db-change

db-change is a skill for Claude Code from mtvrkan/senior-dev-kit. It costs 44 tokens per session (379 once invoked), scanned A, original, MIT.

A planning skill for database tables, collections, models, relationships, queries, indexes, constraints, and data changes. It analyzes the design and migration order before code changes are made.

In plain words
What is it for?
Use it to design a new data model or assess an existing schema change, including affected data, rollback and backfill plans, deployment order, concurrent writes, constraints, indexes, and required tests.
Why use it?
Changing stored data can cause loss, slow queries, failed deployments, or conflicts with code that is being released at the same time. This creates a checklist for those risks and favors changes that can be introduced in stages.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Part of the senior-dev-kit plugin — 25 skills, 6 commands, 9 agents, 1 hook shipped together

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 skills/mtvrkan/senior-dev-kit/db-change
Any agent
npx skills add mtvrkan/senior-dev-kit --skill db-change
Clone the repo
git clone --depth 1 https://github.com/mtvrkan/senior-dev-kit

Made for: Claude Code.

Or install senior-dev-kit, the plugin that ships this one along with the rest of its 25 skills, 6 commands, 9 agents, 1 hook.

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-change

README.md
[![agentmods](https://agentmods.dev/badge/skills/mtvrkan/senior-dev-kit/db-change.svg)](https://agentmods.dev/skills/mtvrkan/senior-dev-kit/db-change)
Your own site
<a href="https://agentmods.dev/skills/mtvrkan/senior-dev-kit/db-change"><img src="https://agentmods.dev/badge/skills/mtvrkan/senior-dev-kit/db-change.svg" alt="Measured on agentmods" height="20"></a>
Per session 44 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 379 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 5.1 $0.00044 $0.00379
Opus 5 $0.00022 $0.00189
Sonnet 5 $0.00009 $0.00076
Haiku 4.5 $0.00004 $0.00038

Measured 5d ago against content hash 8f2b3239e31d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

db-change 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.

skills/db-change/SKILL.md · 32 lines

What it actually says

db-change

Greenfield modeling (no schema exists yet) — produce a data model plan first, no code edits:

ENTITIES: [list] | RELATIONS: [A has-many B, …] | INDEXES: [field → reason]
CONSTRAINTS: [unique, not-null, FK, check] | SQL vs NoSQL: [rationale if a choice is needed]
ANTI-PATTERNS AVOIDED: [what was rejected and why]

Changing an existing schema — produce this analysis before any change:

  1. AFFECTED: tables / collections / models touched
  2. DATA LOSS RISK: DROP, rename, type narrowing, NOT NULL on existing rows
  3. STRATEGY: additive change (nullable column, new table) or multi-step migration
  4. MIGRATION ORDER: deploy order relative to code changes
  5. INDEX/CONSTRAINT IMPACT: new indexes, constraint changes, performance effect
  6. RACE/TRANSACTION RISK: concurrent write safety
  7. TESTS REQUIRED: what must be verified before applying

Prefer additive changes. Never approve destructive operations without explicit user confirmation.

Deep references: agent_docs/zero-downtime-migration.md — expand/contract phases and deploy ordering; agent_docs/architecture.md — where models and repositories live.

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. 5d ago First seen · 32 lines · 44 tokens per session scan A 8f2b3239e31d

Subscribe to this mod's changes

db-change is a skill published in the GitHub repository mtvrkan/senior-dev-kit (5 stars, last pushed 5d ago), licensed MIT. It adds 44 tokens to every session and 379 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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