This release includes 1 security fix for security teams reviewing exposed deployments.
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Summary
AI summaryInitial release of LangChain version 1.3.0a2.
Full changelog
Initial release
release(langchain): 1.3.0a2 (#37225)
release(langchain): 1.3.0a2 (#37224)
fix(langchain): ordered schema resolution — list replaces set so state_schema wins (#37223)
release(langchain): 1.3.0a1 (#37140)
feat(langchain): wire stream_events(version='v3') into create_agent (#37136)
Merge remote-tracking branch 'origin/master' into v1.4
feat(core): stream_events(version='v3') protocol (#37111)
release(fireworks): 1.2.1 (#37113)
release(langchain): 1.2.17 (#37110)
feat(langchain): add respond decision to HITL middleware (#37095)
release(langchain): 1.2.16 (#37085)
chore(docs): update x handle references (#37081)
release(anthropic): 1.4.2 (#37061)
perf(langchain): stop inlining agent state into tool-dispatch Sends (#36960)
docs(langchain): correct import paths in agent middleware docstrings (#36987)
hotfix: bump min core versions (#36996)
release(openai): 1.2.1 (#36995)
feat(core): add content-block-centric streaming (v2) (#36834)
fix(fireworks): honor max_retries (#36973)
release(openai): 1.2.0 (#36961)
docs(langchain): correct import path in ModelCallLimitMiddleware docstring (#36895)
feat(langchain): ls_agent_type tag on create_agent calls (#36774)
release(core): release 1.3.0 (#36851)
chore: bump langsmith from 0.6.3 to 0.7.31 in /libs/langchain_v1 (#36800)
chore(deps): bump pytest to 9.0.3 (#36801)
chore: bump pytest from 9.0.2 to 9.0.3 in /libs/langchain_v1 (#36717)
chore: bump pillow from 12.1.1 to 12.2.0 in /libs/langchain_v1 (#36710)
test(langchain): test cache hit/miss on lru (#36659)
perf(langchain): add lru cache when resolving types (#36649)
perf(langchain): add another init test with middleware (#36644)
chore(core): reduce streaming metadata / perf (#36588)
perf(langchain): add benchmark command (#36641)
chore: bump cryptography from 46.0.6 to 46.0.7 in /libs/langchain_v1 (#36619)
docs(langchain): add missing baseten and litellm to init_chat_model (#36562)
release(core): 1.2.26 (#36511)
release: langchain v1.2.15 (#36496)
chore: bump aiohttp from 3.13.3 to 3.13.4 in /libs/langchain_v1 (#36438)
release(langchain): 1.2.14 (#36396)
chore: pygments>=2.20.0 across all packages (CVE-2026-4539) (#36385)
test(langchain): cover runtime recursion limit override in create_agent (#36376)
perf(langchain): reduce init speed by 15% (#36375)
fix(langchain): update recursion limit for create_agent (#36351)
fix(infra): correct lint_diff relative paths in package makefiles (#36333)
chore: bump cryptography from 46.0.5 to 46.0.6 in /libs/langchain_v1 (#36324)
fix(langchain): recognize ChatAnthropicVertex in _get_approximate_token_counter (#36320)
chore(langchain): remove unnecessary description for toods list as a group (#36315)
chore(langchain): add async implementation to todolist and test (#36313)
chore(langchain): speed up todo list middleware init (#36311)
chore: bump requests from 2.32.5 to 2.33.0 in /libs/langchain_v1 (#36241)
chore(partners): bump langchain-core min to 1.2.21 (#36183)
fix(core,model-profiles): add missing ModelProfile fields, warn on schema drift (#36129)
fix(langchain,langchain-classic): update model provider classes for Azure AI Foundry (#35812)
release(langchain): 1.2.13 (#36111)
ci: suppress pytest streaming output in CI (#36092)
feat: Add LangSmith integration metadata to create_agent and init_chat_model (#35810)
ci: avoid unnecessary dep installs in lint targets (#36046)
chore: bump pyasn1 from 0.6.2 to 0.6.3 in /libs/langchain_v1 (#36029)
chore: bump pyjwt from 2.10.1 to 2.12.0 in /libs/langchain_v1 (#36024)
fix(langchain): export Runtime from agents.middleware (#35975)
chore: bump locks, lint (#35985)
fix(openai): add type: message to Responses API input items (#35693)
chore: bump black from 25.11.0 to 26.3.1 in /libs/langchain_v1 (#35802)
chore: bump orjson from 3.11.5 to 3.11.6 in /libs/langchain_v1 (#35807)
chore(langchain): add baseten to _BUILTIN_PROVIDERS (#35777)
release(langchain_v1): 1.2.12 (#35770)
feat: tracing for wrap model + tool call (#35765)
