Feat: add primitive support for function calls (#6840)

### What problem does this PR solve?

This PR introduces ​**​primitive support for function calls​**​,
enabling the system to handle basic function call capabilities.
However, this feature is currently experimental and ​**​not yet enabled
for general use​**​, as it is only supported by a subset of models,
namely, Qwen and OpenAI models.

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

api/apps/sdk/session.py

@@ -116,7 +116,7 @@ def create_agent_session(tenant_id, agent_id):
 
     for ans in canvas.run(stream=False):
         pass
-    
+
     cvs.dsl = json.loads(str(canvas))
     conv = {"id": get_uuid(), "dialog_id": cvs.id, "user_id": user_id, "message": [{"role": "assistant", "content": canvas.get_prologue()}], "source": "agent", "dsl": cvs.dsl}
     API4ConversationService.save(**conv)
@@ -243,6 +243,11 @@ def chat_completion_openai_like(tenant_id, chat_id):
     msg = None
     msg = [m for m in messages if m["role"] != "system" and (m["role"] != "assistant" or msg)]
 
+    # tools = get_tools()
+    # toolcall_session = SimpleFunctionCallServer()
+    tools = None
+    toolcall_session = None
+
     if req.get("stream", True):
         # The value for the usage field on all chunks except for the last one will be null.
         # The usage field on the last chunk contains token usage statistics for the entire request.
@@ -262,7 +267,7 @@ def chat_completion_openai_like(tenant_id, chat_id):
             }
 
             try:
-                for ans in chat(dia, msg, True):
+                for ans in chat(dia, msg, True, toolcall_session=toolcall_session, tools=tools):
                     answer = ans["answer"]
 
                     reasoning_match = re.search(r"<think>(.*?)</think>", answer, flags=re.DOTALL)
@@ -325,7 +330,7 @@ def chat_completion_openai_like(tenant_id, chat_id):
         return resp
     else:
         answer = None
-        for ans in chat(dia, msg, False):
+        for ans in chat(dia, msg, False, toolcall_session=toolcall_session, tools=tools):
             # focus answer content only
             answer = ans
             break

api/db/services/dialog_service.py

@@ -145,6 +145,9 @@ def chat(dialog, messages, stream=True, **kwargs):
         chat_mdl = LLMBundle(dialog.tenant_id, LLMType.IMAGE2TEXT, dialog.llm_id)
     else:
         chat_mdl = LLMBundle(dialog.tenant_id, LLMType.CHAT, dialog.llm_id)
+        toolcall_session, tools = kwargs.get("toolcall_session"), kwargs.get("tools")
+        if toolcall_session and tools:
+            chat_mdl.bind_tools(toolcall_session, tools)
 
     bind_llm_ts = timer()
 
@@ -338,7 +341,7 @@ def chat(dialog, messages, stream=True, **kwargs):
         langfuse_output = {"time_elapsed:": re.sub(r"\n", "  \n", langfuse_output), "created_at": time.time()}
 
         # Add a condition check to call the end method only if langfuse_tracer exists
-        if langfuse_tracer and 'langfuse_generation' in locals():
+        if langfuse_tracer and "langfuse_generation" in locals():
             langfuse_generation.end(output=langfuse_output)
 
         return {"answer": think + answer, "reference": refs, "prompt": re.sub(r"\n", "  \n", prompt), "created_at": time.time()}

api/db/services/llm_service.py

@@ -102,6 +102,9 @@ class TenantLLMService(CommonService):
         mdlnm, fid = TenantLLMService.split_model_name_and_factory(mdlnm)
         if model_config:
             model_config = model_config.to_dict()
+            llm = LLMService.query(llm_name=mdlnm) if not fid else LLMService.query(llm_name=mdlnm, fid=fid)
+            if llm:
+                model_config["is_tools"] = llm[0].is_tools
         if not model_config:
             if llm_type in [LLMType.EMBEDDING, LLMType.RERANK]:
                 llm = LLMService.query(llm_name=mdlnm) if not fid else LLMService.query(llm_name=mdlnm, fid=fid)
@@ -206,6 +209,8 @@ class LLMBundle:
         model_config = TenantLLMService.get_model_config(tenant_id, llm_type, llm_name)
         self.max_length = model_config.get("max_tokens", 8192)
 
