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 skills add nonlinear-xyz/factory-kit --skill factory-db-migration-engineergit clone --depth 1 https://github.com/nonlinear-xyz/factory-kitWrote 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/nonlinear-xyz/factory-kit/factory-db-migration-engineer)<a href="https://agentmods.dev/skills/nonlinear-xyz/factory-kit/factory-db-migration-engineer"><img src="https://agentmods.dev/badge/skills/nonlinear-xyz/factory-kit/factory-db-migration-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.
<a href="https://agentmods.dev/skills/nonlinear-xyz/factory-kit/factory-db-migration-engineer"><img src="https://agentmods.dev/badge/skills/nonlinear-xyz/factory-kit/factory-db-migration-engineer.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00156 | $0.02633 |
| Opus 5.5 | $0.00062 | $0.01053 |
| Sonnet 5.5 | $0.00031 | $0.00527 |
| Haiku 4.5 | $0.00016 | $0.00263 |
Grade A, and why
factory-db-migration-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.
How it starts
The opening of the file, as written. The whole thing — 186 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Apply the db-migration-engineer specialist workflow. Design and shepherd destructive database changes with senior operational discipline. Load factory-db-migration first through the host's skill capability, followed by factory-data-layer, factory-deployment, and factory-security for adjacent concerns.
The mandate is specific: the act of mutating prod, not the design of the schema (that's db-schema-architect) or the deployment pipeline (that's factory-deployment.md). You are invoked when the user is about to make a change that, if mishandled, costs hours-to-days of recovery and possibly customer trust.
When to invoke
- Always for: schema migrations involving backfill, periodic data imports, DROP CONSTRAINT, one-shot RPCs against prod, any DELETE / UPDATE against prod tables that the operator typed by hand.
- Often for: ADD CONSTRAINT against existing data (needs preflight that no row violates), CREATE INDEX CONCURRENTLY (low risk but coordinate with load), data-type changes on populated columns.
- Skip for: single-column ADD with no backfill, ADD INDEX (non-concurrent on small table), CREATE OR REPLACE FUNCTION with no behavioral change.
How to think (in order)
-
Restate the destructive change in one sentence. What table(s)? What rows? Reversible by what? If you cannot articulate this in one sentence, the request is under-scoped — ask the user to clarify before designing.
-
Classify the blast radius.
- Low — DROP CONSTRAINT (no data touched), CREATE INDEX CONCURRENTLY, CREATE OR REPLACE FUNCTION with same signature.
- Medium — ADD CONSTRAINT (needs row-by-row preflight), data backfill via UPDATE, schema change with column rename.
- High — periodic data import (UPSERT loop), one-shot DELETE, ALTER TYPE on populated enum, DROP COLUMN.
- Catastrophic — TRUNCATE, ALTER TABLE ... USING that rewrites the table, DROP TABLE.
The higher the blast radius, the more layers of the framework must be exercised. Catastrophic changes need explicit user authorization at the gate level, not just the LLM-says-OK level.
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.
- 1mo ago First seen · 186 lines · 156 tokens per session scan A e49fcd9b10de
factory-db-migration-engineer is a skill published in the GitHub repository nonlinear-xyz/factory-kit (9 stars, last pushed 12d ago), licensed MIT. It adds 156 tokens to every session and 2,633 once invoked, about $0.0006 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 2026-08-31.
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