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 ericrisco/rsc-harness --skill planetscalegit clone --depth 1 https://github.com/ericrisco/rsc-harnessWrote 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/ericrisco/rsc-harness/planetscale)<a href="https://agentmods.dev/skills/ericrisco/rsc-harness/planetscale"><img src="https://agentmods.dev/badge/skills/ericrisco/rsc-harness/planetscale/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/ericrisco/rsc-harness/planetscale"><img src="https://agentmods.dev/badge/skills/ericrisco/rsc-harness/planetscale.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00087 | $0.02762 |
| Opus 5 | $0.00044 | $0.01381 |
| Sonnet 5 | $0.00017 | $0.00552 |
| Haiku 4.5 | $0.00009 | $0.00276 |
Grade A, and why
planetscale 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 9d 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 — 199 lines — stays where its author put it; the contents beside it link to each section on GitHub.
PlanetScale — Vitess serverless MySQL: branches, deploy requests, no FKs
PlanetScale is serverless, MySQL-compatible database-as-a-service built on Vitess — the same
horizontal-scaling layer that runs YouTube. You do not ALTER TABLE against production. Schema
changes live on an isolated branch (a full copy of the schema), reach production through a
deploy request (a pull request for your schema), and apply via Online DDL: Vitess builds a
shadow table holding the new schema, replicates rows and in-flight writes old→new with VReplication,
then cuts over with no table lock. Because Online DDL and sharding are the platform's center of
gravity, you design without foreign keys (FKs are now an opt-in but unsharded-only feature). This
skill owns that workflow — not MySQL the engine.
Heuristic for the boundary: would this answer be identical on RDS MySQL? Then it is not this skill.
| When the question is really about | Route to |
|---|---|
A slow query, an EXPLAIN plan, an index decision, JSON columns, locking |
../mysql/SKILL.md for MySQL-engine work; ../postgresdb/SKILL.md when you want the transferable engine reasoning |
| PostgreSQL engine/design — even PlanetScale's own managed Postgres SQL semantics | ../postgresdb/SKILL.md. PlanetScale sells Postgres too; this skill is strictly the Vitess/MySQL branch+deploy-request flow |
| Engine-agnostic migration theory (expand-contract, backfill ordering) | ../db-migrations/SKILL.md. Here you get the concrete PlanetScale realization, not the theory |
| Postgres copy-on-write branches | ../neon/SKILL.md. Postgres BaaS → ../supabase/SKILL.md |
ORM client ergonomics (Prisma updateMany, Drizzle query builder) |
../prisma-orm/SKILL.md / ../drizzle-orm/SKILL.md. This skill owns only the PlanetScale-specific knobs those ORMs expose (relationMode, serverless driver adapter) |
Mental model
| PlanetScale concept | Git analogue | What it actually is |
|---|---|---|
| Branch | branch | A full, isolated copy of the schema. main is your production branch. |
| Deploy request | pull request | The gate that carries schema from a dev branch to production. |
| Schema diff | the PR diff | The exact DDL the deploy will run, computed by PlanetScale. |
| Online DDL | (no git analogue) | Shadow table + VReplication + non-blocking cutover. No ALTER lock. |
| Schema revert | revert commit | A ~30-minute window after deploy to undo while preserving post-deploy writes. |
What ships with it
5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 9d ago First seen · 199 lines · 87 tokens per session scan A 0dee9da5b744
planetscale is a skill published in the GitHub repository ericrisco/rsc-harness (82 stars, last pushed 2d ago), licensed MIT. It adds 87 tokens to every session and 2,762 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 2026-09-03.
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