role-build

role-build is a skill for Claude Code from ryan-scheinberg/harness. It costs 27 tokens per session (654 once invoked), scanned A, original, MIT.

A role for a coding subagent responsible for taking one assigned feature or fix from planning through implementation and verification.

In plain words
What is it for?
Use it to build a coherent change directly with test-driven development, or split a larger change into separate pieces for other subagents.
Why use it?
It gives the subagent a repeatable way to understand the project, choose a sensible implementation approach, and prove the work is complete.

Skill for Claude Code

Written for Claude Code: disable-model-invocation in frontmatter. Also seen: mentions subagents; mentions AGENTS.md; $skill-name invocation.

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.

agentmods
npx agentmods add skills/ryan-scheinberg/harness/role-build
Any agent
npx skills add ryan-scheinberg/harness --skill role-build
Clone the repo
git clone --depth 1 https://github.com/ryan-scheinberg/harness

Made for: Claude Code.

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 role-build

README.md
[![agentmods](https://agentmods.dev/badge/skills/ryan-scheinberg/harness/role-build.svg)](https://agentmods.dev/skills/ryan-scheinberg/harness/role-build)
Your own site
<a href="https://agentmods.dev/skills/ryan-scheinberg/harness/role-build"><img src="https://agentmods.dev/badge/skills/ryan-scheinberg/harness/role-build.svg" alt="Measured on agentmods" height="20"></a>
Per session 27 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 654 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00027 $0.00654
Opus 5 $0.00014 $0.00327
Sonnet 5 $0.00005 $0.00131
Haiku 4.5 $0.00003 $0.00065

Measured 5d ago against content hash 2f3a4175061a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

role-build 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 5d 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.

codex/roles/role-build/SKILL.md · 29 lines

How it starts

The opening of the file, as written. The whole thing — 29 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a build subagent. Root handed you one unit of work — a feature, a fix, a slice of a project — to take from directive to shipped on your own worktree. You won't get to ask Root mid-build, so architect it yourself, build it, prove it works, and return what you did

Order of work

  1. Orient. Read AGENTS.md and README.md in the workdir before touching code. Your change should feel native — same seams, style, and test patterns as what's there
  2. Architect. Scope the unit with define-project — commit the decisions, pick the simplest sound design, don't overengineer. Skip iterate-plan: you can't grill the user, so decide, and put genuine uncertainty in your return for Root rather than guessing past it
  3. Choose how to build — the judgment call:
    • Slice and delegate when the unit is large or splits cleanly: plan-to-slices into SLICES.md, then spawn a subagent per slice, each running complete-slice, and fold the finished slices back into yours. Parallel where independent, ordered where dependent
    • Build it directly when the unit is one coherent piece: run complete-slice yourself — TDD, red → green → refactor
  4. Verify it's fully built. Spawn a subagent with $role-verify — independent eyes, so make it prove what was asked is all there: trace the code through the hard cases, run the unit and integration tests, confirm every acceptance point. Verify in the code; don't stand up a whole environment to do it — that's the waste, and exercising the assembled running system is QA's pass. The project's AGENTS.md says what verifying a unit takes here
  5. Document for the agents who come next with updating-ai-knowledge, usually AGENTS.md
  6. Clean up any extra docs you created like PROJECT_BRIEF.md. Parts probably belong in actual project docs.
  7. Commit, then return. Root merges your branch — uncommitted work doesn't exist. Return what shipped, what you verified, and any genuine open question. Your final message is the report to Root

Read the full file on GitHub · 29 lines

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. 5d ago First seen · 29 lines · 27 tokens per session scan A 2f3a4175061a

Subscribe to this mod's changes

role-build is a skill published in the GitHub repository ryan-scheinberg/harness (2 stars, last pushed 1mo ago), licensed MIT. It adds 27 tokens to every session and 654 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 2026-08-31.

Related

Other skills, from other repositories

gleanin

Rules distilled from past session friction (errors, edit loops, corrections), analyzed by a stronger model and applied to guide future work. Regenerated from glean/artifacts/ plus an index of trigger-loaded protocols from GLEANPROTOCOLDIRS by sync.sh — load every session via CLAUDE.md.

pcx-wave/glean · 62 tokens

exploratory-data-analysis

Perform bounded, local exploratory analysis of explicitly supported scientific files. Use for redacted CSV/TSV/JSON profiles; optional NumPy, HDF5, FASTA/FASTQ, and basic image metadata inspection; missingness/leakage audits; outlier and transformation sensitivity; and rigorous EDA report scaffolds. Other domain…

K-Dense-AI/scientific-agent-skills · 83 tokens

golden-rss

Use when testing the rss golden build.

yusufkaraaslan/Skill_Seekers · 12 tokens

data-charts-tako

Search and visualize the world's data - get charts, insights, and embeddable knowledge cards for finance, economics, demographics, sports, and more.

gooseworks-ai/goose-skills · 35 tokens

google-ads-audit

Google Ads account audit and business context setup. Run this first — it gathers business information, analyzes account health, and saves context that all other ads skills reuse. Trigger on "audit my ads", "ads audit", "set up my ads", "onboard", "account overview", "how's my account", "ads health check", "what should…

nowork-studio/notfair-plugin · 114 tokens

webhook-management

Configure and validate CCAM webhook targets across supported chat, incident, automation, and generic providers. Use when listing provider requirements, creating or updating a target, scoping it to alert rules, sending a test notification, reviewing delivery history, or deleting a target.

hoangsonww/Claude-Code-Agent-Monitor · 56 tokens