Files
langchain/libs
Steffen Hausmann 4065106c2e fix(langchain): add types to human_in_the_loop middleware (#34137)
The `HumanInTheLoopMiddleware` is missing a type annotation for the
context schema. Without the fix in this PR, the following code does not
type check:

```
graph = create_agent(
    "gpt-5",
    tools=[send_email_tool, read_email_tool],
    middleware=[
        HumanInTheLoopMiddleware(
            interrupt_on={
                # Require approval or rejection for sending emails
                "send_email_tool": {
                    "allowed_decisions": ["approve", "reject"],
                },
                # Auto-approve reading emails
                "read_email_tool": False,
            }
        ),
    ],
    context_schema=ContextSchema,
)
```

```
Argument of type "list[HumanInTheLoopMiddleware]" cannot be assigned to parameter "middleware" of type "Sequence[AgentMiddleware[StateT_co@create_agent, ContextT@create_agent]]" in function "create_agent"
  "HumanInTheLoopMiddleware" is not assignable to "AgentMiddleware[AgentState[Unknown], ContextSchema | None]"
    Type parameter "ContextT@AgentMiddleware" is invariant, but "None" is not the same as "ContextSchema | None"
```
2025-12-01 08:46:38 -05:00
..

Packages

Important

View all LangChain integrations packages

This repository is structured as a monorepo, with various packages located in this libs/ directory. Packages to note in this directory include:

core/             # Core primitives and abstractions for langchain
langchain/        # langchain-classic
langchain_v1/     # langchain
partners/         # Certain third-party providers integrations (see below)
standard-tests/   # Standardized tests for integrations
text-splitters/   # Text splitter utilities

(Each package contains its own README.md file with specific details about that package.)

Integrations (partners/)

The partners/ directory contains a small subset of third-party provider integrations that are maintained directly by the LangChain team. These include, but are not limited to:

Most integrations have been moved to their own repositories for improved versioning, dependency management, collaboration, and testing. This includes packages from popular providers such as Google and AWS. Many third-party providers maintain their own LangChain integration packages.

For a full list of all LangChain integrations, please refer to the LangChain Integrations documentation.