feat: Add bard api (Farama-Foundation#36)

* Add bardapi
* Update the dep

chatarena/backends/bard.py

@@ -0,0 +1,76 @@
+from typing import List
+import os
+import re
+import logging
+from tenacity import retry, stop_after_attempt, wait_random_exponential
+
+from .base import IntelligenceBackend
+from ..message import Message, SYSTEM_NAME as SYSTEM
+
+try:
+    import bardapi
+except ImportError:
+    is_bard_available = False
+    logging.warning("bard package is not installed")
+else:
+    bard_api_key = os.environ.get('_BARD_API_KEY')
+    if bard_api_key is None:
+        logging.warning(
+            "Bard API key is not set. Please set the environment variable _BARD_API_KEY")
+        is_bard_available = False
+    else:
+        is_bard_available = True
+
+DEFAULT_MAX_TOKENS = 4096
+
+
+class Bard(IntelligenceBackend):
+    """
+    Interface to the Bard offered by Google.
+    """
+    stateful = False
+    type_name = "bard"
+
+    def __init__(self, max_tokens: int = DEFAULT_MAX_TOKENS, **kwargs):
+        assert is_bard_available, "bard package is not installed or the API key is not set"
+        super().__init__(max_tokens=max_tokens, **kwargs)
+
+        self.max_tokens = max_tokens
+
+        self.client = bardapi.core.Bard()
+
+    @retry(stop=stop_after_attempt(6), wait=wait_random_exponential(min=1, max=60))
+    def _get_response(self, prompt: str):
+        response = self.client.get_answer(
+            input_text=prompt,
+        )
+
+        response = response['content'].strip()
+        return response
+
+    def query(self, agent_name: str, role_desc: str, history_messages: List[Message], global_prompt: str = None,
+              request_msg: Message = None, *args, **kwargs) -> str:
+        """
+        format the input and call the Bard API
+        args:
+            agent_name: the name of the agent
+            role_desc: the description of the role of the agent
+            env_desc: the description of the environment
+            history_messages: the history of the conversation, or the observation for the agent
+            request_msg: the request from the system to guide the agent's next response
+        """
+        all_messages = [(SYSTEM, global_prompt), (SYSTEM, role_desc)
+                        ] if global_prompt else [(SYSTEM, role_desc)]
+
+        for message in history_messages:
+            all_messages.append((message.agent_name, message.content))
+        if request_msg:
+            all_messages.append((SYSTEM, request_msg.content))
+
+        # current bard api doesn't support role system, so just dump the raw messages as prompt
+        response = self._get_response(str(all_messages), *args, **kwargs)
+
+        # Remove the agent name if the response starts with it
+        response = re.sub(rf"^\s*\[{agent_name}]:?", "", response).strip()
+
+        return response

setup.py

@@ -11,6 +11,7 @@
     "prompt_toolkit==3.0.38",
     "pettingzoo==1.23.0",
     "chess==1.9.4",
+    "bardapi==0.1.11",
 ]
 
 with open("README.md", "r") as f: