enh: custom headers for external tool servers

backend/open_webui/routers/configs.py

@@ -144,6 +144,7 @@ class ToolServerConnection(BaseModel):
     path: str
     type: Optional[str] = "openapi"  # openapi, mcp
     auth_type: Optional[str]
+    headers: Optional[dict]
     key: Optional[str]
     config: Optional[dict]
 
@@ -282,10 +283,14 @@ async def verify_tool_servers_config(
                                     token = oauth_token.get("access_token", "")
                         except Exception as e:
                             pass
-
                     if token:
                         headers = {"Authorization": f"Bearer {token}"}
 
+                    if form_data.headers:
+                        if headers is None:
+                            headers = {}
+                        headers.update(form_data.headers)
+
                     await client.connect(form_data.url, headers=headers)
                     specs = await client.list_tool_specs()
                     return {
@@ -303,6 +308,7 @@ async def verify_tool_servers_config(
                         await client.disconnect()
         else:  # openapi
             token = None
+            headers = None
             if form_data.auth_type == "bearer":
                 token = form_data.key
             elif form_data.auth_type == "session":
@@ -323,8 +329,16 @@ async def verify_tool_servers_config(
                 except Exception as e:
                     pass
 
+            if token:
+                headers = {"Authorization": f"Bearer {token}"}
+
+            if form_data.headers:
+                if headers is None:
+                    headers = {}
+                headers.update(form_data.headers)
+
             url = get_tool_server_url(form_data.url, form_data.path)
-            return await get_tool_server_data(token, url)
+            return await get_tool_server_data(url, headers=headers)
     except HTTPException as e:
         raise e
     except Exception as e:

backend/open_webui/utils/middleware.py

@@ -312,7 +312,11 @@ async def chat_completion_tools_handler(
             for message in recent_messages
         )
 
-        prompt = f"History:\n{chat_history}\nQuery: {user_message}" if chat_history else f"Query: {user_message}"
+        prompt = (
+            f"History:\n{chat_history}\nQuery: {user_message}"
+            if chat_history
+            else f"Query: {user_message}"
+        )
 
         return {
             "model": task_model_id,
@@ -1327,7 +1331,6 @@ async def process_chat_payload(request, form_data, user, metadata, model):
                         continue
 
                     auth_type = mcp_server_connection.get("auth_type", "")
-
                     headers = {}
                     if auth_type == "bearer":
                         headers["Authorization"] = (
@@ -1363,6 +1366,11 @@ async def process_chat_payload(request, form_data, user, metadata, model):
                             log.error(f"Error getting OAuth token: {e}")
                             oauth_token = None
 
+                    connection_headers = mcp_server_connection.get("headers", None)
+                    if connection_headers:
+                        for key, value in connection_headers.items():
+                            headers[key] = value
+
                     mcp_clients[server_id] = MCPClient()
                     await mcp_clients[server_id].connect(
                         url=mcp_server_connection.get("url", ""),

backend/open_webui/utils/tools.py

@@ -155,7 +155,9 @@ async def get_tools(
                         auth_type = tool_server_connection.get("auth_type", "bearer")
 
                         cookies = {}
-                        headers = {}
+                        headers = {
+                            "Content-Type": "application/json",
+                        }
 
                         if auth_type == "bearer":
                             headers["Authorization"] = (
@@ -177,7 +179,10 @@ async def get_tools(
                                     f"Bearer {oauth_token.get('access_token', '')}"
                                 )
 
-                        headers["Content-Type"] = "application/json"
+                        connection_headers = tool_server_connection.get("headers", None)
+                        if connection_headers:
+                            for key, value in connection_headers.items():
+                                headers[key] = value
 
                         def make_tool_function(
                             function_name, tool_server_data, headers
@@ -561,20 +566,21 @@ async def get_tool_servers(request: Request):
     return tool_servers
 
 
-async def get_tool_server_data(token: str, url: str) -> Dict[str, Any]:
+async def get_tool_server_data(url: str, headers: Optional[dict]) -> Dict[str, Any]:
-    headers = {
+    _headers = {
         "Accept": "application/json",
         "Content-Type": "application/json",
     }
-    if token:
+
-        headers["Authorization"] = f"Bearer {token}"
+    if headers:
+        _headers.update(headers)
 
     error = None
     try:
         timeout = aiohttp.ClientTimeout(total=AIOHTTP_CLIENT_TIMEOUT_TOOL_SERVER_DATA)
         async with aiohttp.ClientSession(timeout=timeout, trust_env=True) as session:
             async with session.get(
-                url, headers=headers, ssl=AIOHTTP_CLIENT_SESSION_TOOL_SERVER_SSL
+                url, headers=_headers, ssl=AIOHTTP_CLIENT_SESSION_TOOL_SERVER_SSL
             ) as response:
                 if response.status != 200:
                     error_body = await response.json()
@@ -644,7 +650,10 @@ async def get_tool_servers_data(servers: List[Dict[str, Any]]) -> List[Dict[str,
                 openapi_path = server.get("path", "openapi.json")
                 spec_url = get_tool_server_url(server_url, openapi_path)
                 # Fetch from URL
-                task = get_tool_server_data(token, spec_url)
+                task = get_tool_server_data(
+                    spec_url,
+                    {"Authorization": f"Bearer {token}"} if token else None,
+                )
             elif spec_type == "json" and server.get("spec", ""):
                 # Use provided JSON spec
                 spec_json = None

