count public function definitions per context file under lib/my_app/*.ex.
Run mix xref graph --format stats for dependency analysis.
Run mix xref graph --format cycles --label compile for compile-time circular dependencies.
Output Format
## Context Health Assessment
### Overall Score: 82/100 (Good)
| Context | Modules | API | Fan-Out | Fan-In | Score |
|---------|---------|-----|---------|--------|-------|
| Accounts | 5 | 12 | 2 | 4 | 95 |
| Orders | 18 | 45 | 8 | 3 | 62 |
| Shared | 2 | 8 | 0 | 12 | 78 |
### Issues Found
1. **Orders** - Too large (18 modules, 45 funcs)
- Consider: Extract Fulfillment, Invoicing sub-contexts
2. **Orders** - High fan-out (8 contexts)
- Consider: Review if all dependencies necessary
### Recommendations
- Split Orders into Orders + Fulfillment
- Review Accounts ← Billing dependency
Iron Laws - Never Violate These
- Controllers call only contexts - No direct Repo access from web layer
- Schemas are pure data - No side effects, no Repo calls in schema modules
- Contexts own their schemas - Don't import schemas from other contexts
- Explicit dependencies only - Cross-context calls must be intentional
- DO NOT refactor context boundaries without running
mix xreffirst — Refactoring without dependency data creates new violations; always map the dependency graph before moving modules
What ships with it
3 files 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.
- 1mo ago First seen · 138 lines · 20 tokens per session scan A 54c308c18f7f
elixir-phoenix-boundaries is a skill published in the GitHub repository ccarvalho-eng/codex-elixir-phoenix (11 stars, last pushed 5mo ago), licensed MIT. It adds 20 tokens to every session and 1,138 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 88% identical to boundaries, differing in 28 lines, and is treated as a copy.
Other skills, from other repositories
phoenix
Use when building an Elixir web app with Phoenix — contexts, Ecto schemas, changesets and migrations, LiveView, channels and PubSub, the generators, and the boundary between domain logic and the web layer. Covers the classic LiveView over-rendering and Ecto N+1 traps. NOT pure OTP work with no web or Ecto layer …
elixir-expert
Expert-level Elixir, Phoenix, OTP, and concurrent systems. Use when the user mentions Phoenix, OTP, Erlang, concurrent, or functional, or when the task involves Elixir Fundamentals or Phoenix Framework.
writing-review-packets
Create or revise Reviews packet markdown for a code diff, including section strategy, prose, hunk references, validation, and pushing packet revisions with the Reviews CLI. Use when the user asks to write a review packet, organize a diff for review, add prose around hunk refs, update a packet for a new patchset, or…
using-reviews-locally
Run and use the Reviews app locally, including server startup, port checks, local token setup, CLI config, pushing local reviews or new patchsets, and Codex workflow conventions. Use when the user asks to spin up Reviews, push a local review packet or revision, mint/access local API tokens, debug localhost review…
reviews-overview
Explain the Reviews platform to a general agent: what Reviews provides, when to use it during human-in-the-loop or agent-driven development, how review packets structure a diff for humans, and how Reviews can precede public PR creation or integrate with other review processes. Use when an agent needs to decide whether…
elixir-review
Review Elixir/Phoenix code: OTP patterns, GenServer, LiveView, fault tolerance and concurrency.