+        self.is_tools = model_config.get("is_tools", False)
+
         langfuse_keys = TenantLangfuseService.filter_by_tenant(tenant_id=tenant_id)
         if langfuse_keys:
             langfuse = Langfuse(public_key=langfuse_keys.public_key, secret_key=langfuse_keys.secret_key, host=langfuse_keys.host)
@@ -215,6 +220,11 @@ class LLMBundle:
         else:
             self.langfuse = None
 
+    def bind_tools(self, toolcall_session, tools):
+        if not self.is_tools:
+            return
+        self.mdl.bind_tools(toolcall_session, tools)
+
     def encode(self, texts: list):
         if self.langfuse:
             generation = self.trace.generation(name="encode", model=self.llm_name, input={"texts": texts})
@@ -307,11 +317,31 @@ class LLMBundle:
         if self.langfuse:
             span.end()
 
+    def _remove_reasoning_content(self, txt: str) -> str:
+        first_think_start = txt.find("<think>")
+        if first_think_start == -1:
+            return txt
+
+        last_think_end = txt.rfind("</think>")
+        if last_think_end == -1:
+            return txt
+
+        if last_think_end < first_think_start:
+            return txt
+
+        return txt[last_think_end + len("</think>") :]
+
     def chat(self, system, history, gen_conf):
         if self.langfuse:
             generation = self.trace.generation(name="chat", model=self.llm_name, input={"system": system, "history": history})
 
-        txt, used_tokens = self.mdl.chat(system, history, gen_conf)
+        chat = self.mdl.chat
+        if self.is_tools and self.mdl.is_tools:
+            chat = self.mdl.chat_with_tools
+
+        txt, used_tokens = chat(system, history, gen_conf)
+        txt = self._remove_reasoning_content(txt)
+
         if isinstance(txt, int) and not TenantLLMService.increase_usage(self.tenant_id, self.llm_type, used_tokens, self.llm_name):
             logging.error("LLMBundle.chat can't update token usage for {}/CHAT llm_name: {}, used_tokens: {}".format(self.tenant_id, self.llm_name, used_tokens))
 
@@ -325,7 +355,12 @@ class LLMBundle:
             generation = self.trace.generation(name="chat_streamly", model=self.llm_name, input={"system": system, "history": history})
 
         ans = ""
-        for txt in self.mdl.chat_streamly(system, history, gen_conf):
+        chat_streamly = self.mdl.chat_streamly
+
+        if self.is_tools and self.mdl.is_tools:
+            chat_streamly = self.mdl.chat_streamly_with_tools
+
+        for txt in chat_streamly(system, history, gen_conf):
             if isinstance(txt, int):
                 if self.langfuse:
                     generation.end(output={"output": ans})

api/utils/api_utils.py

@@ -13,9 +13,9 @@
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
 #
-import logging
 import functools
 import json
+import logging
 import random
 import time
 from base64 import b64encode
@@ -27,59 +27,60 @@ from uuid import uuid1
 
 import requests
 from flask import (
-    Response, jsonify, send_file, make_response,
+    Response,
+    jsonify,
+    make_response,
+    send_file,
+)
+from flask import (
     request as flask_request,
 )
 from itsdangerous import URLSafeTimedSerializer
 from werkzeug.http import HTTP_STATUS_CODES
 
-from api.db.db_models import APIToken
 from api import settings
+from api.constants import REQUEST_MAX_WAIT_SEC, REQUEST_WAIT_SEC
+from api.db.db_models import APIToken
+from api.utils import CustomJSONEncoder, get_uuid, json_dumps
 