release(langchain_v1): 1.2.11 (#35723)
fix(langchain): normalize custom detector output to prevent KeyError in hash/mask strategies (#35651)
chore: bump the minor-and-patch group across 3 directories with 7 updates (#35605)
chore(langchain): switch refs from gemini-3 to gemini-3.1 (#35535)
chore: bump the langchain-deps group across 3 directories with 7 updates (#35513)
chore: bump langgraph-checkpoint from 3.0.1 to 4.0.0 in /libs/langchain_v1 (#35445)
chore: bump the langchain-deps group across 3 directories with 14 updates (#35441)
chore: bump google-cloud-aiplatform from 1.127.0 to 1.133.0 in /libs/langchain_v1 (#35397)
revert: add ChatAnthropicBedrockWrapper (#35371)
fix(langchain): support anthropic-bedrock in init_chat_model (#35366)
style: fix some ruff noqa (#35321)
fix(langchain): allow Gemini 3 models to use ProviderStrategy with tools (#34464)
docs: fix docstring inaccuracies and update outdated LangSmith URLs (#35283)
feat(openai): support automatic server-side compaction (#35212)
chore: bump the langchain-deps group across 3 directories with 8 updates (#35257)
feat(openrouter): add langchain-openrouter provider package (#35211)
style: bump ruff version to 0.15 (#35042)
chore(deps): bump pillow from 12.0.0 to 12.1.1 in /libs/langchain_v1 (#35174)
chore(core): raise more descriptive model error in init_chat_model (#35167)
chore(deps): bump langsmith from 0.4.42 to 0.6.3 in /libs/langchain_v1 (#35149)
chore(deps): bump cryptography from 46.0.3 to 46.0.5 in /libs/langchain_v1 (#35148)
release(langchain): 1.2.10 (#35137)
chore(deps): bump the langchain-deps group across 3 directories with 40 updates (#35129)
chore(deps): bump the langchain-deps group across 3 directories with 11 updates (#35121)
fix(langchain): fix token counting on partial message sequences (#35101)
refactor(langchain): rename _SUPPORTED_PROVIDERS -> _BUILTIN_PROVIDERS (#35100)
fix(langchain): normalize raw schemas in middleware response_format override (#35019)
feat: support state updates from wrap_model_call with command(s) (#35033)
test(langchain): types in test_tool_call_limit and test_model_retry (#34629)
fix(langchain): bump min core version and improve approximate token counting (#35026)
release: langchain 1.2.9 (#35023)
feat: threading context through create_agent flows + middleware (#34978)
chore: add make type target (#35015)
revert: "chore: add typing target in Makefile" (#35013)
chore: add typing target in Makefile (#35012)
revert: use usage metadata scaling in SummarizationMiddleware default token counter (#35002)
fix(langchain): use usage metadata scaling in SummarizationMiddleware default token counter (#35001)
fix(langchain): avoid UnboundLocalError when no AIMessage exists (#34816)
chore: enrich pyproject.toml files (#34980)
release(langchain): 1.2.8 (#34976)
chore(deps): bump the uv group across 20 directories with 3 updates (#34941)
fix: reuse ToolStrategy in agent factory to prevent name mismatch (#34871)
chore: upgrade urllib3 to 2.6.3 (#34940)
feat(langchain): add ToolCallRequest to middleware exports (#34894)
style(langchain): lint (#34863)
fix(langchain): blocking unit test (#34866)
test(langchain): use blockbuster to detect blocking calls in the async event loop (#34777)
release: langchain 1.2.7 (#34854)
feat: dynamic tool registration via middleware (#34842)
fix(langchain): strip trailing whitespace from the summarization prompt (#34835)
fix(langchain): improve grammar in SummarizationMiddleware system prompt (#34834)
docs(langchain): nit (#34788)
chore(deps): bump the uv group across 5 directories with 5 updates (#34785)
chore(deps): bump the uv group across 8 directories with 6 updates (#34773)
chore(core, langchain): add version consistency check pre-commit hooks (#34782)
release(langchain): 1.2.6 (#34781)
fix(langchain): SummarizationMiddleware signature mismatch & config invocation (#34775)
release(langchain): 1.2.5 (#34772)
fix(langchain): add metadata configuration to summarization model invocation (#34763)
feat(langchain): update summarization prompt (#34754)
chore: add tests for agent name metadata when streaming (#34764)
Revert "metadata"
metadata
