SKILL: GraphQL and Hidden Parameters — Introspection, Batching, and Undocumented Fields
AI LOAD INSTRUCTION
Use this skill when GraphQL exists or when REST documentation suggests optional, deprecated, or undocumented fields. Focus on schema discovery, hidden parameter abuse, and batching as a force multiplier.
1. GRAPHQL FIRST PASS
query
{
__typename
}
query
{
__schema
{
types
{
name
}
}
}
If introspection is restricted, continue with:
field suggestions and error-based discovery
known type probes like
__type(name: "User")
JS and mobile bundle route extraction
2. HIGH-VALUE GRAPHQL TESTS
Theme
Example
IDOR
user(id: "victim")
batching
array of login or object fetch operations
hidden fields
admin-only fields exposed in type definitions
nested authz gaps
related object fields with weaker checks
3. HIDDEN PARAMETER DISCOVERY
Look for:
fields present in admin docs but not public docs
additionalProperties
or permissive schemas
frontend code using richer request bodies than visible UI controls
mobile endpoints carrying role, org, feature-flag, or internal filter fields
4. NEXT ROUTING
If hidden fields affect privilege:
api authorization and bola
If GraphQL batching changes auth or rate behavior:
api auth and jwt abuse
If endpoint discovery is incomplete:
api recon and docs