# Flag Downloads Run as Code in Files

Flag Downloads Run as Code in Files: what it does, its label on each agent, what it misses, and examples.

Catalog policy block-fetch-exec-in-files, version 0.0.3, 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 rollout) when a line added to a script, Dockerfile, Makefile, CI workflow or package.json wires a download into a code runner: curl/wget/aria2c/lynx/iwr/irm piped into a shell, python/perl/ruby/node/php/lua on stdin, pwsh or iex; bash -c, eval, source or a here-string of a $(...) or \<(...) download; Dockerfile ADD of a URL without --checksum. One line at a time: continuation lines, variables, unicode-escaped JSON, split or quoted command names, a download saved to a file and run on a later step, and interpreters or fetchers outside the lists are missed. Never refuses. Friction only.

## 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 commit adds a Dockerfile RUN step that pipes a download into sh.

Allowed: A commit adds a Dockerfile ADD of a remote URL pinned with --checksum.

## More

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


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