release: langchain 1.2.4 (#34755)
chore(langchain): add agent name metadata (#34743)
chore: update twitter URLs (#34736)
chore: add tests for private state attr use (really, lack thereof) (#34725)
docs(langchain): clarify model ID usage for reliable behavior (#34718)
fix(langchain): tag messages generated from summarization (#34693)
fix(langchain): activate test_return_direct_spec tests, fix types (#34565)
chore(langchain): fix types in test_todo, test_tool_retry (#34503)
chore(langchain): fix types in test_shell_tool (#34502)
chore(langchain): activate mypy warn_return_any rule (#34549)
chore(langchain): fix types in test_tool_selection and test_tool_emulator (#34499)
chore(langchain): fix types in test_shell_execution_policies (#34498)
chore(langchain): improve ignore_missing_imports config (#34551)
test(langchain): complete and activate test_responses tests (#34560)
fix(langchain): activate mypy warn-unreachable (#34553)
chore(langchain): fix types in test_injected_runtime_create_agent, test_create_agent_tool_validation (#34568)
chore(langchain): fix types in test_response_format and test_state_schema (#34571)
chore(langchain): remove generic from FakeToolCallingModel (#34572)
chore(langchain): fix types in test_context_editing, test_agent_name, test_response_format_integration (#34574)
chore(langchain): fix types in test_overrides (#34635)
feat(langchain): add state to _ModelRequestOverrides (#34692)
chore(langchain): fix types in test_tools (#34592)
chore(langchain): fix types in test_summarization (#34656)
test(langchain): activate test_responses_spec tests (#34564)
style(langchain): fix some ruff preview rules (#34663)
chore(langchain): fix types in test_framework (#34567)
chore(langchain): fix types in memory_assert, conftest, conftest_checkpointer and conftest_store (#34636)
chore(langchain): fix types in test_system_message (#34634)
style: bump ruff version to 0.14.11 (#34674)
fix: remove relative imports (#34680)
fix(langchain,langchain-classic): more descriptive error msg when dep is not installed (#34679)
fix(langchain): infer provider from mixed-case prefixes (#34672)
fix: add test confirming we don't inject args based on args_schema alone (#34677)
release(langchain): 1.2.3 (#34668)
refactor(langchain): engage summarization based on reported usage_metadata (#34632)
fix(langchain): keep tool call / AIMessage pairings when summarizing (#34609)
test(langchain): cover chat model provider inference (#34657)
fix(langchain): fix copy-paste error on azure_openai embedding provider map (#34655)
fix(langchain): add test to verify version (#34644)
release(langchain): release 1.2.2 (#34643)
fix(langchain): handle parallel usage of the todo tool in planning middleware (#34637)
chore(langchain): fix types in test_wrap_model_call (#34573)
release(langchain): 1.2.1 (#34622)
fix(core,langchain): use get_buffer_string for message summarization (#34607)
chore(langchain): fix types in test_model_fallback (#34615)
chore(langchain): fix types in test_pii (#34617)
chore(langchain): add admonition around redaction_rules (#34618)
chore(langchain): fix types in test_composition (#34580)
chore(langchain): fix types in test_decorators (#34583)
chore(langchain): fix types in test_wrap_tool_call (#34600)
chore(langchain): fix types in test_model_call_limit_types (#34601)
chore(langchain): fix types in test_file_search and test_human_in_the_loop (#34602)
fix(core): exclude injected args from tool schema (#34582)
chore(langchain): fix types in test_diagram and test_sync_async_wrappers (#34591)
style(langchain): add ruff rule PLC0415 (#34559)
fix(langchain): resolve race condition in ShellSession.execute() (#34535)
fix(infra): use langchain_v1 for dev container deps (#34534)
chore(deps): bump mypy to v1.19 and ruff to v1.14 (#34521)
fix(langchain-classic): pass default to config.getoption (#34034)
style(langchain): add ruff rule RUF012 (#34497)
refactor(langchain): refactor optional imports logic (#32813)
style: add ruff ISC001 rule (#34493)
style(langchain): add TC ruff rules (#34496)
style(langchain): fix some ruff preview rules (#34504)
style(langchain): fix some PLC0415 rules (#34475)
