migrate

migrate is a skill for Claude Code, Codex from Hainrixz/claude-db. It costs 96 tokens per session (996 once invoked), scanned A, original, MIT.

A read-only checker for database migrations, which are changes to a database’s structure or data. It examines how the migration affects locks, table rebuilding, reversibility, and possible data loss.

In plain words
What is it for?
It checks an existing migration or compares two database schemas, then explains risky steps and suggests an expand-contract rollout, where changes are introduced gradually.
Why use it?
It helps reveal changes that could block users, take a long time, destroy data, or be difficult to undo before the migration runs.

Skill for Claude CodeCodex

Part of the claude-db plugin — 36 skills, 6 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/hainrixz/claude-db/migrate
Any agent
npx skills add Hainrixz/claude-db --skill migrate
Clone the repo
git clone --depth 1 https://github.com/Hainrixz/claude-db

Made for: Claude Code, Codex.

Or install claude-db, the plugin that ships this one along with the rest of its 36 skills, 6 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 migrate

README.md
[![agentmods](https://agentmods.dev/badge/skills/hainrixz/claude-db/migrate.svg)](https://agentmods.dev/skills/hainrixz/claude-db/migrate)
Your own site
<a href="https://agentmods.dev/skills/hainrixz/claude-db/migrate"><img src="https://agentmods.dev/badge/skills/hainrixz/claude-db/migrate.svg" alt="Measured on agentmods" height="20"></a>
Per session 96 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 996 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 $0.00096 $0.00996
Opus 5 $0.00048 $0.00498
Sonnet 5 $0.00019 $0.00199
Haiku 4.5 $0.00010 $0.00100

Measured 5d ago against content hash 40659a28c871, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

migrate 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/migrate/SKILL.md · 38 lines

How it starts

The opening of the file, as written. The whole thing — 38 lines — stays where its author put it; the contents beside it link to each section on GitHub.

/claude-db:migrate

Migration-safety lint, owned by module db-migration-safety (M22, axis performance) via the db-migration-safety / MSA checks. Default mode is read-only: it analyzes and explains, it does not run the migration.

$ARGUMENTS has two forms:

  • single-file lint<migration-file|migration-dir> [flags]: parse and classify an existing migration (below).
  • diff mode<from-schema> <to-schema> [flags]: two schema paths. Run node scripts/schema-diff.mjs --from <from-schema> --to <to-schema> to generate the up/down migration, then classify the generated migration exactly as in single-file mode.

If no argument is given, ask for one (or point at the project's migration directory).

Diff mode (<from-schema> <to-schema>)

  1. Run node scripts/schema-diff.mjs --from <A> --to <B> to produce the up and down migration; schema-diff.mjs flags destructive steps.
  2. Present the generated up/down migration to the user, with the plain-language summary of each step.
  3. Route every step schema-diff.mjs flagged destructive (DROP TABLE/COLUMN, type narrowing) through the data-loss handshake below before anything is written.
  4. Then classify the generated migration through the same lock/rewrite/reversibility analysis as single-file mode.

What to do (single-file lint)

  1. Parse the migration (raw SQL or generated ORM migration). Detect the engine; load engine-specific lock/rewrite rules.
  2. For each statement, classify:
    • Lock level — e.g. Postgres ACCESS EXCLUSIVE (blocks reads+writes) vs SHARE UPDATE EXCLUSIVE; whether it blocks the table for the duration.
    • Table rewrite — does the change rewrite every row (e.g. adding a NOT NULL column with a volatile default on an old engine, changing a column type)? Rewrites scale with table size.
    • Reversibility — is there a clean down-migration, or is it one-way (data already dropped/coerced)?
    • Destructive / data-lossDROP COLUMN/TABLE, TRUNCATE, narrowing types, enum-value removal, irreversible coercions.
  3. Emit findings per schema/finding.schema.json (status/severity/evidence.observed quoting the offending statement with secrets redacted/verification.reproduce/expected_impact.axis=performance+confidence+magnitude). A destructive migration without reversibility/expand-contract is severity-5 (caps Performance). Never fabricate a row-count or lock-duration — magnitude is banded high|medium|low and scales with table size described, not invented.
  4. Propose an expand-contract rollout for risky changes: expand (add the new nullable column / new table / dual-write), migrate (backfill in batches, online), contract (flip constraints, drop the old shape) — each as a separate, individually-reversible step with the lock level per step.

Read the full file on GitHub · 38 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. 5d ago First seen · 38 lines · 96 tokens per session scan A 40659a28c871

Subscribe to this mod's changes

migrate is a skill published in the GitHub repository Hainrixz/claude-db (19 stars, last pushed 2mo ago), licensed MIT. It adds 96 tokens to every session and 996 once invoked, about $0.0005 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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