x-harness-admission

x-harness-admission is a skill for Claude Code, Codex from BrianNguyen29/x-harness. It costs 11 tokens per session (1,088 once invoked), scanned A, original, MIT.

A guide for x-harness admission, a file-based check that decides whether an AI coding task has enough evidence to be marked complete.

In plain words
What is it for?
Use it to create, update, or check a repository's completion-card.yaml before claiming a task is finished.
Why use it?
It prevents unsupported completion claims by requiring a valid completion card and reproducible evidence such as changed files and command results.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to create, update, or check a repository's completion-card.yaml before claiming a task is finished.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/briannguyen29/x-harness/x-harness-admission
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add BrianNguyen29/x-harness --skill x-harness-admission
Clone the repo
git clone --depth 1 https://github.com/BrianNguyen29/x-harness

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for x-harness-admission

README.md
[![agentmods](https://agentmods.dev/badge/skills/briannguyen29/x-harness/x-harness-admission/github.svg)](https://agentmods.dev/skills/briannguyen29/x-harness/x-harness-admission)
Your own site
<a href="https://agentmods.dev/skills/briannguyen29/x-harness/x-harness-admission"><img src="https://agentmods.dev/badge/skills/briannguyen29/x-harness/x-harness-admission/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for x-harness-admission

Your own site · 80×15
<a href="https://agentmods.dev/skills/briannguyen29/x-harness/x-harness-admission"><img src="https://agentmods.dev/badge/skills/briannguyen29/x-harness/x-harness-admission.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 11 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,088 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00011 $0.01088
Opus 5 $0.00005 $0.00544
Sonnet 5 $0.00002 $0.00218
Haiku 4.5 $0.00001 $0.00109

Measured 12d ago against content hash 9cae3f476861, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

x-harness-admission scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 12d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/x-harness-admission/SKILL.md · 144 lines

How it starts

The opening of the file, as written. The whole thing — 144 lines — stays where its author put it; the contents beside it link to each section on GitHub.

x-harness-admission

Use this skill when you need to create, update, or verify a completion claim in a repository that uses x-harness.

What x-harness is

x-harness is a Go-native, file-first admission and readiness harness for AI coding workflows.

  • It does not run agents.
  • It does not replace CI.
  • It does not guarantee that code is correct.

It evaluates whether a completion claim is admissible under repository policy and emits one of two decisions: accepted or withheld.

When to create or update completion-card.yaml

Create or update completion-card.yaml at the root of the workspace when you finish a task and are ready to propose completion.

Do this before claiming the task is done.

The card must be written as YAML and must validate against the repository schema at schemas/completion-card.schema.json.

How to record evidence

Evidence must be explicit and reproducible.

  1. Files changed: list every file you created or modified.
  2. Command evidence: record the exact commands you ran, their exit codes, and when they ran.
  3. Manual rationale: only use this when no command evidence is possible (light tier).
  4. State: for standard and deep tiers, declare read_set and write_set.

Do not include:

  • hidden network installations
  • commands that auto-enable external services
  • destructive commands without rollback context

How to run verify / check

Run the local verify gate before proposing completion:

./x-harness verify --card completion-card.yaml --strict

or

./x-harness check --card completion-card.yaml --strict

Both commands are aliases for the same read-only verify pipeline.

Interpreting the result

  • outcome: success and acceptance_status: accepted means the claim is admitted.
  • Any other outcome means the claim is withheld.

If withheld, read the validation errors, fix the issues, and re-run verify.

What accepted means

Accepted means the completion claim meets the repository admission policy:

Read the full file on GitHub · 144 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 12d ago First seen · 144 lines · 11 tokens per session scan A 9cae3f476861

Subscribe to this mod's changes

x-harness-admission is a skill published in the GitHub repository BrianNguyen29/x-harness (14 stars, last pushed 29d ago), licensed MIT. It adds 11 tokens to every session and 1,088 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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