style(langchain): add ruff rules PT (#34434)
feat(langchain): enhance init_chat_model with improved validation (#34226)
docs(langchain): Docstring improved to show Streaming custom events (#34353)
feat(langchain): Add support to google_genai provider in init_embeddings (#34388)
release(core): 1.2.3 (#34421)
release(openai): 1.1.6: update max input tokens for gpt-5 series (#34419)
release(openai): 1.1.5 (#34409)
feat(infra): add CI check for out of date lockfiles (#34397)
release(langchain): 1.2 (#34373)
fix(langchain): shell output multithreading race condition (#34333)
refactor(standard-tests): improve VCR config (#33968)
fix(huggingface): Helper logic for init_chat_model with HuggingFace backend (#34259)
chore(langchain): cleanup ruff config (#32810)
fix: little lint thing (#34310)
chore(langchain): check agents integration tests with mypy (#34308)
fix(langchain): add sentinel value to ProviderStrategy / strict (#34290)
chore(langchain): add end to end test for strict mode in provider strategy (#34289)
feat(langchain,openai): add strict flag to ProviderStrategy structured output (#34149)
feat(core,anthropic): extras on BaseTool (#34120)
release(langchain): 1.1.3 (#34255)
feat: add agent name to AIMessage (#34254)
chore(core): improve typing of messages utils functions (#34225)
feat(anthropic): add effort support (#34116)
feat(langchain): add support for Upstage (Solar) in init_chat_model (#34220)
release: langchain 1.1.2 (#34210)
fix: simplify summarization cutoff logic (#34195)
release: langchain 1.1.1 (#34206)
feat: Use uuid7 for run ids (#34172)
fix(langchain): (SummarizationMiddleware) adjust token counts based on model (#34161)
docs(langchain): docstrings for summariziation middleware types (#34158)
fix(langchain): add types to human_in_the_loop middleware (#34137)
docs(anthropic,core,langchain): updates (#34106)
release(langchain): 1.1 (#34090)
feat(langchain): support SystemMessage in create_agent's system_prompt (#34055)
fix: don't reorder tool calls in HITL middleware (#34023)
chore(docs): fix a few refs syntax errors (#34044)
feat(model-profiles): distribute data across packages (#34024)
chore: add more robust test for runtime injection w/ explicit args_schema (#34051)
feat: ModelRetryMiddleware (#34027)
fix: deprecate setattr on ModelCallRequest (#34022)
style(langchain): fix some middleware ref syntax (#33988)
fix: resumable shell, works w/ interrupts (#33978)
feat(langchain): reference model profiles for provider strategy (#33974)
chore: increase coverage for shell, filesystem, and summarization middleware (#33928)
fix(anthropic): execute bash + file tools via tool node (#33960)
fix: adding missing async hooks (#33957)
docs: Fix doc links (#33964)
fix: add filesystem middleware in init (#33955)
chore(langchain): update deps (#33951)
fix(langchain, openai): backward compat for response_format (#33945)
fix(langchain, openai): fix create_agent / response_format for Responses API (#33939)
feat: refactor tests coverage (#33927)
chore: update README.md files (#33919)
feat(langchain): support async summarization in SummarizationMiddleware (#33918)
feat(langchain): (SummarizationMiddleware) support use of model context windows when triggering summarization (#33825)
chore(langchain): pass on reference docstrings (middleware) (#33904)
release(langchain): 1.0.5 (#33893)
revert: Support for SystemMessage in create_agent (#33889)
fix: bump up default recursion limit (#33881)
chore(langchain): Support for SystemMessage in create_agent (#33640)
fix(langchain): Update langchain-core dependency version (#33775)
style: some cleanup (#33857)
chore: attribute package change versions (#33854)
fix: don't trace conditional edges and no todos in input state (#33842)
release: langchain v1.0.4 (#33839)
fix: only increment thread count on successful executions (#33837)
fix: more robust tool call limit middleware (#33817)
feat(langchain): add model-profiles as optional dependency (#33794)
chore: use model IDs, latest anthropic models (#33747)
fix(langchain): use system_prompt in integration tests (#33748)
chore: remove mentions of sonnet 3.5 (#33737)
fix(langchain_v1): remove thread_model_call_count and run_model_call_count from tool node test (#33725)
