Cedardiff MCP Server

Instructions

Implementation Reference

• src/index.ts:88-144 (handler)

  Main handler for the 'edit_file' tool within the CallToolRequestSchema. Validates the tool name, parses arguments, reads the target file, executes the CEDARScript, writes changes back, and returns success/error content.
  this.server.setRequestHandler(CallToolRequestSchema, async (request) => { if (request.params.name !== 'edit_file') { throw new McpError( ErrorCode.MethodNotFound, `Unknown tool: ${request.params.name}` ); } if (!request.params.arguments || typeof request.params.arguments.script !== 'string' || typeof request.params.arguments.workingDir !== 'string') { throw new McpError( ErrorCode.InvalidParams, 'Missing or invalid file/script arguments' ); } const { script, workingDir } = request.params.arguments; try { // Extract file path from script const fileMatch = script.match(/FILE\s+['"]([^'"]+)['"]/i); if (!fileMatch) { throw new Error('Script must specify a file using FILE "path"'); } const filePath = path.resolve(workingDir, fileMatch[1]); // Read the file const content = fs.readFileSync(filePath, 'utf8'); // Parse and execute the CEDARScript const newContent = this.executeCedarScript(content, script); // Write back to file fs.writeFileSync(filePath, newContent); return { content: [ { type: 'text', text: `Successfully edited ${filePath}`, }, ], }; } catch (error: unknown) { const errorMessage = error instanceof Error ? error.message : String(error); return { content: [ { type: 'text', text: `Error editing file: ${errorMessage}`, }, ], isError: true, }; } });
• src/index.ts:70-83 (schema)

  Input schema definition for the 'edit_file' tool, specifying required 'script' and 'workingDir' parameters.
  inputSchema: { type: 'object', properties: { script: { type: 'string', description: 'CEDARScript commands to execute' }, workingDir: { type: 'string', description: 'Working directory for resolving file paths' } }, required: ['script', 'workingDir'], },
• src/index.ts:65-86 (registration)

  Registers the 'edit_file' tool in the ListToolsRequestSchema handler, providing name, description, and schema.
  this.server.setRequestHandler(ListToolsRequestSchema, async () => ({ tools: [ { name: 'edit_file', description: 'Edit a file using CEDARScript syntax', inputSchema: { type: 'object', properties: { script: { type: 'string', description: 'CEDARScript commands to execute' }, workingDir: { type: 'string', description: 'Working directory for resolving file paths' } }, required: ['script', 'workingDir'], }, }, ], }));
• src/index.ts:147-160 (helper)

  Helper function that splits file content into lines, parses the CEDARScript into commands, executes them, and rejoins the lines.
  private executeCedarScript(content: string, script: string): string { const lines = content.split('\n'); let result = [...lines]; // Parse the script into commands const commands = this.parseScript(script); // Execute each command for (const command of commands) { result = this.executeCommand(command, result); } return result.join('\n'); }
• src/index.ts:162-190 (helper)

  Helper function that parses the CEDARScript string into an array of command objects by splitting on semicolons and dispatching to specific parsers.
  private parseScript(script: string): Array<{ type: 'update' | 'create' | 'rm_file' | 'mv_file'; caseStatement?: CaseStatement; filePath?: string; content?: string; targetPath?: string; }> { const commands: Array<{ type: 'update' | 'create' | 'rm_file' | 'mv_file'; targetPath?: string; }> = []; // Split into individual commands (separated by semicolons) const commandStrings = script.split(';').map(cmd => cmd.trim()).filter(Boolean); for (const cmdStr of commandStrings) { if (cmdStr.startsWith('UPDATE')) { commands.push(this.parseUpdateCommand(cmdStr)); } else if (cmdStr.startsWith('CREATE')) { commands.push(this.parseCreateCommand(cmdStr)); } else if (cmdStr.startsWith('RM')) { commands.push(this.parseRmCommand(cmdStr)); } else if (cmdStr.startsWith('MV')) { commands.push(this.parseMvCommand(cmdStr)); } } return commands; }