firebase-auth

firebase-auth is a skill for Claude Code, Codex from GDvega/super-android-kotlin-firebase-skill. It costs 32 tokens per session (581 once invoked), scanned A, original, MIT.

A set of instructions for adding Firebase Authentication, Google's sign-in service, to an application using email, Google accounts, or anonymous sessions.

In plain words
What is it for?
Use it when building sign-up, login, logout, auth-aware screens, profile links, or Firebase rules that restrict data by user.
Why use it?
It provides a consistent structure for login state, user profiles, safe error messages, and authorization checks instead of spreading authentication logic through the interface.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: $skill-name invocation.

Good fit Use it when building sign-up, login, logout, auth-aware screens, profile links, or Firebase rules that restrict data by user.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/gdvega/super-android-kotlin-firebase-skill/firebase-auth
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 GDvega/super-android-kotlin-firebase-skill --skill firebase-auth
Clone the repo
git clone --depth 1 https://github.com/GDvega/super-android-kotlin-firebase-skill

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-auth

README.md
[![agentmods](https://agentmods.dev/badge/skills/gdvega/super-android-kotlin-firebase-skill/firebase-auth/github.svg)](https://agentmods.dev/skills/gdvega/super-android-kotlin-firebase-skill/firebase-auth)
Your own site
<a href="https://agentmods.dev/skills/gdvega/super-android-kotlin-firebase-skill/firebase-auth"><img src="https://agentmods.dev/badge/skills/gdvega/super-android-kotlin-firebase-skill/firebase-auth/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-auth

Your own site · 80×15
<a href="https://agentmods.dev/skills/gdvega/super-android-kotlin-firebase-skill/firebase-auth"><img src="https://agentmods.dev/badge/skills/gdvega/super-android-kotlin-firebase-skill/firebase-auth.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 32 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 581 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 $0.00032 $0.00581
Opus 5 $0.00016 $0.00291
Sonnet 5 $0.00006 $0.00116
Haiku 4.5 $0.00003 $0.00058

Measured 8d ago against content hash c0d97f980a63, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

firebase-auth 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 8d 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/firebase-auth/SKILL.md · 102 lines

How it starts

The opening of the file, as written. The whole thing — 102 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Purpose

Implement authentication without leaking SDK details or weakening authorization.

When to use

  • Adding login, signup or logout.
  • Handling auth state in ViewModel/UI.
  • Linking user profile data.
  • Mapping Firebase Auth errors safely.

Inputs to inspect

  • Required providers and UX flow.
  • Auth state handling.
  • User profile model.
  • Firestore/Storage rules that depend on auth.

Required workflow

  1. Define providers and session UX.
  2. Create or update an AuthRepository boundary.
  3. Expose auth state to ViewModel.
  4. Map errors to user-safe messages.
  5. Add fakes/tests and rule checks.

Rules

  • Do not store passwords or tokens manually.
  • Do not call FirebaseAuth directly from reusable Composables.
  • Never trust UI checks as authorization.
  • Rules must validate request.auth.uid.
  • Keep errors useful but not secret-revealing.

Local skills to invoke

  • firebase-core
  • firestore
  • security-privacy
  • ui-state-design
  • testing

External companion skills to use when installed

Do not assume these companion skills are installed. Prefer the local skills above first, then consult Companion Skills for install and verification commands.

  • firebase/agent-skills — use for deeper Firebase product, Firestore, Security Rules or emulator workflow guidance when installed.

Files commonly touched

  • AuthRepository.kt
  • AuthViewModel.kt
  • login Compose screens
  • firestore.rules
  • storage.rules
  • tests/fakes

Commands to validate

./gradlew test
./gradlew assembleDebug
firebase emulators:exec "npm test"

Common mistakes to avoid

  • Persisting provider tokens.
  • Showing raw Firebase exception internals.
  • Creating profile documents without rules.
  • Ignoring anonymous account upgrade flows.

Checklist

  • AuthRepository boundary exists.
  • Auth state observable.
  • Rules checked.
  • Errors mapped.
  • Tests/fakes added.

Example prompts

  • Use $super-android-kotlin-firebase to add Google Sign-In and email login.
  • Use $super-android-kotlin-firebase to review auth state handling.

Read the full file on GitHub · 102 lines

Files

What ships with it

2 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. 8d ago First seen · 102 lines · 32 tokens per session scan A c0d97f980a63

Subscribe to this mod's changes

firebase-auth is a skill published in the GitHub repository GDvega/super-android-kotlin-firebase-skill (2 stars, last pushed 2mo ago), licensed MIT. It adds 32 tokens to every session and 581 once invoked, about $0.0002 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 2026-08-31.

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