release: core 1.0.2 and langchain 1.0.3 (#33736)
fix(langchain_v1): removed unsed functions in tool_call_limit middleware (#33735)
style: more refs fixes (#33730)
chore: move ToolNode improvements back to langgraph (#33634)
feat: support structured output retry middleware (#33663)
fix(langchain_v1): correct ref url (#33715)
style: more refs work (#33707)
feat(langchain): export UsageMetadata (#33692)
release(core): 1.0.1 (#33639)
chore(langchain_v1): bump version from 1.0.1 to 1.0.2 (#33629)
fix(langchain_v1): remove non llm controllable params from tool message on invocation failure (#33625)
release(langchain_v1): 1.0.1 (#33610)
fix(langchain_v1): ToolRuntime default for args (#33606)
style: more refs polishing (#33601)
docs(langchain): update reference documentation to note moved embeddings modules (#33600)
style(anthropic): use aliases for model names (#33590)
chore: update pyproject.toml url entries (#33587)
release(langchain_v1): v1.0.0 (#33588)
fix: shell tool middleware (#33589)
feat(langchain_v1): Python 3.14 support (#33560)
fix(langchain,langchain_v1): enable huggingface optional dep (#33586)
fix(langchain): conditional tools -> end edge when all client side calls return direct (#33550)
chore(langchain_v1): relax typing on input state (#33552)
feat(langchain_v1): Add ShellToolMiddleware and ClaudeBashToolMiddleware (#33527)
feat(langchain): file-search middleware (#33551)
release: joint rcs for core + langchain (#33549)
chore(langchain): allow injection of ToolRuntime and generic ToolRuntime[ContextT, StateT] (#33546)
fix(langchain): revert conditional edge from tools to end (#33520) (#33539)
release(langchain): cut rc (#33534)
release(core): 1.0.0rc2 (#33530)
docs(langchain_v1): remove absent arg descriptions (#33529)
fix(langchain): conditional edge from tools to end (#33520)
fix(langchain_v1): relax tool node validation to allow claude text editing tools (#33512)
chore(langchain): update state schema doc (#33524)
chore(langchain_v1): adding back state_schema to create_agent (#33519)
chore(langchain): use runtime not tool_runtime for injected tool arg (#33522)
feat(langchain_v1): tool retry middleware (#33503)
chore(langchain_v1): switch order of params in ToolRuntime (#33518)
feat(langchain_v1): injected runtime (#33500)
style: more sweeping refs work (#33513)
style: more work for refs (#33508)
release(langchain_v1): 1.0.0a15 (#33505)
fix(langchain_v1): keep state to relevant middlewares for tool/model call limits (#33493)
release(core): 1.0.0rc1 (#33497)
docs: update package READMEs (#33488)
chore(langchain_v1): remove invocation request (#33482)
feat(langchain_v1): add async implementations to wrap_model_call (#33467)
fix(langchain_v1): can not import "wrap_tool_call" from agents.… (#33472)
feat(langchain_v1): add override to model request and tool call request (#33465)
docs: create_agent style and clarify system_prompt (#33470)
fix(langchain): rename PlanningMiddleware to TodoListMiddleware (#33476)
fix(langchain_v1): export ModelResponse from agents.middleware (#33453) (#33454)
chore(langchain_v1,anthropic): migrate anthropic middleware to langchain_anthropic (#33463)
chore(langchain_v1): use args for HITL (#33442)
chore(langchain_v1): bump release version (#33440)
chore(langchain_v1): improve error message (#33433)
chore(langchain_v1): remove langchain_text_splitters from test group (#33425)
chore(langchain_v1): stricter handling of sync vs. async for wrap_model_call and wrap_tool_call (#33429)
chore(langchain_v1): further namespace clean up (#33428)
feat(langchain_v1): add async implementation for wrap_tool_call (#33420)
chore(langchain_v1): tool error exceptions (#33424)
feat(langchain_v1): expand message exports (#33419)
style: fix tables, capitalization (#33417)
chore(langchain_v1): add RemoveMessage (#33416)
release(langchain_v1): v1.0.0a13 (#33415)
fix(langchain_v1): out of date docstring (#33414)
chore(langchain_v1): update on_tool_call to wrap_tool (#33410)
chore(langchain_v1): update wrap_on_model return (#33408)
feat(langchain_v1): tool emulator (#33357)
feat(langchain_v1): refactoring HITL API (#33397)
