cors-config

cors-config is a skill for Claude Code, Codex from blunotech-dev/agents. It costs 67 tokens per session (1,684 once invoked), scanned A, original, no licence file.

A guide for checking and fixing CORS, the browser rules that control which websites may call an API from another origin. It covers allowed origins, preflight requests, credentials, and response headers.

In plain words
What is it for?
Use it to review wildcard origins, Access-Control headers, OPTIONS handling, credentials, and CORS errors.
Why use it?
It helps resolve blocked cross-origin requests without allowing untrusted websites to access protected API responses.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/blunotech-dev/agents/cors-config
Any agent
npx skills add blunotech-dev/agents --skill cors-config
Clone the repo
git clone --depth 1 https://github.com/blunotech-dev/agents

Made for: Claude Code, Codex.

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 cors-config

README.md
[![agentmods](https://agentmods.dev/badge/skills/blunotech-dev/agents/cors-config.svg)](https://agentmods.dev/skills/blunotech-dev/agents/cors-config)
Your own site
<a href="https://agentmods.dev/skills/blunotech-dev/agents/cors-config"><img src="https://agentmods.dev/badge/skills/blunotech-dev/agents/cors-config.svg" alt="Measured on agentmods" height="20"></a>
Per session 67 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,684 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. Scan, not verified.
Origin unknown 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 $0.00067 $0.01684
Opus 5 $0.00034 $0.00842
Sonnet 5 $0.00013 $0.00337
Haiku 4.5 $0.00007 $0.00168

Measured yesterday against content hash a1538354fd8f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

cors-config scanned grade A with 1 finding 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 yesterday.

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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

CORS is a browser enforcement mechanism. It doesn't protect your API from non-browser clients (curl, server-to-server) — it prevents *other websites* from making credentialed requests on behalf of your users.
security/cors-config/SKILL.md · 202 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

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. yesterday First seen · 202 lines · 67 tokens per session scan A a1538354fd8f

Subscribe to this mod's changes

cors-config is a skill published in the GitHub repository blunotech-dev/agents (2 stars, last pushed 3mo ago), with no licence file. It adds 67 tokens to every session and 1,684 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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