Prompt Injection Defense
sickn33/agentic-awesome-skills
Defend AI systems against prompt injection and indirect prompt attacks using input controls, tool permissions, output validation, and isolation boundaries.
Change eXeLearning service logic, injected collaborators, file operations or service cleanup.
AGPL-3.0Auto-check passed
Install Backend Service
$ npx skills add exelearning/exelearning --skill backend-service -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install exelearning/exelearning backend-service --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/exelearning/exelearning.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/backend-service .claude/skills/backend-service && 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 "backend-service" agent skill from https://github.com/exelearning/exelearning/tree/main/.agents/skills/backend-service into .claude/skills/backend-service/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "backend-service", 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/exelearning/exelearning/tree/main/.agents/skills/backend-serviceType 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 exelearning/exelearning --skill backend-service -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install exelearning/exelearning backend-service --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/exelearning/exelearning.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.agents/skills/backend-service .agents/skills/backend-service && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "backend-service" agent skill from https://github.com/exelearning/exelearning/tree/main/.agents/skills/backend-service into .agents/skills/backend-service/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "backend-service", 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 exelearning/exelearning --skill backend-service -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install exelearning/exelearning backend-service --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/exelearning/exelearning.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.agents/skills/backend-service .cursor/skills/backend-service && 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 "backend-service" agent skill from https://github.com/exelearning/exelearning/tree/main/.agents/skills/backend-service into .cursor/skills/backend-service/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "backend-service", 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/exelearning/exelearning.git --path .agents/skills/backend-service--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 exelearning/exelearning --skill backend-service -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install exelearning/exelearning backend-service --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/exelearning/exelearning.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.agents/skills/backend-service .gemini/skills/backend-service && 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 "backend-service" agent skill from https://github.com/exelearning/exelearning/tree/main/.agents/skills/backend-service into .gemini/skills/backend-service/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "backend-service", 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 exelearning/exelearning backend-serviceInstalls 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 exelearning/exelearning --skill backend-service -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/exelearning/exelearning.git skills-src && mkdir -p .github/skills && cp -r skills-src/.agents/skills/backend-service .github/skills/backend-service && 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 "backend-service" agent skill from https://github.com/exelearning/exelearning/tree/main/.agents/skills/backend-service into .github/skills/backend-service/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "backend-service", 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 exelearning/exelearning --skill backend-service -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install exelearning/exelearning backend-service --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/exelearning/exelearning.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.agents/skills/backend-service .opencode/skills/backend-service && 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 "backend-service" agent skill from https://github.com/exelearning/exelearning/tree/main/.agents/skills/backend-service into .opencode/skills/backend-service/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "backend-service", 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
backend-service- GitHub stars
- 146
- Token cost
- ~459 tokens
- SKILL.md length
- 220 words
- Files
- 1
- Skills in repo
- 17
- Repo updated
- First seen
- Licence
- AGPL-3.0
At a glance
Change eXeLearning service logic, injected collaborators, file operations or service cleanup.
- Calls bun
What it does
Backend Service is an agent skill from exelearning/exelearning. Change eXeLearning service logic, injected collaborators, file operations or service cleanup.
Its SKILL.md is about 460 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
The repository describes itself as: eXeLearning is an AGPL-licensed free/libre tool to create and publish open educational resources. The licence is AGPL-3.0.
Example prompts
- “/backend-service”
What it can do on your machine
Read from SKILL.md and the folder at commit 319b5d2. 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
Shell commands in SKILL.md call:
bun
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
Backend Service loads about 459 tokens when it runs. Until then it costs about 27 tokens; SKILL.md has 220 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); files beside SKILL.md are not scanned.
SKILL.md
The full file from exelearning/exelearning at commit 319b5d2, republished under its AGPL-3.0 licence (© exelearning). 220 words, ~459 tokens.
Download SKILL.mdSave it as
.claude/skills/backend-service/SKILL.md (or your agent's skills folder).- name
- backend-service
- description
- Change eXeLearning service logic, injected collaborators, file operations or service cleanup.
Backend services
Read the service, callers and colocated specs under src/services/, along with affected query functions
under src/db/queries/ and error types in src/exceptions/.