style: .. code-block:: admonition translations (#33400)
style: address Sphinx double-backtick snippet syntax (#33389)
chore: update Sphinx links to markdown (#33386)
style: remove more Optional syntax (#33371)
chore(langchain_v1): rename on_model_call to wrap_model_call (#33370)
chore(langchain_v1): update the uv lock file (#33369)
chore(langchain_v1): replace modify model request with on model call (#33368)
chore(langchain): add unit tests for wrap_tool_call decorator (#33367)
chore(langchain_v1): rename on_tool_call to wrap_tool_call (#33366)
chore(langchain_v1): add runtime and context to model request (#33365)
chore(langchain_v1): update on_tool_call to regular callbacks (#33364)
style: monorepo pass for refs (#33359)
chore(langchain_v1): simplify on model call logic (#33358)
chore: fix dropdown default open admonition in refs (#33354)
chore(langchain_v1): remove unused internal namespace (#33352)
feat(langchain_v1): add on_tool_call middleware hook (#33329)
feat(langchain_v1): on_model_call middleware (#33328)
remove runtime where not needed
fix(langchain_v1): injection logic in tool node (#33344)
chore: enrich pyproject.toml files with links to new references, others (#33343)
chore: clean up pyproject.toml files, use core a7 (#33334)
chore(langchain): clean Makefile (#33335)
fix(langchain_v1): fix edges when there's no middleware (#33321)
release(langchain_v1): 1.0.0a12 (#33314)
chore(langchain_v1): rename model_request node -> model (#33310)
release(langchain_v1): 1.0.0a11 (#33307)
chore(langchain_v1): remove support for ToolNode in create_agent (#33306)
feat(langchain_v1): simplify to use ONE agent (#33302)
chore(langchain_v1): remove text splitters from langchain v1 namespace (#33297)
chore(langchain_v1): expose rate_limiters from langchain_core (#33305)
fix(langchain_v1): tool selector should use last human message (#33294)
feat(langchain_v1): before_agent and after_agent hooks (#33279)
feat(langchain_v1): Implement Context Editing Middleware (#33267)
feat(openai): enable stream_usage when using default base URL and client (#33205)
chore(infra): pdm -> hatchling (#33289)
feat(langchain_v1): Add retry_model_request middleware hook, add ModelFallbackMiddleware (#33275)
fix(langchain_v1): linting fixes for llm tool selector (#33278)
feat(langchain_v1): add llm selection middleware (#33272)
feat(langchain_v1): represent server side tools in modifyModelRequest and update tool handling (#33274)
feat(langchain_v1): Implement PIIMiddleware (#33271)
fix(langchain_v1): dynamic response format (#33273)
chore(langchain_v1): remove union return type in init_embeddings (#33062)
feat(langchain_v1): Add ToolCallLimitMiddleware (#33269)
chore(langchain_v1): change modifyModelRequest back to tools (#33270)
fix(langchain_v1): handle switching resposne format strategy based on model identity (#33259)
feat(langchain_v1): implement nicer devx for dynamic prompt (#33264)
feat(langchain_v1): description generator for HITL middleware (#33195)
chore(core,langchain,langchain_v1)!: remove globals from langchain-v1, update globals in langchain-classic, langchain-core (#33251)
chore(langchain_v1)!: Remove ToolNode from agents (#33250)
feat(langchain): model call limits (#33178)
chore: delete deprecated items (#33192)
chore(langchain_v1): uncomment some optional deps (#33244)
docs: v1 docs updates (#33173)
release: v1.0.0 (#32567)
feat(langchain_v1): update messages namespace (#33207)
feat(langchain): use decorators for jumps instead (#33179)
feat(langchain_v1): add async support for create_agent (#33175)
chore(langchain_v1): use list[str] for modifyModelRequest (#33166)
feat(langchain): Using Structured Response as Key in Output Schema for Middleware Agent (#33159)
chore(langchain_v1): expose middleware decorators and selected messages (#33163)
feat(langchain): todo middleware (#33152)
fix(langchain): handle gpt-5 model name in init_chat_model (#33148)
fix(langchain): add context_management to Anthropic chat model init (#33150)
fix(langchain): fix response action for HITL (#33131)
chore(langchain_v1): move tool node to tools namespace (#33132)
docs: more standardization (#33124)
docs: standardize .. code-block directive usage (#33122)
