Moving all `ToolNode` related improvements back to LangGraph and
importing them in LC!
pairing w/ https://github.com/langchain-ai/langgraph/pull/6321
this fixes a couple of things:
1. `InjectedState`, store etc will continue to work as expected no
matter where the import is from
2. `ToolRuntime` is now usable w/in langgraph, woohoo!
Refactor tool call middleware from generator-based to handler-based
pattern
Simplifies on_tool_call middleware by replacing the complex generator
protocol with a straightforward handler pattern. Instead of yielding
requests and receiving results via .send(),
handlers now receive an execute callable that can be invoked multiple
times for retry logic.
Before vs. After
Before (Generator):
```python
class RetryMiddleware(AgentMiddleware):
def on_tool_call(self, request, state, runtime):
for attempt in range(3):
response = yield request # Yield request, receive result via .send()
if is_valid(response) or attempt == 2:
return # Final result is last value sent to generator
```
After (Handler):
```python
class RetryMiddleware(AgentMiddleware):
def on_tool_call(self, request, handler):
for attempt in range(3):
result = handler(request) # Direct function call
if is_valid(result):
return result
return result
```
Follow up after this PR:
* Rename the interceptor to wrap_tool_call
* Fix the async path for the ToolNode
Further clean up of namespace:
- Removed prompts (we'll re-add in a separate commit)
- Remove LocalFileStore until we can review whether all the
implementation details are necessary
- Remove message processing logic from memory (we'll figure out where to
expose it)
- Remove `Tool` primitive (should be sufficient to use `BaseTool` for
typing purposes)
- Remove utilities to create kv stores. Unclear if they've had much
usage outside MultiparentRetriever
This PR adds scaffolding for langchain 1.0 entry package.
Most contents have been removed.
Currently remaining entrypoints for:
* chat models
* embedding models
* memory -> trimming messages, filtering messages and counting tokens
[we may remove this]
* prompts -> we may remove some prompts
* storage: primarily to support cache backed embeddings, may remove the
kv store
* tools -> report tool primitives
Things to be added:
* Selected agent implementations
* Selected workflows
* Common primitives: messages, Document
* Primitives for type hinting: BaseChatModel, BaseEmbeddings
* Selected retrievers
* Selected text splitters
Things to be removed:
* Globals needs to be removed (needs an update in langchain core)
Todos:
* TBD indexing api (requires sqlalchemy which we don't want as a
dependency)
* Be explicit about public/private interfaces (e.g., likely rename
chat_models.base.py to something more internal)
* Remove dockerfiles
* Update module doc-strings and README.md
