search
Middleware Classes
Text Editor Tools
- StateClaudeTextEditorToolMiddleware: In-memory text editor using agent state
- FilesystemClaudeTextEditorToolMiddleware: Text editor operating on real filesystem
Implementing Claude's text editor tools
https://docs.claude.com/en/docs/agents-and-tools/tool-use/text-editor-tool Operations:
view, create, str_replace, insert
Memory Tools
- StateClaudeMemoryToolMiddleware: Memory persistence in agent state
- FilesystemClaudeMemoryToolMiddleware: Memory persistence on filesystem
Implementing Claude's memory tools
https://docs.claude.com/en/docs/agents-and-tools/tool-use/memory-tool Operations: Same
as text editor plus delete and rename
File Search Tools
- StateFileSearchMiddleware: Search state-based files
- FilesystemFileSearchMiddleware: Search real filesystem
Provides Glob and Grep tools with same schema as used by Claude Code (but compatible
with any model)
- Glob: Pattern matching (e.g., **/*.py, src/**/*.ts), sorted by modification time
- Grep: Regex content search with output modes (files_with_matches, content, count)
Usage
``` from langchain.agents import create_agent from langchain.agents.middleware import (
StateTextEditorToolMiddleware, StateFileSearchMiddleware, )
agent = create_agent( model=model, tools=[], middleware=[
StateTextEditorToolMiddleware(), StateFileSearchMiddleware(), ], ) ```
The one risk point that I can see here is that model + tool call
counting now occurs in the `after_model` hook which introduces order
dependency (what if you have HITL execute before this hook and we jump
early to `model`, for example).
This is something users can work around at the moment and we can
document. We could also introduce a priority concept to middleware.
## Description
Fixes#33453
`ModelResponse` was defined in `types.py` and included in its `__all__`
list, but was not exported from the middleware package's `__init__.py`.
This caused `ImportError` when attempting to import it directly
from `langchain.agents.middleware`, despite being documented as a public
export.
## Changes
- Added `ModelResponse` to the import statement in
`langchain/agents/middleware/__init__.py`
- Added `ModelResponse` to the `__all__` list in
`langchain/agents/middleware/__init__.py`
- Added comprehensive unit tests in `test_imports.py` to verify the
import works correctly
## Issue
The original issue reported that the following import failed:
```python
from langchain.agents.middleware import ModelResponse
# ImportError: cannot import name 'ModelResponse' from
'langchain.agents.middleware'
The workaround was to import from the submodule:
from langchain.agents.middleware.types import ModelResponse # Workaround
Solution
After this fix, ModelResponse can be imported directly as documented:
from langchain.agents.middleware import ModelResponse # Now works!
Testing
- ✅ Added 3 unit tests in
tests/unit_tests/agents/middleware/test_imports.py
- ✅ All tests pass locally: make format, make lint, make test
- ✅ Verified ModelResponse is properly exported and importable
- ✅ Verified ModelResponse appears in __all__ list
Dependencies
None. This is a simple export fix with no new dependencies.
---------
Co-authored-by: Eugene Yurtsev <eugene@langchain.dev>
Co-authored-by: Eugene Yurtsev <eyurtsev@gmail.com>
This is tool emulation middleware. The idea is to help test out an agent
that may have some tools that either take a long time to run or are
expensive to set up. This could allow simulating the behavior a bit.
