Automated summary
This skill reads the actual source of a library or system to reconstruct how it truly works when the documentation is missing, outdated, or misleading.
Strengths
- Drives reading of the implementation instead of the documented API surface
- Traces the real execution path, internal state, and side effects
- Tests hypotheses against behavior with small experiments
- Explicitly flags doc-versus-reality divergences and hidden gotchas
Limitations
- Requires source access, so it cannot be used on closed binaries or remote services
- Time-consuming on large codebases without a scoped target
- Explanation quality depends on the model's ability to read large amounts of code
Use it when observed behavior contradicts the documentation and you need a reliable mental model grounded in the implementation.
Avoid it when up-to-date official docs are sufficient, or when the source code is unavailable.
Security analysis
SafeThis is a pure instruction/persona file with no declared tools and no executable payloads, network calls, file writes, or credential handling. It directs the agent to read source code and run small confirmatory experiments, which is legitimate reverse-engineering behavior; nothing destructive, obfuscated, or exfiltrating is present.
No concerns found
How this analysis is madeExamples
/basement-hacker The docs for this caching library say entries expire after TTL, but I'm seeing stale values. Read the source and tell me how expiration actually works./basement-hacker Calling this function seems to mutate global state. Trace the implementation and explain exactly where and why./basement-hacker Go through this SDK's source and list every place where the README contradicts the actual behavior.name: basement-hacker description: Goes underground to reverse-engineer internals, read the source nobody reads, and explain how something actually works; invoke via /basement-hacker when documentation is missing or lying and you need ground truth from the implementation itself.
Basement Hacker
Down past the docs, past the abstractions, into the source nobody opens. This mode reverse-engineers how a thing actually works — not how the README claims it does — and comes back up with the real mental model.
When to use
- Docs are missing, outdated, or contradicting the observed behavior.
- You need ground-truth understanding of a library, API, or system's internals.
Behavior
- Go to the source — read the actual implementation, not just the public API surface or docs.
- Trace the real execution path: entry points, internal calls, state, and side effects.
- Reconstruct the underlying data model and control flow from the code itself.
- Test hypotheses against behavior — small experiments to confirm how it really responds.
- Note where the documented behavior and the actual behavior diverge.
- Surface the hidden gotchas: undocumented assumptions, magic constants, order dependencies.
- Explain the mechanism in plain language with citations to the specific source you read.
Output
A ground-truth explanation of how the thing actually works, citing the specific source, plus a list of doc-vs-reality discrepancies and hidden gotchas.
From the file to a first result
The download contains exactly the content displayed on this page. This copy may differ from the latest version in the source repository.
View the source and supporting filesThis download contains SKILL.md only. Any scripts, references, templates and dependencies are not included. Get the required files from the source, preserving their directory structure, before continuing.
1. Download the file
Download SKILL.mdFrom the root of a test project, save the file as .skill-downloads/basement-hacker-code-internals-mtnxbsn5/SKILL.md, or use the command below. This folder is for inspecting the skill before installation.
Command for macOS/Linux or WSL: requires a POSIX shell and curl. On Windows without WSL, use the download button and create the folder manually.
mkdir -p '.skill-downloads/basement-hacker-code-internals-mtnxbsn5' && curl --fail --show-error --location 'https://skills-guides.com/api/skills/basement-hacker-code-internals-mtnxbsn5/download' --output '.skill-downloads/basement-hacker-code-internals-mtnxbsn5/SKILL.md.part' && mv '.skill-downloads/basement-hacker-code-internals-mtnxbsn5/SKILL.md.part' '.skill-downloads/basement-hacker-code-internals-mtnxbsn5/SKILL.md'2. Check prerequisites
Read SKILL.md before using it. If it references scripts or external services, inspect them and prepare the required access in your test environment.
No recognized prerequisites section in this file. This does not mean it is self-contained: libraries, tools and access requirements may be mentioned elsewhere in the content or source repository.
The platforms on this page are catalog indications. The paths below follow tool documentation; they do not prove this skill has been run in those tools. No minimum tool version is confirmed for this listing.
3. Load the skill
After inspection, copy the complete folder into your project using one of the commands below, then open a new tool session. The command stops if a folder with the same name already exists: compare the files before replacing it.
Claude Code
test -f '.skill-downloads/basement-hacker-code-internals-mtnxbsn5/SKILL.md' && test -s '.skill-downloads/basement-hacker-code-internals-mtnxbsn5/SKILL.md' && mkdir -p '.claude/skills' && test ! -e '.claude/skills/basement-hacker' && cp -R '.skill-downloads/basement-hacker-code-internals-mtnxbsn5' '.claude/skills/basement-hacker'Cursor
test -f '.skill-downloads/basement-hacker-code-internals-mtnxbsn5/SKILL.md' && test -s '.skill-downloads/basement-hacker-code-internals-mtnxbsn5/SKILL.md' && mkdir -p '.cursor/skills' && test ! -e '.cursor/skills/basement-hacker' && cp -R '.skill-downloads/basement-hacker-code-internals-mtnxbsn5' '.cursor/skills/basement-hacker'Codex
test -f '.skill-downloads/basement-hacker-code-internals-mtnxbsn5/SKILL.md' && test -s '.skill-downloads/basement-hacker-code-internals-mtnxbsn5/SKILL.md' && mkdir -p '.agents/skills' && test ! -e '.agents/skills/basement-hacker' && cp -R '.skill-downloads/basement-hacker-code-internals-mtnxbsn5' '.agents/skills/basement-hacker'OpenSkills
OpenSkills must already be installed. The local install/read procedure is checked with OpenSkills 1.5.0, which requires Node.js ≥ 20.6.0. Catalog slugs are not resolved automatically.
Official OpenSkills installationopenskills install './.skill-downloads/basement-hacker-code-internals-mtnxbsn5'openskills read 'basement-hacker-code-internals-mtnxbsn5'Reading should display the installed file content and its base directory. It does not run the skill or install its dependencies.
For an agent that reads AGENTS.md, then sync the index. This command changes AGENTS.md: review the diff before using it.
openskills syncManual method or another tool: attach SKILL.md to a conversation, or open it in an agent that can read files. Include any required supporting resources. No universal folder is recognized by every tool.
4. Try a first task
Use a short, synthetic input: an API endpoint, a small document or an interface brief. In a new conversation, attach the file or give the agent its path, then adapt this request:
Read .skill-downloads/basement-hacker-code-internals-mtnxbsn5/SKILL.md and apply its instructions to this example: [describe a test input]. Identify any missing files, dependencies or access. Produce the result requested by the skill without inventing data or running unreviewed scripts.Expected result: output matching the skill instructions, or a precise list of missing prerequisites. A read confirmation alone does not validate a first use. If an external resource is unavailable, that path remains untested.
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