-from api.utils import CustomJSONEncoder, get_uuid
-from api.utils import json_dumps
-from api.constants import REQUEST_WAIT_SEC, REQUEST_MAX_WAIT_SEC
-
-requests.models.complexjson.dumps = functools.partial(
-    json.dumps, cls=CustomJSONEncoder)
+requests.models.complexjson.dumps = functools.partial(json.dumps, cls=CustomJSONEncoder)
 
 
 def request(**kwargs):
     sess = requests.Session()
-    stream = kwargs.pop('stream', sess.stream)
-    timeout = kwargs.pop('timeout', None)
-    kwargs['headers'] = {
-        k.replace(
-            '_',
-            '-').upper(): v for k,
-                                v in kwargs.get(
-            'headers',
-            {}).items()}
+    stream = kwargs.pop("stream", sess.stream)
+    timeout = kwargs.pop("timeout", None)
+    kwargs["headers"] = {k.replace("_", "-").upper(): v for k, v in kwargs.get("headers", {}).items()}
     prepped = requests.Request(**kwargs).prepare()
 
     if settings.CLIENT_AUTHENTICATION and settings.HTTP_APP_KEY and settings.SECRET_KEY:
         timestamp = str(round(time() * 1000))
         nonce = str(uuid1())
-        signature = b64encode(HMAC(settings.SECRET_KEY.encode('ascii'), b'\n'.join([
-            timestamp.encode('ascii'),
-            nonce.encode('ascii'),
-            settings.HTTP_APP_KEY.encode('ascii'),
-            prepped.path_url.encode('ascii'),
-            prepped.body if kwargs.get('json') else b'',
-            urlencode(
-                sorted(
-                    kwargs['data'].items()),
-                quote_via=quote,
-                safe='-._~').encode('ascii')
-            if kwargs.get('data') and isinstance(kwargs['data'], dict) else b'',
-        ]), 'sha1').digest()).decode('ascii')
+        signature = b64encode(
+            HMAC(
+                settings.SECRET_KEY.encode("ascii"),
+                b"\n".join(
+                    [
+                        timestamp.encode("ascii"),
+                        nonce.encode("ascii"),
+                        settings.HTTP_APP_KEY.encode("ascii"),
+                        prepped.path_url.encode("ascii"),
+                        prepped.body if kwargs.get("json") else b"",
+                        urlencode(sorted(kwargs["data"].items()), quote_via=quote, safe="-._~").encode("ascii") if kwargs.get("data") and isinstance(kwargs["data"], dict) else b"",
+                    ]
+                ),
+                "sha1",
+            ).digest()
+        ).decode("ascii")
 
-        prepped.headers.update({
-            'TIMESTAMP': timestamp,
-            'NONCE': nonce,
-            'APP-KEY': settings.HTTP_APP_KEY,
-            'SIGNATURE': signature,
-        })
+        prepped.headers.update(
+            {
+                "TIMESTAMP": timestamp,
+                "NONCE": nonce,
+                "APP-KEY": settings.HTTP_APP_KEY,
+                "SIGNATURE": signature,
+            }
+        )
 
     return sess.send(prepped, stream=stream, timeout=timeout)
 
@@ -87,7 +88,7 @@ def request(**kwargs):
 def get_exponential_backoff_interval(retries, full_jitter=False):
     """Calculate the exponential backoff wait time."""
     # Will be zero if factor equals 0
-    countdown = min(REQUEST_MAX_WAIT_SEC, REQUEST_WAIT_SEC * (2 ** retries))
+    countdown = min(REQUEST_MAX_WAIT_SEC, REQUEST_WAIT_SEC * (2**retries))
     # Full jitter according to
     # https://aws.amazon.com/blogs/architecture/exponential-backoff-and-jitter/
     if full_jitter:
@@ -96,12 +97,9 @@ def get_exponential_backoff_interval(retries, full_jitter=False):
     return max(0, countdown)
 
