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principle-boundary-discipline SKILL.md skillA

principle-boundary-discipline 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-boundary-discipline@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-boundary-discipline/SKILL.md
Versions recorded: 1
Latest version: git:20260827.04830a9, committed Aug 27, 2026
Size: 1,888 bytes
Repository stars: 12
License: MIT

Apply when wiring validation, error handling, or framework adapters. Concentrate guards at system boundaries (CLI, config, network, external APIs); trust internal types and keep business logic in pure functions.

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

# Boundary Discipline

Place validation, type narrowing, and error handling at system boundaries. Trust internal code unconditionally. Business logic lives in pure functions; the shell is thin and mechanical.

**Why:** Scattered validation is noisy, redundant, and gives a false sense of safety. Validate data once at the boundary. Keep logic out of framework wiring so it can be tested without the framework.

**The pattern:**
- **At boundaries** (CLI args, config files, external APIs, network protocols): validate, return errors, handle defensively.
- **Inside the system:** typed data, error propagation, no re-validation. Trust the types.
- **Across the boundary.** Expose domain concepts, not the boundary's private representation. Keep general-purpose mechanism inside and special-purpose policy at the edge.

**Applications:**

Validation and error handling:
- Validate config at parse time (the boundary), not inside business logic
- Parse raw data into domain types at the boundary
- Do not re-export transport, storage, framework, or wire types through the public surface
- No redundant nil checks deep in call chains if the boundary already validated

Code organization:
…

Read the whole file at its exact version.

How to install

The exact contents, by fingerprint

mdr add painhardcore/pstack/principle-boundary-discipline@sha256:3fee7ce89a74a991

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_saclrhcspakovh33.svg)](https://markdownregistry.com/a/art_saclrhcspakovh33)

2 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	1,888 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 (1888 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_saclrhcspakovh33
GET https://markdownregistry.com/api/v1/resolve?ref=painhardcore/pstack/principle-boundary-discipline
GET https://markdownregistry.com/api/v1/blob/3fee7ce89a74a9911e769e38b39f4505887b06842c36902e7a1733a4e5a07576

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.

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