Event handler context

Event handler functions receive two arguments: event and context.

The context object exposes the entities defined in schema.graphql and the contracts defined in ponder.config.ts.

type Context = {
  // Keyed by entity type names from schema.graphql
  entities: Record<string, EntityModel>;
  // Keyed by contract names from ponder.config.ts
  contracts: Record<string, ReadOnlyContract>;
};

Entities

context.entities an object-relational mapper for each entity in your schema.graphql. You can use these objects to insert and update entities that will be served automatically by the GraphQL server.

type EntityModel = {
  get: (id: string) => Promise<Entity | null>;
  insert: (id: string, obj: Omit<Entity, "id">) => Promise<Entity>;
  update: (id: string, obj: Partial<Omit<Entity, "id">>) => Promise<Entity>;
  delete: (id: string) => Promise<boolean>;
  upsert: (id: string, obj: Omit<Entity, "id">) => Promise<Entity>;
};

Contracts

context.contracts contains a ReadOnlyContract object for each contract in your ponder.config.ts. You can use these to read data directly from the smart contract using RPC calls.