convex-backend

convex-backend is a skill for Claude Code, Codex from BagelHole/DevOps-Security-Agent-Skills. It costs 39 tokens per session (2,027 once invoked), scanned B, original, MIT.

A guide to building reactive backends with Convex, a managed service that combines a database with server functions and automatically updates connected clients when data changes.

In plain words
What is it for?
Use it to define database schemas, validate data, write server functions, connect authentication, and build collaborative apps, chat, dashboards, multiplayer features, or AI status screens.
Why use it?
It reduces the infrastructure work needed for real-time applications and keeps server functions and stored data type-checked. It is suited to apps where users need current data without manual refreshes.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Needs its repository: it reads a path above its own folder, which exists only inside the repository. The line is import { api } from "../convex/_generated/api";.

Good fit Use it to define database schemas, validate data, write server functions, connect authentication, and build collaborative apps, chat, dashboards, multiplayer features, or AI status screens.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/BagelHole/DevOps-Security-Agent-Skills
agentmods
npx agentmods add skills/bagelhole/devops-security-agent-skills/convex-backend

Made for: Claude Code, Codex.

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 convex-backend

README.md
[![agentmods](https://agentmods.dev/badge/skills/bagelhole/devops-security-agent-skills/convex-backend/github.svg)](https://agentmods.dev/skills/bagelhole/devops-security-agent-skills/convex-backend)
Your own site
<a href="https://agentmods.dev/skills/bagelhole/devops-security-agent-skills/convex-backend"><img src="https://agentmods.dev/badge/skills/bagelhole/devops-security-agent-skills/convex-backend/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.

agentmods 80×15 button for convex-backend

Your own site · 80×15
<a href="https://agentmods.dev/skills/bagelhole/devops-security-agent-skills/convex-backend"><img src="https://agentmods.dev/badge/skills/bagelhole/devops-security-agent-skills/convex-backend.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 39 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,027 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 13 findings, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high Privilege Escalation · line 264
    Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.
    Fix: Remove references to credential paths. Use environment variables or secrets managers. For docs, use placeholder paths (e.g., /path/to/config). Never load .env or token files in production code paths.
  • medium MCP Rug Pull · line 34
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 261
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 264
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 267
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 268
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 271
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 272
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 275
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 313
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 315
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium Data Exfiltration · line 151
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
  • medium Data Exfiltration · line 151
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
How audits are shown
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 $0.00039 $0.02027
Opus 5 $0.00019 $0.01014
Sonnet 5 $0.00008 $0.00405
Haiku 4.5 $0.00004 $0.00203

Measured 5d ago against content hash 88e496a813f6, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade B, and why

convex-backend scanned grade B with 1 finding 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.

Sends data to an external URLmediumData exfiltration

A POST to an outside endpoint may be telemetry or may be exfiltration; either way the mod talks to somewhere, and you should know where.

const response = await fetch("https://api.anthropic.com/v1/messages", { method: "POST",
infrastructure/platforms/convex-backend/SKILL.md · 322 lines

How it starts

The opening of the file, as written. The whole thing — 322 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Convex Backend

Use Convex to build type-safe backend logic with realtime data sync.

When to Use This Skill

Use this skill when:

  • Building real-time collaborative apps (chat, dashboards, multiplayer)
  • Need a backend with zero infrastructure management
  • Want type-safe server functions with automatic caching
  • Building AI apps that need reactive data (agent status, streaming results)
  • Prototyping quickly with a managed database + functions

Prerequisites

  • Node.js 18+
  • npm or pnpm
  • Convex account (free tier: 1M function calls/month)

Quick Start

# Initialize Convex in an existing project
npm install convex
npx convex dev     # Start local development (syncs with cloud)

# In a new project
npm create convex@latest

Schema Definition

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

export default defineSchema({
  users: defineTable({
    name: v.string(),
    email: v.string(),
    role: v.union(v.literal("admin"), v.literal("member")),
    avatarUrl: v.optional(v.string()),
    createdAt: v.number(),
  })
    .index("by_email", ["email"])
    .index("by_role", ["role"]),

  messages: defineTable({
    userId: v.id("users"),
    channelId: v.id("channels"),
    body: v.string(),
    attachments: v.optional(v.array(v.string())),
    createdAt: v.number(),
  })
    .index("by_channel", ["channelId", "createdAt"])
    .index("by_user", ["userId"]),

  channels: defineTable({
    name: v.string(),
    description: v.optional(v.string()),
    isPrivate: v.boolean(),
  }),
});

Queries (Real-Time Reads)

// convex/messages.ts
import { query } from "./_generated/server";
import { v } from "convex/values";

export const listByChannel = query({
  args: {
    channelId: v.id("channels"),
    limit: v.optional(v.number()),
  },
  handler: async (ctx, args) => {
    const messages = await ctx.db
      .query("messages")
      .withIndex("by_channel", (q) => q.eq("channelId", args.channelId))
      .order("desc")
      .take(args.limit ?? 50);

    // Resolve user data for each message
    return Promise.all(
      messages.map(async (msg) => {
        const user = await ctx.db.get(msg.userId);
        return { ...msg, user: user ? { name: user.name, avatarUrl: user.avatarUrl } : null };
      })
    );
  },
});

Read the full file on GitHub · 322 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 · 322 lines · 39 tokens per session scan B 88e496a813f6

Subscribe to this mod's changes

convex-backend is a skill published in the GitHub repository BagelHole/DevOps-Security-Agent-Skills (1,067 stars, last pushed 3mo ago), licensed MIT. It adds 39 tokens to every session and 2,027 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it B with 1 finding (sends data to an external url). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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