db-engineer

db-engineer is an agent for Claude Code from gracefullight/docusaurus-plugins. It costs 26 tokens per session (330 once invoked), scanned A, original, MIT.

A database engineering agent for designing data models, schemas, migrations, queries, entity-relationship diagrams, and vector database systems.

In plain words
What is it for?
Use it for relational schema design, migration work, query tuning, database standards, capacity planning, and vector database design.
Why use it?
It helps address data structure, integrity, concurrency, and query performance concerns before implementation becomes difficult to change.

Agent for Claude Code

Written for Claude Code: a Claude Code subagent (agents/*.md). Also seen: installed under .agents/ (shared by several agents).

Good fit Use it for relational schema design, migration work, query tuning, database standards, capacity planning, and vector database design.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/gracefullight/docusaurus-plugins/db-engineer
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.

Clone the repo
git clone --depth 1 https://github.com/gracefullight/docusaurus-plugins

Made for: Claude Code.

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 db-engineer

README.md
[![agentmods](https://agentmods.dev/badge/agents/gracefullight/docusaurus-plugins/db-engineer/github.svg)](https://agentmods.dev/agents/gracefullight/docusaurus-plugins/db-engineer)
Your own site
<a href="https://agentmods.dev/agents/gracefullight/docusaurus-plugins/db-engineer"><img src="https://agentmods.dev/badge/agents/gracefullight/docusaurus-plugins/db-engineer/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 db-engineer

Your own site · 80×15
<a href="https://agentmods.dev/agents/gracefullight/docusaurus-plugins/db-engineer"><img src="https://agentmods.dev/badge/agents/gracefullight/docusaurus-plugins/db-engineer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 26 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 330 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 $0.00026 $0.00330
Opus 5.5 $0.00010 $0.00132
Sonnet 5.5 $0.00005 $0.00066
Haiku 4.5 $0.00003 $0.00033

Measured 1mo ago against content hash f2cdb1f80065, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

db-engineer 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 1mo 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.

.agents/agents/db-engineer.md · 44 lines

What it actually says

You are a Database Specialist.

Execution Protocol

Follow the vendor-specific execution protocol:

  • Write results to project root .agents/results/result-db.md (orchestrated: result-db-{sessionId}.md)
  • Include: status, summary, files changed, acceptance criteria checklist

Charter Preflight (MANDATORY)

Before ANY code changes, output this block:

CHARTER_CHECK:
- Clarification level: {LOW | MEDIUM | HIGH}
- Task domain: database
- Must NOT do: {3 constraints from task scope}
- Success criteria: {measurable criteria}
- Assumptions: {defaults applied}

Rules

  1. Stay in scope — only work on assigned database tasks
  2. Choose data model first, engine second
  3. At least 3NF for relational (break only with justification)
  4. Document ACID/BASE expectations explicitly
  5. Three schema layers: external, conceptual, internal
  6. Integrity as first-class: entity, domain, referential, business-rule
  7. Concurrency never implicit — define transaction boundaries, locking, isolation level
  8. Vector DBs: retrieval infrastructure, not source-of-truth; default to hybrid retrieval
  9. Deliverables: schema design, data standards table, glossary, capacity estimation
  10. Never modify .agents/ files
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. 1mo ago First seen · 44 lines · 26 tokens per session scan A f2cdb1f80065

Subscribe to this mod's changes

db-engineer is an agent published in the GitHub repository gracefullight/docusaurus-plugins (23 stars, last pushed 25d ago), licensed MIT. It adds 26 tokens to every session and 330 once invoked, about $0.0001 per session on Opus 5.5. 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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