Update writer integration (#4363)

# Update Writer LLM integration

Changes the parameters and base URL to be in line with Writer's current
API.
Based on the documentation on this page:
https://dev.writer.com/reference/completions-1

langchain/llms/writer.py

@@ -13,8 +13,8 @@ from langchain.utils import get_from_dict_or_env
 class Writer(LLM):
     """Wrapper around Writer large language models.
 
-    To use, you should have the environment variable ``WRITER_API_KEY``
-    set with your API key.
+    To use, you should have the environment variable ``WRITER_API_KEY`` and
+    ``WRITER_ORG_ID`` set with your API key and organization ID respectively.
 
     Example:
         .. code-block:: python
@@ -23,56 +23,44 @@ class Writer(LLM):
             writer = Writer(model_id="palmyra-base")
     """
 
-    model_id: str = "palmyra-base"
+    writer_org_id: Optional[str] = None
+    """Writer organization ID."""
+
+    model_id: str = "palmyra-instruct"
     """Model name to use."""
 
-    tokens_to_generate: int = 24
-    """Max number of tokens to generate."""
+    min_tokens: Optional[int] = None
+    """Minimum number of tokens to generate."""
 
-    logprobs: bool = False
-    """Whether to return log probabilities."""
+    max_tokens: Optional[int] = None
+    """Maximum number of tokens to generate."""
 
-    temperature: float = 1.0
+    temperature: Optional[float] = None
     """What sampling temperature to use."""
 
-    length: int = 256
-    """The maximum number of tokens to generate in the completion."""
-
-    top_p: float = 1.0
+    top_p: Optional[float] = None
     """Total probability mass of tokens to consider at each step."""
 
-    top_k: int = 1
-    """The number of highest probability vocabulary tokens to
-    keep for top-k-filtering."""
+    stop: Optional[List[str]] = None
+    """Sequences when completion generation will stop."""
+
+    presence_penalty: Optional[float] = None
+    """Penalizes repeated tokens regardless of frequency."""
 
-    repetition_penalty: float = 1.0
+    repetition_penalty: Optional[float] = None
     """Penalizes repeated tokens according to frequency."""
 
-    random_seed: int = 0
-    """The model generates random results.
-    Changing the random seed alone will produce a different response
-    with similar characteristics. It is possible to reproduce results
-    by fixing the random seed (assuming all other hyperparameters
-    are also fixed)"""
-
-    beam_search_diversity_rate: float = 1.0
-    """Only applies to beam search, i.e. when the beam width is >1.
-    A higher value encourages beam search to return a more diverse
-    set of candidates"""
+    best_of: Optional[int] = None
+    """Generates this many completions server-side and returns the "best"."""
 
-    beam_width: Optional[int] = None
-    """The number of concurrent candidates to keep track of during
-    beam search"""
+    logprobs: bool = False
+    """Whether to return log probabilities."""
 
-    length_pentaly: float = 1.0
-    """Only applies to beam search, i.e. when the beam width is >1.
-    Larger values penalize long candidates more heavily, thus preferring
-    shorter candidates"""
+    n: Optional[int] = None
+    """How many completions to generate."""
 
     writer_api_key: Optional[str] = None
-
-    stop: Optional[List[str]] = None
-    """Sequences when completion generation will stop"""
+    """Writer API key."""
 
     base_url: Optional[str] = None
     """Base url to use, if None decides based on model name."""
@@ -84,34 +72,41 @@ class Writer(LLM):
 
     @root_validator()
     def validate_environment(cls, values: Dict) -> Dict:
-        """Validate that api key exists in environment."""
+        """Validate that api key and organization id exist in environment."""
+
         writer_api_key = get_from_dict_or_env(
             values, "writer_api_key", "WRITER_API_KEY"
         )
         values["writer_api_key"] = writer_api_key
+
+        writer_org_id = get_from_dict_or_env(values, "writer_org_id", "WRITER_ORG_ID")
+        values["writer_org_id"] = writer_org_id
+
         return values
 
     @property
     def _default_params(self) -> Mapping[str, Any]:
         """Get the default parameters for calling Writer API."""
         return {
-            "tokens_to_generate": self.tokens_to_generate,
+            "minTokens": self.min_tokens,
+            "maxTokens": self.max_tokens,
+            "temperature": self.temperature,
+            "topP": self.top_p,
             "stop": self.stop,
+            "presencePenalty": self.presence_penalty,
+            "repetitionPenalty": self.repetition_penalty,
+            "bestOf": self.best_of,
             "logprobs": self.logprobs,
-            "temperature": self.temperature,
-            "top_p": self.top_p,
-            "top_k": self.top_k,
-            "repetition_penalty": self.repetition_penalty,
-            "random_seed": self.random_seed,
-            "beam_search_diversity_rate": self.beam_search_diversity_rate,
-            "beam_width": self.beam_width,
-            "length_pentaly": self.length_pentaly,
+            "n": self.n,
         }
 
     @property
     def _identifying_params(self) -> Mapping[str, Any]:
         """Get the identifying parameters."""
-        return {**{"model_id": self.model_id}, **self._default_params}
+        return {
+            **{"model_id": self.model_id, "writer_org_id": self.writer_org_id},
+            **self._default_params,
+        }
 
     @property
     def _llm_type(self) -> str:
@@ -124,7 +119,7 @@ class Writer(LLM):
         stop: Optional[List[str]] = None,
         run_manager: Optional[CallbackManagerForLLMRun] = None,
     ) -> str:
-        """Call out to Writer's complete endpoint.
+        """Call out to Writer's completions endpoint.
 
         Args:
             prompt: The prompt to pass into the model.
@@ -142,12 +137,15 @@ class Writer(LLM):
             base_url = self.base_url
         else:
             base_url = (
-                "https://api.llm.writer.com/v1/models/{self.model_id}/completions"
+                "https://enterprise-api.writer.com/llm"
+                f"/organization/{self.writer_org_id}"
+                f"/model/{self.model_id}/completions"
             )
+
         response = requests.post(
             url=base_url,
             headers={
-                "Authorization": f"Bearer {self.writer_api_key}",
+                "Authorization": f"{self.writer_api_key}",
                 "Content-Type": "application/json",
                 "Accept": "application/json",
             },