firebase

firebase is a skill for Claude Code, Codex from j4flmao/agent-skills. It costs 91 tokens per session (5,228 once invoked), scanned A, original, MIT.

A guide for designing applications with Firebase, Google's platform for databases, user sign-in, file storage, server-side functions, and web hosting.

In plain words
What is it for?
It helps design Firestore collections, authentication providers, Cloud Functions, Storage rules, Hosting settings, and Firebase project architecture.
Why use it?
It brings the main Firebase decisions together, including data structure, security rules, authentication, and serverless operations.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions Codex.

Good fit It helps design Firestore collections, authentication providers, Cloud Functions, Storage rules, Hosting settings, and Firebase project architecture.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/j4flmao/agent-skills/firebase
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 j4flmao/agent-skills --skill firebase
Clone the repo
git clone --depth 1 https://github.com/j4flmao/agent-skills

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

README.md
[![agentmods](https://agentmods.dev/badge/skills/j4flmao/agent-skills/firebase/github.svg)](https://agentmods.dev/skills/j4flmao/agent-skills/firebase)
Your own site
<a href="https://agentmods.dev/skills/j4flmao/agent-skills/firebase"><img src="https://agentmods.dev/badge/skills/j4flmao/agent-skills/firebase/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 firebase

Your own site · 80×15
<a href="https://agentmods.dev/skills/j4flmao/agent-skills/firebase"><img src="https://agentmods.dev/badge/skills/j4flmao/agent-skills/firebase.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 91 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,228 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 $0.00091 $0.05228
Opus 5 $0.00046 $0.02614
Sonnet 5 $0.00018 $0.01046
Haiku 4.5 $0.00009 $0.00523

Measured 6d ago against content hash e6cdf0212e2d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

firebase 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.

skills/backend/universal/firebase/SKILL.md · 597 lines

How it starts

The opening of the file, as written. The whole thing — 597 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Firebase

Purpose

Architect serverless backends on Firebase — Firestore document modeling, Authentication providers, Cloud Functions triggers, Storage security, Hosting configuration, and operational best practices.

Agent Protocol

Trigger

User request includes: Firebase, Firestore, Firebase Auth, Cloud Functions, Firebase Storage, Firebase Hosting, security rules, Firebase Admin, Firebase Extensions, Firebase App Check, Firebase Remote Config, Firebase emulator, Firebase cost.

Input Context

  • All Firebase capabilities needed (DB, auth, storage, functions, hosting)
  • Target platforms (web, iOS, Android, Node.js admin)
  • Estimated user/request scale
  • Auth providers (email, Google, Apple, custom)

Output Artifact

Firebase project architecture, security rules, data model, function triggers, hosting config.

Response Format

Produce artifact directly. No preamble, no postamble, no explanations. No filler, no hedging, no transitions. Strip articles a/an/the where unambiguous. Compress output — why use many token when few do trick.

Completion Criteria

  • Firestore data model designed (collections, documents, indexes, subcollections)
  • Security rules defined (read/write/validate per collection)
  • Auth providers configured (web + mobile SDK setup)
  • Cloud Functions triggers mapped (onCreate, onUpdate, onDelete, onRequest, scheduled)
  • Storage security rules + Hosting config (rewrites, headers, redirects)
  • Cost optimization plan (read/write counts, indexes, function timeout/memory)

Max Response Length

4096 tokens

Decision Tree

Firestore vs Realtime Database?

What data access pattern do you need?
  ├── Complex queries, filtering, sorting, transactions
  │   └── Firestore — rich querying, multi-collection, auto-scaling
  ├── Low-latency real-time sync, simple key-value data
  │   └── Realtime Database — lower latency, simpler pricing (bandwidth), WebSocket-native
  └── I need both
      └── Use Firestore for structured data, RTDB for presence/live cursors

Read the full file on GitHub · 597 lines

Files

What ships with it

6 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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 · 597 lines · 91 tokens per session scan A e6cdf0212e2d

Subscribe to this mod's changes

firebase is a skill published in the GitHub repository j4flmao/agent-skills (22 stars, last pushed 3d ago), licensed MIT. It adds 91 tokens to every session and 5,228 once invoked, about $0.0005 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.

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