shared-plane-packages

shared-plane-packages is a cursor rule for Cursor from prisma/prisma-next. It costs 0 tokens per session (1,169 once invoked), scanned A, a copy of shared-plane-packages, Apache-2.0.

An architecture rule for placing side-effect-free types, validators, and factories in packages shared by code that defines database changes and code that runs the application.

In plain words
What is it for?
It helps decide when to create a shared package for common types, validation, or data construction.
Why use it?
It allows both parts of the system to use the same definitions without crossing package boundaries or importing file and migration logic into runtime code.

Cursor rule for Cursor ✓ vendor

Written for Cursor: a Cursor rule (.mdc). Also seen: installed under .agents/ (shared by several agents).

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 rules/prisma/prisma-next/shared-plane-packages
Clone the repo
git clone --depth 1 https://github.com/prisma/prisma-next

Made for: Cursor.

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 shared-plane-packages

README.md
[![agentmods](https://agentmods.dev/badge/rules/prisma/prisma-next/shared-plane-packages.svg)](https://agentmods.dev/rules/prisma/prisma-next/shared-plane-packages)
Your own site
<a href="https://agentmods.dev/rules/prisma/prisma-next/shared-plane-packages"><img src="https://agentmods.dev/badge/rules/prisma/prisma-next/shared-plane-packages.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 1,169 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 91% copy Near-identical to another mod 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 $0.00000 $0.01169
Opus 5 $0.00000 $0.00584
Sonnet 5 $0.00000 $0.00234
Haiku 4.5 $0.00000 $0.00117

Measured 3d ago against content hash 4a7db3cb4fd7, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

shared-plane-packages 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.

Origin

This is a copy

91% identical to shared-plane-packages — 14 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.agents/rules/shared-plane-packages.mdc · 138 lines

How it starts

The opening of the file, as written. The whole thing — 138 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Shared Plane Packages

Overview

Shared plane packages contain side-effect-free code (types, validators, factories) that can be safely imported by both migration-plane (authoring, emitter, targets) and runtime-plane (lanes, runtime, adapters) packages. This pattern allows runtime-plane packages to import type definitions without violating plane boundaries.

When to Create a Shared Plane Package

Create a shared plane package when:

  1. Types are needed by both planes: Type definitions that are used by both migration-plane (e.g., emitter, authoring) and runtime-plane (e.g., lanes, runtime) packages
  2. Validators are pure: Arktype validators that perform structural validation without side effects
  3. Factories are pure: Factory functions that construct data structures without IO or external dependencies
  4. No migration-specific logic: The package contains no code that depends on migration-plane concerns (file I/O, pack loading, emitter hooks)

Examples

SQL Contract Types (@prisma-next/sql-contract)

Located at packages/sql/contract/ (shared plane):

  • Types: SqlContract, SqlStorage, StorageTable, ModelDefinition
  • Validators: Arktype validators for contract structures
  • Factories: Pure factory functions for constructing contract IR

Used by:

  • Migration plane: authoring, emitter (for validation and IR construction)
  • Runtime plane: lanes, runtime (for type definitions)

SQL Operations Types (planned: @prisma-next/sql-operations)

When moved to shared plane at packages/sql/operations/:

  • Types: LoweringSpec, OperationSignature
  • Assembly: Pure function assembleOperationRegistry(manifests) that takes plain manifest objects
  • Validators: (optional) Arktype validators for operation manifests

Used by:

  • Migration plane: emitter (for assembling operations from extension packs)
  • Runtime plane: lanes, runtime (for operation type definitions)

Package Structure

Shared plane packages follow this structure:

Read the full file on GitHub · 138 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. 3d ago First seen · 138 lines · 0 tokens per session scan A 4a7db3cb4fd7

Subscribe to this mod's changes

shared-plane-packages is a cursor rule published in the GitHub repository prisma/prisma-next (418 stars, last pushed 12d ago), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 1,169 tokens. A static security scan graded it A with 0 findings. It is 91% identical to shared-plane-packages, differing in 14 lines, and is treated as a copy.