# Scan Hidden Content

Scan Hidden Content: what it does, its label on each agent, what it misses, and examples.

Catalog policy scan-hidden-content, version 0.0.2, labelled warns on Claude Code.

> Ask the user before running any command on this page: each one changes how their agent or repository behaves.

## What it does

Warns (observe) when a change adds text a reader cannot see, or a URL that carries data out, to Markdown, HTML, SVG, XML, Word, agent instruction files, docs and templates: instruction-like or long comments, CSS-hidden, white or 1pt text, hidden Word runs, URLs with secret words, long queries, placeholders or encoded parts, remote embeds, camo runs, HTML data URIs. Runs: commit, agent write, turn's end. Waiver: a person's marker comment line above. Friction, not a boundary.

## On each agent

| Agent | Label | What it does there |
| --- | --- | --- |
| Claude Code | Warns | Warns on an agent's file writes and at turn end |
| Cursor | Warns | Warns on an agent's file writes and at turn end |
| Codex | Warns | Warns on an agent's file writes and at turn end. If the hook errors, the action goes through (not witnessed; the vendor's row is only partly live-run) |
| GitHub Copilot | Warns | Warns at turn end only. It does not check a file write when it happens. If the hook errors, the action goes through (not witnessed; the vendor's row is only partly live-run) |
| Devin | Warns | Warns at turn end only. It does not check a file write when it happens. If the hook errors, the action goes through (vendor docs only, not witnessed) |
| Grok | Not graded | Not graded yet for Grok |
| goose | Not graded | Not graded yet for goose |
| Antigravity | Not graded | Not graded yet for Antigravity |
| OpenHands | Not graded | Not graded yet for OpenHands |
| Kimi Code | Not graded | Not graded yet for Kimi Code |
| Factory Droid | Not graded | Not graded yet for Factory Droid |

## What it misses

This policy does not state what it misses.

## Examples from its eval suite

Warns: A README gains a Markdown image whose query sends a token to an outside host.

Allowed: A README gains shields.io and GitHub Actions badges without a query.

## More

- [The policy on the catalog pages](https://chock.sh/coding/policies/scan-hidden-content/)
- [Source at the pinned catalog commit](https://github.com/open-coder-ai/chock-catalog/tree/1e60d211c1bb767152c6ab0167932da06ab3a10f/base/scan-hidden-content)


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Built from engine [5a4b6287a46e](https://github.com/open-coder-ai/chock/commit/5a4b6287a46e07f9f856d9bbe10622bd1ff2e021) and catalog [1e60d211c1bb](https://github.com/open-coder-ai/chock-catalog/commit/1e60d211c1bb767152c6ab0167932da06ab3a10f).