Agent skill

Impl Validator

Independently check whether an implementation matches its stated goal and return PASS/WARN/FAIL with actionable issues.

MITAuto-check passedKnowledge Management

Install Impl Validator

skills CLI

$ npx skills add Ar9av/obsidian-wiki --skill impl-validator -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install Ar9av/obsidian-wiki impl-validator --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/Ar9av/obsidian-wiki.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.skills/impl-validator .claude/skills/impl-validator && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "impl-validator" agent skill from https://github.com/Ar9av/obsidian-wiki/tree/main/.skills/impl-validator into .claude/skills/impl-validator/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "impl-validator", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/Ar9av/obsidian-wiki/tree/main/.skills/impl-validator

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add Ar9av/obsidian-wiki --skill impl-validator -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install Ar9av/obsidian-wiki impl-validator --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/Ar9av/obsidian-wiki.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.skills/impl-validator .agents/skills/impl-validator && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "impl-validator" agent skill from https://github.com/Ar9av/obsidian-wiki/tree/main/.skills/impl-validator into .agents/skills/impl-validator/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "impl-validator", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add Ar9av/obsidian-wiki --skill impl-validator -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install Ar9av/obsidian-wiki impl-validator --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/Ar9av/obsidian-wiki.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.skills/impl-validator .cursor/skills/impl-validator && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "impl-validator" agent skill from https://github.com/Ar9av/obsidian-wiki/tree/main/.skills/impl-validator into .cursor/skills/impl-validator/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "impl-validator", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/Ar9av/obsidian-wiki.git --path .skills/impl-validator

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add Ar9av/obsidian-wiki --skill impl-validator -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install Ar9av/obsidian-wiki impl-validator --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/Ar9av/obsidian-wiki.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.skills/impl-validator .gemini/skills/impl-validator && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "impl-validator" agent skill from https://github.com/Ar9av/obsidian-wiki/tree/main/.skills/impl-validator into .gemini/skills/impl-validator/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "impl-validator", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install Ar9av/obsidian-wiki impl-validator

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add Ar9av/obsidian-wiki --skill impl-validator -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/Ar9av/obsidian-wiki.git skills-src && mkdir -p .github/skills && cp -r skills-src/.skills/impl-validator .github/skills/impl-validator && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "impl-validator" agent skill from https://github.com/Ar9av/obsidian-wiki/tree/main/.skills/impl-validator into .github/skills/impl-validator/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "impl-validator", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add Ar9av/obsidian-wiki --skill impl-validator -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install Ar9av/obsidian-wiki impl-validator --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/Ar9av/obsidian-wiki.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.skills/impl-validator .opencode/skills/impl-validator && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "impl-validator" agent skill from https://github.com/Ar9av/obsidian-wiki/tree/main/.skills/impl-validator into .opencode/skills/impl-validator/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "impl-validator", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: impl-validator
GitHub stars: 3.5k
Token cost: ~1.2k tokens
SKILL.md length: 547 words
Files: 1
Skills in repo: 39
Repo updated: Oct 6, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Independently check whether an implementation matches its stated goal and return PASS/WARN/FAIL with actionable issues.

Works in 5 steps: Understand the Goal → Check Each Artifact → Run the Provided Checks → …
Second-opinion validation of an implementation
SKILL.md covers Input Format (Subagent Mode), Input Format (User Mode), Validation Protocol and What NOT to check, plus 1 more section
Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Impl Validator is an agent skill from Ar9av/obsidian-wiki. Independently check whether an implementation matches its stated goal and return PASS/WARN/FAIL with actionable issues. Use for second-opinion validation of an implementation or generated output.

Its SKILL.md is about 1.2k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Knowledge Management. The repository describes itself as: Framework for AI agents to build and maintain a digital brain through Obsidian wiki | Memory System for Agents. The licence is MIT.

When your agent uses it

Second-opinion validation of an implementation
Generated output

Example prompts

“/impl-validator”

Workflow steps

5 steps, taken from the step headings in SKILL.md.

Understand the Goal
Check Each Artifact
Run the Provided Checks
Produce Verdict
Return to Caller

What it can do on your machine

Read from SKILL.md and the folder at commit 0cc5d90. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md.
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Impl Validator loads about 1.2k tokens when it runs. Until then it costs about 53 tokens; SKILL.md has 547 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~53
When it runs · the whole SKILL.md, loaded when a task matches: ~1.2k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from Ar9av/obsidian-wiki at commit 0cc5d90, republished under its MIT licence (© Ar9av). 547 words, ~1,155 tokens.

