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 agentmods add skills/appsvortex/arness/arn-code-execute-plannpx skills add AppsVortex/arness --skill arn-code-execute-plangit clone --depth 1 https://github.com/AppsVortex/arnessWhat 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 | $0.00134 | $0.02967 |
| Opus 5 | $0.00067 | $0.01484 |
| Sonnet 5 | $0.00027 | $0.00593 |
| Haiku 4.5 | $0.00013 | $0.00297 |
Grade A, and why
arn-code-execute-plan 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 2d 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 — 189 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Arness Execute Plan
Execute a structured project plan by dispatching parallel batches of arn-code-task-executor agents and validating each completed task through a arn-code-task-reviewer agent before marking it done. Independent tasks run concurrently; dependent tasks wait for their blockers to clear. Each task goes through an execute-review-gate cycle: the executor implements and tests, the reviewer validates against patterns and acceptance criteria, and the orchestrator (this skill) decides whether to pass, retry, or escalate.
Key architectural constraint: Subagents cannot spawn other subagents. The dispatch loop MUST stay in the main session (this skill).
Pipeline position:
arn-code-init -> arn-code-feature-spec / arn-code-bug-spec -> arn-code-plan -> arn-code-save-plan -> arn-code-review-plan -> arn-code-taskify -> **arn-code-execute-plan** (dispatch -> execute -> review -> gate) -> arn-code-review-implementation -> arn-code-document-project -> arn-code-ship
Prerequisites
If no ## Arness section exists in the project's CLAUDE.md, inform the user: "Arness is not configured for this project yet. Run /arn-implementing to get started — it will set everything up automatically." Do not proceed without it.
Workflow
Step 1: Load Configuration
-
Read the project's CLAUDE.md and extract the
## Arnesssection to find:- Plans directory -- base path where project plans are saved
- Code patterns -- path to the directory containing stored pattern documentation
- Template path -- path to the report template set (JSON templates)
- Template version -- plugin version the templates were copied from (if present)
- Template updates -- user preference:
ask,auto, ormanual(if present) - Specs directory -- path to the directory containing specification files (if present)
Template version check: If
Template versionandTemplate updatesfields are present, run the template version check procedure documented in arn-code-save-plan Step 1 (Template Version Check) before proceeding. If## Arnessdoes not contain these fields, treat as legacy and skip.
What ships with it
2 files 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.
- 2d ago First seen · 189 lines · 134 tokens per session scan A 28dc8924ed6e
arn-code-execute-plan is a skill published in the GitHub repository AppsVortex/arness (33 stars, last pushed 1mo ago), licensed MIT. It adds 134 tokens to every session and 2,967 once invoked, about $0.0007 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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