EntityExtractorService

Kind: Service

Source: atloria-monorepo/apps/api/src/graph/services/entity-extractor.service.ts

EntityExtractorService is a NestJS backend service responsible for extracting KGEntity records from a document. It supports the graph subsystem by transforming document content into entities that can be persisted, linked, or used to build knowledge-graph relationships.

Methods

Dependencies

• PrismaService
• AIService

Where it refuses work

• EntityExtractorService stops the work with an early return when !document.

When something fails

• EntityExtractorService handles failure in 2 places: it logs it and continues in 1, and turns it into a return value in 1.

Diagram

mermaid
sequenceDiagram
    participant Caller as Graph Workflow
    participant Extractor as EntityExtractorService
    participant Document as Source Document
    participant KG as Knowledge Graph

    Caller->>Extractor: extractFromDocument()
    Extractor->>Document: Read document content
    Extractor->>Extractor: Identify and normalize entities
    Extractor-->>Caller: Promise<KGEntity[]>
    Caller->>KG: Store or link extracted entities

Usage

ts
import { Injectable } from '@nestjs/common';
import { EntityExtractorService } from './entity-extractor.service';
import type { KGEntity } from '../types/kg-entity.type';

@Injectable()
export class GraphIngestionService {
  constructor(
    private readonly entityExtractorService: EntityExtractorService,
  ) {}

  async extractEntities(): Promise<KGEntity[]> {
    const entities =
      await this.entityExtractorService.extractFromDocument();

    // Persist entities or create graph relationships here.
    return entities;
  }
}

AI Coding Instructions

• Keep entity extraction logic inside EntityExtractorService; callers should consume the returned KGEntity[] rather than duplicate parsing logic.
• Treat extractFromDocument() as asynchronous and always await its result before creating graph nodes or relationships.
• Preserve the expected KGEntity shape when adding normalization or enrichment logic so downstream graph operations remain compatible.
• Handle empty extraction results gracefully; an empty array can be valid when no entities are found.
• Register and inject the service through its NestJS module rather than constructing it manually.

Relationships

• DEPENDS_ON → PrismaService
• DEPENDS_ON → AIService

Referenced By

• GraphController (DEPENDS_ON)
• GraphModule (MODULE_PROVIDES)
• GraphModule (MODULE_EXPORTS)