fix(docs): correct broken LangGraph integration examples#517
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- Add langgraph-checkpoint-sqlite to the install command; SqliteSaver lives in a separate package that wasn't listed, causing ModuleNotFoundError - Fix SqliteSaver.from_conn_string usage: it is a context manager and must be used with `with`, not assigned directly, otherwise workflow.compile(checkpointer=...) raises a TypeError - Remove the ToolExecutor/ToolInvocation import from langgraph.prebuilt; these symbols were removed from langgraph's public API and were unused in the example, causing an immediate ImportError - Define and register the handle_no_results node referenced by the Conditional Routing example; without it workflow.compile() raises ValueError for an unknown edge target - Add a warning noting that langchain-community (source of FalkorDBGraph) was archived on 2026-06-19 and is no longer maintained, with a pointer to the LangChain integration page - Mention InMemorySaver as a lighter-weight, dependency-free alternative to SqliteSaver for simple in-process memory All examples were re-verified end-to-end against a live FalkorDB instance and current package versions (langgraph 1.2.7, langchain-community 0.4.2, falkordb 1.6.1). Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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Pull request overview
Fixes multiple broken Python snippets in the LangGraph + FalkorDB documentation so that readers can run the examples verbatim with current LangGraph/LangChain package versions, and adds an explicit maintenance-risk warning about the upstream langchain-community dependency.
Changes:
- Updated the install command to include the missing
langgraph-checkpoint-sqlitedependency needed by the documentedSqliteSaverexample. - Fixed the Memory Integration example by using
SqliteSaver.from_conn_string(...)as a context manager and added anInMemorySaveralternative note. - Removed a broken, unused
langgraph.prebuiltimport and added the missinghandle_no_resultsnode referenced by conditional routing.
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Summary
Reviewed https://docs.falkordb.com/genai-tools/langgraph.html end-to-end against a live FalkorDB instance and current package versions. Found and fixed 3 code bugs that break the documented examples verbatim, plus added a callout about an important upstream maintenance risk.
Changes
langgraph-checkpoint-sqlite, which is required by the Memory Integration section'sfrom langgraph.checkpoint.sqlite import SqliteSaverbut was missing, causingModuleNotFoundError.SqliteSaver.from_conn_string(":memory:")usage. In currentlanggraph-checkpoint-sqlite, this is a@contextmanagergenerator — assigning its return value directly (as the doc did) yields a_GeneratorContextManager, not a saver, soworkflow.compile(checkpointer=memory)raisedTypeError: Invalid checkpointer provided. Now wrapped inwith ... as memory:. Also added a note pointing toInMemorySaver(bundled withlanggraph, no extra install) as a lighter alternative.from langgraph.prebuilt import ToolExecutor, ToolInvocation— both symbols were removed fromlanggraph.prebuilt's public API in current releases (ImportError), and neither was actually used anywhere in the example, so the import was simply dead and broken.should_continuerouting map targets a"handle_no_results"node that was never defined/registered anywhere in the doc. Copying the snippet into the Quick Start workflow madeworkflow.compile()raiseValueError: ... found unknown target 'handle_no_results'. Added the missing node function,add_node, and an edge toEND.FalkorDBGraph(used throughout this page) lives inlangchain-community, which was archived by the LangChain team on 2026-06-19 and is no longer maintained. The examples still work against the last published release, but there's currently no drop-in standalone successor package for the graph/schema wrapper (langchain-falkordbonly covers chat history and vector stores). Flagged this so readers can make an informed choice and pin versions.Testing
falkordb/falkordb:edgein Docker and installed current PyPI releases (langgraph1.2.7,langgraph-checkpoint-sqlite3.1.0,langchain1.3.11,langchain-community0.4.2,falkordb1.6.1,langchain-openai1.3.3).TypeError,ValueError) before fixing.ChatOpenAI, since no OpenAI credentials are available in this environment) — all sections (Quick Start steps 1-4, Multi-Agent GraphRAG, Conditional Routing, Memory Integration,InMemorySaveralternative) ran successfully end-to-end with no errors.Memory / Performance Impact
N/A — documentation only.
Related Issues
N/A — found via manual doc review, no pre-existing issue filed.