firestore

firestore is a skill for Claude Code, Codex from GDvega/super-android-kotlin-firebase-skill. It costs 40 tokens per session (633 once invoked), scanned A, original, MIT.

A guide to designing Firebase Firestore collections and Realtime Database paths, queries, indexes, transactions, offline behavior, and access rules.

In plain words
What is it for?
Use it to model data, plan queries and indexes, write Security Rules, design role-based access, add transactions or batch writes, and test permissions with the Firebase emulator.
Why use it?
It connects the database structure to how the application reads and writes data, while addressing permissions, consistency, synchronization, and usage costs. It helps prevent insecure rules and inefficient broad listeners.

Skill for Claude CodeCodex

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

Good fit Use it to model data, plan queries and indexes, write Security Rules, design role-based access, add transactions or batch writes, and test permissions with the Firebase emulator.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/gdvega/super-android-kotlin-firebase-skill/firestore
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 firestore
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 firestore

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

Your own site · 80×15
<a href="https://agentmods.dev/skills/gdvega/super-android-kotlin-firebase-skill/firestore"><img src="https://agentmods.dev/badge/skills/gdvega/super-android-kotlin-firebase-skill/firestore.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 40 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 633 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 $0.00040 $0.00633
Opus 5 $0.00020 $0.00316
Sonnet 5 $0.00008 $0.00127
Haiku 4.5 $0.00004 $0.00063

Measured 9d ago against content hash 67865ddd6791, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

firestore 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 9d 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/firestore/SKILL.md · 105 lines

How it starts

The opening of the file, as written. The whole thing — 105 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Purpose

Design Firebase databases around access patterns, rules, sync and cost.

When to use

  • Modeling Firestore collections or Realtime Database paths.
  • Adding queries, listeners, transactions or batch writes.
  • Writing or auditing Security Rules.
  • Designing caregiver/patient, team, role or ownership access.

Inputs to inspect

  • Entities and access patterns.
  • Readers, writers and roles.
  • Queries, indexes and listener frequency.
  • Current firestore.rules/database.rules.json.
  • Expected data volume and offline needs.

Required workflow

  1. List access patterns before schema.
  2. Choose paths/collections and denormalization intentionally.
  3. Design rules with schema and roles.
  4. Identify indexes and cost-sensitive listeners.
  5. Add repository code and emulator allow/deny tests.

Rules

  • Rules are part of the feature, not an afterthought.
  • Do not trust client-provided owner fields alone.
  • Validate required fields, types and immutable fields.
  • Use transactions for invariants.
  • Mention cost risks for broad listeners.

Local skills to invoke

  • firebase-core
  • firestore-costs-quotas
  • security-privacy
  • firebase-emulator-ci
  • 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

  • firestore.rules
  • database.rules.json
  • indexes config
  • repository/data source files
  • Firebase emulator tests

Commands to validate

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

Common mistakes to avoid

  • Open rules.
  • Queries that rules cannot authorize.
  • Missing indexes.
  • Unbounded realtime listeners.
  • Denormalization without write strategy.

Read the full file on GitHub · 105 lines

Files

What ships with it

4 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. 9d ago First seen · 105 lines · 40 tokens per session scan A 67865ddd6791

Subscribe to this mod's changes

firestore is a skill published in the GitHub repository GDvega/super-android-kotlin-firebase-skill (2 stars, last pushed 2mo ago), licensed MIT. It adds 40 tokens to every session and 633 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.

Related

Other skills, from other repositories

database-hana

Apply SAP HANA database standards for SQL parameterization, in-memory engine optimization, dynamic IN query chunking, column aliasing on joins, and datatype casting. Use when writing SQL for SAP HANA, optimizing HANA queries, or diagnosing HANA driver errors.

HoangNguyen0403/agent-skills-standard · 57 tokens

database-mongodb

Apply MongoDB data-modeling, indexing, and query rules from access patterns. Use when designing schemas, choosing embed vs reference, or tuning MongoDB query behavior.

HoangNguyen0403/agent-skills-standard · 37 tokens

database-postgresql

Apply PostgreSQL standards for migrations, indexing, transactions, and ORM boundaries. Use when editing entities, Prisma schema, migrations, RLS, or query-performance work for PostgreSQL.

HoangNguyen0403/agent-skills-standard · 40 tokens

database-redis

Optimize Redis as cache and coordination infrastructure with TTL, eviction, and latency-aware key design. Use when implementing Redis caching, key invalidation, or Redis performance work.

HoangNguyen0403/agent-skills-standard · 37 tokens

database-migrations

Plan additive, zero-downtime schema migrations with rollout, backfill, and rollback awareness. Use when renaming columns, backfilling data, or shipping risky database changes.

HoangNguyen0403/agent-skills-standard · 40 tokens

database-query-performance

Diagnose database latency with explain plans, index ownership, and query-shape review. Use when a query is slow, an index is missing, or scans and N+1 patterns appear.

HoangNguyen0403/agent-skills-standard · 42 tokens