mirror of
https://github.com/hwchase17/langchain.git
synced 2026-04-03 19:04:23 +00:00
64a848a03b
Add a durable maintainer override to the "Require Issue Link" workflow. The existing maintainer-reopen path skipped enforcement once but didn't persist that decision — a subsequent PR edit could re-trigger closure. Maintainers now have two override paths (reopen the PR or remove `missing-issue-link`), both converging on `applyMaintainerBypass()` which reopens the PR, cleans up `missing-issue-link`, and applies a durable `bypass-issue-check` label so future triggers skip enforcement. ## Changes - Add `unlabeled` to `pull_request_target` trigger types and gate it on `missing-issue-link` removal + `external` label presence in the job-level `if` - Introduce `bypass-issue-check` as a new skip label alongside `trusted-contributor` — scoped per-PR (not per-author) so maintainers can override individual PRs without blanket trust - Extract three helpers in the check-link script: `ensureAndAddLabel` (idempotent label creation), `senderIsOrgMember` (org membership check), and `applyMaintainerBypass` (remove label → reopen → add bypass) - `applyMaintainerBypass` reopens the PR *before* adding the bypass label so a failed reopen (deleted branch, permissions) leaves a more actionable state; reopen failure is caught and surfaced via `core.warning` instead of crashing the step - Non-member label removal defensively re-adds `missing-issue-link` and early-returns with failure outputs (re-add failure is non-fatal so the downstream "Add label" step can retry) - Replace hardcoded `'langchain-ai'` org in `senderIsOrgMember` with `context.repo.owner` for portability - Auto-close comments now include a maintainer override hint: *"reopen this PR or remove the `missing-issue-link` label to bypass this check"* - Live-label race guard also checks for `bypass-issue-check`
The agent engineering platform.
LangChain is a framework for building agents and LLM-powered applications. It helps you chain together interoperable components and third-party integrations to simplify AI application development — all while future-proofing decisions as the underlying technology evolves.
Note
Looking for the JS/TS library? Check out LangChain.js.
Quickstart
pip install langchain
# or
uv add langchain
from langchain.chat_models import init_chat_model
model = init_chat_model("openai:gpt-5.4")
result = model.invoke("Hello, world!")
If you're looking for more advanced customization or agent orchestration, check out LangGraph, our framework for building controllable agent workflows.
Tip
For developing, debugging, and deploying AI agents and LLM applications, see LangSmith.
LangChain ecosystem
While the LangChain framework can be used standalone, it also integrates seamlessly with any LangChain product, giving developers a full suite of tools when building LLM applications.
- Deep Agents — Build agents that can plan, use subagents, and leverage file systems for complex tasks
- LangGraph — Build agents that can reliably handle complex tasks with our low-level agent orchestration framework
- Integrations — Chat & embedding models, tools & toolkits, and more
- LangSmith — Agent evals, observability, and debugging for LLM apps
- LangSmith Deployment — Deploy and scale agents with a purpose-built platform for long-running, stateful workflows
Why use LangChain?
LangChain helps developers build applications powered by LLMs through a standard interface for models, embeddings, vector stores, and more.
- Real-time data augmentation — Easily connect LLMs to diverse data sources and external/internal systems, drawing from LangChain's vast library of integrations with model providers, tools, vector stores, retrievers, and more
- Model interoperability — Swap models in and out as your engineering team experiments to find the best choice for your application's needs. As the industry frontier evolves, adapt quickly — LangChain's abstractions keep you moving without losing momentum
- Rapid prototyping — Quickly build and iterate on LLM applications with LangChain's modular, component-based architecture. Test different approaches and workflows without rebuilding from scratch, accelerating your development cycle
- Production-ready features — Deploy reliable applications with built-in support for monitoring, evaluation, and debugging through integrations like LangSmith. Scale with confidence using battle-tested patterns and best practices
- Vibrant community and ecosystem — Leverage a rich ecosystem of integrations, templates, and community-contributed components. Benefit from continuous improvements and stay up-to-date with the latest AI developments through an active open-source community
- Flexible abstraction layers — Work at the level of abstraction that suits your needs — from high-level chains for quick starts to low-level components for fine-grained control. LangChain grows with your application's complexity
Documentation
- docs.langchain.com – Comprehensive documentation, including conceptual overviews and guides
- reference.langchain.com/python – API reference docs for LangChain packages
- Chat LangChain – Chat with the LangChain documentation and get answers to your questions
Discussions: Visit the LangChain Forum to connect with the community and share all of your technical questions, ideas, and feedback.
Additional resources
- Contributing Guide – Learn how to contribute to LangChain projects and find good first issues.
- Code of Conduct – Our community guidelines and standards for participation.
- LangChain Academy – Comprehensive, free courses on LangChain libraries and products, made by the LangChain team.