Vibe-Coder MCP Server

Implementation Reference

• src/mcp-server.ts:692-739 (handler)

  The main handler function for the 'save_document' tool. Validates inputs, checks feature and document existence, maps string to DocumentType enum, and delegates saving to documentStorage helpers based on whether custom filePath is provided.

  async ({ featureId, documentType, filePath }) => {
    try {
      // Check if the feature exists
      const feature = getFeature(featureId);
      if (!feature) {
        throw new Error(`Feature ${featureId} not found`);
      }
      
      // Map the string to DocumentType enum
      let docType: DocumentType;
      if (documentType === 'prd') {
        docType = DocumentType.PRD;
      } else if (documentType === 'implementation-plan') {
        docType = DocumentType.IMPLEMENTATION_PLAN;
      } else {
        throw new Error(`Invalid document type: ${documentType}. Expected 'prd' or 'implementation-plan'`);
      }
      
      // Check if the document exists
      if (!documentStorage.hasDocument(feature.id, docType)) {
        throw new Error(`Document of type ${documentType} not found for feature ${feature.id}`);
      }
      
      let savedPath: string;
      
      // If a custom path was provided, use it; otherwise, save to the default path
      if (filePath) {
        savedPath = await documentStorage.saveDocumentToCustomPath(feature.id, docType, filePath);
      } else {
        savedPath = await documentStorage.saveDocumentToFile(feature.id, docType);
      }
      
      return {
        content: [{
          type: "text",
          text: `Document saved successfully to: ${savedPath}`
        }]
      };
    } catch (error) {
      return {
        content: [{
          type: "text",
          text: `Error saving document: ${error instanceof Error ? error.message : String(error)}`
        }],
        isError: true
      };
    }
  }

• src/mcp-server.ts:687-690 (schema)

  Zod input schema for the save_document tool parameters: featureId (required), documentType (required, e.g. 'prd'), filePath (optional custom path).

  {
    featureId: z.string().min(1),
    documentType: z.string().min(1),
    filePath: z.string().min(1).optional()

• src/mcp-server.ts:685-740 (registration)

  Registration of the save_document tool on the MCP server using server.tool(name, inputSchema, handlerFn).

  server.tool(
    "save_document",
    {
      featureId: z.string().min(1),
      documentType: z.string().min(1),
      filePath: z.string().min(1).optional()
    },
    async ({ featureId, documentType, filePath }) => {
      try {
        // Check if the feature exists
        const feature = getFeature(featureId);
        if (!feature) {
          throw new Error(`Feature ${featureId} not found`);
        }
        
        // Map the string to DocumentType enum
        let docType: DocumentType;
        if (documentType === 'prd') {
          docType = DocumentType.PRD;
        } else if (documentType === 'implementation-plan') {
          docType = DocumentType.IMPLEMENTATION_PLAN;
        } else {
          throw new Error(`Invalid document type: ${documentType}. Expected 'prd' or 'implementation-plan'`);
        }
        
        // Check if the document exists
        if (!documentStorage.hasDocument(feature.id, docType)) {
          throw new Error(`Document of type ${documentType} not found for feature ${feature.id}`);
        }
        
        let savedPath: string;
        
        // If a custom path was provided, use it; otherwise, save to the default path
        if (filePath) {
          savedPath = await documentStorage.saveDocumentToCustomPath(feature.id, docType, filePath);
        } else {
          savedPath = await documentStorage.saveDocumentToFile(feature.id, docType);
        }
        
        return {
          content: [{
            type: "text",
            text: `Document saved successfully to: ${savedPath}`
          }]
        };
      } catch (error) {
        return {
          content: [{
            type: "text",
            text: `Error saving document: ${error instanceof Error ? error.message : String(error)}`
          }],
          isError: true
        };
      }
    }
  );

• src/document-storage.ts:250-267 (helper)

  Helper function that saves a document to its default file path (computed as documents/{featureId}/{type}.md), ensures directory exists, writes content, updates isSaved metadata.

  public async saveDocumentToFile(featureId: string, type: DocumentType): Promise<string> {
    const document = this.getDocument(featureId, type);
    
    if (!document) {
      throw new Error(`Document not found: ${featureId}:${type}`);
    }
    
    const filePath = document.metadata.filePath!;
    const dirPath = path.dirname(filePath);
    
    await this.ensureDir(dirPath);
    await fs.writeFile(filePath, document.content, 'utf-8');
    
    // Update metadata
    document.metadata.isSaved = true;
    
    return filePath;
  }

• src/document-storage.ts:276-298 (helper)

  Helper function that saves a document to a custom file path after validating it (path traversal protection, .md extension, within rootDir), ensures dir, writes content, marks saved.

  public async saveDocumentToCustomPath(
    featureId: string, 
    type: DocumentType, 
    customPath: string
  ): Promise<string> {
    const document = this.getDocument(featureId, type);
    
    if (!document) {
      throw new Error(`Document not found: ${featureId}:${type}`);
    }
    
    const validatedPath = this.validateCustomPath(customPath);
    const dirPath = path.dirname(validatedPath);
    
    await this.ensureDir(dirPath);
    await fs.writeFile(validatedPath, document.content, 'utf-8');
    
    // Don't update metadata.filePath as we want to keep the default path
    // Just mark it as saved
    document.metadata.isSaved = true;
    
    return validatedPath;
  }