secrets-hygiene

A set of rules for handling secrets such as tokens and environment settings. It says not to read environment files or MCP configuration files that may contain credentials.

In plain words
What is it for?
Use it to guide safe file access and prevent accidental reading of sensitive configuration.
Why use it?
It reduces the risk of exposing authentication details while working in a codebase.

Cursor rule

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 rules/runlayer/plugins/secrets-hygiene
Clone the repo
git clone --depth 1 https://github.com/runlayer/plugins
Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 184 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 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 $0.00000 $0.00184
Opus 5 $0.00000 $0.00092
Sonnet 5 $0.00000 $0.00037
Haiku 4.5 $0.00000 $0.00018

Measured yesterday against content hash d57703898704, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade B, and why

secrets-hygiene scanned grade B 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.

Reads MCP configurationmediumAgent snooping

mcp.json carries server URLs and auth tokens; reading it lets a mod discover and abuse other integrations.

- NEVER read, open, or output the contents of `mcp.json`, `.mcp.json`, or `mcp_config.json` files. These may contain OAuth tokens, API keys, and secrets.
cursor-plugin/rules/secrets-hygiene.mdc · 18 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 · 18 lines · 0 tokens per session scan B d57703898704

Subscribe to this mod's changes

secrets-hygiene is a cursor rule published in the GitHub repository runlayer/plugins (6 stars, last pushed 6mo ago), with no licence file. It costs nothing until one of its globs matches a file; then it loads 184 tokens. A static security scan graded it B with 1 finding (reads mcp configuration). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.