A project-aware verification loop for Elixir and Phoenix changes that discovers the project's configured compile, formatting, and test commands before running them. It can use project aliases or the ex_check tool, which combines common checks.

Use it after implementing or fixing code to compile the project, format files, and run unit tests in the project's preferred order.

It avoids running checks the project does not use and catches problems before a pull request. It also requires actual command output before calling the work successful.

phx-verify — Skill for Claude Code and Codex by oliver-kriska

Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo

git clone --depth 1 https://github.com/oliver-kriska/claude-elixir-phoenix

agentmods

npx agentmods add skills/oliver-kriska/claude-elixir-phoenix/phx-verify

Made for: Claude Code, Codex.

Wrote 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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/oliver-kriska/claude-elixir-phoenix/phx-verify/github.svg)](https://agentmods.dev/skills/oliver-kriska/claude-elixir-phoenix/phx-verify)

Your own site

<a href="https://agentmods.dev/skills/oliver-kriska/claude-elixir-phoenix/phx-verify"><img src="https://agentmods.dev/badge/skills/oliver-kriska/claude-elixir-phoenix/phx-verify/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/oliver-kriska/claude-elixir-phoenix/phx-verify"><img src="https://agentmods.dev/badge/skills/oliver-kriska/claude-elixir-phoenix/phx-verify.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 36 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,370 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin 98% copy Near-identical to another mod in the catalogue.

Token cost

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	$0.01370
Opus 5	$0.00018	$0.00685
Sonnet 5	$0.00007	$0.00274
Haiku 4.5	$0.00004	$0.00137

Measured 6d ago against content hash b5bbe922cc04, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

phx-verify 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 6d 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.

Origin

This is a copy

98% identical to verify — 12 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.

targets/amp/skills/phx-verify/SKILL.md · 123 lines

How it starts

The opening of the file, as written. The whole thing — 123 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Verification Loop

Project-aware verification for Elixir/Phoenix. Reads mix.exs and .check.exs to discover tools, test commands, and custom aliases before running anything.

Iron Laws

Discover before running — Read mix.exs first; never run mix credo if credo isn't a dependency
Prefer ex_check — If :ex_check + .check.exs exists, mix check replaces individual steps
Prefer project aliases — If mix ci or composite alias exists, use it over individual steps
Run in order — Later steps assume earlier ones pass
Ask before E2E tests — Unit tests run automatically; E2E/integration tests need user confirmation
NEVER report success without showing actual command output — "should work" is not verification

Step 0: Project Discovery (ALWAYS FIRST)

Read mix.exs — extract deps/0, aliases/0, and cli/0 (for preferred_envs). Also check for .check.exs. See references/project-discovery.md for full patterns.

Discover tools (deps): :credo, :dialyxir, :sobelow, :ex_check, :excoveralls, :boundary

Discover test commands (aliases + deps):

Unit: mix test (always), or custom alias like mix test.with_coverage
E2E: mix playwright.test, mix cypress.run, or similar (check preferred_envs for MIX_ENV)
Fast E2E: mix playwright.run (skips setup — for re-runs)

Discover composite runner: If .check.exs exists, read it — mix check may handle compile, format, credo, test, dialyzer, sobelow, and more.

Report discovery:

Project tools: compile ✓ | format ✓ | credo ✓ | dialyzer ✓ | sobelow ✓ | ex_check ✓
Test commands: mix test (unit) | mix playwright.test (E2E, MIX_ENV=int_test)
Composite runner: mix check (.check.exs covers: compiler, formatter, credo, dialyzer, sobelow, tests)
Strategy: Running `mix check` then asking about E2E

Verification Sequence

CRITICAL: Before using ANY discovered alias or composite command, verify it works:

Check the dependency is in mix.lock (not just mix.exs) — deps may not be fetched
Run the command — if it fails with "command not found" or dependency error, fall back to individual steps
Log the fallback: "mix check failed (ex_check not installed?), falling back to individual steps"

Read the full file on GitHub · 123 lines

Files

What ships with it

1 file 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.

references/project-discovery.md 8.4 KB

Changes

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.

6d ago First seen · 123 lines · 36 tokens per session scan A b5bbe922cc04

Subscribe to this mod's changes

phx-verify is a skill published in the GitHub repository oliver-kriska/claude-elixir-phoenix (542 stars, last pushed 4d ago), licensed MIT. It adds 36 tokens to every session and 1,370 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 98% identical to verify, differing in 12 lines, and is treated as a copy.

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