Semantic D1 MCP

Instructions

Implementation Reference

• src/application/use-cases/GetRelationshipsUseCase.ts:88-109 (handler)

  Core handler function that fetches cached schema, extracts relationships via analyzer, filters by optional tableName if provided, formats into DTOs, and returns the structured response.
  async execute(request: GetRelationshipsRequest): Promise<RelationshipsResponse> { const environment = request.environment; // Get or fetch schema (with caching) const schema = await this.getSchema(environment); // Extract relationships using domain service const allRelationships = this.relationshipAnalyzer.extractRelationships([...schema.tables]); // Filter by table if specified const relationships = request.tableName ? this.filterRelationshipsByTable(allRelationships, request.tableName) : allRelationships; // Format and return response return { databaseName: schema.name, environment: schema.environment, relationships: relationships.map((rel) => this.formatRelationship(rel)), relationshipCount: relationships.length, }; }
• src/presentation/mcp/MCPServer.ts:217-236 (handler)

  MCP-specific tool handler that validates/parses input arguments, invokes the GetRelationshipsUseCase, serializes the result to JSON, and returns it in MCP content format.
  private async handleGetRelationships(args: unknown) { const { environment, tableName } = args as { environment: string; tableName?: string; }; const result = await this.getRelationshipsUseCase.execute({ environment: parseEnvironment(environment), tableName, }); return { content: [ { type: 'text', text: JSON.stringify(result, null, 2), }, ], }; }
• src/presentation/mcp/MCPServer.ts:103-122 (registration)

  Registers the "get_table_relationships" MCP tool including its name, description, and input schema validation.
  { name: 'get_table_relationships', description: 'Extract and analyze foreign key relationships between tables in the database', inputSchema: { type: 'object', properties: { environment: { type: 'string', enum: ['development', 'staging', 'production'], description: 'Database environment to analyze', }, tableName: { type: 'string', description: 'Optional: Filter relationships for specific table', }, }, required: ['environment'], }, },
• src/application/use-cases/GetRelationshipsUseCase.ts:37-40 (schema)

  TypeScript interface defining the input parameters for the relationships extraction use case, matching the MCP tool inputSchema.
  export interface GetRelationshipsRequest { environment: Environment; tableName?: string; }
• src/domain/services/RelationshipAnalyzer.ts:28-40 (helper)

  Domain service method that constructs Relationship domain entities from foreign key constraints in table metadata.
  extractRelationships(tables: TableInfo[]): Relationship[] { const relationships: Relationship[] = []; for (const table of tables) { for (const fk of table.foreignKeys) { relationships.push( new Relationship(fk.table, fk.column, fk.referencesTable, fk.referencesColumn, fk.onDelete, fk.onUpdate) ); } } return relationships; }