fix(mcp): guard undefined url in probe and use canonical McpAuthType

Author: waleedlatif1

apps/sim/app/api/mcp/servers/test-connection/route.ts

@@ -14,7 +14,7 @@ import {
 import { getParsedBody, withMcpAuth } from '@/lib/mcp/middleware'
 import { detectMcpAuthType } from '@/lib/mcp/oauth'
 import { resolveMcpConfigEnvVars } from '@/lib/mcp/resolve-config'
-import type { McpTransport } from '@/lib/mcp/types'
+import type { McpAuthType, McpTransport } from '@/lib/mcp/types'
 import { createMcpErrorResponse, createMcpSuccessResponse } from '@/lib/mcp/utils'
 
 const logger = createLogger('McpServerTestAPI')
@@ -33,7 +33,7 @@ interface TestConnectionResult {
   success: boolean
   error?: string
   authRequired?: boolean
-  authType?: 'none' | 'headers' | 'oauth'
+  authType?: McpAuthType
   serverInfo?: {
     name: string
     version: string
@@ -168,13 +168,15 @@ export const POST = withRouteHandler(
       const result: TestConnectionResult = { success: false }
 
       // Skip unauth connect when the server returns an RFC 9728 OAuth challenge.
-      const detectedAuthType = await detectMcpAuthType(testConfig.url)
-      if (detectedAuthType === 'oauth') {
-        result.authRequired = true
-        result.authType = 'oauth'
-        return createMcpSuccessResponse(result, 200)
+      if (testConfig.url) {
+        const detectedAuthType = await detectMcpAuthType(testConfig.url)
+        if (detectedAuthType === 'oauth') {
+          result.authRequired = true
+          result.authType = 'oauth'
+          return createMcpSuccessResponse(result, 200)
+        }
+        result.authType = detectedAuthType
       }
-      result.authType = detectedAuthType
 
       let client: McpClient | null = null
 

apps/sim/app/workspace/[workspaceId]/settings/components/mcp/components/mcp-server-form-modal/mcp-server-form-modal.tsx

@@ -17,7 +17,7 @@ import {
   Textarea,
 } from '@/components/emcn'
 import { cn } from '@/lib/core/utils/cn'
-import type { McpTransport } from '@/lib/mcp/types'
+import type { McpAuthType, McpTransport } from '@/lib/mcp/types'
 import {
   checkEnvVarTrigger,
   EnvVarDropdown,
@@ -52,7 +52,7 @@ export interface McpServerFormConfig {
   timeout: number
   oauthClientId?: string
   oauthClientSecret?: string
-  authType?: 'none' | 'headers' | 'oauth'
+  authType?: McpAuthType
 }
 
 export interface McpServerFormModalProps {

apps/sim/hooks/queries/mcp.ts

@@ -22,7 +22,13 @@ import {
 } from '@/lib/api/contracts/mcp'
 import { isLoopbackHostname } from '@/lib/core/utils/urls'
 import { sanitizeForHttp, sanitizeHeaders } from '@/lib/mcp/shared'
-import type { McpServerStatusConfig, McpTool, McpTransport, StoredMcpTool } from '@/lib/mcp/types'
+import type {
+  McpAuthType,
+  McpServerStatusConfig,
+  McpTool,
+  McpTransport,
+  StoredMcpTool,
+} from '@/lib/mcp/types'
 import { workflowMcpServerKeys } from '@/hooks/queries/workflow-mcp-servers'
 
 const logger = createLogger('McpQueries')
@@ -54,7 +60,7 @@ export interface McpServerInput {
   enabled: boolean
   oauthClientId?: string
   oauthClientSecret?: string
-  authType?: 'none' | 'headers' | 'oauth'
+  authType?: McpAuthType
 }
 
 async function fetchMcpServers(workspaceId: string, signal?: AbortSignal): Promise<McpServer[]> {