diff --git a/public/index.html b/public/index.html
index b0693b9c0..251da83eb 100644
--- a/public/index.html
+++ b/public/index.html
@@ -1739,7 +1739,7 @@
                                             </span>
                                         </div>
                                     </div>
-                                    <div class="range-block" data-source="openai,cohere,mistralai,custom">
+                                    <div class="range-block" data-source="openai,cohere,mistralai,custom,claude,openrouter">
                                         <label for="openai_function_calling" class="checkbox_label flexWrap widthFreeExpand">
                                             <input id="openai_function_calling" type="checkbox" />
                                             <span data-i18n="Enable function calling">Enable function calling</span>
diff --git a/public/scripts/openai.js b/public/scripts/openai.js
index f542d3f14..75c866096 100644
--- a/public/scripts/openai.js
+++ b/public/scripts/openai.js
@@ -1968,7 +1968,7 @@ async function registerFunctionTools(type, data) {
 }
 
 async function checkFunctionToolCalls(data) {
-    if ([chat_completion_sources.OPENAI, chat_completion_sources.CUSTOM, chat_completion_sources.MISTRALAI].includes(oai_settings.chat_completion_source)) {
+    if ([chat_completion_sources.OPENAI, chat_completion_sources.CUSTOM, chat_completion_sources.MISTRALAI, chat_completion_sources.OPENROUTER].includes(oai_settings.chat_completion_source)) {
         if (!Array.isArray(data?.choices)) {
             return;
         }
@@ -1999,6 +1999,21 @@ async function checkFunctionToolCalls(data) {
         }
     }
 
+    if ([chat_completion_sources.CLAUDE].includes(oai_settings.chat_completion_source)) {
+        if (!Array.isArray(data?.content)) {
+            return;
+        }
+
+        for (const content of data.content) {
+            if (content.type === 'tool_use') {
+                /** @type {FunctionToolCall} */
+                const args = { name: content.name, arguments: JSON.stringify(content.input) };
+                await eventSource.emit(event_types.LLM_FUNCTION_TOOL_CALL, args);
+                data.allowEmptyResponse = true;
+            }
+        }
+    }
+
     if ([chat_completion_sources.COHERE].includes(oai_settings.chat_completion_source)) {
         if (!Array.isArray(data?.tool_calls)) {
             return;
@@ -2028,6 +2043,8 @@ export function isFunctionCallingSupported() {
         chat_completion_sources.COHERE,
         chat_completion_sources.CUSTOM,
         chat_completion_sources.MISTRALAI,
+        chat_completion_sources.CLAUDE,
+        chat_completion_sources.OPENROUTER,
     ];
     return supportedSources.includes(oai_settings.chat_completion_source);
 }
diff --git a/src/endpoints/backends/chat-completions.js b/src/endpoints/backends/chat-completions.js
index 0d91f9657..33346c7ff 100644
--- a/src/endpoints/backends/chat-completions.js
+++ b/src/endpoints/backends/chat-completions.js
@@ -115,6 +115,7 @@ async function sendClaudeRequest(request, response) {
         request.socket.on('close', function () {
             controller.abort();
         });
+        const additionalHeaders = {};
         let use_system_prompt = (request.body.model.startsWith('claude-2') || request.body.model.startsWith('claude-3')) && request.body.claude_use_sysprompt;
         let converted_prompt = convertClaudeMessages(request.body.messages, request.body.assistant_prefill, use_system_prompt, request.body.human_sysprompt_message, request.body.char_name, request.body.user_name);
         // Add custom stop sequences
@@ -136,6 +137,14 @@ async function sendClaudeRequest(request, response) {
         if (use_system_prompt) {
             requestBody.system = converted_prompt.systemPrompt;
         }
+        if (Array.isArray(request.body.tools) && request.body.tools.length > 0) {
+            additionalHeaders['anthropic-beta'] = 'tools-2024-05-16';
+            requestBody.tool_choice = { type: request.body.tool_choice === 'required' ? 'any' : 'auto' };
+            requestBody.tools = request.body.tools
+                .filter(tool => tool.type === 'function')
+                .map(tool => tool.function)
+                .map(fn => ({ name: fn.name, description: fn.description, input_schema: fn.parameters }));
+        }
         console.log('Claude request:', requestBody);
 
         const generateResponse = await fetch(apiUrl + '/messages', {
@@ -146,6 +155,7 @@ async function sendClaudeRequest(request, response) {
                 'Content-Type': 'application/json',
                 'anthropic-version': '2023-06-01',
                 'x-api-key': apiKey,
+                ...additionalHeaders,
             },
             timeout: 0,
         });
@@ -163,8 +173,8 @@ async function sendClaudeRequest(request, response) {
             const responseText = generateResponseJson.content[0].text;
             console.log('Claude response:', generateResponseJson);
 
-            // Wrap it back to OAI format
-            const reply = { choices: [{ 'message': { 'content': responseText } }] };
+            // Wrap it back to OAI format + save the original content
+            const reply = { choices: [{ 'message': { 'content': responseText } }], content: generateResponseJson.content };
             return response.send(reply);
         }
     } catch (error) {