Fix integer parameter conversion in OpenAPI endpoints (#306)

Co-authored-by: samanhappy <samanhappy@gmail.com>

src/controllers/openApiController.ts

@@ -5,12 +5,83 @@ import {
   getToolStats,
   OpenAPIGenerationOptions,
 } from '../services/openApiGeneratorService.js';
+import { getServerByName } from '../services/mcpService.js';
 
 /**
  * Controller for OpenAPI generation endpoints
  * Provides OpenAPI specifications for MCP tools to enable OpenWebUI integration
  */
 
+/**
+ * Convert query parameters to their proper types based on the tool's input schema
+ */
+function convertQueryParametersToTypes(
+  queryParams: Record<string, any>,
+  inputSchema: Record<string, any>,
+): Record<string, any> {
+  if (!inputSchema || typeof inputSchema !== 'object' || !inputSchema.properties) {
+    return queryParams;
+  }
+
+  const convertedParams: Record<string, any> = {};
+  const properties = inputSchema.properties;
+
+  for (const [key, value] of Object.entries(queryParams)) {
+    const propDef = properties[key];
+    if (!propDef || typeof propDef !== 'object') {
+      // No schema definition found, keep as is
+      convertedParams[key] = value;
+      continue;
+    }
+
+    const propType = propDef.type;
+
+    try {
+      switch (propType) {
+        case 'integer':
+        case 'number':
+          // Convert string to number
+          if (typeof value === 'string') {
+            const numValue = propType === 'integer' ? parseInt(value, 10) : parseFloat(value);
+            convertedParams[key] = isNaN(numValue) ? value : numValue;
+          } else {
+            convertedParams[key] = value;
+          }
+          break;
+
+        case 'boolean':
+          // Convert string to boolean
+          if (typeof value === 'string') {
+            convertedParams[key] = value.toLowerCase() === 'true' || value === '1';
+          } else {
+            convertedParams[key] = value;
+          }
+          break;
+
+        case 'array':
+          // Handle array conversion if needed (e.g., comma-separated strings)
+          if (typeof value === 'string' && value.includes(',')) {
+            convertedParams[key] = value.split(',').map((item) => item.trim());
+          } else {
+            convertedParams[key] = value;
+          }
+          break;
+
+        default:
+          // For string and other types, keep as is
+          convertedParams[key] = value;
+          break;
+      }
+    } catch (error) {
+      // If conversion fails, keep the original value
+      console.warn(`Failed to convert parameter '${key}' to type '${propType}':`, error);
+      convertedParams[key] = value;
+    }
+  }
+
+  return convertedParams;
+}
+
 /**
  * Generate and return OpenAPI specification
  * GET /api/openapi.json
@@ -99,8 +170,24 @@ export const executeToolViaOpenAPI = async (req: Request, res: Response): Promis
     // Import handleCallToolRequest function
     const { handleCallToolRequest } = await import('../services/mcpService.js');
 
+    // Get the server info to access the tool's input schema
+    const serverInfo = getServerByName(serverName);
+    let inputSchema: Record<string, any> = {};
+
+    if (serverInfo) {
+      // Find the tool in the server's tools list
+      const fullToolName = `${serverName}-${toolName}`;
+      const tool = serverInfo.tools.find(
+        (t: any) => t.name === fullToolName || t.name === toolName,
+      );
+      if (tool && tool.inputSchema) {
+        inputSchema = tool.inputSchema as Record<string, any>;
+      }
+    }
+
     // Prepare arguments from query params (GET) or body (POST)
-    const args = req.method === 'GET' ? req.query : req.body || {};
+    let args = req.method === 'GET' ? req.query : req.body || {};
+    args = convertQueryParametersToTypes(args, inputSchema);
 
     // Create a mock request structure that matches what handleCallToolRequest expects
     const mockRequest = {

src/services/mcpService.ts

@@ -614,7 +614,7 @@ export const getServersInfo = (): Omit<ServerInfo, 'client' | 'transport'>[] =>
 };
 
 // Get server by name
-const getServerByName = (name: string): ServerInfo | undefined => {
+export const getServerByName = (name: string): ServerInfo | undefined => {
   return serverInfos.find((serverInfo) => serverInfo.name === name);
 };