How to pass retrieved context to later steps in the chain

[ignaceHelsen]

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Example Code

chain_with_context = (RunnablePassthrough.assign(
                        question=lambda input: input.get('question', ''),
                        context=history_aware_retriever,
                        chat_history=lambda input: input.get("chat_history", [])
            ) | RunnablePassthrough.assign(
                        question=lambda input: input.get('question', ''),
                        context=perform_reranking,
                        chat_history=lambda input: input.get("chat_history", []))
                    | prompt
                    | self.answer_generation_llm
                    | StrOutputParser()
            )

chain = RunnableParallel(
                context=lambda input: input.get('context', []),
                chat_history=lambda input: input.get("chat_history", []),
                question=lambda input: input.get("question", '')
             ).assign(baseline_response=rag_chain
        ) | RunnablePassthrough.assign(
            verification_question_template=verification_question_template_chain
        ) | RunnablePassthrough.assign(
            verification_answers=verification_chain
        ) | final_answer_chain

Description

Greetings,

I'm trying to access the retrieved context from 'chain_with_context' in 'chain'. However, the only things that are being passed are:
{
"context": [],
"question": "..."
"chat_history": [...],
}

Although I see a filled context in my logs, the context is empty because it's not passed from chain_with_context. What am I doing wrong here?

Any help is greatly appreciated!

System Info

System Information

OS: Linux
OS Version: #141~20.04.1-Ubuntu SMP Thu Jan 16 18:38:51 UTC 2025
Python Version: 3.11.11 (main, Dec 11 2024, 16:28:39) [GCC 11.2.0]

Package Information

langchain_core: 0.3.39
langchain: 0.3.19
langchain_community: 0.3.18
langsmith: 0.3.1
langchain_cli: 0.0.35
langchain_huggingface: 0.1.2
langchain_localai: 0.1.2
langchain_nvidia: Installed. No version info available.
langchain_nvidia_ai_endpoints: 0.3.8
langchain_ollama: 0.2.2
langchain_openai: 0.3.7
langchain_qdrant: 0.2.0
langchain_redis: 0.1.2
langchain_text_splitters: 0.3.6
langgraph_sdk: 0.1.51
langserve: 0.3.1

Other Dependencies

aiohttp: 3.11.11
aiohttp<4.0.0,>=3.8.3: Installed. No version info available.
async-timeout<5.0.0,>=4.0.0;: Installed. No version info available.
dataclasses-json<0.7,>=0.5.7: Installed. No version info available.
fastapi: 0.115.7
fastembed: 0.4.0
gitpython: 3.1.44
gritql: 0.1.5
httpx: 0.24.1
httpx-sse<1.0.0,>=0.4.0: Installed. No version info available.
huggingface-hub: 0.27.1
jsonpatch<2.0,>=1.33: Installed. No version info available.
langchain-anthropic;: Installed. No version info available.
langchain-aws;: Installed. No version info available.
langchain-cohere;: Installed. No version info available.
langchain-community;: Installed. No version info available.
langchain-core<1.0.0,>=0.3.34: Installed. No version info available.
langchain-core<1.0.0,>=0.3.35: Installed. No version info available.
langchain-core<1.0.0,>=0.3.37: Installed. No version info available.
langchain-core<1.0.0,>=0.3.39: Installed. No version info available.
langchain-deepseek;: Installed. No version info available.
langchain-fireworks;: Installed. No version info available.
langchain-google-genai;: Installed. No version info available.
langchain-google-vertexai;: Installed. No version info available.
langchain-groq;: Installed. No version info available.
langchain-huggingface;: Installed. No version info available.
langchain-mistralai;: Installed. No version info available.
langchain-ollama;: Installed. No version info available.
langchain-openai;: Installed. No version info available.
langchain-text-splitters<1.0.0,>=0.3.6: Installed. No version info available.
langchain-together;: Installed. No version info available.
langchain-xai;: Installed. No version info available.
langchain<1.0.0,>=0.3.19: Installed. No version info available.
langserve[all]: Installed. No version info available.
langsmith-pyo3: Installed. No version info available.
langsmith<0.4,>=0.1.125: Installed. No version info available.
langsmith<0.4,>=0.1.17: Installed. No version info available.
numpy: 1.26.4
numpy<2,>=1.26.4;: Installed. No version info available.
numpy<3,>=1.26.2;: Installed. No version info available.
ollama: 0.4.7
openai: 1.64.0
openai<2.0.0,>=1.58.1: Installed. No version info available.
orjson: 3.10.15
packaging<25,>=23.2: Installed. No version info available.
pydantic: 2.10.6
pydantic-settings<3.0.0,>=2.4.0: Installed. No version info available.
pydantic<3.0.0,>=2.5.2;: Installed. No version info available.
pydantic<3.0.0,>=2.7.4: Installed. No version info available.
pydantic<3.0.0,>=2.7.4;: Installed. No version info available.
pytest: 8.3.4
python-ulid: 2.7.0
PyYAML>=5.3: Installed. No version info available.
qdrant-client: 1.13.2
redisvl: 0.3.9
requests: 2.32.3
requests-toolbelt: 1.0.0
requests<3,>=2: Installed. No version info available.
rich: 13.9.4
sentence-transformers: 3.4.0
SQLAlchemy<3,>=1.4: Installed. No version info available.
sse-starlette: 1.8.2
tenacity!=8.4.0,<10,>=8.1.0: Installed. No version info available.
tenacity!=8.4.0,<10.0.0,>=8.1.0: Installed. No version info available.
tiktoken<1,>=0.7: Installed. No version info available.
tokenizers: 0.21.0
tomlkit: 0.13.2
transformers: 4.47.1
typer[all]: Installed. No version info available.
typing-extensions>=4.7: Installed. No version info available.
uvicorn: 0.32.1
zstandard: 0.23.0