fix(ai-proxy): (multiple)(AG-154) fixed tools-functions calls coming back empty

changelog/unreleased/kong/ai-anthropic-fix-function-calling.yml

@@ -0,0 +1,3 @@
+message: "**ai-proxy**: Fixed a bug where tools (function) calls to Anthropic would return empty results."
+type: bugfix
+scope: Plugin

changelog/unreleased/kong/ai-bedrock-fix-function-calling.yml

@@ -0,0 +1,3 @@
+message: "**ai-proxy**: Fixed a bug where tools (function) calls to Bedrock would return empty results."
+type: bugfix
+scope: Plugin

changelog/unreleased/kong/ai-bedrock-fix-guardrails.yml

@@ -0,0 +1,3 @@
+message: "**ai-proxy**: Fixed a bug where Bedrock Guardrail config was ignored."
+type: bugfix
+scope: Plugin

changelog/unreleased/kong/ai-cohere-fix-function-calling.yml

@@ -0,0 +1,3 @@
+message: "**ai-proxy**: Fixed a bug where tools (function) calls to Cohere would return empty results."
+type: bugfix
+scope: Plugin

changelog/unreleased/kong/ai-gemini-blocks-content-safety.yml

@@ -0,0 +1,3 @@
+message: "**ai-proxy**: Fixed a bug where Gemini provider would return an error if content safety failed in AI Proxy."
+type: bugfix
+scope: Plugin

changelog/unreleased/kong/ai-gemini-fix-function-calling.yml

@@ -0,0 +1,3 @@
+message: "**ai-proxy**: Fixed a bug where tools (function) calls to Gemini (or via Vertex) would return empty results."
+type: bugfix
+scope: Plugin

kong/llm/drivers/anthropic.lua

@@ -44,25 +44,54 @@ local function kong_messages_to_claude_prompt(messages)
   return buf:get()
 end
 
+local inject_tool_calls = function(tool_calls)
+  local tools
+  for _, n in ipairs(tool_calls) do
+    tools = tools or {}
+    table.insert(tools, {
+      type = "tool_use",
+      id = n.id,
+      name = n["function"].name,
+      input = cjson.decode(n["function"].arguments)
+    })
+  end
+
+  return tools
+end
+
 -- reuse the messages structure of prompt
 -- extract messages and system from kong request
 local function kong_messages_to_claude_messages(messages)
   local msgs, system, n = {}, nil, 1
 
   for _, v in ipairs(messages) do
-    if v.role ~= "assistant" and v.role ~= "user" then
+    if v.role ~= "assistant" and v.role ~= "user" and v.role ~= "tool" then
       system = v.content
-
     else
-      msgs[n] = v
+      if v.role == "assistant" and v.tool_calls then
+        msgs[n] = {
+          role = v.role,
+          content = inject_tool_calls(v.tool_calls),
+        }
+      elseif v.role == "tool" then
+        msgs[n] = {
+          role = "user",
+          content = {{
+            type = "tool_result",
+            tool_use_id = v.tool_call_id,
+            content = v.content
+          }},
+        }
+      else
+        msgs[n] = v
+      end
       n = n + 1
     end
   end
 
   return msgs, system
 end
 
-
 local function to_claude_prompt(req)
   if req.prompt then
     return kong_prompt_to_claude_prompt(req.prompt)
@@ -83,6 +112,21 @@ local function to_claude_messages(req)
   return nil, nil, "request is missing .messages command"
 end
 
+local function to_tools(in_tools)
+  local out_tools = {}
+
+  for i, v in ipairs(in_tools) do
+    if v['function'] then
+      v['function'].input_schema = v['function'].parameters
+      v['function'].parameters = nil
+
+      table.insert(out_tools, v['function'])
+    end
+  end
+
+  return out_tools
+end
+
 local transformers_to = {
   ["llm/v1/chat"] = function(request_table, model)
     local messages = {}
@@ -98,6 +142,10 @@ local transformers_to = {
     messages.model = model.name or request_table.model
     messages.stream = request_table.stream or false  -- explicitly set this if nil
 
+    -- handle function calling translation from OpenAI format
+    messages.tools = request_table.tools and to_tools(request_table.tools)
+    messages.tool_choice = request_table.tool_choice
+
     return messages, "application/json", nil
   end,
 
@@ -243,16 +291,37 @@ local transformers_from = {
     local function extract_text_from_content(content)
       local buf = buffer.new()
       for i, v in ipairs(content) do
-        if i ~= 1 then
-          buf:put("\n")
+        if v.text then
+          if i ~= 1 then
+            buf:put("\n")
+          end
+          buf:put(v.text)
         end
-
-        buf:put(v.text)
       end
 
       return buf:tostring()
     end
 
+    local function extract_tools_from_content(content)
+      local tools
+      for i, v in ipairs(content) do
+        if v.type == "tool_use" then
+          tools = tools or {}
+
+          table.insert(tools, {
+            id = v.id,
+            type = "function",
+            ['function'] = {
+              name = v.name,
+              arguments = cjson.encode(v.input),
+            }
+          })
+        end
+      end
+
+      return tools
+    end
+
     if response_table.content then
       local usage = response_table.usage
 
@@ -275,13 +344,14 @@ local transformers_from = {
             message = {
               role = "assistant",
               content = extract_text_from_content(response_table.content),
+              tool_calls = extract_tools_from_content(response_table.content)
             },
             finish_reason = response_table.stop_reason,
           },
         },
         usage = usage,
         model = response_table.model,
-        object = "chat.content",
+        object = "chat.completion",
       }
 
       return cjson.encode(res)
@@ -330,7 +400,10 @@ function _M.from_format(response_string, model_info, route_type)
   end
 
   local ok, response_string, err, metadata = pcall(transform, response_string, model_info, route_type)
-  if not ok or err then
+  if not ok then
+    err = response_string
+  end
+  if err then
     return nil, fmt("transformation failed from type %s://%s: %s",
                     model_info.provider,
                     route_type,
@@ -488,7 +561,7 @@ function _M.configure_request(conf)
     end
   end
 
-  -- if auth_param_location is "form", it will have already been set in a pre-request hook
+  -- if auth_param_location is "body", it will have already been set in a pre-request hook
   return true, nil
 end