System Design
ninehills/skills
Design scalable distributed systems using structured approaches for load balancing, caching, database scaling, and message queues.
Test authorized web-cache key construction, variation, partitioning, authenticated response handling, revalidation, poisoning, deception, purge, and TTL behavior.
Install Test Web Cache Behavior
$ npx skills add cyberful/cyberful --skill test-web-cache-behavior -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install cyberful/cyberful test-web-cache-behavior --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/cyberful/cyberful.git skills-src && mkdir -p .claude/skills && cp -r skills-src/cyberful/builtin/skills/test-web-cache-behavior .claude/skills/test-web-cache-behavior && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "test-web-cache-behavior" agent skill from https://github.com/cyberful/cyberful/tree/main/cyberful/builtin/skills/test-web-cache-behavior into .claude/skills/test-web-cache-behavior/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-web-cache-behavior", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/cyberful/cyberful/tree/main/cyberful/builtin/skills/test-web-cache-behaviorType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add cyberful/cyberful --skill test-web-cache-behavior -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install cyberful/cyberful test-web-cache-behavior --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/cyberful/cyberful.git skills-src && mkdir -p .agents/skills && cp -r skills-src/cyberful/builtin/skills/test-web-cache-behavior .agents/skills/test-web-cache-behavior && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "test-web-cache-behavior" agent skill from https://github.com/cyberful/cyberful/tree/main/cyberful/builtin/skills/test-web-cache-behavior into .agents/skills/test-web-cache-behavior/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-web-cache-behavior", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add cyberful/cyberful --skill test-web-cache-behavior -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install cyberful/cyberful test-web-cache-behavior --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/cyberful/cyberful.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/cyberful/builtin/skills/test-web-cache-behavior .cursor/skills/test-web-cache-behavior && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "test-web-cache-behavior" agent skill from https://github.com/cyberful/cyberful/tree/main/cyberful/builtin/skills/test-web-cache-behavior into .cursor/skills/test-web-cache-behavior/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-web-cache-behavior", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/cyberful/cyberful.git --path cyberful/builtin/skills/test-web-cache-behavior--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add cyberful/cyberful --skill test-web-cache-behavior -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install cyberful/cyberful test-web-cache-behavior --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/cyberful/cyberful.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/cyberful/builtin/skills/test-web-cache-behavior .gemini/skills/test-web-cache-behavior && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "test-web-cache-behavior" agent skill from https://github.com/cyberful/cyberful/tree/main/cyberful/builtin/skills/test-web-cache-behavior into .gemini/skills/test-web-cache-behavior/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-web-cache-behavior", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install cyberful/cyberful test-web-cache-behaviorInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add cyberful/cyberful --skill test-web-cache-behavior -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/cyberful/cyberful.git skills-src && mkdir -p .github/skills && cp -r skills-src/cyberful/builtin/skills/test-web-cache-behavior .github/skills/test-web-cache-behavior && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "test-web-cache-behavior" agent skill from https://github.com/cyberful/cyberful/tree/main/cyberful/builtin/skills/test-web-cache-behavior into .github/skills/test-web-cache-behavior/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-web-cache-behavior", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add cyberful/cyberful --skill test-web-cache-behavior -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install cyberful/cyberful test-web-cache-behavior --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/cyberful/cyberful.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/cyberful/builtin/skills/test-web-cache-behavior .opencode/skills/test-web-cache-behavior && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "test-web-cache-behavior" agent skill from https://github.com/cyberful/cyberful/tree/main/cyberful/builtin/skills/test-web-cache-behavior into .opencode/skills/test-web-cache-behavior/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-web-cache-behavior", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
test-web-cache-behavior- GitHub stars
- 135
- Token cost
- ~631 tokens
- SKILL.md length
- 207 words
- Files
- 9 (incl. scripts, references, assets)
- Skills in repo
- 85
- Repo updated
- First seen
- Licence
- AGPL-3.0
At a glance
Test authorized web-cache key construction, variation, partitioning, authenticated response handling, revalidation, poisoning, deception, purge, and TTL behavior.
