TL;DR
Convex is a secure reactive backend platform with a strong security model. Server functions run in isolated environments, data validation is built-in, and authentication integrates with major providers. The "query" vs "mutation" separation enforces read/write permissions at the architecture level. A safe choice for real-time applications.
What is Convex?
Convex is a reactive backend platform that combines database, server functions, and real-time sync. It uses TypeScript functions for queries and mutations, with automatic caching and real-time updates. Popular for collaborative apps, dashboards, and real-time features.
Our Verdict
What's Good
- Server functions (not client-side)
- Built-in data validation
- Query/mutation separation
- Auth provider integration
- Automatic ACID transactions
What to Watch
- Public queries need auth checks
- Newer platform
- Custom auth complexity
Security Architecture
Server-Side by Default: Unlike Firebase, Convex functions run on the server. No security rules to misconfigure-your TypeScript code controls access.
Function Types
| Function Type | Purpose | Security |
|---|---|---|
| Query | Read data | Add auth checks in code |
| Mutation | Write data | Add auth checks in code |
| Action | External APIs | Runs in isolated environment |
| Internal | Backend-only | Not callable from client |
Authentication
Convex integrates with authentication providers:
- Clerk: First-class integration
- Auth0: JWT verification
- Custom: Any JWT provider
- Anonymous: For public data
Key Point: Authentication verifies identity, but you must add authorization checks in your functions to control what authenticated users can access.
Data Validation
Convex provides built-in validation:
- Schema validation: Define types for all tables
- Argument validation: Validate function inputs
- Type safety: TypeScript catches errors at compile time
- Runtime checks: Schema enforced on every write
Security Best Practices
| Practice | Implementation |
|---|---|
| Auth checks | Check ctx.auth in every query/mutation |
| Data ownership | Store userId with records, verify on access |
| Input validation | Use argument validators (v.string(), etc.) |
| Sensitive operations | Use internal functions, call from mutations |
Is Convex safe for production?
Yes, Convex is designed for production with server-side functions, ACID transactions, and built-in validation. Add proper auth checks to your functions and you have a secure backend.
How does Convex compare to Firebase?
Convex functions run server-side (safer by default), while Firebase relies on security rules. Convex uses TypeScript for logic; Firebase uses a custom rules language. Both can be secure, but Convex's model is harder to misconfigure.
Can clients call any Convex function?
Clients can call queries, mutations, and actions (not internal functions). You control access by checking authentication and authorization in each function before returning or modifying data.