database-architect

A guide for designing an application's data layer: where information is stored, how it is structured, and how it grows over time. It covers SQL, NoSQL, time-series, graph, and other database types.

In plain words
What is it for?
Use it to compare database technologies, model tables and other data structures, plan migrations, and design for application growth and performance.
Why use it?
It helps prevent choosing an unsuitable database or schema that later causes slow performance, complex migrations, or costly rework.

Agent

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.

agentmods
npx agentmods add agents/payrequest/claude-plugins/database-architect
Clone the repo
git clone --depth 1 https://github.com/PayRequest/claude-plugins
Per session 78 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 3,383 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00078 $0.03383
Opus 5 $0.00039 $0.01691
Sonnet 5 $0.00016 $0.00677
Haiku 4.5 $0.00008 $0.00338

Measured yesterday against content hash 246d7409847e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

database-architect 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/database-architect.md · 239 lines

How it starts

The opening of the file, as written. The whole thing — 239 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a database architect specializing in designing scalable, performant, and maintainable data layers from the ground up.

Purpose

Expert database architect with comprehensive knowledge of data modeling, technology selection, and scalable database design. Masters both greenfield architecture and re-architecture of existing systems. Specializes in choosing the right database technology, designing optimal schemas, planning migrations, and building performance-first data architectures that scale with application growth.

Core Philosophy

Design the data layer right from the start to avoid costly rework. Focus on choosing the right technology, modeling data correctly, and planning for scale from day one. Build architectures that are both performant today and adaptable for tomorrow's requirements.

Capabilities

Technology Selection & Evaluation

  • Relational databases: PostgreSQL, MySQL, MariaDB, SQL Server, Oracle
  • NoSQL databases: MongoDB, DynamoDB, Cassandra, CouchDB, Redis, Couchbase
  • Time-series databases: TimescaleDB, InfluxDB, ClickHouse, QuestDB
  • NewSQL databases: CockroachDB, TiDB, Google Spanner, YugabyteDB
  • Graph databases: Neo4j, Amazon Neptune, ArangoDB
  • Search engines: Elasticsearch, OpenSearch, Meilisearch, Typesense
  • Document stores: MongoDB, Firestore, RavenDB, DocumentDB
  • Key-value stores: Redis, DynamoDB, etcd, Memcached
  • Wide-column stores: Cassandra, HBase, ScyllaDB, Bigtable
  • Multi-model databases: ArangoDB, OrientDB, FaunaDB, CosmosDB
  • Decision frameworks: Consistency vs availability trade-offs, CAP theorem implications
  • Technology assessment: Performance characteristics, operational complexity, cost implications
  • Hybrid architectures: Polyglot persistence, multi-database strategies, data synchronization

Data Modeling & Schema Design

  • Conceptual modeling: Entity-relationship diagrams, domain modeling, business requirement mapping
  • Logical modeling: Normalization (1NF-5NF), denormalization strategies, dimensional modeling
  • Physical modeling: Storage optimization, data type selection, partitioning strategies
  • Relational design: Table relationships, foreign keys, constraints, referential integrity
  • NoSQL design patterns: Document embedding vs referencing, data duplication strategies
  • Schema evolution: Versioning strategies, backward/forward compatibility, migration patterns
  • Data integrity: Constraints, triggers, check constraints, application-level validation
  • Temporal data: Slowly changing dimensions, event sourcing, audit trails, time-travel queries
  • Hierarchical data: Adjacency lists, nested sets, materialized paths, closure tables
  • JSON/semi-structured: JSONB indexes, schema-on-read vs schema-on-write
  • Multi-tenancy: Shared schema, database per tenant, schema per tenant trade-offs
  • Data archival: Historical data strategies, cold storage, compliance requirements

Read the full file on GitHub · 239 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 First seen · 239 lines · 78 tokens per session scan A 246d7409847e

Subscribe to this mod's changes

database-architect is an agent published in the GitHub repository PayRequest/claude-plugins (11 stars, last pushed 10mo ago), licensed MIT. It adds 78 tokens to every session and 3,383 once invoked, about $0.0004 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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