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 agentmods add skills/nacre-work/nacre/db-migrationnpx skills add nacre-work/nacre --skill db-migrationgit clone --depth 1 https://github.com/nacre-work/nacreWrote 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/nacre-work/nacre/db-migration)<a href="https://agentmods.dev/skills/nacre-work/nacre/db-migration"><img src="https://agentmods.dev/badge/skills/nacre-work/nacre/db-migration.svg" alt="Measured on agentmods" 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 | $0.00076 | $0.00976 |
| Opus 5 | $0.00038 | $0.00488 |
| Sonnet 5 | $0.00015 | $0.00195 |
| Haiku 4.5 | $0.00008 | $0.00098 |
Grade A, and why
db-migration 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 3d 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 — 84 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Changing the schema
Migrations live in packages/core/migrations, numbered and forward-only.
Never edit a migration that has been applied anywhere; add another.
The schema is the source of truth for tenants, permissions, metadata, and audit. Vectors are in Qdrant and originals in S3 — if a change would put content that needs a transaction into either of those, it belongs here instead.
Every table carrying tenant data
-
org_id NOT NULL REFERENCES organizations(id) ON DELETE CASCADE, even when it is reachable through a parent. The duplication is the point: it lets RLS work on the table directly. -
Enable RLS, force it, and add the
org_isolationpolicy in the same migration as the table:ALTER TABLE thing ENABLE ROW LEVEL SECURITY; ALTER TABLE thing FORCE ROW LEVEL SECURITY; CREATE POLICY org_isolation ON thing USING (org_id = current_setting('app.current_org')::uuid);FORCEis not optional and its absence is silent.ENABLEalone does not apply to the role that owns the table, and migrations run as the owner — so any deployment that reuses that connection for the application gets policies that are switched on and inert. That was the state of this schema until migration 0002: a connection scoped to one organization could read another's documents, layers, and users, with every policy reporting enabled.Superusers bypass RLS regardless. The application must not connect as one, and
withOrg'sroleoption exists for deployments that cannot easily split the roles.RLS is the second line of defense, not the mechanism. The application still filters, and invariant 1 is still verified again at serialization. A table added without RLS is one forgotten
WHEREaway from a cross-tenant leak. -
A foreign key that crosses tenants needs a composite key. A plain
REFERENCES groups(id)lets a row join an object in one organization to an object in another.group_membershad exactly that shape: one row joining a foreign user to a group would have handed that user every grant the group holds. Reference(id, org_id)against aUNIQUE (id, org_id)so the database enforces it rather than the code that writes the insert. -
Indexes that the permission filter needs. A filter that falls back to a scan does not fail a test; it just gets slow enough to matter at a customer's volume, which is the worst way to find out.
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.
- 3d ago First seen · 84 lines · 76 tokens per session scan A ae7a1249f0c2
db-migration is a skill published in the GitHub repository nacre-work/nacre (0 stars, last pushed 6d ago), licensed Apache-2.0. It adds 76 tokens to every session and 976 once invoked, about $0.0004 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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