src/lib/components/AddConnectionModal.svelte

@@ -426,7 +426,7 @@
 									<div class="flex-1">
 										<Tooltip
 											content={$i18n.t(
-												'Enter additional headers in JSON format (e.g. {{\'{{"X-Custom-Header": "value"}}\'}})'
+												'Enter additional headers in JSON format (e.g. {"X-Custom-Header": "value"}'
 											)}
 										>
 											<Textarea

src/lib/components/AddToolServerModal.svelte

@@ -22,6 +22,7 @@
 	import AccessControl from './workspace/common/AccessControl.svelte';
 	import Spinner from '$lib/components/common/Spinner.svelte';
 	import XMark from '$lib/components/icons/XMark.svelte';
+	import Textarea from './common/Textarea.svelte';
 
 	export let onSubmit: Function = () => {};
 	export let onDelete: Function = () => {};
@@ -44,6 +45,7 @@
 
 	let auth_type = 'bearer';
 	let key = '';
+	let headers = '';
 
 	let accessControl = {};
 
@@ -110,6 +112,20 @@
 			}
 		}
 
+		if (headers) {
+			try {
+				let _headers = JSON.parse(headers);
+				if (typeof _headers !== 'object' || Array.isArray(_headers)) {
+					_headers = null;
+					throw new Error('Headers must be a valid JSON object');
+				}
+				headers = JSON.stringify(_headers, null, 2);
+			} catch (error) {
+				toast.error($i18n.t('Headers must be a valid JSON object'));
+				return;
+			}
+		}
+
 		if (direct) {
 			const res = await getToolServerData(
 				auth_type === 'bearer' ? key : localStorage.token,
@@ -128,6 +144,7 @@
 				path,
 				type,
 				auth_type,
+				headers: headers ? JSON.parse(headers) : undefined,
 				key,
 				config: {
 					enable: enable,
@@ -177,6 +194,7 @@
 				if (data.path) path = data.path;
 
 				if (data.auth_type) auth_type = data.auth_type;
+				if (data.headers) headers = JSON.stringify(data.headers, null, 2);
 				if (data.key) key = data.key;
 
 				if (data.info) {
@@ -210,6 +228,7 @@
 				path,
 
 				auth_type,
+				headers: headers ? JSON.parse(headers) : undefined,
 				key,
 
 				info: {
@@ -256,6 +275,19 @@
 			}
 		}
 
+		if (headers) {
+			try {
+				const _headers = JSON.parse(headers);
+				if (typeof _headers !== 'object' || Array.isArray(_headers)) {
+					throw new Error('Headers must be a valid JSON object');
+				}
+				headers = JSON.stringify(_headers, null, 2);
+			} catch (error) {
+				toast.error($i18n.t('Headers must be a valid JSON object'));
+				return;
+			}
+		}
+
 		const connection = {
 			type,
 			url,
@@ -265,9 +297,12 @@
 			path,
 
 			auth_type,
+			headers: headers ? JSON.parse(headers) : undefined,
+
 			key,
 			config: {
 				enable: enable,
+
 				access_control: accessControl
 			},
 			info: {
@@ -313,6 +348,8 @@
 			path = connection?.path ?? 'openapi.json';
 
 			auth_type = connection?.auth_type ?? 'bearer';
+			headers = connection?.headers ? JSON.stringify(connection.headers, null, 2) : '';
+
 			key = connection?.key ?? '';
 
 			id = connection.info?.id ?? '';
@@ -657,6 +694,33 @@
 						</div>
 
 						{#if !direct}
+							<div class="flex gap-2 mt-2">
+								<div class="flex flex-col w-full">
+									<label
+										for="headers-input"
+										class={`mb-0.5 text-xs text-gray-500
+								${($settings?.highContrastMode ?? false) ? 'text-gray-800 dark:text-gray-100' : ''}`}
+										>{$i18n.t('Headers')}</label
+									>
+
+									<div class="flex-1">
+										<Tooltip
+											content={$i18n.t(
+												'Enter additional headers in JSON format (e.g. {"X-Custom-Header": "value"}'
+											)}
+										>
+											<Textarea
+												className="w-full text-sm outline-hidden"
+												bind:value={headers}
+												placeholder={$i18n.t('Enter additional headers in JSON format')}
+												required={false}
+												minSize={30}
+											/>
+										</Tooltip>
+									</div>
+								</div>
+							</div>
+
 							<hr class=" border-gray-100 dark:border-gray-700/10 my-2.5 w-full" />
 
 							<div class="flex gap-2">