 
-def get_data_error_result(code=settings.RetCode.DATA_ERROR,
-                          message='Sorry! Data missing!'):
+def get_data_error_result(code=settings.RetCode.DATA_ERROR, message="Sorry! Data missing!"):
     logging.exception(Exception(message))
-    result_dict = {
-        "code": code,
-        "message": message}
+    result_dict = {"code": code, "message": message}
     response = {}
     for key, value in result_dict.items():
         if value is None and key != "code":
@@ -119,23 +117,27 @@ def server_error_response(e):
     except BaseException:
         pass
     if len(e.args) > 1:
-        return get_json_result(
-            code=settings.RetCode.EXCEPTION_ERROR, message=repr(e.args[0]), data=e.args[1])
+        return get_json_result(code=settings.RetCode.EXCEPTION_ERROR, message=repr(e.args[0]), data=e.args[1])
     if repr(e).find("index_not_found_exception") >= 0:
-        return get_json_result(code=settings.RetCode.EXCEPTION_ERROR,
-                               message="No chunk found, please upload file and parse it.")
+        return get_json_result(code=settings.RetCode.EXCEPTION_ERROR, message="No chunk found, please upload file and parse it.")
 
     return get_json_result(code=settings.RetCode.EXCEPTION_ERROR, message=repr(e))
 
 
 def error_response(response_code, message=None):
     if message is None:
-        message = HTTP_STATUS_CODES.get(response_code, 'Unknown Error')
+        message = HTTP_STATUS_CODES.get(response_code, "Unknown Error")
 
-    return Response(json.dumps({
-        'message': message,
-        'code': response_code,
-    }), status=response_code, mimetype='application/json')
+    return Response(
+        json.dumps(
+            {
+                "message": message,
+                "code": response_code,
+            }
+        ),
+        status=response_code,
+        mimetype="application/json",
+    )
 
 
 def validate_request(*args, **kwargs):
@@ -160,13 +162,10 @@ def validate_request(*args, **kwargs):
             if no_arguments or error_arguments:
                 error_string = ""
                 if no_arguments:
-                    error_string += "required argument are missing: {}; ".format(
-                        ",".join(no_arguments))
+                    error_string += "required argument are missing: {}; ".format(",".join(no_arguments))
                 if error_arguments:
-                    error_string += "required argument values: {}".format(
-                        ",".join(["{}={}".format(a[0], a[1]) for a in error_arguments]))
-                return get_json_result(
-                    code=settings.RetCode.ARGUMENT_ERROR, message=error_string)
+                    error_string += "required argument values: {}".format(",".join(["{}={}".format(a[0], a[1]) for a in error_arguments]))
+                return get_json_result(code=settings.RetCode.ARGUMENT_ERROR, message=error_string)
             return func(*_args, **_kwargs)
 
         return decorated_function
@@ -180,8 +179,7 @@ def not_allowed_parameters(*params):
             input_arguments = flask_request.json or flask_request.form.to_dict()
             for param in params:
                 if param in input_arguments:
-                    return get_json_result(
-                        code=settings.RetCode.ARGUMENT_ERROR, message=f"Parameter {param} isn't allowed")
+                    return get_json_result(code=settings.RetCode.ARGUMENT_ERROR, message=f"Parameter {param} isn't allowed")
             return f(*args, **kwargs)
 
         return wrapper
@@ -190,14 +188,14 @@ def not_allowed_parameters(*params):
 
 
 def is_localhost(ip):
-    return ip in {'127.0.0.1', '::1', '[::1]', 'localhost'}
+    return ip in {"127.0.0.1", "::1", "[::1]", "localhost"}
 
 
 def send_file_in_mem(data, filename):
     if not isinstance(data, (str, bytes)):
         data = json_dumps(data)
     if isinstance(data, str):
-        data = data.encode('utf-8')
+        data = data.encode("utf-8")
 
     f = BytesIO()
     f.write(data)
@@ -206,7 +204,7 @@ def send_file_in_mem(data, filename):
     return send_file(f, as_attachment=True, attachment_filename=filename)
 
