GraphQL has become a common choice for apps built quickly with AI coding tools, since its flexibility, letting the frontend request exactly the fields it needs in a single call, is genuinely convenient to build with. That same flexibility comes with a specific set of security considerations worth their own checklist, distinct from what I've written about for more traditional REST-style APIs.
Introspection left enabled in production
GraphQL includes a built-in feature called introspection, letting anyone query the API for its own complete schema: every type, every field, every available query and mutation, effectively documentation the API hands out for free to anyone who asks. Genuinely useful during development. Left enabled in production, it hands a complete map of your entire API's capabilities to anyone who wants to look, including fields and operations you never intended to advertise publicly. Check whether introspection is disabled in your production environment specifically, most frameworks default it to on.
Field-level access control, not just query-level
A REST API often gates access at the endpoint level: this route requires login, this one requires admin. GraphQL typically exposes one single endpoint, with access decisions needing to happen per field and per resolver instead. It's possible to correctly protect an entire query while accidentally leaving one specific nested field, tucked inside a related object, unprotected, because the access check was written at the wrong layer. Every field that touches sensitive data needs its own explicit check, not just the top-level query it's nested under.
Overfetching and expensive queries
Because GraphQL lets a caller shape their own query, it's possible to construct a single request that asks for deeply nested, expensive-to-compute data, sometimes recursively, in a way that puts far more load on your server than a normal request would. Without limits on query depth or complexity, this becomes both a performance risk and, at scale, a denial-of-service angle, all through queries that are technically valid, just excessively expensive to fulfill.
Batch queries bypassing rate limits
GraphQL often allows multiple operations in a single request. If your rate limiting counts requests rather than the actual operations within them, someone can bundle many actions into one request and quietly sidestep a limit that looked reasonable when measured the simpler way.
The condensed checklist
- Disable introspection in production, or at minimum restrict it to authenticated, trusted contexts.
- Apply access checks at the resolver or field level for anything sensitive, not just at the top of a query.
- Set limits on query depth and complexity to prevent excessively expensive requests.
- Make sure rate limiting accounts for batched operations within a single request, not just the request count itself.
- Run the same fundamental test as everything else on this blog: log in as two accounts and try to query data that belongs to the other one.
GraphQL's flexibility is a real, genuine benefit for building fast. It just moves several security decisions to a different layer than a REST API would, and those decisions still need to actually get made, not skipped because the framework feels more modern or more capable by default.