LangChain 0.3 for JavaScript: 39 entrypoints move to @langchain/community, six are gone

LangChain 0.3 removed the document loaders and the Python interpreter tool that had been duplicated in @langchain/community since the packages split, 39 subpaths in all, each still published there under the same name. It also collapsed langchain/memory/index into langchain/memory, and removed five self-query translator entrypoints plus the NotionDB loader, which the migration notes point at integration packages rather than at a subpath this entry can name.

What changed

• 39 document loader and tool subpaths moved to @langchain/community, same names. langchain/document_loaders/fs/*, langchain/document_loaders/web/* and langchain/experimental/tools/pyinterpreter are gone from langchain and published by @langchain/community 0.3.0 under the identical subpath and export names. The map was derived by diffing the exports of langchain 0.2.20 against 0.3.0 and keeping every removed subpath the community package still publishes.
• langchain/memory/index collapsed into langchain/memory. The two entrypoints re-exported the same module in 0.2.20, so only the specifier changes.
• Six entrypoints left with no equivalent subpath. The five retrievers/self_query translators (chroma, pinecone, supabase, vectara, weaviate) and document_loaders/web/notiondb are gone from both packages under their old name. The migration notes point self-query users at the matching integration package; the NotionDB loader has no documented replacement.

Before and after

A loader import built against 0.2.20:

import { PDFLoader } from 'langchain/document_loaders/fs/pdf';
import { CSVLoader } from 'langchain/document_loaders/fs/csv';

After npx emendant fix, only the package in front of the subpath changes:

import { PDFLoader } from '@langchain/community/document_loaders/fs/pdf';
import { CSVLoader } from '@langchain/community/document_loaders/fs/csv';

The same rewrite handles langchain/memory/index to langchain/memory: one specifier, no package added. There is no after for the self-query translators or the NotionDB loader. The entry carries no fix, so langchain/retrievers/self_query/pinecone keeps failing to resolve until you find its integration package by hand.

Migration guidance and its limits

Apply the two deterministic patches: the community entrypoint rewrite and the memory/index collapse. Neither installs @langchain/community for you. Add it to your manifest before running the fix, or the rewritten imports fail to resolve in its place.

Emendant does not fix the self-query translators or the NotionDB loader. No patch is offered because the entry carries none: the five translators moved into per-store integration packages this map cannot pin one subpath for, and the NotionDB loader has no documented replacement at all. A scan reports these as findings for you to resolve by hand.

No change in this release is assisted, so no model provider is needed for anything a clean scan finds here. A clean scan proves your imports still resolve. It does not prove the migrated code loads the same documents the old entrypoints did, since @langchain/community 0.3.0 is a different package resolving its own dependencies.

What Emendant detects, fixes and verifies

3 changes in langchain 0.3.0. 2 patched by a transform, 0 patched only with a model provider you name, 1 report only. Every patch is proved in a copy of your repository before it is offered, and its header names the checks that passed. This table is generated from the feed entry, so it cannot claim more than the entry does.

emendant explain <change-id> prints any row's entry, guidance and sources at the terminal.

Coverage

Snapshot

2026-08-28.1, sequence 11, signed 28 August 2026

Minimum CLI

emendant@0.1.0

Feed entry

feed/npm/langchain/0.3.0.json

emendant feed status shows the snapshot your machine holds, and emendant feed update fetches the latest.

Primary sources

Every claim above was checked against these, each pinned to the release rather than to a default branch.

• Indexlangchain-ai/langchainjs at 0.3.5
• langchain@0.3.0npm registry, the published package
• langchain@0.2.20npm registry, the published package

Scan your repository

Runs locally, reads your lockfile and source, sends nothing anywhere.

npx emendant scan

Then npx emendant fix writes the patches the table says exist. The getting started guide covers the flags and the patch grades.