indexing-schema - SKILL.md Agent Skill

name: indexing-schema description: >- Use when defining or editing schema.graphql. Entity types, scalar types, enums, relationships, @derivedFrom, @index, @config directives, array rules, naming conventions, and schema-to-TypeScript type mapping.

Schema Reference (schema.graphql)

Entity Rules

Every type is an entity — no @entity decorator (unlike TheGraph)
Must have id: ID! as first field
Names: 1-63 chars, alphanumeric + underscore, no reserved words
Use _id suffix for relationships: token_id: String! not token: Token!

Scalar Types

Schema Type	TypeScript Type	Notes
`ID!`	`string`	Required on every entity
`String!`	`string`
`Int!`	`number`
`Float!`	`number`
`Boolean!`	`boolean`
`BigInt!`	`bigint`	Use `@config(precision: N)` for custom precision
`BigDecimal!`	`BigDecimal`	Use `@config(precision: N, scale: M)`
`Bytes!`	`string`	Hex-encoded
`Timestamp!`	`Date`
`Json!`	`any`

Enums

enum Status {
  Active
  Inactive
  Paused
}

type Pool {
  id: ID!
  status: Status!
  allowedStatuses: [Status!]!  # enum arrays supported
}

@derivedFrom

Virtual reverse-lookup — cannot access in handlers, only in API queries:

type Pool {
  id: ID!
  swaps: [Swap!]! @derivedFrom(field: "pool")
}

type Swap {
  id: ID!
  pool_id: String!  # the FK field
}

The field argument must reference an _id relationship field on the derived entity.

@index

Single-field index for faster queries:

type Transfer {
  id: ID!
  from: String! @index
  to: String! @index
  timestamp: BigInt! @index
}

Composite index with optional DESC direction:

type Trade @index(fields: ["poolId", ["date", "DESC"]]) {
  id: ID!
  poolId: String!
  date: BigInt!
  volume: BigDecimal!
}

Fields default to ASC; use ["field", "DESC"] for descending
IDs and @derivedFrom fields are automatically indexed
Only @index fields are queryable via context.Entity.getWhere()

@config

Customize precision for numeric types:

type Token {
  id: ID!
  totalSupply: BigInt! @config(precision: 100)
  price: BigDecimal! @config(precision: 30, scale: 15)
}

BigInt default precision: 76 digits
BigDecimal default: precision 76, scale 32

Array Rules

Supported: [Type!]! — non-nullable elements, non-nullable array
Not supported: [Type]! (nullable elements), nested arrays, [Boolean!]!, [Timestamp!]!
Entity arrays require @derivedFrom — bare [Swap!]! without it causes EE211 error

Example

enum PoolType {
  UniswapV2
  UniswapV3
}

type Pool @index(fields: ["token0_id", "token1_id"]) {
  id: ID!
  poolType: PoolType!
  token0_id: String!
  token1_id: String!
  reserve0: BigInt!
  reserve1: BigInt!
  totalValueLocked: BigDecimal! @config(precision: 30, scale: 15)
  swaps: [Swap!]! @derivedFrom(field: "pool")
}

type Swap {
  id: ID!
  pool_id: String! @index
  sender: String! @index
  amount0In: BigInt!
  amount1In: BigInt!
  timestamp: BigInt! @index
}

Deep Documentation

Full reference: https://docs.envio.dev/docs/HyperIndex-LLM/hyperindex-complete