refactor: Replace Chains with Runnables across applicable classes (#84)

This pull request refactors the codebase to replace the legacy "Chain"
terminology with the Langchains "Runnable" terminology. It updates class
names, file names, and dependency injections throughout the project,
improving code clarity and consistency. The changes also rename tracer
classes and their usage to match the new naming convention.

### Core Terminology Refactor

* Replaced all instances of `AsyncChain` with `AsyncRunnable` across the
codebase, updating class definitions in files such as
`information_enhancer.py`, `summarizer.py`, `graph_base.py`, and answer
generation/rephrasing chains.
(`[[1]](diffhunk://#diff-9dc8459159718f57a3fa0bf9957a7371f3a048f48316801a73dc308e41f2bb1bL9-R15)`,
`[[2]](diffhunk://#diff-667a3ff4405d85b37364dacfd6010fc86d7f54378759061f54ea92a94bb28046L8-R14)`,
`[[3]](diffhunk://#diff-5339bc54ab240f4fc8ff429c1eb10b9426078d68eb135d4c5d07762da0b3d6a4L10-R13)`,
`[[4]](diffhunk://#diff-383d1b454a8f86bcd6e83561f9404bf94b3fe9877d1a045bcb3586105b0fa5cdL10-R17)`,
`[[5]](diffhunk://#diff-8133279f7c0d324fdfc28838bb487748c091179dc11fc23c79c4f3f489bc3827L9-R16)`)
* Renamed the file `async_chain.py` to `async_runnable.py` and updated
the base class name accordingly.
(`[libs/rag-core-lib/src/rag_core_lib/runnables/async_runnable.pyL10-R10](diffhunk://#diff-ab5426af1a107aabc1976b764b6cacb37827d2196a730c172d03f5da64ad39c9L10-R10)`)

### Tracer Class and Dependency Updates

* Replaced `TracedGraph` with `TracedRunnable` and updated the
corresponding file name from `traced_chain.py` to `traced_runnable.py`.
(`[libs/rag-core-lib/src/rag_core_lib/tracers/traced_runnable.pyL10-R16](diffhunk://#diff-d6877e89effd4fb71dd24a4ce13a5ded94fac87eab9ff78eee0345d6f7100b83L10-R16)`)
* Replaced `LangfuseTracedGraph` with `LangfuseTracedRunnable` and
updated the file name from `langfuse_traced_chain.py` to
`langfuse_traced_runnable.py`.
(`[libs/rag-core-lib/src/rag_core_lib/impl/tracers/langfuse_traced_runnable.pyL9-R12](diffhunk://#diff-b9a916afc928c0acd5b57f6bd46a1213dc898d37f01bd2372d0033cb1941b7caL9-R12)`)
* Updated dependency containers in both `admin-api-lib` and
`rag-core-api` to use `LangfuseTracedRunnable` instead of
`LangfuseTracedGraph`.
(`[[1]](diffhunk://#diff-8b7c1816cb3e0a40b7965721c550eefdc184c5d914ec023e36527255613381e7L68-R68)`,
`[[2]](diffhunk://#diff-8b7c1816cb3e0a40b7965721c550eefdc184c5d914ec023e36527255613381e7L150-R150)`,
`[[3]](diffhunk://#diff-483b37f4ebbc24c973c3b170542171d90c65f3c6b68f1a6d598ce8964a94be7bL67-R67)`,
`[[4]](diffhunk://#diff-483b37f4ebbc24c973c3b170542171d90c65f3c6b68f1a6d598ce8964a94be7bL221-R221)`)

### API and Service Integration

* Updated constructor parameters in API endpoint and service classes
(`DefaultChat`, `UseCaseChat`) to accept `TracedRunnable` instead of
`TracedGraph`.
(`[[1]](diffhunk://#diff-3a92501b36d164b12ce941a944afcbfc440f7fb7093635cb1a405b714ecc6345L8-R14)`,
`[[2]](diffhunk://#diff-3532c3cdfb76374337d778f1aeef03f010fb44852319f3e09dcbfc1025852d97L7-R13)`)

These changes ensure the codebase is up-to-date with the latest
LangChain abstractions and make the tracing and runnable logic clearer
and more maintainable.

Author: a-klos

libs/admin-api-lib/src/admin_api_lib/dependency_container.py

@@ -65,7 +65,7 @@
 from rag_core_lib.impl.settings.ollama_llm_settings import OllamaSettings
 from rag_core_lib.impl.settings.rag_class_types_settings import RAGClassTypeSettings
 from rag_core_lib.impl.settings.stackit_vllm_settings import StackitVllmSettings
-from rag_core_lib.impl.tracers.langfuse_traced_chain import LangfuseTracedGraph
+from rag_core_lib.impl.tracers.langfuse_traced_runnable import LangfuseTracedRunnable
 from rag_core_lib.impl.utils.async_threadsafe_semaphore import AsyncThreadsafeSemaphore
 
 
@@ -147,7 +147,7 @@ class DependencyContainer(DeclarativeContainer):
         summary_enhancer,
     )
     information_enhancer = Singleton(
-        LangfuseTracedGraph,
+        LangfuseTracedRunnable,
         inner_chain=untraced_information_enhancer,
         settings=langfuse_settings,
     )

libs/admin-api-lib/src/admin_api_lib/information_enhancer/information_enhancer.py

@@ -6,13 +6,13 @@
 from langchain_core.documents import Document
 from langchain_core.runnables import RunnableConfig
 
-from rag_core_lib.chains.async_chain import AsyncChain
+from rag_core_lib.runnables.async_runnable import AsyncRunnable
 
 RetrieverInput = list[Document]
 RetrieverOutput = list[Document]
 
 
-class InformationEnhancer(AsyncChain[RetrieverInput, RetrieverOutput], ABC):
+class InformationEnhancer(AsyncRunnable[RetrieverInput, RetrieverOutput], ABC):
     """The base class for an information enhancer."""
 
