GraphQL Compatibility

Detailed feature compatibility reference for HeliosDB’s GraphQL implementation.

GraphQL Specification Compliance

Feature	Status	Notes
Query Operations	Supported	Full support
Mutation Operations	Supported	CRUD mutations
Subscription Operations	Supported	Real-time via WebSocket
Fragments	Supported	Inline and named
Variables	Supported	All types
Directives	Supported	Built-in and custom
Introspection	Supported	Full schema introspection

Schema Features

Types

Type	Status	Notes
Scalar	Supported	String, Int, Float, Boolean, ID
Object	Supported	Auto-generated from tables
Input Object	Supported	For mutations
Enum	Supported	From table columns
List	Supported	Arrays and connections
Non-Null	Supported	Required fields
Interface	Supported	For polymorphic types
Union	Supported	Multiple return types

Custom Scalars

Scalar	Status	Database Type
DateTime	Supported	TIMESTAMP
Date	Supported	DATE
Time	Supported	TIME
JSON	Supported	JSONB
UUID	Supported	UUID
BigInt	Supported	BIGINT
Decimal	Supported	DECIMAL
Upload	Supported	For file uploads

Directives

Directive	Status	Description
@skip	Supported	Conditional field skip
@include	Supported	Conditional field include
@deprecated	Supported	Mark as deprecated
@specifiedBy	Supported	Scalar URL specification
@auth	Supported	Authentication required
@rbac	Supported	Role-based access
@cache	Supported	Response caching
@rateLimit	Supported	Field-level rate limiting

Query Capabilities

Filtering

Operator	Example	Description
`_eq`	`{status: {_eq: "active"}}`	Equal
`_neq`	`{status: {_neq: "deleted"}}`	Not equal
`_gt`	`{age: {_gt: 18}}`	Greater than
`_gte`	`{age: {_gte: 18}}`	Greater or equal
`_lt`	`{price: {_lt: 100}}`	Less than
`_lte`	`{price: {_lte: 100}}`	Less or equal
`_in`	`{id: {_in: [1, 2, 3]}}`	In list
`_nin`	`{id: {_nin: [1, 2]}}`	Not in list
`_like`	`{name: {_like: "%john%"}}`	SQL LIKE
`_ilike`	`{name: {_ilike: "%JOHN%"}}`	Case-insensitive LIKE
`_is_null`	`{deleted_at: {_is_null: true}}`	IS NULL
`_contains`	`{tags: {_contains: ["a"]}}`	Array contains
`_contained_in`	`{tags: {_contained_in: ["a", "b"]}}`	Array contained in

Sorting

query {
  users(order_by: [
    { created_at: desc },
    { name: asc }
  ]) {
    id
    name
  }
}

Pagination

Style	Status	Description
Offset	Supported	`limit` and `offset`
Cursor	Supported	Relay-style connections

# Offset pagination
query {
  users(limit: 10, offset: 20) {
    id
    name
  }
}

# Cursor pagination
query {
  usersConnection(first: 10, after: "cursor123") {
    edges {
      node { id name }
      cursor
    }
    pageInfo {
      hasNextPage
      endCursor
    }
  }
}

Aggregations

query {
  users_aggregate(where: {status: {_eq: "active"}}) {
    aggregate {
      count
      sum { balance }
      avg { age }
      max { created_at }
      min { created_at }
    }
  }
}

Mutations

Insert

mutation {
  insert_users(objects: [
    { name: "Alice", email: "alice@example.com" }
  ]) {
    affected_rows
    returning {
      id
      name
    }
  }
}

Update

mutation {
  update_users(
    where: { id: { _eq: 1 } },
    _set: { status: "inactive" }
  ) {
    affected_rows
    returning {
      id
      status
    }
  }
}

Delete

mutation {
  delete_users(where: { status: { _eq: "deleted" } }) {
    affected_rows
  }
}

Upsert

mutation {
  insert_users(
    objects: [{ id: 1, name: "Alice", email: "alice@example.com" }],
    on_conflict: {
      constraint: users_pkey,
      update_columns: [name, email]
    }
  ) {
    affected_rows
  }
}

Subscriptions

subscription {
  users(where: { status: { _eq: "active" } }) {
    id
    name
    status
  }
}

Federation

Apollo Federation v2 Support

Directive	Status	Description
@key	Supported	Entity key
@external	Supported	External field
@requires	Supported	Required fields
@provides	Supported	Provided fields
@extends	Supported	Type extension
@shareable	Supported	Shareable field
@inaccessible	Supported	Hide from schema
@override	Supported	Override field
@tag	Supported	Schema tagging

Performance Features

Feature	Status	Description
Query Batching	Supported	Multiple queries in one request
DataLoader	Supported	N+1 query prevention
Persistent Queries	Supported	APQ for reduced bandwidth
Response Caching	Supported	Configurable TTL
Query Complexity	Supported	Cost analysis
Depth Limiting	Supported	Max query depth

Client Compatibility

Client	Status	Notes
Apollo Client	Tested	Full support
Relay	Tested	Connection spec
urql	Tested	Full support
graphql-request	Tested	Lightweight client
gql (Python)	Tested	Full support
graphql-go	Tested	Full support

Last Updated: January 2026