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.
npx skills add Jamie-BitFlight/claude_skills --skill development-harnessgit clone --depth 1 https://github.com/Jamie-BitFlight/claude_skillsWrote 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.
[](https://agentmods.dev/skills/jamie-bitflight/claude_skills/development-harness)<a href="https://agentmods.dev/skills/jamie-bitflight/claude_skills/development-harness"><img src="https://agentmods.dev/badge/skills/jamie-bitflight/claude_skills/development-harness/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.
<a href="https://agentmods.dev/skills/jamie-bitflight/claude_skills/development-harness"><img src="https://agentmods.dev/badge/skills/jamie-bitflight/claude_skills/development-harness.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Excessive Agency · line 4 Skill selects an external model or provider that may use a different account or billing plan than the operator expects. Undisclosed model switches can cause unexpected cost or quota consumption.Fix: Remove the model/provider override or disclose it prominently and require explicit operator approval before invoking an external coding CLI or billed model.
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00056 | $0.01467 |
| Opus 5 | $0.00028 | $0.00733 |
| Sonnet 5 | $0.00011 | $0.00293 |
| Haiku 4.5 | $0.00006 | $0.00147 |
Grade A, and why
development-harness 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 4d 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.
How it starts
The opening of the file, as written. The whole thing — 95 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Development Harness — Plugin Overview and Skill Router
This skill routes to the correct entry point for the development lifecycle. Read it to decide which skill to invoke — not to execute work.
SAM Workflow Pipeline
/dh:add-new-feature ──> /dh:implement-feature ──> /dh:complete-implementation
(planning) (execution loop) (quality gates)
What This Plugin Provides
The development-harness plugin implements the structured development lifecycle for tracked backlog items. It spans capture through verified closure using a chain of skills backed by the configured backlog backend provider as the source of truth and ~/.dh/projects/{slug}/ as the local state directory. The repository's default configuration currently selects GitHub Issues.
Skills available: /dh:create-backlog-item, /dh:groom-backlog-item, /dh:work-backlog-item, /dh:add-new-feature, /dh:implement-feature, /dh:complete-implementation, /dh:gate-push, /dh:work-milestone
Plugin-level source copies exist at plugins/development-harness/skills/ for each skill.
Skill Router — "I want to do X"
flowchart TD
Start([What do you want to do?]) --> Q1{Intent?}
Q1 -->|Capture new work —<br>bug, feature idea, observation| Create["/dh:create-backlog-item<br>Modes: guided intake, quick title, --auto title<br>Writes to ~/.dh/projects/{slug}/backlog/"]
Q1 -->|Prepare an item for planning —<br>verify claims, map impact, estimate effort| Groom["/dh:groom-backlog-item {title|section|all}<br>RT-ICA + parallel swarm: fact-checker,<br>impact-analyst, rtica-assessor, classifier, groomer<br>Requires: item exists in backlog"]
Q1 -->|Plan AND execute a backlog item<br>end-to-end through closure| Work["/dh:work-backlog-item {title|#N|--auto}<br>Handles: auto-groom, RT-ICA gate, SAM planning,<br>GitHub sync, close, resolve<br>STOPS if item already has a Plan field"]
Q1 -->|Plan a feature — produce SAM artifacts<br>without executing| Plan["/dh:add-new-feature {feature description}<br>Phases: discovery → codebase analysis →<br>architecture spec → task decomposition →<br>validation → context manifest<br>Output: feature slug + P{id} task plan"]
Q1 -->|Execute an existing plan —<br>task plan already produced| Execute["/dh:implement-feature {plan path or slug}<br>Loops ready tasks, dispatches agents,<br>calls complete-implementation when all tasks COMPLETE"]
Q1 -->|Work a single specific task<br>inside an existing plan| Single["/dh:start-task {plan path} --task {task-id}<br>Used by implement-feature per-task dispatch —<br>invoke directly to target one task"]
Q1 -->|Run quality gates after<br>all tasks are COMPLETE| QG["/dh:complete-implementation {plan path|#N}<br>7-phase SAM path (with plan) or<br>3-phase proportional path (issue only):<br>multi-perspective review → code review →<br>verification → integration →<br>doc drift → doc update → context refinement"]
Q1 -->|Work a full milestone<br>in parallel isolated worktrees| Milestone["/dh:work-milestone<br>Wave-based parallel execution — each item<br>gets its own worktree. Use /dh:groom-milestone first."]
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.
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.
- 4d ago First seen · 95 lines · 56 tokens per session scan A 809f02c99b0a
development-harness is a skill published in the GitHub repository Jamie-BitFlight/claude_skills (66 stars, last pushed yesterday), licensed MIT. It adds 56 tokens to every session and 1,467 once invoked, about $0.0003 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 2026-09-03.
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