 
-def get_json_result(code=settings.RetCode.SUCCESS, message='success', data=None):
+def get_json_result(code=settings.RetCode.SUCCESS, message="success", data=None):
     response = {"code": code, "message": message, "data": data}
     return jsonify(response)
 
@@ -214,27 +212,24 @@ def get_json_result(code=settings.RetCode.SUCCESS, message='success', data=None)
 def apikey_required(func):
     @wraps(func)
     def decorated_function(*args, **kwargs):
-        token = flask_request.headers.get('Authorization').split()[1]
+        token = flask_request.headers.get("Authorization").split()[1]
         objs = APIToken.query(token=token)
         if not objs:
-            return build_error_result(
-                message='API-KEY is invalid!', code=settings.RetCode.FORBIDDEN
-            )
-        kwargs['tenant_id'] = objs[0].tenant_id
+            return build_error_result(message="API-KEY is invalid!", code=settings.RetCode.FORBIDDEN)
+        kwargs["tenant_id"] = objs[0].tenant_id
         return func(*args, **kwargs)
 
     return decorated_function
 
 
-def build_error_result(code=settings.RetCode.FORBIDDEN, message='success'):
+def build_error_result(code=settings.RetCode.FORBIDDEN, message="success"):
     response = {"code": code, "message": message}
     response = jsonify(response)
     response.status_code = code
     return response
 
 
-def construct_response(code=settings.RetCode.SUCCESS,
-                       message='success', data=None, auth=None):
+def construct_response(code=settings.RetCode.SUCCESS, message="success", data=None, auth=None):
     result_dict = {"code": code, "message": message, "data": data}
     response_dict = {}
     for key, value in result_dict.items():
@@ -253,7 +248,7 @@ def construct_response(code=settings.RetCode.SUCCESS,
     return response
 
 
-def construct_result(code=settings.RetCode.DATA_ERROR, message='data is missing'):
+def construct_result(code=settings.RetCode.DATA_ERROR, message="data is missing"):
     result_dict = {"code": code, "message": message}
     response = {}
     for key, value in result_dict.items():
@@ -264,7 +259,7 @@ def construct_result(code=settings.RetCode.DATA_ERROR, message='data is missing'
     return jsonify(response)
 
 
-def construct_json_result(code=settings.RetCode.SUCCESS, message='success', data=None):
+def construct_json_result(code=settings.RetCode.SUCCESS, message="success", data=None):
     if data is None:
         return jsonify({"code": code, "message": message})
     else:
@@ -286,7 +281,7 @@ def construct_error_response(e):
 def token_required(func):
     @wraps(func)
     def decorated_function(*args, **kwargs):
-        authorization_str = flask_request.headers.get('Authorization')
+        authorization_str = flask_request.headers.get("Authorization")
         if not authorization_str:
             return get_json_result(data=False, message="`Authorization` can't be empty")
         authorization_list = authorization_str.split()
@@ -295,11 +290,8 @@ def token_required(func):
         token = authorization_list[1]
         objs = APIToken.query(token=token)
         if not objs:
-            return get_json_result(
-                data=False, message='Authentication error: API key is invalid!',
-                code=settings.RetCode.AUTHENTICATION_ERROR
-            )
-        kwargs['tenant_id'] = objs[0].tenant_id
+            return get_json_result(data=False, message="Authentication error: API key is invalid!", code=settings.RetCode.AUTHENTICATION_ERROR)
+        kwargs["tenant_id"] = objs[0].tenant_id
         return func(*args, **kwargs)
 
     return decorated_function
@@ -316,11 +308,11 @@ def get_result(code=settings.RetCode.SUCCESS, message="", data=None):
     return jsonify(response)
 