- Reuse the existing injection contract: some services expose configure/reset functions, others accept dependencies or a database argument. Do not introduce a global singleton, factory or interface solely for a test. Pass the caller's transaction through related operations.
- Tests use
bun:testand injected behavior, not newmock.module()calls. Restore configured dependencies, environment changes, timers and caches after each test. Use a real isolated DB when testing DB behavior; a stub is appropriate only when the database is fully replaced by injected collaborators. - Keep the existing error type, translation and response mapping. Test success and failure at the shared implementation so every caller receives the same fix.
- For files, use
src/services/file-helper.tsandasset-storage. Validate user-derived paths, create directories when writing, and close handles/stop processes before deletion on Windows. - Preserve an existing cache's invalidation, expiry and ownership; add a new cache only for a measured problem. Test invalidation as well as hits, not only reduced dependency call counts.
- If server and static builds consume the same configuration, reuse the shared implementation. Avoid extracting a new abstraction when an existing helper already covers the behavior.
Run bun test src/services/<affected>.spec.ts, then verify-change.
Check caller behavior, failed-operation cleanup and the affected executable-line coverage.
© exelearning, 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
Just SKILL.md in .agents/skills/backend-service of exelearning/exelearning.
Open the folder on GitHubat commit 319b5d2
Compare with similar skills
Backend Service 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 |
|---|---|---|---|---|---|---|
| Backend Service this skillexelearning/exelearning | 146 | — | ~459 | Automated safety check: Pass | AGPL-3.0 | |
| Prompt Injection Defensesickn33/agentic-awesome-skills | 47k | 2 repos | ~4.2k | Automated safety check: Warn | MIT | |
| Logical Propertiesthedaviddias/Front-End-Checklist | 74k | — | ~526 | Automated safety check: Pass | MIT | |
| Writing Kea LogicsPostHog/posthog | 40k | — | ~2.3k | Automated safety check: Pass | Custom licence | |
| Detecting AI Model Prompt Injection Attacksmukul975/Anthropic-Cybersecurity-Skills | 34k | — | ~1.9k | Automated safety check: Warn | Apache-2.0 | |
| Logic Reviewsickn33/agentic-awesome-skills | 47k | 1 repos | ~3.5k | Automated safety check: Pass | MIT |
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Questions about Backend Service
What does Backend Service do?
Change eXeLearning service logic, injected collaborators, file operations or service cleanup. Backend Service is an agent skill from exelearning/exelearning. Change eXeLearning service logic, injected collaborators, file operations or service cleanup.
How do I install Backend Service in Claude Code?
Run `npx skills add exelearning/exelearning --skill backend-service -a claude-code`. Or copy the skill folder (.agents/skills/backend-service in exelearning/exelearning) into .claude/skills/backend-service in your project. Claude Code loads it when a task matches its description.
How do I install Backend Service in Codex?
Run `npx skills add exelearning/exelearning --skill backend-service -a codex`. Or copy the skill folder (.agents/skills/backend-service in exelearning/exelearning) into .agents/skills/backend-service in your project. Codex loads it when a task matches its description.
Can I use Backend Service 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 exelearning/exelearning --skill backend-service -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/backend-service, .gemini/skills/backend-service, .github/skills/backend-service and .opencode/skills/backend-service in your project.
What does Backend Service need to run?
Going by SKILL.md and its folder, Backend Service needs the command-line tools its instructions call (bun).
Does Backend Service 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 Backend Service 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. Review the folder before installing.
What licence does Backend Service use?
Backend Service 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 Backend Service use?
About 459 tokens (SKILL.md is roughly 1.8k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Backend Service?
Skills that share tags, products or a category with Backend Service: Prompt Injection Defense (sickn33/agentic-awesome-skills, 47k stars), Logical Properties (thedaviddias/Front-End-Checklist, 74k stars), Writing Kea Logics (PostHog/posthog, 40k stars) and Detecting AI Model Prompt Injection Attacks (mukul975/Anthropic-Cybersecurity-Skills, 34k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Backend Service?
exelearning (a GitHub organization) maintains it in exelearning/exelearning, which has 146 GitHub stars. The repository holds 17 skills in this directory. The repository was last updated on October 7, 2026.
Source: exelearning/exelearning on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.