201-convex

201-convex is a cursor rule for Cursor from johnpolacek/vibecode.party.starter. It costs 0 tokens per session (972 once invoked), scanned A, original, MIT.

A project rulebook for using Convex, a backend platform that provides a database, schema, and server functions, with a Next.js application.

In plain words
What is it for?
It helps initialise Convex, configure its URL, define schemas and indexes, write queries and updates, and organise related service wrappers.
Why use it?
It keeps Convex setup, data definitions, backend logic, and client code in predictable locations and formats.

Cursor rule for Cursor

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/johnpolacek/vibecode.party.starter/201-convex
Clone the repo
git clone --depth 1 https://github.com/johnpolacek/vibecode.party.starter

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 201-convex

README.md
[![agentmods](https://agentmods.dev/badge/rules/johnpolacek/vibecode.party.starter/201-convex.svg)](https://agentmods.dev/rules/johnpolacek/vibecode.party.starter/201-convex)
Your own site
<a href="https://agentmods.dev/rules/johnpolacek/vibecode.party.starter/201-convex"><img src="https://agentmods.dev/badge/rules/johnpolacek/vibecode.party.starter/201-convex.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 972 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found 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 $0.00972
Opus 5 $0.00000 $0.00486
Sonnet 5 $0.00000 $0.00194
Haiku 4.5 $0.00000 $0.00097

Measured 5d ago against content hash ed243acbd6c6, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

201-convex 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 5d 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.

.cursor/rules/200-database/201-convex.mdc · 160 lines

How it starts

The opening of the file, as written. The whole thing — 160 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Convex Implementation Guide

Setup & Configuration

Convex Project Initialization

  1. Install Convex CLI
    pnpm add convex
    pnpm dlx convex dev
    
  2. Initialize Convex
    pnpm dlx convex init
    
  3. Configure Convex URL
    • Add NEXT_PUBLIC_CONVEX_URL to your .env file.

Directory Structure

  • Place Convex schema and functions in /convex/
  • Place Convex client config in /lib/convex/
  • Place service wrappers in /lib/services/

Implementation Patterns

Convex Schema & Functions

Define your schema and backend logic in /convex/schema.ts and /convex/[module].ts:

// convex/schema.ts
import { defineSchema, v } from "convex/schema";

export default defineSchema({
  visits: {
    path: v.string(),
    userId: v.optional(v.string()),
    metadata: v.any(),
    createdAt: v.number(),
    updatedAt: v.number(),
    indexes: [
      { fields: ["userId", "_creationTime"] },
      { fields: ["path", "_creationTime"] },
      { fields: ["createdAt", "_creationTime"] },
    ],
  },
});
// convex/visits.ts
import { mutation, query } from "convex/server";
import { v } from "convex/values";

export const recordVisit = mutation({
  args: {
    path: v.string(),
    userId: v.optional(v.string()),
    metadata: v.any(),
    createdAt: v.number(),
    updatedAt: v.number(),
  },
  handler: async (ctx, args) => {
    return await ctx.db.insert("visits", args);
  },
});

export const getVisitsByUser = query({
  args: { userId: v.string(), limit: v.optional(v.number()) },
  handler: async (ctx, args) => {
    return await ctx.db
      .query("visits")
      .withIndex("by_user", (q) => q.eq("userId", args.userId))
      .order("desc")
      .take(args.limit ?? 10);
  },
});

Service Layer Pattern

Create service functions to wrap Convex client calls:

// lib/services/visits.ts
import { api } from "@/convex/_generated/api";
import { ConvexReactClient } from "convex/react";

const convex = new ConvexReactClient(process.env.NEXT_PUBLIC_CONVEX_URL!);

export async function recordVisit(args) {
  return convex.mutation(api.visits.recordVisit, args);
}

export async function getVisitsByUser(userId, limit = 10) {
  return convex.query(api.visits.getVisitsByUser, { userId, limit });
}

Read the full file on GitHub · 160 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. 5d ago First seen · 160 lines · 0 tokens per session scan A ed243acbd6c6

Subscribe to this mod's changes

201-convex is a cursor rule published in the GitHub repository johnpolacek/vibecode.party.starter (27 stars, last pushed 1y ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 972 tokens. 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 2026-08-30.