Type LLMChain.llm as runnable (#12385)

libs/langchain/langchain/chains/combine_documents/stuff.py

@@ -150,7 +150,7 @@ class StuffDocumentsChain(BaseCombineDocumentsChain):
         """
         inputs = self._get_inputs(docs, **kwargs)
         prompt = self.llm_chain.prompt.format(**inputs)
-        return self.llm_chain.llm.get_num_tokens(prompt)
+        return self.llm_chain._get_num_tokens(prompt)
 
     def combine_docs(
         self, docs: List[Document], callbacks: Callbacks = None, **kwargs: Any

libs/langchain/langchain/chains/conversational_retrieval/base.py

@@ -284,7 +284,7 @@ class ConversationalRetrievalChain(BaseConversationalRetrievalChain):
             self.combine_docs_chain, StuffDocumentsChain
         ):
             tokens = [
-                self.combine_docs_chain.llm_chain.llm.get_num_tokens(doc.page_content)
+                self.combine_docs_chain.llm_chain._get_num_tokens(doc.page_content)
                 for doc in docs
             ]
             token_count = sum(tokens[:num_docs])

libs/langchain/langchain/chains/llm.py

@@ -2,7 +2,7 @@
 from __future__ import annotations
 
 import warnings
-from typing import Any, Dict, List, Optional, Sequence, Tuple, Union
+from typing import Any, Dict, List, Optional, Sequence, Tuple, Union, cast
 
 from langchain.callbacks.manager import (
     AsyncCallbackManager,
@@ -17,12 +17,25 @@ from langchain.prompts.prompt import PromptTemplate
 from langchain.pydantic_v1 import Extra, Field
 from langchain.schema import (
     BaseLLMOutputParser,
+    BaseMessage,
     BasePromptTemplate,
+    ChatGeneration,
+    Generation,
     LLMResult,
     PromptValue,
     StrOutputParser,
 )
-from langchain.schema.language_model import BaseLanguageModel
+from langchain.schema.language_model import (
+    BaseLanguageModel,
+    LanguageModelInput,
+)
+from langchain.schema.runnable import (
+    Runnable,
+    RunnableBinding,
+    RunnableBranch,
+    RunnableWithFallbacks,
+)
+from langchain.schema.runnable.configurable import DynamicRunnable
 from langchain.utils.input import get_colored_text
 
 
@@ -48,7 +61,9 @@ class LLMChain(Chain):
 
     prompt: BasePromptTemplate
     """Prompt object to use."""
-    llm: BaseLanguageModel
+    llm: Union[
+        Runnable[LanguageModelInput, str], Runnable[LanguageModelInput, BaseMessage]
+    ]
     """Language model to call."""
     output_key: str = "text"  #: :meta private:
     output_parser: BaseLLMOutputParser = Field(default_factory=StrOutputParser)
@@ -100,12 +115,25 @@ class LLMChain(Chain):
     ) -> LLMResult:
         """Generate LLM result from inputs."""
         prompts, stop = self.prep_prompts(input_list, run_manager=run_manager)
-        return self.llm.generate_prompt(
+        callbacks = run_manager.get_child() if run_manager else None
-            prompts,
+        if isinstance(self.llm, BaseLanguageModel):
-            stop,
+            return self.llm.generate_prompt(
-            callbacks=run_manager.get_child() if run_manager else None,
+                prompts,
-            **self.llm_kwargs,
+                stop,
-        )
+                callbacks=callbacks,
+                **self.llm_kwargs,
+            )
+        else:
+            results = self.llm.bind(stop=stop, **self.llm_kwargs).batch(
+                cast(List, prompts), {"callbacks": callbacks}
+            )
+            generations: List[List[Generation]] = []
+            for res in results:
+                if isinstance(res, BaseMessage):
+                    generations.append([ChatGeneration(message=res)])
+                else:
+                    generations.append([Generation(text=res)])
+            return LLMResult(generations=generations)
 
     async def agenerate(
         self,
@@ -114,12 +142,25 @@ class LLMChain(Chain):
     ) -> LLMResult:
         """Generate LLM result from inputs."""
         prompts, stop = await self.aprep_prompts(input_list, run_manager=run_manager)
-        return await self.llm.agenerate_prompt(
+        callbacks = run_manager.get_child() if run_manager else None
-            prompts,
+        if isinstance(self.llm, BaseLanguageModel):
-            stop,
+            return await self.llm.agenerate_prompt(
-            callbacks=run_manager.get_child() if run_manager else None,
+                prompts,
-            **self.llm_kwargs,
+                stop,
-        )
+                callbacks=callbacks,
+                **self.llm_kwargs,
+            )
+        else:
+            results = await self.llm.bind(stop=stop, **self.llm_kwargs).abatch(
+                cast(List, prompts), {"callbacks": callbacks}
+            )
+            generations: List[List[Generation]] = []
+            for res in results:
+                if isinstance(res, BaseMessage):
+                    generations.append([ChatGeneration(message=res)])
+                else:
+                    generations.append([Generation(text=res)])
+            return LLMResult(generations=generations)
 
     def prep_prompts(
         self,
@@ -343,3 +384,22 @@ class LLMChain(Chain):
         """Create LLMChain from LLM and template."""
         prompt_template = PromptTemplate.from_template(template)
         return cls(llm=llm, prompt=prompt_template)
+
+    def _get_num_tokens(self, text: str) -> int:
+        return _get_language_model(self.llm).get_num_tokens(text)
+
+
+def _get_language_model(llm_like: Runnable) -> BaseLanguageModel:
+    if isinstance(llm_like, BaseLanguageModel):
+        return llm_like
+    elif isinstance(llm_like, RunnableBinding):
+        return _get_language_model(llm_like.bound)
+    elif isinstance(llm_like, RunnableWithFallbacks):
+        return _get_language_model(llm_like.runnable)
+    elif isinstance(llm_like, (RunnableBranch, DynamicRunnable)):
+        return _get_language_model(llm_like.default)
+    else:
+        raise ValueError(
+            f"Unable to extract BaseLanguageModel from llm_like object of type "
+            f"{type(llm_like)}"
+        )

libs/langchain/langchain/chains/qa_with_sources/retrieval.py

@@ -31,9 +31,7 @@ class RetrievalQAWithSourcesChain(BaseQAWithSourcesChain):
             self.combine_documents_chain, StuffDocumentsChain
         ):
             tokens = [
-                self.combine_documents_chain.llm_chain.llm.get_num_tokens(
+                self.combine_documents_chain.llm_chain._get_num_tokens(doc.page_content)
-                    doc.page_content
-                )
                 for doc in docs
             ]
             token_count = sum(tokens[:num_docs])

libs/langchain/langchain/chains/qa_with_sources/vector_db.py

@@ -36,9 +36,7 @@ class VectorDBQAWithSourcesChain(BaseQAWithSourcesChain):
             self.combine_documents_chain, StuffDocumentsChain
         ):
             tokens = [
-                self.combine_documents_chain.llm_chain.llm.get_num_tokens(
+                self.combine_documents_chain.llm_chain._get_num_tokens(doc.page_content)
-                    doc.page_content
-                )
                 for doc in docs
             ]
             token_count = sum(tokens[:num_docs])