strict-api

# Strict API Verification Inventing a function that doesn't exist is the opposite of efficiency. You wrote a line that looks minimal. You shipped a bug that takes an hour to debug. The true minimal path is: use only what is provably there. ## Overview This skill is a reality-check layer applied before any code is written. It is not about being slow — it is about being correct the first time. Use it alongside `minimalist` when the user wants both less code and verified code. ## The Only Rule Before you write any function call, import, or method access, you must be able to answer: **"Does this exist in the version the user is running?"** If the answer is "probably" or "I think so" — **stop**. You don't know. Say so. ## What This Blocks **Made-up methods:** - `fs.readFileLines()` does not exist in Node.js. - `path.combine()` is .NET, not Node.js. - `csv.read_csv()` is pandas, not Python's `csv` module. Writing these is not minimal code — it is confident garbage. **Framework confusion.** Every framework has a twin that sounds like it: - `render_template` (Flask) vs `render()` (Django) - `useForm()` (react-hook-form) vs nothing built into React - `app.listen()` (Express) vs `server.listen()` (raw Node.js `http`) **Deprecated APIs.** Writing a deprecated method is writing code that will break on the next upgrade. ## Workflow 1. **Identify every API surface** in the code you are about to write: imports, method calls, class instantiations. 2. **Verify each one** against the user's stated version. If no version is stated, ask once. 3. **Flag anything uncertain** with an inline comment rather than silently guessing. 4. **Prefer verbose-but-correct** over terse-but-wrong. When you are not sure if a method exists, annotate it inline: // verify fs.openAsBlob exists in your Node.js version (>= 20.0) const blob = await fs.openAsBlob(path); One comment costs nothing. A silent wrong call costs an hour of the user's time. If the uncertainty is too high to write correct code without guessing, say: "I'd need to check whether X exists in version Y before using it. What version are you on?" ## Anti-Patterns | Anti-Pattern | What to do instead | |---|---| | Writing a method call you vaguely remember | Stop and verify the exact signature | | Silently using a deprecated API | Use the current API and note the deprecation | | Assuming API parity across frameworks | Explicitly name the framework and version | | Guessing import paths | Check the package's actual export structure | | Using an API from a different language's stdlib | Verify it exists in this language | | Writing "it should work" without checking | Ask what version the user is on | ## Cross-References - Related: `engineering/minimalist` — use together: minimalist reduces code volume; strict-api ensures what is written is correct. - Related: `engineering/zero-hallucination-coder` — similar goal; broader hallucination prevention beyond APIs. - Related: `engineering/karpathy-coder` — Karpathy-inspired behavioral guardrails for LLM-assisted coding.