flins: Skill for Claude Code

Convex Security Audit

Comprehensive security review patterns for Convex applications including authorization logic, data access boundaries, action isolation, rate limiting, and protecting sensitive operations.

Documentation Sources

Before implementing, do not assume; fetch the latest documentation:

• Primary: https://docs.convex.dev/auth/functions-auth
• Production Security: https://docs.convex.dev/production
• For broader context: https://docs.convex.dev/llms.txt

Instructions

Security Audit Areas

1. Authorization Logic - Who can do what
2. Data Access Boundaries - What data users can see
3. Action Isolation - Protecting external API calls
4. Rate Limiting - Preventing abuse
5. Sensitive Operations - Protecting critical functions

Authorization Logic Audit

Role-Based Access Control (RBAC)

// convex/lib/auth.ts
import { QueryCtx, MutationCtx } from "./_generated/server";
import { ConvexError } from "convex/values";
import { Doc } from "./_generated/dataModel";

type UserRole = "user" | "moderator" | "admin" | "superadmin";

const roleHierarchy: Record<UserRole, number> = {
  user: 0,
  moderator: 1,
  admin: 2,
  superadmin: 3,
};

export async function getUser(ctx: QueryCtx | MutationCtx): Promise<Doc<"users"> | null> {
  const identity = await ctx.auth.getUserIdentity();
  if (!identity) return null;
  
  return await ctx.db
    .query("users")
    .withIndex("by_tokenIdentifier", (q) => 
      q.eq("tokenIdentifier", identity.tokenIdentifier)
    )
    .unique();
}

export async function requireRole(
  ctx: QueryCtx | MutationCtx, 
  minRole: UserRole
): Promise<Doc<"users">> {
  const user = await getUser(ctx);
  
  if (!user) {
    throw new ConvexError({
      code: "UNAUTHENTICATED",
      message: "Authentication required",
    });
  }
  
  const userRoleLevel = roleHierarchy[user.role as UserRole] ?? 0;
  const requiredLevel = roleHierarchy[minRole];
  
  if (userRoleLevel < requiredLevel) {
    throw new ConvexError({
      code: "FORBIDDEN",
      message: `Role '${minRole}' or higher required`,
    });
  }
  
  return user;
}

// Permission-based check
type Permission = "read:users" | "write:users" | "delete:users" | "admin:system";

const rolePermissions: Record<UserRole, Permission[]> = {
  user: ["read:users"],
  moderator: ["read:users", "write:users"],
  admin: ["read:users", "write:users", "delete:users"],
  superadmin: ["read:users", "write:users", "delete:users", "admin:system"],
};

export async function requirePermission(
  ctx: QueryCtx | MutationCtx,
  permission: Permission
): Promise<Doc<"users">> {
  const user = await getUser(ctx);
  
  if (!user) {
    throw new ConvexError({ code: "UNAUTHENTICATED", message: "Authentication required" });
  }
  
  const userRole = user.role as UserRole;
  const permissions = rolePermissions[userRole] ?? [];
  
  if (!permissions.includes(permission)) {
    throw new ConvexError({
      code: "FORBIDDEN",
      message: `Permission '${permission}' required`,
    });
  }
  
  return user;
}