PureScript MCP Server

Instructions

Implementation Reference

• index.js:800-812 (handler)

  Handler function that implements the getModuleName tool. Parses PureScript code using Tree-sitter, queries for the qualified_module node, extracts and cleans the module name text.

  "getModuleName": async (args) => {
      if (!treeSitterInitialized) throw new Error("Tree-sitter not initialized.");
      const code = await getCodeFromInput(args, true);
      const tree = purescriptTsParser.parse(code);
      // Corrected query to capture the full text of the qualified_module node
      const query = new Query(PureScriptLanguage, `(purescript name: (qualified_module) @module.qname)`);
      const captures = query.captures(tree.rootNode);
      if (captures.length > 0 && captures[0].name === 'module.qname') {
          // The text of the qualified_module node itself is the full module name
          return { content: [{ type: "text", text: JSON.stringify(captures[0].node.text.replace(/\s+/g, ''), null, 2) }] };
      }
      return { content: [{ type: "text", text: JSON.stringify(null, null, 2) }] };
  },

• index.js:575-587 (schema)

  Input schema definition for the getModuleName tool, specifying parameters filePath or code.

  {
      name: "getModuleName",
      description: "Extract the module name (like 'Data.List' or 'Main') from PureScript code. Works on files or code snippets without needing the IDE server. Useful for understanding code structure.",
      inputSchema: {
          type: "object",
          properties: {
              filePath: { type: "string", description: "Absolute path to the PureScript file. Only absolute paths are supported." },
              code: { type: "string", description: "PureScript code string." }
          },
          additionalProperties: false,
          description: "Exactly one of 'filePath' or 'code' must be provided."
      }
  },

• index.js:1159-1164 (registration)

  Registration via tools/list endpoint that returns the TOOL_DEFINITIONS array including getModuleName.

      const toolsToExclude = ['query_purescript_ast', 'query_purs_ide']; // Keep query_purs_ide for now, for direct access if needed
      const filteredToolDefinitions = TOOL_DEFINITIONS.filter(
          tool => !toolsToExclude.includes(tool.name)
      );
      return createSuccessResponse(id, { tools: filteredToolDefinitions });
  }

• index.js:125-151 (helper)

  Helper function getCodeFromInput used by getModuleName to retrieve code from either filePath or inline code argument.

  // Helper to get code from input args (filePath or code string)
  async function getCodeFromInput(args, isModuleOriented = true) {
      if (isModuleOriented) {
          const hasFilePath = args && typeof args.filePath === 'string';
          const hasCode = args && typeof args.code === 'string';
  
          if ((hasFilePath && hasCode) || (!hasFilePath && !hasCode)) {
              throw new Error("Invalid input: Exactly one of 'filePath' or 'code' must be provided for module-oriented tools.");
          }
          if (hasFilePath) {
              if (!path.isAbsolute(args.filePath)) {
                  throw new Error(`Invalid filePath: '${args.filePath}' is not an absolute path. Only absolute paths are supported.`);
              }
              try {
                  return await fs.readFile(args.filePath, 'utf-8');
              } catch (e) {
                  throw new Error(`Failed to read file at ${args.filePath}: ${e.message}`);
              }
          }
          return args.code;
      } else { // Snippet-oriented
          if (!args || typeof args.code !== 'string') {
              throw new Error("Invalid input: 'code' (string) is required for snippet-oriented tools.");
          }
          return args.code;
      }
  }