cache-key-discriminator-audit SKILL.md skillA
cache-key-discriminator-audit from testland/qa is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add testland/qa/cache-key-discriminator-audit@git:20260728.1bce424Pins git:20260728.1bce424 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- testland/qa
- Path
plugins/qa-cache-testing/skills/cache-key-discriminator-audit/SKILL.md- Versions recorded
- 2
- Latest version
- git:20260728.1bce424, committed Jul 28, 2026
- First version recorded
- Jul 19, 2026
- Size
- 19,620 bytes
- Repository stars
- 11
- License
- MIT
Audits whether a cache key carries every discriminator the cached response actually depends on, so two requests that must not share a slot cannot collide. Ranks identity discriminators (tenant, user, authorization scope, plan tier) above presentation ones (locale, region, currency, feature flag), maps each missing discriminator to the data-exposure or wrong-content consequence it causes, classifies each key-and-value pair into a critical / high / medium severity band…
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
# cache-key-discriminator-audit ## The defect this finds A cache key is a function of an operation plus a set of **discriminators**: the request dimensions the response body actually varies on. If the response varies on something the key does not carry, two different requests hash to the same slot and the second requester is served the first requester's response. The worst version of this is not slow, and it is not stale. It is a **data-exposure defect**: one user's data served to another user. A missing `tenant_id` in a multi-tenant cache is a confidentiality bug with the same blast radius as a missing authorization check, because the cache is doing the serving and the authorization code never runs on the second request. Triage it as a security defect, not as a performance or freshness issue. The exposure only reaches other people when the cache is shared. RFC 9111 §1 splits caches into a **shared cache** (stores responses for reuse by more than one user) and a **private cache** (dedicated to a single user) ([RFC 9111 §1](https://www.rfc-editor.org/rfc/rfc9111.html)). A CDN, a reverse proxy, and a Redis or Memcached instance behind the …
Read the whole file at its exact version.
How to install
mdr add testland/qa/cache-key-discriminator-audit@sha256:a00aea5761a9e6d7The line at the top of this page pins the label git:20260728.1bce424, 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_63l2d5lhjxxsudkt)
1 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 2 versions of this file, between Jul 19, 2026 and Jul 28, 2026, about one every 9 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260728.1bce424 latest | 2026-07-28 | 1bce424 | 19,620 B | A | view · diff |
| git:20260719.364dc50 | 2026-07-19 | 364dc50 | 22,791 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 (19620 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
testland/qa · 11 stars · license MIT · pushed 2026-10-20 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_63l2d5lhjxxsudkt GET https://markdownregistry.com/api/v1/resolve?ref=testland/qa/cache-key-discriminator-audit GET https://markdownregistry.com/api/v1/blob/a00aea5761a9e6d7b4a3457d59dca445d785084bbe52a792c5f96daa20cb151d
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.