import { ConceptNode, ConceptRelation, RelationType } from '../types';
interface ExtractedConcepts {
    concepts: ConceptNode[];
    relations: ConceptRelation[];
}
/**
 * Service for natural language processing operations
 */
export declare class NLPService {
    private openai;
    private model;
    private systemPrompt;
    private logger;
    constructor(apiKey: string, model?: string);
    extractConcepts(text: string): Promise<ExtractedConcepts>;
    calculateSimilarity(text1: string | null, text2: string | null): Promise<number>;
    classifyRelation(source: string | null, target: string | null): Promise<{
        type: RelationType;
        confidence: number;
    }>;
    private convertToExtractedConcepts;
}
export {};