langchain-community-migrate

Find the replacement for every langchain_community import in your project, rewrite the 1:1 moves, and vendor the classes that never got a standalone package.

Unofficial community tool. Not affiliated with or endorsed by LangChain. Stdlib only, Python 3.9+.

Why

langchain-community was sunset on 2026-05-22 (no more fixes or security patches, repo archived 2026-06-19) but is still downloaded ~27M times a month. Teams have to work out, for each loader, vector store, chat model and tool they import, whether a standalone package replaces it (langchain-openai, langchain-chroma, langchain-postgres, ...), whether the API changed, or whether nothing replaces it. The official docs only link index pages. langchain-cli migrate needs the grit binary and covers a handful of partners.

This tool ships a mapping table generated from the real packages: the public symbols of langchain-community 0.2.19, 0.3.31 and 0.4.2 matched against the exports of 70+ partner packages plus langchain-core, with curated overrides for renames and API changes (see scripts/ in the repo; regenerate it yourself). 1,856 symbols: 152 with a replacement, 29 to verify, 1,675 with no standalone package.

pip install langchain-community-migrate     # or: pip install git+https://github.com/rafal-one/langchain-community-migrate

scan: what do I use and what replaces it?

$ langchain-community-migrate scan src/
src/app.py:1:1: vectorstores.Chroma -> moved
    from langchain_chroma import Chroma  [pip install langchain-chroma]
src/app.py:1:1: vectorstores.FAISS -> orphaned
    no standalone package; vendor it (`vendor`) or stay on a pinned langchain-community
src/app.py:1:1: vectorstores.Pinecone -> moved, API change
    from langchain_pinecone import PineconeVectorStore  [pip install langchain-pinecone]
      note: renamed; construct with an index handle: PineconeVectorStore(index=..., embedding=...) ...

9 reference(s) in 1 file(s): 5 moved, 1 moved, API change, 3 orphaned
install: pip install langchain-chroma langchain-huggingface langchain-ollama langchain-openai langchain-pinecone

It understands from langchain_community.x[.y] import Z, aliases, import langchain_community.x as m; m.Z, langchain_community.x.Z chains, and the legacy from langchain.llms import OpenAI style paths that forwarded to langchain-community. Statuses:

--format json|markdown for reports, -q to drop the footer. Exit codes: 0 nothing found (or --fail-on never), 1 references found (--fail-on orphaned: only orphaned/unknown), 2 bad usage or missing path.

fix: rewrite imports and dependencies

Dry run by default (unified diff); --write applies it.

langchain-community-migrate fix src/                          # diff
langchain-community-migrate fix src/ --write                  # apply
langchain-community-migrate fix src/ --write --include-api-changes

• Rewrites from langchain_community.vectorstores import Chroma, FAISS into from langchain_community.vectorstores import FAISS + from langchain_chroma import Chroma; aliases and multi-line imports are kept; renamed classes get as OldName so the rest of the file still works.
• API-change moves are only rewritten with --include-api-changes, and get a TODO comment with the note.
• Adds the needed packages to requirements*.txt / pyproject.toml (next to langchain-community), and drops langchain-community only when no reference is left anywhere under the given paths.
• It never touches import langchain_community.x as m style usage; scan lists those.

vendor: keep the orphans, drop the dependency

pip install 'langchain-community<0.5'   # source of the code to copy; needed once
langchain-community-migrate vendor src/ --dest src/myapp/_vendor            # dry run
langchain-community-migrate vendor src/ --dest src/myapp/_vendor --write

Copies the module of every orphaned symbol you import (e.g. FAISS) plus the langchain_community modules it imports (static closure) into _vendor/langchain_community/..., rewrites their imports to the vendored copy, rewrites your imports, and copies the MIT licence next to them. Third-party packages the vendored code needs (faiss-cpu, numpy, ...) are listed for you to add. --source DIR uses an unpacked copy instead of the installed package; --only NAME limits it. Vendored code is yours to maintain: nobody patches it upstream anymore.

lookup

$ langchain-community-migrate lookup PGVector
vectorstores:PGVector [moved, API change]  langchain_community.vectorstores.pgvector
    from langchain_postgres import PGVector  [pip install langchain-postgres]
      note: connection string argument is now `connection=`; table schema differs ...

Limits

The mapping matches names, not behaviour: always read the notes, run your tests, and treat "verify" entries as suggestions. It reflects the partner packages as of 2026-10-18; a partner package that adds a class later will show up as orphaned until the mapping is regenerated. Only Python source is scanned (no notebooks or YAML configs).

Development

pytest (39 tests), Python 3.9 and 3.14; wheel and sdist clean installs checked. python scripts/fetch_partners.py WORK exports.json then python scripts/gen_mapping.py exports.json out.json 0.4.2=DIR 0.3.31=DIR ... rebuilds mapping.json.

Donate

If this saved your team a migration week: https://paypal.me/RafalBaranowski

MIT licensed.