- Service-worker caching may cross users
- SKILL.md covers Establish cache ownership, Use isolated variants and Confirmation standard
- Runs Python scripts from its folder
- Representations
What it does
Test Web Cache Behavior is an agent skill from cyberful/cyberful. Test authorized web-cache key construction, variation, partitioning, authenticated response handling, revalidation, poisoning, deception, purge, and TTL behavior. Use when CDN, reverse-proxy, gateway, framework, browser, or service-worker caching may cross users, tenants, routes, representations, or authorization boundaries.
Its SKILL.md is about 630 tokens, which your agent loads only when the skill is triggered. The skill folder holds 13 other files, including scripts, reference files and assets (for example `agents/openai.yaml`, `assets/cache-evidence.schema.json` and `assets/cache-probe.example.json`).
It sits in Backend & APIs, covering Cloud networking and Caching. The repository describes itself as: Cyberful is an open-source AI Red Team for discovering, exploiting, verifying, and remediating vulnerabilities. The licence is AGPL-3.0.
When your agent uses it
- Service-worker caching may cross users
- Representations
- Authorization boundaries
Example prompts
- “/test-web-cache-behavior”
Requirements
- Python 3
What it can do on your machine
Read from SKILL.md and the folder at commit ec598a6. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Ships 2 files in scripts/ (Python), which the agent can run.
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Test Web Cache Behavior loads about 631 tokens when it runs, and up to ~872 if it reads all its reference files. Until then it costs about 88 tokens; SKILL.md has 207 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); the scripts in this folder are not scanned.
SKILL.md
The full file from cyberful/cyberful at commit ec598a6, republished under its AGPL-3.0 licence (© cyberful). 207 words, ~631 tokens.
Download SKILL.mdSave it as
.claude/skills/test-web-cache-behavior/SKILL.md (or your agent's skills folder). This skill also uses 8 other files; get the full folder from GitHub.- name
- test-web-cache-behavior
- description
- Test authorized web-cache key construction, variation, partitioning, authenticated response handling, revalidation, poisoning, deception, purge, and TTL behavior. Use when CDN, reverse-proxy, gateway, framework, browser, or service-worker caching may cross users, tenants, routes, representations, or authorization boundaries.
- metadata.domain
- application-security
- metadata.subdomain
- web-cache-security
- metadata.triggers
- web cache poisoning, web cache deception, authenticated response caching, cache key collision, cache partitioning, vary header security
- metadata.tags
- cache, CDN, cache-poisoning, cache-deception, partitioning, revalidation
Test Web Cache Behavior
Model the cache key and response-selection policy before probing. A reflected header or changing age value is not poisoning; prove that attacker-controlled input selects or changes a representation later served across an unauthorized boundary.
Establish cache ownership
Identify every cache layer, key fields, normalization, ignored inputs, Vary handling, credential partitioning, bypass rules, cacheable status and methods, TTL, stale behavior, purge domain, and service-worker interaction. Read references/cache-key-proof.md.
Use isolated variants
Create a unique, authorized cache namespace that cannot collide with ordinary users. Use paired prime and observation requests with one varied dimension, a stable marker, bounded TTL, and an explicit cleanup or natural-expiry plan. Never poison a shared victim-reachable key without express authorization.
Use scripts/run_cache_probe.py for a small discriminating set. The runner requires exact origins, an explicit isolation token in every URL, and request/rate ceilings. The campaign cannot select transport: non-loopback traffic requires the proxy and CA route inherited from the Cyberful gateway after the model boundary, while literal-IP loopback traffic explicitly disables proxies. It preserves bounded raw responses without deciding exploitability.
Confirmation standard
Report cache layer, reconstructed key, omitted or normalized dimension, prime and observation identities, response provenance, age or cache-status transition, persistence window, purge behavior, matched miss control, and unauthorized security effect.
© cyberful, AGPL-3.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
SKILL.md and 8 other files (scripts, references, assets) in cyberful/builtin/skills/test-web-cache-behavior of cyberful/cyberful.