Download SKILL.mdSave it as .claude/skills/impl-validator/SKILL.md (or your agent's skills folder).

name: impl-validator
description: Independently check whether an implementation matches its stated goal and return PASS/WARN/FAIL with actionable issues. Use for second-opinion validation of an implementation or generated output.

Implementation Validator — Quality Subagent

You are a critical reviewer. Another skill or agent has just done work and wants you to check it. Your job is to verify that what was produced actually matches what was intended — not to be encouraging, but to catch real problems before the user sees them.

This skill runs in two modes:

Subagent mode — spawned programmatically by another skill passing a structured check: block. Read the block, run the checks, return structured output.
User mode — the user invokes /impl-validator directly, usually with a description of what was just done.

Input Format (Subagent Mode)

When spawned by another skill, you receive a block like:

impl-validator check:
  goal: "<what the implementation was supposed to accomplish>"
  artifacts: [<list of files written, commands run, or text output produced>]
  checks:
    - <specific thing to verify>
    - <specific thing to verify>
    ...

Parse this block and treat each field as your mandate.

Input Format (User Mode)

The user describes what was just done. Infer the goal and artifacts from context. Ask one clarifying question if the goal is ambiguous — do not proceed on a guess for critical checks.

Validation Protocol

Step 1: Understand the Goal

Restate the goal in one sentence. If you can't, the goal is underspecified — flag this as a WARN.

Step 2: Check Each Artifact

For each artifact (file, output, config):

Existence check — does the file/output actually exist? Read it.
Completeness check — does it contain all required sections/fields the goal implies?
Correctness check — does the content logically match the stated goal? Look for:
- Placeholder text left in place (<TODO>, {{variable}}, INSERT HERE)
- Copy-paste errors (wrong tool name, wrong path, stale dates)
- Logical contradictions (e.g. a diff that claims page X is "only in codex" but also lists it under claude)
- Missing required fields (e.g. a SKILL.md missing name: or description: frontmatter)
- Off-by-one or empty-set edge cases (e.g. page count = 0 when vault is known non-empty)
Convention check — does it follow the project's established patterns?
- Skills: has YAML frontmatter with name and description; instructions are in imperative voice; steps are numbered; no placeholder text
- Wiki pages: has all required frontmatter fields (title, category, tags, sources, created, updated)
- Shell scripts: have a shebang line; are chmod +x-able; use set -e
- Plist files: valid XML; Label matches filename; ProgramArguments references a real path

Show full SKILL.md (192 more words)Show less

Step 3: Run the Provided Checks

For each check in the checks: list, evaluate it explicitly. Don't skip. Answer each with:

PASS — verified true
WARN — probably fine but worth noting
FAIL — definitively wrong or missing

Step 4: Produce Verdict

## impl-validator Report

**Goal:** <restated goal>

### Checks
| Check | Result | Note |
|-------|--------|------|
| <check 1> | PASS/WARN/FAIL | <one-line explanation> |
| <check 2> | PASS/WARN/FAIL | <one-line explanation> |
...

### Overall: PASS / WARN / FAIL

**Issues to fix (FAIL):**
- <specific issue with file path and line if applicable>

**Worth noting (WARN):**
- <non-blocking observation>

Overall verdict rules:

Any FAIL → overall FAIL
No FAILs but any WARNs → overall WARN
All PASS → overall PASS

Step 5: Return to Caller

In subagent mode: return the full report as your response. The calling skill reads it and decides whether to fix issues before presenting output to the user.

In user mode: present the report directly. If overall FAIL, offer to fix the issues.

What NOT to check

Style preferences (Oxford comma, variable naming) unless they break a convention
Performance or efficiency — out of scope unless the goal mentions it
Whether the goal itself is a good idea — check implementation against goal, not goal against your opinion
Hypothetical future problems — only flag actual issues in the current artifact

Severity Guide

Severity	Example
FAIL	Required frontmatter field missing; file doesn't exist; check is definitively false
WARN	Hardcoded path that might break on other machines; page count suspiciously low
PASS	Check is verified true

Files

Just SKILL.md in .skills/impl-validator of Ar9av/obsidian-wiki.