     @abstractmethod

libs/admin-api-lib/src/admin_api_lib/summarizer/summarizer.py

@@ -5,13 +5,13 @@
 
 from langchain_core.runnables import RunnableConfig
 
-from rag_core_lib.chains.async_chain import AsyncChain
+from rag_core_lib.runnables.async_runnable import AsyncRunnable
 
 SummarizerInput = str
 SummarizerOutput = str
 
 
-class Summarizer(AsyncChain[SummarizerInput, SummarizerOutput], ABC):
+class Summarizer(AsyncRunnable[SummarizerInput, SummarizerOutput], ABC):
     """Baseclass for summarizers."""
 
     @abstractmethod

libs/rag-core-api/src/rag_core_api/dependency_container.py

@@ -64,7 +64,7 @@
 from rag_core_lib.impl.settings.ollama_llm_settings import OllamaSettings
 from rag_core_lib.impl.settings.rag_class_types_settings import RAGClassTypeSettings
 from rag_core_lib.impl.settings.stackit_vllm_settings import StackitVllmSettings
-from rag_core_lib.impl.tracers.langfuse_traced_chain import LangfuseTracedGraph
+from rag_core_lib.impl.tracers.langfuse_traced_runnable import LangfuseTracedRunnable
 from rag_core_lib.impl.utils.async_threadsafe_semaphore import AsyncThreadsafeSemaphore
 
 
@@ -218,7 +218,7 @@ class DependencyContainer(DeclarativeContainer):
 
     # wrap graph in tracer
     traced_chat_graph = Singleton(
-        LangfuseTracedGraph,
+        LangfuseTracedRunnable,
         inner_chain=chat_graph,
         settings=langfuse_settings,
     )

libs/rag-core-api/src/rag_core_api/graph/graph_base.py

@@ -7,10 +7,10 @@
 from langchain_core.runnables.utils import Input, Output
 from langgraph.graph import StateGraph
 
-from rag_core_lib.chains.async_chain import AsyncChain
+from rag_core_lib.runnables.async_runnable import AsyncRunnable
 
 
-class GraphBase(AsyncChain[Input, Output], ABC):
+class GraphBase(AsyncRunnable[Input, Output], ABC):
     """
     Base class for a langgraph graph.
 

libs/rag-core-api/src/rag_core_api/impl/answer_generation_chains/answer_generation_chain.py

@@ -7,14 +7,14 @@
 from langchain_core.output_parsers import StrOutputParser
 
 from rag_core_api.impl.graph.graph_state.graph_state import AnswerGraphState
-from rag_core_lib.chains.async_chain import AsyncChain
+from rag_core_lib.runnables.async_runnable import AsyncRunnable
 from rag_core_lib.impl.langfuse_manager.langfuse_manager import LangfuseManager
 
 RunnableInput = AnswerGraphState
 RunnableOutput = str
 
 
-class AnswerGenerationChain(AsyncChain[RunnableInput, RunnableOutput]):
+class AnswerGenerationChain(AsyncRunnable[RunnableInput, RunnableOutput]):
     """Base class for LLM answer generation chain."""
 
     def __init__(self, langfuse_manager: LangfuseManager):

libs/rag-core-api/src/rag_core_api/impl/answer_generation_chains/rephrasing_chain.py

@@ -6,14 +6,14 @@
 from langchain_core.runnables import Runnable, RunnableConfig
 
 from rag_core_api.impl.graph.graph_state.graph_state import AnswerGraphState
-from rag_core_lib.chains.async_chain import AsyncChain
+from rag_core_lib.runnables.async_runnable import AsyncRunnable
 from rag_core_lib.impl.langfuse_manager.langfuse_manager import LangfuseManager
 
 RunnableInput = AnswerGraphState
 RunnableOutput = str
 
 
-class RephrasingChain(AsyncChain[RunnableInput, RunnableOutput]):
+class RephrasingChain(AsyncRunnable[RunnableInput, RunnableOutput]):
     """Base class for rephrasing of the input question."""
 
     def __init__(self, langfuse_manager: LangfuseManager):

libs/rag-core-api/src/rag_core_api/impl/api_endpoints/default_chat.py

@@ -5,13 +5,13 @@
 from rag_core_api.api_endpoints.chat import Chat
 from rag_core_api.models.chat_request import ChatRequest
 from rag_core_api.models.chat_response import ChatResponse
-from rag_core_lib.tracers.traced_chain import TracedGraph
+from rag_core_lib.tracers.traced_runnable import TracedRunnable
 
 
 class DefaultChat(Chat):
     """DefaultChat is a class that handles chat interactions using a traced graph."""
 
-    def __init__(self, chat_graph: TracedGraph):
+    def __init__(self, chat_graph: TracedRunnable):
         """
         Initialize the DefaultChat instance.
 

libs/rag-core-lib/src/rag_core_lib/impl/tracers/langfuse_traced_chain.py renamed to libs/rag-core-lib/src/rag_core_lib/impl/tracers/langfuse_traced_runnable.py

@@ -6,10 +6,10 @@
 from langfuse.langchain import CallbackHandler
 
 from rag_core_lib.impl.settings.langfuse_settings import LangfuseSettings
-from rag_core_lib.tracers.traced_chain import TracedGraph
+from rag_core_lib.tracers.traced_runnable import TracedRunnable
 
 
-class LangfuseTracedGraph(TracedGraph):
+class LangfuseTracedRunnable(TracedRunnable):
     """A class to trace the execution of a Runnable using Langfuse.
 
     This class wraps an inner Runnable and adds tracing capabilities using the Langfuse tracer.