docs: correct ported over directives (#33121)
chore: bump ruff version to 0.13 (#33043)
chore: bump locks (#33114)
release(langchain): v1.0.0a9 (#33098)
fix(langchain): extra arg for anthropic caching, __end__ -> end for jump_to (#33097)
fix(langchain_v1): version equality check (#33095)
release(langchain): 1.0.0a8 (#33090)
feat(langchain): improvements to anthropic prompt caching (#33058)
style: repo linting pass (#33089)
fix(langchain): need to inject all state for tools registered by middleware (#33087)
chore(langchain): renaming for HITL (#33067)
chore(langchain): simplifying HITL condition (#33065)
fix(langchain_v1): only interrupt if at least one ToolConfig value is True (#33064)
feat(langchain): new decorator pattern for dynamically generated middleware (#33053)
fix(langchain): HITL bug causing dupe interrupt (#33052)
chore: update pyproject.toml files, remove codespell (#33028)
release(langchain): 1.0.0a6 (#33024)
fix(langchain): use state schema as input schema to middleware nodes (#33023)
feat(langchain): dynamic system prompt middleware (#33006)
feat(langchain): improved HITL patterns (#32996)
chore: restore commented out optional deps (#32971)
chore: bump mypy version to 1.18 (#32914)
release(langchain): v1.0.0a5 (#32917)
fix(langchain): use messages from model request (#32908)
fix(core): resolve mermaid node id collisions when special chars are used (#32857)
revert: "chore: remove ruff target-version" (#32895)
chore: remove ruff target-version (#32880)
chore(docs): update package READMEs (#32869)
feat(langchain): support PEP604 ( | union) in tool node error handlers (#32861)
chore(langchain): add ruff rule E501 in langchain_v1 (#32812)
chore(langchain): add ruff rule UP007 in langchain_v1 (#32811)
chore(langchain): enable ruff docstring-code-format in langchain_v1 (#32855)
chore(core): enable ruff docstring-code-format (#32834)
feat(langchain): middleware support in create_agent (#32828)
fix(langchain): fix mypy versions in langchain_v1 (#32816)
chore(langchain): cleanup langchain_v1 mypy config (#32809)
chore(langchain): add ruff rules D for langchain_v1 (#32808)
fix(langchain): update init version (#32793)
release(langchain): v1.0.0a3 (#32791)
chore(langchain): rename create_react_agent -> create_agent (#32789)
chore(langchain): remove upper bound at v1 for core (#32737)
chore(langchain): also bump text splitters (#32722)
chore(langchain): use latest core (#32720)
chore(langchain): revert back to static versioning for now (#32719)
release(langchain): v1.0.0a1 (#32718)
feat(langchain): revamped create_react_agent (#32705)
chore(langchain): remove untested chains for first alpha (#32710)
chore(langchain): drop Python 3.9 to prep for v1 (#32704)
chore: adress pytest-asyncio deprecation warnings + other nits (#32696)
chore: update references to use the latest version of Claude-3.5 Sonnet (#32594)
docs: update outdated README.md content (#32540)
fix(tests): add anthropic_proxy to configurable test parameters (for v1)
chore: formatting across codebase (#32466)
feat(openai): minimal and verbosity (#32455)
feat(langchain): add stuff and map reduce chains (#32333)
fix: use new Google model names in examples (#32288)
fix: update bar_model to use the correct model version claude-3-7-sonnet-20250219 (#32284)
refactor: remove references to unsupported model claude-3-sonnet-20240229 (#32281)
fix: formatting issues in docstrings (#32265)
feat(docs): improve devx, fix Makefile targets (#32237)
chore(langchain_v1): clean anything uncertain (#32228)
feat(langchain): v1 scaffolding (#32166)
Security Fixes
- CVE-2026-4539
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Related context
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Earlier breaking changes
- vlangchain-core==1.4.0 Deletes schema items marked for removal in schemas.py
- vlangchain-core==1.4.0 Deletes function_calling.py utils marked for removal
- vlangchain-core==1.4.0 Deletes get_relevant_documents function from API
- vlangchain-core==1.4.0 Deletes pydantic_v1 module entirely from codebase
- vlangchain-core==1.4.0 Deletes BaseMemory module, moved to langchain-classic
Beta — feedback welcome: [email protected]