# Introspection Control
Disable GraphQL introspection in production to prevent schema discovery attacks.
## Disabling Introspection
```rust
let gateway = Gateway::builder()
.with_descriptor_set_bytes(DESCRIPTORS)
.disable_introspection()
.build()?;
```
## What It Blocks
When introspection is disabled, these queries return errors:
```graphql
# Blocked
{
__schema {
types {
name
}
}
}
# Blocked
{
__type(name: "User") {
fields {
name
}
}
}
```
## Error Response
```json
{
"errors": [
{
"message": "Introspection is disabled",
"extensions": {
"code": "INTROSPECTION_DISABLED"
}
}
]
}
```
## Environment-Based Toggle
Enable introspection only in development:
```rust
let is_production = std::env::var("ENV")
.map(|e| e == "production")
.unwrap_or(false);
let mut builder = Gateway::builder()
.with_descriptor_set_bytes(DESCRIPTORS);
if is_production {
builder = builder.disable_introspection();
}
let gateway = builder.build()?;
```
## Security Benefits
Disabling introspection:
- Prevents attackers from discovering your schema structure
- Reduces attack surface for GraphQL-specific exploits
- Hides internal type names and field descriptions
## When to Disable
| Development | ✅ Enabled |
| Staging | ⚠️ Consider disabling |
| Production | ❌ Disabled |
## Alternative: Authorization
Instead of fully disabling, you can selectively allow introspection:
```rust
struct IntrospectionMiddleware {
allowed_keys: HashSet<String>,
}
impl Middleware for IntrospectionMiddleware {
async fn call(&self, ctx: &mut Context, next: ...) -> Result<()> {
// Check if request is introspection
if is_introspection_query(ctx) {
let api_key = ctx.headers().get("x-api-key");
if !self.allowed_keys.contains(api_key) {
return Err(Error::new("Introspection not allowed"));
}
}
next(ctx).await
}
}
```
## See Also
- **[Query Whitelisting](../production/query-whitelisting.md)** - For maximum security, combine introspection control with query whitelisting to restrict both schema discovery and query execution
- [DoS Protection](dos-protection.md) - Query depth and complexity limits