Borrowing it
Nothing to install: this file belongs to anam-org/metaxy. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/anam-org/metaxy/main/.claude/skills/tach/SKILL.mdgit clone --depth 1 https://github.com/anam-org/metaxyWrote 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/anam-org/metaxy/tach)<a href="https://agentmods.dev/skills/anam-org/metaxy/tach"><img src="https://agentmods.dev/badge/skills/anam-org/metaxy/tach.svg" alt="Measured on agentmods" 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 | $0.00109 | $0.01150 |
| Opus 5 | $0.00055 | $0.00575 |
| Sonnet 5 | $0.00022 | $0.00230 |
| Haiku 4.5 | $0.00011 | $0.00115 |
Grade A, and why
tach 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 5d 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 — 130 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Tach
Tach enforces module boundaries in Python codebases. It verifies that imports between modules respect declared dependencies and public interfaces, with no runtime impact.
For full documentation: https://docs.gauge.sh/
How This Project Uses Tach
The project defines three architectural layers in tach.toml: cli > ext > core. Higher layers may import from lower layers without declaring dependencies. Same-layer imports require explicit depends_on declarations. Unlayered facade and primitive modules (e.g., metaxy, metaxy._decorators) sit outside the layer hierarchy.
Run uv run tach check to verify boundaries. The pre-commit hook runs this automatically on src/ changes.
Run uv run pytest --tach to skip tests unaffected by changes (uses tach's module dependency graph for impact analysis).
Core Commands
| Command | Purpose |
|---|---|
tach init |
Guided setup: walks through tach mod, tach sync, tach show |
tach mod |
Interactive terminal UI to mark module boundaries |
tach sync |
Sync tach.toml with actual imports (--add to only add) |
tach check |
Report boundary/interface violations (--exact for unused deps) |
tach check-external |
Validate 3rd-party imports match pyproject.toml |
tach show |
Visualize dependency graph (--web, --mermaid, -o) |
tach map |
JSON dependency map between files (--closure for transitives) |
tach report |
Dependencies/usages of a module (--dependencies, --usages) |
tach test |
Run only tests impacted by changes |
tach install |
Install as pre-commit hook |
Full command reference: https://docs.gauge.sh/usage/commands/
Key Concepts
Modules
A module is a Python package or file with dependencies configured in tach.toml. Identified by import path from the nearest source root (e.g., metaxy.config for src/metaxy/config/).
[[modules]]
path = "metaxy.config"
layer = "core"
depends_on = ["metaxy._decorators", "metaxy.models"]
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.
- 5d ago First seen · 130 lines · 109 tokens per session scan A 35ef61b7c82f
tach is a skill published in the GitHub repository anam-org/metaxy (119 stars, last pushed 16d ago), licensed Apache-2.0. It adds 109 tokens to every session and 1,150 once invoked, about $0.0005 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 2026-09-01.
Other skills, from other repositories
mcore-linting-and-formatting
Linting and formatting for Megatron-LM. Covers running autoformat.sh, tools (ruff, black, isort, pylint, mypy), and code style rules.
plankton-code-quality
Write-time code quality enforcement using Plankton — auto-formatting, linting, and Claude-powered fixes on every file edit via hooks.
coding.make_function_private
Identify private / public functions in a file and rename them with an underscore or not.
code-review-python
Provides Python-specific code review rules for the dh code-reviewer agent. Activates on pyproject.toml or .py file detection — enforces uv, ruff, ty, pytest, type annotation, error handling, and Python 3.11+ idioms including pathlib, match statements, and modern union syntax.
coding_qa.review
Review Python files for bugs, suggest fixes, and provide test cases.
coding.fix_use_helpers
Identify and replace Python code with code in the helpers package.