platform: Skill for Claude Code

.agents/skills/firebase-security-rules-auditor/SKILL.md

firebase-security-rules-auditor is a skill for Claude Code, Codex from tutur3u/platform. It costs 21 tokens per session (807 once invoked), scanned A, original, Apache-2.0.

A security-audit guide for Firestore security rules, which control who can read and change data in Firebase's cloud database. It reviews rules from an attacker's perspective.

In plain words
What is it for?
Auditing Firestore create and update rules, checking ownership and administrator fields, testing bypasses, and evaluating whether the application's intended users can access the right data.
Why use it?
It helps uncover permission gaps that may be hidden in complicated rules, such as creating valid data and later updating it into an unsafe state. It also checks whether the rules match the application's real sharing needs.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: installed under .agents/ (shared by several agents).

This is tutur3u/platform's own configuration. It tells Claude Code and Codex how to work on platform itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything platform configures →

Reuse

Borrowing it

Nothing to install: this file belongs to tutur3u/platform. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/tutur3u/platform/main/.agents/skills/firebase-security-rules-auditor/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/tutur3u/platform

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 firebase-security-rules-auditor

README.md
[![agentmods](https://agentmods.dev/badge/skills/tutur3u/platform/firebase-security-rules-auditor.svg)](https://agentmods.dev/skills/tutur3u/platform/firebase-security-rules-auditor)
Your own site
<a href="https://agentmods.dev/skills/tutur3u/platform/firebase-security-rules-auditor"><img src="https://agentmods.dev/badge/skills/tutur3u/platform/firebase-security-rules-auditor.svg" alt="Measured on agentmods" height="20"></a>
Per session 21 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 807 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.
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 $0.00021 $0.00807
Opus 5 $0.00010 $0.00404
Sonnet 5 $0.00004 $0.00161
Haiku 4.5 $0.00002 $0.00081

Measured yesterday against content hash 44ee76d3b54d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

firebase-security-rules-auditor 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 yesterday.

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.

.agents/skills/firebase-security-rules-auditor/SKILL.md · 71 lines

How it starts

The opening of the file, as written. The whole thing — 71 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Overview

This skill acts as an auditor for Firebase Security Rules, evaluating them against a rigorous set of criteria to ensure they are secure, robust, and correctly implemented.

Scoring Criteria

Assessment: Security Validator (Red Team Edition)

You are a Senior Security Auditor and Penetration Tester specializing in Firestore. Your goal is to find "the hole in the wall." Do not assume a rule is secure because it looks complex; instead, actively try to find a sequence of operations to bypass it.

Mandatory Audit Checklist:

  1. The Update Bypass: Compare 'create' and 'update' rules. Can a user create a valid document and then 'update' it into an invalid or malicious state (e.g., changing their role, bypassing size limits, or corrupting data types)?
  2. Authority Source: Does the security rely on user-provided data (request.resource.data) for sensitive fields like 'role', 'isAdmin', or 'ownerId'? Carefully consider the source for that authority.
  3. Business Logic vs. Rules: Does the rule set actually support the app's purpose? (e.g., In a collaboration app, can collaborators actually read the data? If not, the rules are "broken" or will force insecure workarounds).
  4. Storage Abuse: Are there string length or array size limits? If not, label it as a "Resource Exhaustion/DoS" risk.
  5. Type Safety: Are fields checked with 'is string', 'is int', or 'is timestamp'?
  6. Field-Level vs. Identity-Level Security: Be careful with rules that use `hasOnly()` or `diff()`. While these restrict which fields can be updated, they do NOT restrict who can update them unless an ownership check (e.g., `resource.data.uid == request.auth.uid`) is also present. If a rule allows any authenticated user to update fields on another user's document without a corresponding ownership check, it is a data integrity vulnerability.

Admin Bootstrapping & Privileges:

The admin bootstrapping process is limited in this app. If the rules use a single hardcoded admin email (e.g., checking request.auth.token.email == '[email protected]'), this should NOT count against the score as long as:

Read the full file on GitHub · 71 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. yesterday Changed · -20 tokens per session 44ee76d3b54d
  2. 7d ago First seen · 71 lines · 41 tokens per session scan A 41ce481ad48b

Subscribe to this mod's changes

firebase-security-rules-auditor is a skill published in the GitHub repository tutur3u/platform (53 stars, last pushed yesterday), licensed Apache-2.0. It adds 21 tokens to every session and 807 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 2026-08-30.

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