 
-def get_error_data_result(message='Sorry! Data missing!', code=settings.RetCode.DATA_ERROR,
-                          ):
-    result_dict = {
-        "code": code,
-        "message": message}
+def get_error_data_result(
+    message="Sorry! Data missing!",
+    code=settings.RetCode.DATA_ERROR,
+):
+    result_dict = {"code": code, "message": message}
     response = {}
     for key, value in result_dict.items():
         if value is None and key != "code":
@@ -348,8 +340,7 @@ def valid_parameter(parameter, valid_values):
 
 
 def dataset_readonly_fields(field_name):
-    return field_name in ["chunk_count", "create_date", "create_time", "update_date", "update_time",
-                          "created_by", "document_count", "token_num", "status", "tenant_id", "id"]
+    return field_name in ["chunk_count", "create_date", "create_time", "update_date", "update_time", "created_by", "document_count", "token_num", "status", "tenant_id", "id"]
 
 
 def get_parser_config(chunk_method, parser_config):
@@ -358,8 +349,7 @@ def get_parser_config(chunk_method, parser_config):
     if not chunk_method:
         chunk_method = "naive"
     key_mapping = {
-        "naive": {"chunk_token_num": 128, "delimiter": "\\n!?;。；！？", "html4excel": False, "layout_recognize": "DeepDOC",
-                  "raptor": {"use_raptor": False}},
+        "naive": {"chunk_token_num": 128, "delimiter": "\\n!?;。；！？", "html4excel": False, "layout_recognize": "DeepDOC", "raptor": {"use_raptor": False}},
         "qa": {"raptor": {"use_raptor": False}},
         "tag": None,
         "resume": None,
@@ -370,10 +360,10 @@ def get_parser_config(chunk_method, parser_config):
         "laws": {"raptor": {"use_raptor": False}},
         "presentation": {"raptor": {"use_raptor": False}},
         "one": None,
-        "knowledge_graph": {"chunk_token_num": 8192, "delimiter": "\\n!?;。；！？",
-                            "entity_types": ["organization", "person", "location", "event", "time"]},
+        "knowledge_graph": {"chunk_token_num": 8192, "delimiter": "\\n!?;。；！？", "entity_types": ["organization", "person", "location", "event", "time"]},
         "email": None,
-        "picture": None}
+        "picture": None,
+    }
     parser_config = key_mapping[chunk_method]
     return parser_config
 
@@ -421,21 +411,23 @@ def get_data_openai(id=None,
 def valid_parser_config(parser_config):
     if not parser_config:
         return
-    scopes = set([
-        "chunk_token_num",
-        "delimiter",
-        "raptor",
-        "graphrag",
-        "layout_recognize",
-        "task_page_size",
-        "pages",
-        "html4excel",
-        "auto_keywords",
-        "auto_questions",
-        "tag_kb_ids",
-        "topn_tags",
-        "filename_embd_weight"
-    ])
+    scopes = set(
+        [
+            "chunk_token_num",
+            "delimiter",
+            "raptor",
+            "graphrag",
+            "layout_recognize",
+            "task_page_size",
+            "pages",
+            "html4excel",
+            "auto_keywords",
+            "auto_questions",
+            "tag_kb_ids",
+            "topn_tags",
+            "filename_embd_weight",
+        ]
+    )
     for k in parser_config.keys():
         assert k in scopes, f"Abnormal 'parser_config'. Invalid key: {k}"
 
@@ -457,7 +449,7 @@ def check_duplicate_ids(ids, id_type="item"):
     """
     Check for duplicate IDs in a list and return unique IDs and error messages.
 
-    Args: 
+    Args:
         ids (list): List of IDs to check for duplicates
         id_type (str): Type of ID for error messages (e.g., 'document', 'dataset', 'chunk')
 
@@ -468,17 +460,15 @@ def check_duplicate_ids(ids, id_type="item"):
     """
     id_count = {}
     duplicate_messages = []
-    
+
     # Count occurrences of each ID
     for id_value in ids:
         id_count[id_value] = id_count.get(id_value, 0) + 1
-    
+
     # Check for duplicates
     for id_value, count in id_count.items():
         if count > 1:
             duplicate_messages.append(f"Duplicate {id_type} ids: {id_value}")
-    
+
     # Return unique IDs and error messages
     return list(set(ids)), duplicate_messages
-
-