- SKILL.md
- agents/openai.yaml
- assets/cache-evidence.schema.json
- assets/cache-probe.example.json
- assets/cache-probe.schema.json
- references/cache-key-proof.md
- scripts/manifest.json
- scripts/run_cache_probe.py
- tests/test_run_cache_probe.py
Open the folder on GitHubat commit ec598a6
Compare with similar skills
Test Web Cache Behavior next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Test Web Cache Behavior this skillcyberful/cyberful | 135 | — | ~631 | Automated safety check: Pass | AGPL-3.0 | |
| System Designninehills/skills | 281 | — | ~4.7k | Automated safety check: Pass | MIT | |
| System Designwondelai/skills | 2.4k | — | ~4k | Automated safety check: Pass | MIT | |
| LLM Gatewaysickn33/agentic-awesome-skills | 47k | 1 repos | ~2.1k | Automated safety check: Pass | MIT | |
| Phy HTTP Cache AuditLeoYeAI/openclaw-master-skills | 2.2k | — | ~4.1k | Automated safety check: Pass | Apache-2.0 | |
| Cloudfrontaws/agent-toolkit-for-aws | 2.8k | — | ~1.3k | Automated safety check: Pass | Apache-2.0 |
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Related
Categories
Questions about Test Web Cache Behavior
What does Test Web Cache Behavior do?
Test authorized web-cache key construction, variation, partitioning, authenticated response handling, revalidation, poisoning, deception, purge, and TTL behavior. Test Web Cache Behavior is an agent skill from cyberful/cyberful. Test authorized web-cache key construction, variation, partitioning, authenticated response handling, revalidation, poisoning, deception, purge, and TTL behavior.
When should I use Test Web Cache Behavior?
Test Web Cache Behavior fits situations like: service-worker caching may cross users; representations; authorization boundaries.
How do I install Test Web Cache Behavior in Claude Code?
Run `npx skills add cyberful/cyberful --skill test-web-cache-behavior -a claude-code`. Or copy the skill folder (cyberful/builtin/skills/test-web-cache-behavior in cyberful/cyberful) into .claude/skills/test-web-cache-behavior in your project. Claude Code loads it when a task matches its description.
How do I install Test Web Cache Behavior in Codex?
Run `npx skills add cyberful/cyberful --skill test-web-cache-behavior -a codex`. Or copy the skill folder (cyberful/builtin/skills/test-web-cache-behavior in cyberful/cyberful) into .agents/skills/test-web-cache-behavior in your project. Codex loads it when a task matches its description.
Can I use Test Web Cache Behavior in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add cyberful/cyberful --skill test-web-cache-behavior -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/test-web-cache-behavior, .gemini/skills/test-web-cache-behavior, .github/skills/test-web-cache-behavior and .opencode/skills/test-web-cache-behavior in your project.
What does Test Web Cache Behavior need to run?
Going by SKILL.md and its folder, Test Web Cache Behavior needs Python for the scripts in its folder. Our summary lists: Python 3.
Does Test Web Cache Behavior access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Test Web Cache Behavior safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. The check reads SKILL.md only: the scripts in the folder are not scanned, so read them before running anything.
What licence does Test Web Cache Behavior use?
Test Web Cache Behavior is published under the AGPL-3.0 licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Test Web Cache Behavior use?
About 631 tokens (SKILL.md is roughly 2.5k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 241 tokens, read only when the agent opens those files.
What are the alternatives to Test Web Cache Behavior?
Skills that share tags, products or a category with Test Web Cache Behavior: System Design (ninehills/skills, 281 stars), System Design (wondelai/skills, 2.4k stars), LLM Gateway (sickn33/agentic-awesome-skills, 47k stars) and Phy HTTP Cache Audit (LeoYeAI/openclaw-master-skills, 2.2k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Test Web Cache Behavior?
cyberful (a GitHub organization) maintains it in cyberful/cyberful, which has 135 GitHub stars. The repository holds 85 skills in this directory. The repository was last updated on August 24, 2026.
Source: cyberful/cyberful on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.