extend

extend is a command for coding agents from nguyenthienthanh/aura-frog. It costs 0 tokens per session (1,170 once invoked), scanned A, original, MIT.

A project command for creating and managing reusable skills, rules, and commands in a project's `.claude/` folder.

In plain words
What is it for?
Use it to propose, create, list, or remove project extensions such as coding rules, reusable skills, and custom commands.
Why use it?
It keeps project-specific agent instructions separate from the add-on itself and guides you through proposing and approving new files before they are written.

Command

Part of the aura-frog plugin — 17 skills, 24 commands, 15 agents, 10 hooks, 6 MCP servers shipped together

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 commands/nguyenthienthanh/aura-frog/extend
Clone the repo
git clone --depth 1 https://github.com/nguyenthienthanh/aura-frog

Or install aura-frog, the plugin that ships this one along with the rest of its 17 skills, 24 commands, 15 agents, 10 hooks, 6 MCP servers.

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 extend

README.md
[![agentmods](https://agentmods.dev/badge/commands/nguyenthienthanh/aura-frog/extend.svg)](https://agentmods.dev/commands/nguyenthienthanh/aura-frog/extend)
Your own site
<a href="https://agentmods.dev/commands/nguyenthienthanh/aura-frog/extend"><img src="https://agentmods.dev/badge/commands/nguyenthienthanh/aura-frog/extend.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,170 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 $0.00000 $0.01170
Opus 5 $0.00000 $0.00585
Sonnet 5 $0.00000 $0.00234
Haiku 4.5 $0.00000 $0.00117

Measured 4d ago against content hash ccf229524fa9, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

extend 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.

aura-frog/commands/extend.md · 84 lines

How it starts

The opening of the file, as written. The whole thing — 84 lines — stays where its author put it; the contents beside it link to each section on GitHub.

/aura-frog:extend

Create project-level skills / rules / commands. Always writes to .claude/ in the user's project — NEVER to the plugin's aura-frog/ folder.


Usage

/aura-frog:extend propose <kind> <description>           # interview-driven skeleton; no write yet
/aura-frog:extend create  <kind> <name>                  # write file from approved skeleton
/aura-frog:extend list                                   # show project extensions
/aura-frog:extend remove <kind> <name>                   # delete a project extension (confirm required)

<kind>skill | rule | command.

Protocol — propose <kind> <description>

  1. Verify project context. Refuse if no .claude/CLAUDE.md exists ("not an Aura Frog project; run /project init first").
  2. Read project context.claude/CLAUDE.md, recent prompts/turns, file tree. Ground the proposal in actual usage.
  3. Draft a skeleton with the right frontmatter for the kind:
    • skill → name, description, when_to_use, autoInvoke (default false), user-invocable: false, allowed-tools, effort
    • rule → priority (Critical/High/Medium), tier (core/agent/workflow), applies_to
    • command → usage block, protocol (imperative), tie-ins
  4. Show the skeleton to the user with the target path printed.
  5. Wait for explicit confirmation. y / yes / looks good / create it advances to step 6. Anything else aborts.
  6. Run /aura-frog:extend create <kind> <name> with the approved skeleton.

Protocol — create <kind> <name>

  1. Resolve target path based on kind:
    • skill → .claude/skills/<name>/SKILL.md
    • rule → .claude/rules/<tier>/<name>.md (tier from frontmatter)
    • command → .claude/commands/<name>.md
  2. Refuse if path collides with aura-frog/ — explicit error: "/aura-frog:extend writes only to .claude/, never to plugin folder".
  3. Refuse if file already exists — suggest propose to draft an update instead.
  4. Create parent directory if missing (.claude/skills/<name>/ etc.).
  5. Write the approved skeleton verbatim.
  6. Run reference integrity audit (per CLAUDE.md "LESSON LEARNED — Reference Integrity Rule"):
    • For new rules: confirm ≥1 inbound reference will exist (or output: "rule created but currently orphaned — wire it from a skill/agent")
    • For new skills: confirm description triggers don't shadow an existing plugin skill
    • For new commands: confirm name doesn't collide with a plugin command
  7. Append .claude/extensions.log (project-local, gitignored by default):
    {"ts":"<ISO>","kind":"skill","name":"<name>","path":"<rel-path>","reason":"<one-line>"}
    
  8. Render the post-create summary: kind, path, audit findings.

Read the full file on GitHub · 84 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 · 84 lines · 0 tokens per session scan A ccf229524fa9

Subscribe to this mod's changes

extend is a command published in the GitHub repository nguyenthienthanh/aura-frog (24 stars, last pushed 10d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,170 tokens. 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.