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.
npx agentmods add skills/bestagentkits/ck-skills/databasesnpx skills add bestagentkits/ck-skills --skill databasesgit clone --depth 1 https://github.com/bestagentkits/ck-skillsWrote 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.
[](https://agentmods.dev/skills/bestagentkits/ck-skills/databases)<a href="https://agentmods.dev/skills/bestagentkits/ck-skills/databases"><img src="https://agentmods.dev/badge/skills/bestagentkits/ck-skills/databases.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00044 | $0.00832 |
| Opus 5 | $0.00022 | $0.00416 |
| Sonnet 5 | $0.00009 | $0.00166 |
| Haiku 4.5 | $0.00004 | $0.00083 |
Grade A, and why
ck:databases 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 5d 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.
This is a copy
95% identical to ck:databases — 5 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 88 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Databases Skill
Unified guide for working with MongoDB (document-oriented) and PostgreSQL (relational) databases. Choose the right database for your use case and master both systems.
When to Use This Skill
Use when:
- Designing database schemas and data models
- Writing queries (SQL or MongoDB query language)
- Building aggregation pipelines or complex joins
- Optimizing indexes and query performance
- Implementing database migrations
- Setting up replication, sharding, or clustering
- Configuring backups and disaster recovery
- Managing database users and permissions
- Analyzing slow queries and performance issues
- Administering production database deployments
Reference Navigation
Database Design
- db-design.md - Activate when user requests: Database/table design for transactional (OLTP), analytics (OLAP), create or extend schema, design fact/dimension tables, analyze/review CSV/JSON/SQL files to create tables, or need advice on data storage structure.
MongoDB References
- mongodb-crud.md - CRUD operations, query operators, atomic updates
- mongodb-aggregation.md - Aggregation pipeline, stages, operators, patterns
- mongodb-indexing.md - Index types, compound indexes, performance optimization
- mongodb-atlas.md - Atlas cloud setup, clusters, monitoring, search
PostgreSQL References
- postgresql-queries.md - SELECT, JOINs, subqueries, CTEs, window functions
- postgresql-psql-cli.md - psql commands, meta-commands, scripting
- postgresql-performance.md - EXPLAIN, query optimization, vacuum, indexes
- postgresql-administration.md - User management, backups, replication, maintenance
Python Utilities
What ships with it
27 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.
- analytics.md 5.3 KB
- db-design.md 6.3 KB
- incremental-etl.md 5.4 KB
- references/mongodb-aggregation.md 9.1 KB
- references/mongodb-atlas.md 9.1 KB
- references/mongodb-crud.md 8.2 KB
- references/mongodb-indexing.md 10 KB
- references/postgresql-administration.md 12 KB
- references/postgresql-performance.md 11 KB
- references/postgresql-psql-cli.md 10 KB
- references/postgresql-queries.md 9.9 KB
- scripts/.coverage 52 KB
- scripts/db_backup.py 16 KB runs code
- scripts/db_migrate.py 14 KB runs code
- scripts/db_performance_check.py 16 KB runs code
- scripts/requirements.txt 558 B
- scripts/tests/coverage-db.json 46 KB
- scripts/tests/requirements.txt 69 B
- scripts/tests/test_db_backup.py 11 KB runs code
- scripts/tests/test_db_migrate.py 9.3 KB runs code
- scripts/tests/test_db_performance_check.py 12 KB runs code
- stacks/bigquery.md 5.1 KB
- stacks/d1_cloudflare.md 3.4 KB
- stacks/mysql.md 5.5 KB
- stacks/postgres.md 5.8 KB
- stacks/sqlite.md 6.4 KB
- transactional.md 4.7 KB
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.
- 5d ago First seen · 88 lines · 44 tokens per session scan A a9f7d06eca62
ck:databases is a skill published in the GitHub repository bestagentkits/ck-skills (6 stars, last pushed 3mo ago), licensed MIT. It adds 44 tokens to every session and 832 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 95% identical to ck:databases, differing in 5 lines, and is treated as a copy.
Other skills, from other repositories
database-migrator
Migrates databases between providers (Postgres, MySQL, Supabase, PlanetScale, MongoDB). Reads source schema, generates migration scripts, handles data type mapping, foreign keys, indexes, triggers, stored procedures. Validates migration with row counts and checksums. Generates migration-plan.md with step-by-step…
database-schema-designer
Design optimized database schemas for SQL and NoSQL databases including tables, relationships, indexes, and constraints. Creates ERD diagrams, migration scripts, and data modeling best practices. Use when users need database design, schema optimization, or data architecture planning.
db-whisperer
Diagnoses and improves application-layer databases: Postgres, MySQL, SQLite, and MongoDB. Covers EXPLAIN ANALYZE, slow query detection, index strategy, N+1 detection, schema migrations with up/down scripts, connection pooling, replication setup, and vacuum/analyze operations. Use this skill when the user says "this…
prisma-database-setup
Guides for configuring Prisma with different database providers (PostgreSQL, MySQL, SQLite, MongoDB, etc.). Use when setting up a new project, changing databases, or troubleshooting connection issues. Triggers on "configure postgres", "connect to mysql", "setup mongodb", "sqlite setup".
database-optimizer
Optimizes database queries and improves performance across PostgreSQL and MySQL systems. Use when investigating slow queries, analyzing execution plans, or optimizing database performance. Invoke for index design, query rewrites, configuration tuning, partitioning strategies, lock contention resolution.
postgres-pro
Use when optimizing PostgreSQL queries, configuring replication, or implementing advanced database features. Invoke for EXPLAIN analysis, JSONB operations, extension usage, VACUUM tuning, performance monitoring.