## Description
Updates the X/Twitter social links to point to the new `@langchain_oss`
account across README badges and Python package metadata.
## Test Plan
- [ ] Verify README badges and package metadata point to
`@langchain_oss` on X
_Opened collaboratively by Mason Daugherty and open-swe._
---------
Co-authored-by: open-swe[bot] <open-swe@users.noreply.github.com>
Co-authored-by: Mason Daugherty <61371264+mdrxy@users.noreply.github.com>
Co-authored-by: Mason Daugherty <mason@langchain.dev>
## Summary
Extends `ToolNode` so that a single tool invocation can return
`list[Command | ToolMessage]` instead of only a single `Command` or
`ToolMessage`. This brings `ToolNode`'s per-tool-call contract in line
with the rest of LangGraph, where nodes can already return multiple
Commands.
Depends on langchain-ai/langchain#36963 which allows
`list[ToolOutputMixin]` to pass through `BaseTool._format_output`
unchanged.
## Changes
### `libs/prebuilt/langgraph/prebuilt/tool_node.py`
**New list-return gate in `_execute_tool_sync` / `_execute_tool_async`**
— After the existing `Command` and `ToolMessage` checks, a new branch
accepts `list[Command | ToolMessage]` and routes it through
`_validate_tool_command_list`. Lists with non-`Command`/`ToolMessage`
elements raise `TypeError`. Both sync and async paths are updated
symmetrically.
**`_validate_tool_command_list`** — Enforces the terminating-ToolMessage
rule: exactly one `ToolMessage` in the list must carry `tool_call_id ==
<outer_id>` (top-level or nested inside a `Command.update["messages"]`).
Zero or multiple terminators raise `_MissingToolMessageError`.
Individual Commands in the list are validated via the existing
`_validate_tool_command`; when a Command lacks the terminator (which is
allowed since the list-level check handles it), the
`_MissingToolMessageError` is caught and the already-normalized command
from the exception is used.
**`_MissingToolMessageError`** — A `ValueError` subclass raised by
`_validate_tool_command` (and `_validate_tool_command_list`) when no
matching `ToolMessage` is found. Carries the already-normalized command
so callers can recover without re-doing deepcopy/message-conversion
work. Using a typed exception avoids brittle string-matching on error
messages.
**`_combine_tool_outputs`** — Flattens list entries at the top of the
method so downstream combiner logic (parent-`goto` accumulation,
ToolMessage wrapping) is unchanged.
**Response processing moved inside try/except** — In both sync and async
execute methods, the response validation (Command/ToolMessage/list
checks) now runs inside the existing error-handling try block, so
validation errors from the list path go through `_handle_tool_errors`
like other tool errors.
**Return type signatures** widened on `_execute_tool_sync`,
`_execute_tool_async`, `_run_one`, `_arun_one` to include `list[Command
| ToolMessage]`.
### `libs/prebuilt/tests/test_tool_node.py`
New tests covering: valid list returns (top-level terminator, nested
terminator, parent-goto + terminator), regression tests for single
Command/ToolMessage returns, invalid cases (no terminator, multiple
terminators), async parity, integration with mixed list/non-list tool
calls, and `_handle_tool_errors` interaction.
---------
Co-authored-by: Sydney Runkle <sydneymarierunkle@gmail.com>
namespace decisions
```
langgraph.prebuilt
├── ToolRuntime # new
# all of the other stuff that was already there
langgraph.prebuilt.tool_node
├── ToolNode
├── ToolCallRequest # new
├── ToolRuntime # new
├── InjectedState
├── InjectedStore
├── ToolCallWrapper
├── AsyncToolCallWrapper
├── tools_condition
```
```
langchain.tools
├── ToolRuntime # now from langgraph.prebuilt
├── InjectedState # now from langgraph.prebuilt
├── InjectedStore # now from langgraph.prebuilt
├── ToolException
├── tool
├── BaseTool
├── InjectedToolArg
├── InjectedToolCallId
```
bumping core dependency for `langgraph-prebuilt` to `>1.0.0` so that we
can take advantage of internal utils that allow `ToolRuntime` injection.
We were previously bumping the version in lock step with prebuilt (prev
version was 0.3.67), so this pattern is in line with that.
Also updating snapshots accordingly:
* New mermaid syntax for a few graphs
* Removal of `examples` from `AIMessage`
In this PR:
- Bump `langgraph-checkpoint` to 3.0
- Bump `langgraph-checkpoint-sqlite` to 3.0; Update
`langgraph-checkpoint` deps to >=3,<4
- Bump `langgraph-checkpoint-postgres` to 3.0; Update
`langgraph-checkpoint` max to <4 (keep prior min since the deprecated
functionality wasn't explicitly used)
- Bump `langgraph` to 1.0.1; update `langgraph-checkpoint` max bound to
4
- Bump `prebuilt` to 1.0.1; update `langgraph-checkpoint` max bound to 4
* catching error thrown by asyncio
* using 2nd check for annotations given Pydantic 2.12 changes
* skipping tests for remote graph bc langgraph-api is dependent on
`jsonschema-rs`
* skipping tests w/ pydantic v1 models
```bash
hint: This usually indicates a problem with the package or the build environment.
help: `jsonschema-rs` (v0.29.1) was included because `langgraph:dev` (v1.0.0rc1) depends on `langgraph-cli[inmem]` which
depends on `langgraph-api` (v0.4.29) which depends on `jsonschema-rs`
```
not yet testing for free threaded python, that'll be much more involved!
ended up separating lint / testing deps during this process bc I was
getting a ton of not required deps while testing that were complicating
things :/
* Migrate to `uv`
* Format `pyproject.toml` files properly
* Remove upper bounds on dependencies, and bounds on dev dependencies
(we should be using latest)
* Move to hatch for packaing
In the future we should:
* Set up dependabot / automate lockfile updates and tests
* Add tests for min compatible versions (I'll do this right after merge)
* Use dynamic versioning
* Bump `pydantic` to v2.11.4 in the lockfile, we have some tests failing
