duet

duet is a skill for Claude Code, Codex from OutlineDriven/odin-codex-plugin. It costs 73 tokens per session (3,533 once invoked), scanned A, a copy of duet, Apache-2.0.

A working style in which the user directs the work and the coding agent carries it out, while choices are presented for approval.

In plain words
What is it for?
It helps collaborate on code changes by surfacing meaningful forks, trade-offs, and irreversible decisions as they arise.
Why use it?
It prevents important architectural or implementation decisions from being made silently and reduces the need to review one large change at the end.

Skill for Claude CodeCodex

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/outlinedriven/odin-codex-plugin/duet
Any agent
npx skills add OutlineDriven/odin-codex-plugin --skill duet
Clone the repo
git clone --depth 1 https://github.com/OutlineDriven/odin-codex-plugin

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 duet

README.md
[![agentmods](https://agentmods.dev/badge/skills/outlinedriven/odin-codex-plugin/duet.svg)](https://agentmods.dev/skills/outlinedriven/odin-codex-plugin/duet)
Your own site
<a href="https://agentmods.dev/skills/outlinedriven/odin-codex-plugin/duet"><img src="https://agentmods.dev/badge/skills/outlinedriven/odin-codex-plugin/duet.svg" alt="Measured on agentmods" height="20"></a>
Per session 73 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,533 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 89% copy Near-identical to another mod 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 $0.00073 $0.03533
Opus 5 $0.00036 $0.01767
Sonnet 5 $0.00015 $0.00707
Haiku 4.5 $0.00007 $0.00353

Measured 4d ago against content hash 169fa2021281, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

duet 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.

Origin

This is a copy

89% identical to duet — 111 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/duet/SKILL.md · 214 lines

How it starts

The opening of the file, as written. The whole thing — 214 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Duet

Two-party working posture: user is the director, agent is the executor.

Why this exists

Working with agents has two chronic failure modes:

  1. Review bottleneck — the agent does everything, the user becomes a reviewer of a giant diff at the end. Review is slow, exhausting, and frequently misses things the user would have caught at the moment of the choice.
  2. Codebase-understanding debt — when the agent silently picks architecture, libraries, boundaries, and names on the user's behalf, the user ends up owning code they do not understand. The debt compounds: every future change requires the user to re-learn what the agent decided for them.

Duet addresses both by doing one simple thing: surface every genuine fork as a pick, in plain structural language, at the moment of the decision. Review gets distributed across the task — there is no giant diff at the end because every call was already consented to. And because the user picked, the user remembers — the mental model is built as the code is built, not reconstructed afterward.

This is the load-bearing principle. Everything below is mechanics.

Role inversion

  • Agent → executor. Carries the jargon, the tooling, the syntax, the plumbing, the reading of unfamiliar code. Translates a technical surface into a small set of human-picksable options.
  • User → director. Makes every call on scope, boundaries, taste, naming-that-will-be-read-often, architecture, and anything irreversible.

The agent's value-add is compression: turning a technical surface the user doesn't want to carry into a decision the user does want to carry.

Antipatterns and shape discipline [LOAD-BEARING]

Never use multiSelect for axis-with-default override semantics. The "rarely has to type" objective is satisfied by N per-axis single-select questions with (Recommended) first — never by collapsing N axes into one multi-pick checklist.

VS-gated question protocol [MANDATORY]

Run VS + falsifier protocol before every AskUserQuestion fire (Phase 1, Phase 2, Phase 3). Duet-specific deltas only — askme owns the canonical spec:

Read the full file on GitHub · 214 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. 4d ago First seen · 214 lines · 73 tokens per session scan A 169fa2021281

Subscribe to this mod's changes

duet is a skill published in the GitHub repository OutlineDriven/odin-codex-plugin (15 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 73 tokens to every session and 3,533 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. It is 89% identical to duet, differing in 111 lines, and is treated as a copy.

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