a0-create-plugin

a0-create-plugin is a skill for Claude Code, Codex from Gen-Verse/PAST-Bench. It costs 54 tokens per session (3,577 once invoked), scanned A, original, Apache-2.0.

A development guide for creating and changing Agent Zero plugins, which are extensions that add features to the agent. It covers plugin files, settings, user-interface hooks, and server-side handlers.

In plain words
What is it for?
Use it to build local or community plugins, add interface elements or API handlers, extend the plugin lifecycle, and create plugin settings screens.
Why use it?
It gives developers the required structure and conventions, reducing mistakes when adding extensions or deciding whether a plugin is private or shared.

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/gen-verse/past-bench/a0-create-plugin
Any agent
npx skills add Gen-Verse/PAST-Bench --skill a0-create-plugin
Clone the repo
git clone --depth 1 https://github.com/Gen-Verse/PAST-Bench

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 a0-create-plugin

README.md
[![agentmods](https://agentmods.dev/badge/skills/gen-verse/past-bench/a0-create-plugin.svg)](https://agentmods.dev/skills/gen-verse/past-bench/a0-create-plugin)
Your own site
<a href="https://agentmods.dev/skills/gen-verse/past-bench/a0-create-plugin"><img src="https://agentmods.dev/badge/skills/gen-verse/past-bench/a0-create-plugin.svg" alt="Measured on agentmods" height="20"></a>
Per session 54 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,577 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. 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 $0.00054 $0.03577
Opus 5 $0.00027 $0.01788
Sonnet 5 $0.00011 $0.00715
Haiku 4.5 $0.00005 $0.00358

Measured 4d ago against content hash 27ed9357b771, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

a0-create-plugin scanned grade A with 1 finding 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.

Runs shell commandslowCapability

Expected in a hook, worth knowing in a rule or an instructions file.

result = subprocess.run(
agents/agent-zero/skills/a0-create-plugin/SKILL.md · 378 lines

How it starts

The opening of the file, as written. The whole thing — 378 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Agent Zero Plugin Development

[!IMPORTANT] Always create new plugins in /a0/usr/plugins/<plugin_name>/. The /a0/plugins/ directory is reserved for core system plugins.

Related skills: /a0/skills/a0-review-plugin/SKILL.md | /a0/skills/a0-contribute-plugin/SKILL.md | /a0/skills/a0-manage-plugin/SKILL.md

Primary references:

  • /a0/AGENTS.md (Full-stack architecture & AgentContext)
  • /a0/docs/agents/AGENTS.components.md (Component system deep dive)
  • /a0/docs/agents/AGENTS.modals.md (Modal system & CSS conventions)
  • /a0/docs/agents/AGENTS.plugins.md (Extension points, plugin.yaml, settings system, Plugin Index)
  • /a0/docs/developer/plugins.md (Developer lifecycle and publishing)

Step 0: Ask First — Local or Community Plugin?

Before starting, ask the user one question:

"Should this plugin be local only (stays in your Agent Zero installation) or a community plugin (published to the Plugin Index so others can install it)?"

  • Local plugin: Create it in /a0/usr/plugins/<plugin_name>/. No repository needed. Skip to the manifest section below.
  • Community plugin: The plugin must live in its own GitHub repository (runtime manifest at the repo root), and then a separate index submission PR is made to https://github.com/agent0ai/a0-plugins. Guide the user through both steps.

Plugin Manifest (plugin.yaml)

Every plugin must have a plugin.yaml or it will not be discovered.

name: my_plugin              # required for community plugins; must match dir name (^[a-z0-9_]+$)
title: My Plugin
description: What this plugin does.
version: 1.0.0
settings_sections:
  - agent
per_project_config: false
per_agent_config: false

name: lowercase, numbers, underscores only (^[a-z0-9_]+$). Required by CI when submitting to the Plugin Index - must exactly match the index folder name.

settings_sections controls which Settings tabs show a subsection for this plugin. Valid values: agent, external, mcp, developer, backup. Use [] for no subsection.

Read the full file on GitHub · 378 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 · 378 lines · 54 tokens per session scan A 27ed9357b771

Subscribe to this mod's changes

a0-create-plugin is a skill published in the GitHub repository Gen-Verse/PAST-Bench (24 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 54 tokens to every session and 3,577 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 1 finding (runs shell commands). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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