Home / painhardcore / pstack · GitHub

principle-make-operations-idempotent SKILL.md skillA

principle-make-operations-idempotent from painhardcore/pstack is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.

Install it, pinned

mdr add painhardcore/pstack/principle-make-operations-idempotent@git:20260827.04830a9

Pins git:20260827.04830a9 in mdr.lock. Pin the fingerprint instead.

Audit grade: A, 17 of 17 checks passed
Kind: SKILL.md skill
Repository: painhardcore/pstack
Path: .opencode/skills/principle-make-operations-idempotent/SKILL.md
Versions recorded: 1
Latest version: git:20260827.04830a9, committed Aug 27, 2026
Size: 1,359 bytes
Repository stars: 12
License: MIT

Apply when designing commands, lifecycle steps, or processing loops that run amid crashes, restarts, and retries. Converge to the same end state regardless of partial prior runs.

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

# Make Operations Idempotent

Design operations so they converge to the correct state regardless of how many times they run or where they start from. Every state-mutating operation should answer: "What happens if this runs twice? What happens if the previous run crashed halfway?"

**Why:** Commands, lifecycle operations, and processing loops run where crashes, restarts, and retries are normal. If partial state changes the next run's outcome, every restart becomes a debugging session.

**The pattern:**
- Convergent startup: scan for existing state, clean stale artifacts, adopt live sessions
- Content-based cleanup: compare by content equivalence, not creation order
- Self-healing locks: use PID-based stale lock detection
- Idempotent scheduling: failed work respawns cleanly, fresh input regenerated after each cycle

**The test:**
1. What happens if this runs twice in a row?
2. What happens if the previous run crashed at every possible point?
3. Does re-execution converge to the same end state?

If any answer is "it depends on what state was left behind," the operation needs a reconciliation step.

Read the whole file at its exact version.

How to install

The exact contents, by fingerprint

mdr add painhardcore/pstack/principle-make-operations-idempotent@sha256:6ff9aed07af7c3e5

The line at the top of this page pins the label git:20260827.04830a9, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.

Badge

[![mdr](https://markdownregistry.com/badge/art_luj2w65iviyd4jbw.svg)](https://markdownregistry.com/a/art_luj2w65iviyd4jbw)

1 badge image fetches in 30 days. What the badge shows.

Versions

The registry has recorded 1 version of this file, committed on Aug 27, 2026.

version	committed	commit	size	audit
git:20260827.04830a9 latest	2026-08-27	04830a9	1,359 B	A	view

Audit of the latest version

A 17 of 17 checks passed. Fixed automatic checks with no AI involved, so the same checks give the same answer every run.

pass: Frontmatter block present
pass: Frontmatter declares a name
pass: Frontmatter declares a description
pass: Size between 200 bytes and 200 KB (1359 bytes)
pass: No zero-width or bidi control characters
pass: No instruction hidden inside an HTML comment
pass: No link to an exfiltration or paste host
pass: No credential-shaped string
pass: No instruction to send local credentials anywhere
pass: No text hidden with inline styles
pass: No prompt-injection phrasing
pass: No curl or wget piped into a shell
pass: No recursive delete of root, home or parent
pass: No instruction to read or print local credentials
pass: No base64 blob over 200 characters
pass: No link to a raw IP address
pass: No script tag

Source

GitHub

painhardcore/pstack · 12 stars · license MIT · pushed 2026-10-16 · branch master

API

GET https://markdownregistry.com/api/v1/artifacts/art_luj2w65iviyd4jbw
GET https://markdownregistry.com/api/v1/resolve?ref=painhardcore/pstack/principle-make-operations-idempotent
GET https://markdownregistry.com/api/v1/blob/6ff9aed07af7c3e57c4ef247f1a236b6ffdd1b294732cfedb9845413395d659c

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.

Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.

More from painhardcore/pstack

architect SKILL.md skill

painhardcore/pstack · .opencode/skills/architect/SKILL.md · Sketch types, signatures, and module structure before code, then stay in the loop while implementation fills in. Use…