Apply when debugging. Trace each symptom back to the first place the system went wrong and fix it there. A guard is a fix only when the state it handles is legitimate.
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
# Fix Root Causes
When debugging, fix the fault, not the place where it surfaced. The symptom is where a wrong state became visible. The root cause is the first place the system did something it should not do, or failed to handle a state it should handle.
**Why:** A symptom fix hides the evidence and leaves the fault free to surface somewhere else. Each one makes the system harder to reason about, because the code now carries a workaround for a bug that nobody named.
**Pattern:**
- Reproduce first.
- Ask "why" at each step until the answer is a wrong decision in the code, not a consequence of an earlier one.
- When stuck, instrument. Read the actual error and the actual state. Do not guess.
- Ask whether the state that triggered the symptom is legitimate. If the system may be in that state, the code that broke on it is the root cause, and handling the state there is the fix. If the state should never exist, a check where it broke hides the bug. Find what produced the state. Guards, retries, swallowed errors, clamped values, and discarded state are the usual ways to hide a bug.
…
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A 17 of 17 checks passed. Fixed automatic checks with no AI involved, so the same checks give the same answer every run.
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Source
GitHub
creedants/pstack-t3 · 15 stars · license MIT · pushed 2026-10-19 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_bessakc6dafzwh4r
GET https://markdownregistry.com/api/v1/resolve?ref=creedants/pstack-t3/principle-fix-root-causes
GET https://markdownregistry.com/api/v1/blob/e148a7bdbb56c9e1b1382d9fd2c2239acf672b98dfd0027458884dc33c30a71b
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.
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