access-control

access-control is a skill for Claude Code, Codex from PurpleAILAB/Decepticon. It costs 26 tokens per session (1,720 once invoked), scanned A, original, Apache-2.0.

A smart-contract security playbook for finding missing or incorrect authorization checks on functions that change blockchain state.

In plain words
What is it for?
It is for reviewing public and external functions, access modifiers such as onlyOwner or onlyRole, sender checks, trusted forwarders, and role administration.
Why use it?
It helps detect functions that anyone can call even though they can change ownership, configuration, balances, or other protected data.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit It is for reviewing public and external functions, access modifiers such as onlyOwner or onlyRole, sender checks, trusted forwarders, and role administration.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/purpleailab/decepticon/access-control
About the project

Decepticon is an autonomous red-team agent that coordinates AI agents, security tools, sandboxes, and supporting services for authorized cybersecurity assessments. Security researchers and red teams can run it through its Docker stack, cloud service, command-line interface, or Python SDK, with the catalogue entries representing its available skills.

PurpleAILAB/Decepticon · 5,471 stars · on GitHub · decepticon.red

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.

Any agent
npx skills add PurpleAILAB/Decepticon --skill access-control
Clone the repo
git clone --depth 1 https://github.com/PurpleAILAB/Decepticon

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 access-control

README.md
[![agentmods](https://agentmods.dev/badge/skills/purpleailab/decepticon/access-control/github.svg)](https://agentmods.dev/skills/purpleailab/decepticon/access-control)
Your own site
<a href="https://agentmods.dev/skills/purpleailab/decepticon/access-control"><img src="https://agentmods.dev/badge/skills/purpleailab/decepticon/access-control/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.

agentmods 80×15 button for access-control

Your own site · 80×15
<a href="https://agentmods.dev/skills/purpleailab/decepticon/access-control"><img src="https://agentmods.dev/badge/skills/purpleailab/decepticon/access-control.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 26 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,720 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 5.1 $0.00026 $0.01720
Opus 5 $0.00013 $0.00860
Sonnet 5 $0.00005 $0.00344
Haiku 4.5 $0.00003 $0.00172

Measured 6d ago against content hash 007c0470c7c5, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

access-control 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 6d 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

Copies of this mod

1 near-identical copy found in the catalogue:

packages/decepticon/decepticon/skills/standard/contracts/access-control/SKILL.md · 204 lines

How it starts

The opening of the file, as written. The whole thing — 204 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Access Control Playbook

Access control bugs are the most boring class — and the most common in production audits. They're cheap to find with grep + LSP. They drain millions when missed (LeetSwap, Audius, Saddle, Akropolis).

Audit steps

1. Find every state-changing function

# Functions that are NOT view/pure and NOT internal/private
grep -rE 'function [a-zA-Z_]+\(.*\)(public|external)' src/ | grep -v 'view\|pure'

# Or via slither
slither . --print function-summary

2. For each external/public state-changer, ask

  • Does it modify storage that affects user funds, ownership, or configuration?
  • Is there a modifier (onlyOwner, onlyRole, onlyDAO, custom auth)?
  • If yes, what's the modifier checking?
  • If no, should there be one?

3. Audit each modifier

Common modifier patterns + bugs:

Pattern Bug
require(msg.sender == owner) owner settable by anyone? setOwner unprotected?
require(msg.sender == tx.origin) Wrong — tx.origin breaks meta-transactions, AND it's phishable
_msgSender() in OZ ERC2771Context Forwarder trusted but anyone can forward — does the contract validate the forwarder?
onlyRole(MINTER) Who can grant MINTER? Is the admin a multisig or single key?
require(initialized == false) Initializer can be called twice if initialized writeable elsewhere
require(block.timestamp > deployTime + 24 hours) Time-based is often a fake delay — check if deployTime is settable
require(approvedSigners[msg.sender]) Approval list managed by single key?

4. Specific anti-patterns to grep

# Functions accidentally external (default in Solidity <0.5)
grep -rn 'function [a-zA-Z_]*[^ ]* *{' src/ | grep -v 'internal\|private\|public\|external'

# msg.sender == tx.origin (phishable)
grep -rn 'tx.origin' src/

# Reentrancy in access-control checks
grep -rn 'onlyOwner.*nonReentrant' src/   # both? often wrong order

# `delegatecall` without auth gate
grep -rn 'delegatecall' src/

# `selfdestruct` available
grep -rn 'selfdestruct\|suicide(' src/

Read the full file on GitHub · 204 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. 6d ago First seen · 204 lines · 26 tokens per session scan A 007c0470c7c5

Subscribe to this mod's changes

access-control is a skill published in the GitHub repository PurpleAILAB/Decepticon (5,471 stars, last pushed 10d ago), licensed Apache-2.0. It adds 26 tokens to every session and 1,720 once invoked, about $0.0001 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.