ctx-lint

ctx-lint is a skill for Claude Code, Codex from OXI-717/ai-native-toolkit. It costs 56 tokens per session (899 once invoked), scanned A, original, MIT.

A validator for AGENTS.md files, which are project instructions read by coding agents. It checks that their @-imports point to existing files and that required end markers or shared context links are present.

In plain words
What is it for?
Use it to check context files in standalone projects, shared repositories, and projects that link to a common ecosystem folder.
Why use it?
It finds broken or missing context links before an agent follows incomplete project instructions. It can also fix simple problems automatically.

Skill for Claude CodeCodex

Written for Claude Code and Codex: ${CLAUDE_PLUGIN_ROOT} variable, but also agents/openai.yaml present. Also seen: mentions CLAUDE.md; mentions AGENTS.md.

Runs only inside its plugin — its command needs a path that Claude Code sets for a plugin’s own hooks and for nothing else. Install the plugin, not this.

Part of the ctx plugin — 2 skills shipped together

Good fit Use it to check context files in standalone projects, shared repositories, and projects that link to a common ecosystem folder.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.

Claude Code
/plugin marketplace add OXI-717/ai-native-toolkit
Claude Code
/plugin install ctx

Made for: Claude Code, Codex.

Or install ctx, the plugin that ships this one along with the rest of its 2 skills.

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.

agentmods badge for ctx-lint

README.md
[![agentmods](https://agentmods.dev/badge/skills/oxi-717/ai-native-toolkit/ctx-lint/github.svg)](https://agentmods.dev/skills/oxi-717/ai-native-toolkit/ctx-lint)
Your own site
<a href="https://agentmods.dev/skills/oxi-717/ai-native-toolkit/ctx-lint"><img src="https://agentmods.dev/badge/skills/oxi-717/ai-native-toolkit/ctx-lint/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.

agentmods 80×15 button for ctx-lint

Your own site · 80×15
<a href="https://agentmods.dev/skills/oxi-717/ai-native-toolkit/ctx-lint"><img src="https://agentmods.dev/badge/skills/oxi-717/ai-native-toolkit/ctx-lint.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 56 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 899 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 original No closer match found 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00056 $0.00899
Opus 5 $0.00028 $0.00449
Sonnet 5 $0.00011 $0.00180
Haiku 4.5 $0.00006 $0.00090

Measured 9d ago against content hash 920a82143a6f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

ctx-lint 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 9d 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.

plugins/ctx/skills/ctx-lint/SKILL.md · 62 lines

How it starts

The opening of the file, as written. The whole thing — 62 lines — stays where its author put it; the contents beside it link to each section on GitHub.

ctx-lint — context validator

Scans projects with AGENTS.md, validates @-imports and end-markers. Reports broken links and can fix trivial cases.

Supported load_strategy values

Value For what Checks
alpha Hub / standalone project with flat @-imports imports, end-marker
orchestrator Shared-pack AGENTS.md (e.g. _ecosystem/AGENTS.md in an ecosystem repo) imports (key ones), no end-marker requirement
symlink-consumer Project repo importing orchestrator via _ecosystem/ symlink imports + presence of _ecosystem/ (symlink or dir) + required @./_ecosystem/AGENTS.md import

Projects without load_strategy in frontmatter are unmanaged (ctx-lint skips import checks, but CLAUDE.md thin-wrapper check still runs).

Separately detectable issue types for the symlink pattern:

  • missing_ecosystem_link — consumer project has no _ecosystem/
  • broken_ecosystem_link_ecosystem symlink points to a non-existent path
  • consumer_missing_orchestrator_import_ecosystem/ exists but AGENTS.md has no @-import resolving to <repo>/_ecosystem/AGENTS.md

Subcommands

  • ctx-lint — check projects in CWD scope (see below)
  • ctx-lint <path> — check one specific project
  • ctx-lint --all — force-check all discovered projects
  • ctx-lint --here — only the current project (enclosing CWD)
  • ctx-lint --json — machine-readable output for agent parsing
  • ctx-lint --fix — apply safe auto-fixes (high-confidence only)
  • ctx-lint --list-projects — show all discovered paths (ignores scope)

Default scope (auto-scope)

Without explicit path and without --all/--here, scope is the union of the enclosing project (if CWD is inside one) and all projects directly under CWD:

  • CWD is deep inside a project with no nested sub-projects → just that one project
  • CWD is project root but has sub-projects under it → checks both the project and all sub-projects
  • CWD is a container for projects → all projects under it
  • CWD is neither inside nor above any known project → falls back to all discovered

Read the full file on GitHub · 62 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.

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.

  1. 9d ago First seen · 62 lines · 56 tokens per session scan A 920a82143a6f

Subscribe to this mod's changes

ctx-lint is a skill published in the GitHub repository OXI-717/ai-native-toolkit (8 stars, last pushed 16d ago), licensed MIT. It adds 56 tokens to every session and 899 once invoked, about $0.0003 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.