Open the folder on GitHubat commit 0cc5d90

Compare with similar skills

Impl Validator next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Impl Validator compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Impl Validator this skillAr9av/obsidian-wiki	3.5k	—	~1.2k	Automated safety check: Pass	MIT	yesterday
Ontology1mancompany/OneManCompany	438	2 repos	~1.5k	Automated safety check: Pass	Apache-2.0	1 mo ago
Open Knowledge Write Skillinkeep/open-knowledge	4.4k	—	~3.7k	Automated safety check: Pass	GPL-3.0	today
Auditpricklywiggles/niamos	192	—	~1.4k	Automated safety check: Pass	None	3 mo ago
Joplinalondmnt/joplin-mcp	172	—	~897	Automated safety check: Pass	MIT	25 days ago
Guideline Writingalfadur7/llm-wiki-newsroom	170	—	~2.4k	Automated safety check: Pass	MIT	2 days ago

Similar skills

Ontology
1mancompany/OneManCompany
Typed knowledge graph for structured agent memory and composable skills.
438 GitHub starsUsed in 2 repos~1.5k tokens
Knowledge ManagementAuto-check passed
Open Knowledge Write Skill
inkeep/open-knowledge
A skill your agent uses when the user wants to create, author, write, or design a new Agent Skill (a SKILL.md) — for OpenKnowledge or for their editors — including requests like 'help me write a…
4.4k GitHub stars~3.7k tokensUpdated today
Knowledge ManagementAuto-check passed
Audit
pricklywiggles/niamos
Scan this Obsidian vault for content that's drifted from the conventions in CLAUDE.md (status↔folder drift, missing required fields, naming violations, stale active items, frontmatter health issues…
192 GitHub stars~1.4k tokensUpdated 3 mo ago
Knowledge ManagementAuto-check passed
Joplin
alondmnt/joplin-mcp
Orchestration guidance for Joplin note, notebook, and tag management tools
172 GitHub stars~897 tokensUpdated 25 days ago
Knowledge ManagementAuto-check passed
Guideline Writing
alfadur7/llm-wiki-newsroom
Guideline-authoring craft for instruction SoTs (.claude/ guides, CLAUDE.md, plan files) — operative rules vs recital, MUST/SHOULD/MAY force tiers, pruning, bloat control, blind review protocol…
170 GitHub stars~2.4k tokensUpdated 2 days ago
Knowledge ManagementAuto-check passed
Brief
Fergana-Labs/stash
Brief the user on what they saved in a period — the thread running through it, not a list.
333 GitHub stars~524 tokensUpdated today
Knowledge ManagementAuto-check passed

Questions about Impl Validator

What does Impl Validator do?

Independently check whether an implementation matches its stated goal and return PASS/WARN/FAIL with actionable issues. Impl Validator is an agent skill from Ar9av/obsidian-wiki. Independently check whether an implementation matches its stated goal and return PASS/WARN/FAIL with actionable issues.

When should I use Impl Validator?

Impl Validator fits situations like: second-opinion validation of an implementation; generated output.

How do I install Impl Validator in Claude Code?

Run `npx skills add Ar9av/obsidian-wiki --skill impl-validator -a claude-code`. Or copy the skill folder (.skills/impl-validator in Ar9av/obsidian-wiki) into .claude/skills/impl-validator in your project. Claude Code loads it when a task matches its description.

How do I install Impl Validator in Codex?

Run `npx skills add Ar9av/obsidian-wiki --skill impl-validator -a codex`. Or copy the skill folder (.skills/impl-validator in Ar9av/obsidian-wiki) into .agents/skills/impl-validator in your project. Codex loads it when a task matches its description.

Can I use Impl Validator in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add Ar9av/obsidian-wiki --skill impl-validator -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/impl-validator, .gemini/skills/impl-validator, .github/skills/impl-validator and .opencode/skills/impl-validator in your project.

What does Impl Validator need to run?

SKILL.md names no scripts, command-line tools or credentials: Impl Validator is instructions for the agent only.

Does Impl Validator access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Impl Validator safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Impl Validator use?

Impl Validator is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Impl Validator use?

About 1.2k tokens (SKILL.md is roughly 4.6k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Impl Validator?

Skills that share tags, products or a category with Impl Validator: Ontology (1mancompany/OneManCompany, 438 stars), Open Knowledge Write Skill (inkeep/open-knowledge, 4.4k stars), Audit (pricklywiggles/niamos, 192 stars) and Joplin (alondmnt/joplin-mcp, 172 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Impl Validator?

Ar9av (a GitHub user) maintains it in Ar9av/obsidian-wiki, which has 3,529 GitHub stars. The repository holds 39 skills in this directory. The repository was last updated on October 6, 2026.

Source: Ar9av/obsidian-wiki on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install Impl Validator

Facts

At a glance

What it does

When your agent uses it

Example prompts

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Implementation Validator — Quality Subagent

Input Format (Subagent Mode)

Input Format (User Mode)

Validation Protocol

Step 1: Understand the Goal

Step 2: Check Each Artifact

Step 3: Run the Provided Checks

Step 4: Produce Verdict

Step 5: Return to Caller

What NOT to check

Severity Guide

Files

Compare with similar skills

Similar skills

More from Ar9av/obsidian-wiki

Related

Questions about Impl Validator