MCP Think Tank

Instructions

Implementation Reference

• src/memory/tools.ts:165-201 (handler)

  The core execute function for the 'create_relations' tool. It processes an array of relations, attempts to add each to the graph using graph.addRelation, checks for existence of source/target entities or duplicate relations for failures, collects results, saves the memory store, and returns a JSON string with created/failed counts and details.

  execute: async (args) => {
    const results = {
      created: [] as Array<{from: string, to: string, relationType: string}>,
      failed: [] as Array<{from: string, to: string, relationType: string, reason: string}>
    };
  
    // Using the lower-level graph for relations for now
    // In a future update, we can add relation handling to the MemoryStore itself
    for (const relation of args.relations) {
      const success = graph.addRelation(relation);
      if (success) {
        results.created.push(relation);
      } else {
        // Determine failure reason
        let reason = "Unknown error";
        if (!graph.entities.has(relation.from)) {
          reason = `Source entity '${relation.from}' doesn't exist`;
        } else if (!graph.entities.has(relation.to)) {
          reason = `Target entity '${relation.to}' doesn't exist`;
        } else {
          reason = "Relation already exists";
        }
        
        results.failed.push({...relation, reason});
      }
    }
  
    // Save changes
    await memoryStore.save();
  
    // Return as string
    return JSON.stringify({
      created: results.created.length > 0 ? results.created : null,
      failed: results.failed.length > 0 ? results.failed : null,
      message: `Created ${results.created.length} new relations. ${results.failed.length} relations failed.`
    });
  }

• src/utils/validation.ts:30-32 (schema)

  Zod schema defining the input parameters for the create_relations tool: an array of relations.

  export const CreateRelationsSchema = z.object({
    relations: z.array(RelationSchema).describe('Array of relations to create')
  });

• src/memory/tools.ts:161-202 (registration)

  Registers the 'create_relations' tool on the FastMCP server with name, description, schema, and inline execute handler.

  server.addTool({
    name: 'create_relations',
    description: 'Create multiple new relations between entities in the knowledge graph. Relations should be in active voice',
    parameters: Schemas.CreateRelationsSchema,
    execute: async (args) => {
      const results = {
        created: [] as Array<{from: string, to: string, relationType: string}>,
        failed: [] as Array<{from: string, to: string, relationType: string, reason: string}>
      };
  
      // Using the lower-level graph for relations for now
      // In a future update, we can add relation handling to the MemoryStore itself
      for (const relation of args.relations) {
        const success = graph.addRelation(relation);
        if (success) {
          results.created.push(relation);
        } else {
          // Determine failure reason
          let reason = "Unknown error";
          if (!graph.entities.has(relation.from)) {
            reason = `Source entity '${relation.from}' doesn't exist`;
          } else if (!graph.entities.has(relation.to)) {
            reason = `Target entity '${relation.to}' doesn't exist`;
          } else {
            reason = "Relation already exists";
          }
          
          results.failed.push({...relation, reason});
        }
      }
  
      // Save changes
      await memoryStore.save();
  
      // Return as string
      return JSON.stringify({
        created: results.created.length > 0 ? results.created : null,
        failed: results.failed.length > 0 ? results.failed : null,
        message: `Created ${results.created.length} new relations. ${results.failed.length} relations failed.`
      });
    }
  });

• src/core/tools.ts:15-16 (registration)

  Invokes registerMemoryTools(server) as part of registering all tools, which includes the create_relations tool.

  console.error('[INFO] [tools] Registering memory tools...');
  registerMemoryTools(server);

• src/utils/validation.ts:12-16 (helper)

  Zod schema for individual relation objects used in CreateRelationsSchema.

  const RelationSchema = z.object({
    from: z.string().min(1).describe('Source entity name'),
    to: z.string().min(1).describe('Target entity name'),
    relationType: z.string().min(1).describe('Type of relationship (in active voice)')
  });