avoid-eval SKILL.md skillA
avoid-eval from thedaviddias/front-end-checklist is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add thedaviddias/front-end-checklist/avoid-eval@git:20261004.4b0ddb9Pins git:20261004.4b0ddb9 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- thedaviddias/front-end-checklist
- Path
skills/avoid-eval/SKILL.md- Versions recorded
- 2
- Latest version
- git:20261004.4b0ddb9, committed Oct 4, 2026
- First version recorded
- May 29, 2026
- Size
- 2,220 bytes
- Repository stars
- 74,516
- License
- MIT
Use when reviewing scripts, client components, bundles, or runtime behavior related to Never use eval() or unsafe dynamic code execution. Inspect both source code and the browser execution path so fixes target the real bottleneck or bug.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Never use eval() or unsafe dynamic code execution
eval() and its equivalents are the root cause of some of the most severe XSS vulnerabilities. If any user-controlled string reaches eval(), an attacker can execute arbitrary JavaScript in your users' browsers — stealing sessions, making requests as the user, or redirecting to malicious sites. Content Security Policy (CSP) blocks eval() but not new Function(), and there is never a legitimate use case that can't be solved without it.
## Quick Reference
- eval() executes arbitrary strings as code — any user input passed to it is a critical security hole
- new Function() is equally dangerous and not caught by CSP eval restrictions
- setTimeout('code', delay) and setInterval('code', delay) also evaluate strings — use function references instead
- Use JSON.parse() instead of eval() for parsing JSON
## Check
Search this codebase for any use of eval(), new Function(), or setTimeout/setInterval with string arguments.
## Fix
Replace eval() calls with safe alternatives: JSON.parse for data, object lookups for dynamic dispatch, and Function references for timers.
## Explain
…Read the whole file at its exact version.
How to install
mdr add thedaviddias/front-end-checklist/avoid-eval@sha256:5c668b1631321824The line at the top of this page pins the label git:20261004.4b0ddb9, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_nvrkw4kexlqxa4sj)
3 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 2 versions of this file, between May 29, 2026 and Oct 4, 2026, about one every 128 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20261004.4b0ddb9 latest | 2026-10-04 | 4b0ddb9 | 2,220 B | A | view · diff |
| git:20260529.7c05904 | 2026-05-29 | 7c05904 | 2,226 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (2220 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
thedaviddias/front-end-checklist · 74,516 stars · license MIT · pushed 2026-10-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_nvrkw4kexlqxa4sj GET https://markdownregistry.com/api/v1/resolve?ref=thedaviddias/front-end-checklist/avoid-eval GET https://markdownregistry.com/api/v1/blob/5c668b1631321824e21e909953df56f13a0f7042c6dae5a01b11424d04dfd1fd
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.