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 jxoesneon/Ciel --skill database-migrationsgit clone --depth 1 https://github.com/jxoesneon/CielWrote 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/jxoesneon/ciel/database-migrations)<a href="https://agentmods.dev/skills/jxoesneon/ciel/database-migrations"><img src="https://agentmods.dev/badge/skills/jxoesneon/ciel/database-migrations/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/jxoesneon/ciel/database-migrations"><img src="https://agentmods.dev/badge/skills/jxoesneon/ciel/database-migrations.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 | $0.00018 | $0.00526 |
| Opus 5 | $0.00009 | $0.00263 |
| Sonnet 5 | $0.00004 | $0.00105 |
| Haiku 4.5 | $0.00002 | $0.00053 |
Grade A, and why
database-migrations 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 8d 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.
What it actually says
CIEL ADAPTATION: Database Migrations (Schema Safety)
This skill formalizes the process for making reversible, zero-downtime database changes. It prioritizes table safety over implementation speed.
Core Mandates
- Forward-Only: In production, rollbacks use a NEW forward migration.
- Downtime Prevention:
- Adding Column: Must be nullable or have a default (Postgres 11+).
- Adding Index: Use
CREATE INDEX CONCURRENTLY(Postgres). - Renaming: Use the Expand-Contract Pattern (Add new -> Backfill -> Read/Write Both -> Contract).
- Data/Schema Split: Never mix DDL (Schema) and DML (Data) in a single migration.
Batch Data Migration
For large tables (>10M rows), the Orchestrator MUST use a batching loop:
- Update in chunks of 5,000-10,000 rows.
- Use
FOR UPDATE SKIP LOCKEDwhere appropriate. - Log progress and include a manual halt mechanism.
Tool-Specific Standards
- Prisma: Use
prisma migrate devfor schema; manual SQL forCONCURRENTLY. - Drizzle: Generate migrations into dedicated files; verify ordering.
- Django: Use
SeparateDatabaseAndStateto decouple model state from DB state during complex drops.
Anti-Patterns
- Inline Table Rewrites: Adding a
NOT NULLcolumn without a default to an existing large table. - Manual SQL: Executing DDL directly in production without a migration file.
- Amnesiac Rollbacks: Marking a migration as irreversible without documenting the specific reason.
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.
- 8d ago First seen · 55 lines · 18 tokens per session scan A f48294c9fdcf
database-migrations is a skill published in the GitHub repository jxoesneon/Ciel (1 stars, last pushed 4d ago), licensed Apache-2.0. It adds 18 tokens to every session and 526 once invoked, about $0.0001 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 2026-09-03.
Other skills, from other repositories
supabase-cli
This skill should be used when user asks to "use supabase CLI", "supabase init", "supabase start", "run migrations", "deploy edge functions", "manage Supabase project", or works with the supabase command-line tool for local development and project management.
supabase-js
This skill should be used when user asks to "use supabase-js", "query Supabase database", "supabase auth", "supabase storage", "supabase realtime", "supabase edge functions", or works with the @supabase/supabase-js JavaScript/TypeScript SDK.
polar-local-environment
This skill should be used when setting up or managing Polar local development environment with Docker.
claimable-postgres
Provision instant temporary Postgres databases via Claimable Postgres by Neon (pg.new). No login or credit card required. Use for quick Postgres environments and throwaway DATABASEURL for prototyping.
postgresql-optimization
PostgreSQL database optimization workflow for query tuning, indexing strategies, performance analysis, and production database management.
cloud-sql-postgres-health
Use these skills when you need to audit database health, identify storage bloat, find invalid indexes, analyze table statistics, and manage maintenance configurations like autovacuum.