`stream_events(version="v3")` / `astream_events(version="v3")` drops
`input_token_details` and `output_token_details` from the usage metadata
on the assembled message and the `on_llm_end` payload: the conversion to
the protocol `UsageInfo` shape copied only the flat token counts.
Providers fold cached tokens into `input_tokens` and break them out in
`input_token_details`, so tracers (e.g. LangSmith) price every input
token at the uncached rate on the v3 path, inflating reported cost for
prompt-cached runs (cache reads bill at roughly a tenth of the base
input rate). The v2 events path and `astream` aggregation preserve the
details and report correctly; reasoning-token breakdowns in
`output_token_details` are lost the same way.
The detail breakdowns now live on the wire type itself:
`input_token_details` / `output_token_details` were added to `UsageInfo`
in `langchain-protocol` 0.0.17 (alongside `InputTokenDetails` /
`OutputTokenDetails`), so core imports `UsageInfo` directly instead of
carrying a local subclass. The v3 usage accumulator threads the details
through end to end, shallow-copying the nested dicts (`_isolate_usage`)
so later accumulator mutation cannot leak into already-emitted events.
Since native provider converters share `build_message_finish`, this also
covers provider-native v3 streams.
Verified against a live claude-sonnet-4-6 call with a cached prompt: v3
`on_llm_end` usage now matches v2, with `cache_read` / `cache_creation`
intact. Requires `langchain-protocol>=0.0.17` (core pin bumped
accordingly).
Enables mypy's `warn_unreachable` rule for `langchain-core`, bringing it
in line with the other strict libraries in the monorepo. Previously this
rule was intentionally disabled by a code comment, because under mypy
2.x it false-flags intentional defensive runtime checks — most notably
the SSRF / IP-policy guards in `langchain_core/_security/` — as
unreachable.
This PR resolves all of those warnings without deleting or
blanket-ignoring the defensive guards, so contributors get
unreachable-code coverage going forward and accidental dead code is
caught in CI.
The bulk of the change is mechanical: a targeted `# type:
ignore[unreachable]` on each defensive `else`/error branch that mypy
considers unreachable but that we deliberately keep as a runtime guard
against unexpected input. A few changes are more substantive and worth a
closer look:
- **`coro_with_context` (`runnables/utils.py`) — behavior change on
Python < 3.11.** The pre-3.11 path is rewritten to always route through
`context.run(asyncio.create_task, coro)`, so the supplied context is
reliably propagated to the task. Previously, on 3.10 the helper returned
the bare coroutine (run in the caller's context) when
`create_task=False`, and dropped the context entirely when
`create_task=True`. The new behavior matches 3.11+. The `create_task`
parameter is now inert but retained for signature compatibility. All
callers `await` the result, so returning a `Task` rather than a
coroutine is transparent.
- **`_create_template_from_message_type` (`prompts/chat.py`) — signature
widening.** This private helper's `template` parameter now accepts
`bool` inside the list, accurately reflecting the existing `["{var}",
is_optional]` placeholder form. No public-API impact.
- **`PydanticOutputFunctionsParser`
(`output_parsers/openai_functions.py`).** The `pydantic_schema` field is
typed as `TypeBaseModel` (which covers both v1 and v2 model classes,
unlike the prior annotation), and the `args_only` parse path now
dispatches explicitly on `BaseModel` vs `BaseModelV1` rather than
duck-typing via `hasattr`. This also yields clearer errors for
unsupported / dict schemas.
- **`_security/_policy.py`.** Loop variables are renamed so mypy can
narrow their types, which lets the old `# type: ignore[assignment]`
comments be dropped. The IP-blocklist logic is unchanged.
---------
Co-authored-by: Mason Daugherty <mason@langchain.dev>
Co-authored-by: Mason Daugherty <github@mdrxy.com>
Bumps `langchain-core` to `1.4.7` for the next patch release and updates
downstream minimum `langchain-core` requirements so package locks
resolve against the new core version.
This also refreshes the runnable snapshots that embed `lc_versions`
metadata so the version consistency check continues to validate
checked-in artifacts.
Validated with `python libs/core/scripts/check_version.py`, `uv lock
--check` across package lockfiles, and the core runnable tests that own
the updated snapshots with local LangSmith tracing env disabled.
Originally a narrow bump of mypy to `1.20` in four packages. Expanded to
get the whole monorepo onto a single, current mypy and a consistent
type-check configuration, so contributors no longer hit different mypy
versions and divergent behavior depending on which package they touch.
### What changed
- **Unified the mypy pin to `>=2.1.0,<2.2.0`** in every mypy-using
package (6 libs + 14 partners), replacing the previously scattered pins
(`1.10`/`1.17`/`1.18`/`1.19`/`1.20`, with assorted upper bounds).
- **Unified the `[tool.mypy]` base per tier:**
- libs: `plugins = ["pydantic.mypy"]`, `strict = true`,
`enable_error_code = "deprecated"`, `warn_unreachable = true`
- partners: `disallow_untyped_defs = true`
- Normalized style (`disallow_untyped_defs = "True"` string → bool,
quote/key consistency).
- **Fixed the 20 real errors** mypy 2.1 surfaces: `redundant-cast` from
improved narrowing (`core`, `langchain-classic`), a `var-annotated` for
`_LOGGED`, a return-type widening in `langchain-groq`'s
`_convert_from_v1_to_groq` (it can legitimately return a bare `str`),
and stale `type-arg`/`unused-ignore` in `langchain-model-profiles`
tests.
### Deliberate non-uniformity (documented inline in the relevant
`pyproject.toml`s)
Going fully byte-identical would surface ~196 additional errors that are
*not* real bugs, so two settings are kept package-appropriate:
- **`warn_unreachable`** is enabled on every strict lib **except
`core`**, where it false-flags intentional defensive code — including
the SSRF / IP-policy guards in `_security/` — as unreachable.
- **`pydantic.mypy` plugin** is used only on `anthropic` and
`perplexity` (their code is authored against it and reports ~99/~132
errors without it). It is *not* added to the other partners, where it
only flags the public alias constructor API (e.g. `ChatGroq(model=...)`)
in tests rather than finding bugs.
- **`ollama`** is left on its `ty` type checker; it does not use mypy.
---------
Co-authored-by: Mason Daugherty <github@mdrxy.com>
Bumps the `langchain-tests` minimum across the monorepo from `1.0.0` to
`1.1.9` and adds a partner-level `Makefile` so partner lockfiles can be
regenerated in one command, matching the existing convention under
`libs/`.
Dependabot has been stripping upper/lower bounds from internal
`langchain-*` deps in partner `pyproject.toml` files (e.g. #37288
reduced `langchain-core>=1.3.2,<2.0.0` to bare `langchain-core`). Locks
down the config so bumps preserve existing specifiers, and restores the
bounds it already mangled across the monorepo.
## Changes
- Add `versioning-strategy: increase` to every `uv` ecosystem block in
`.github/dependabot.yml` so future bumps move the lower bound in place
instead of rewriting the constraint.
- Ignore workspace-internal packages (`langchain-core`, `langchain`,
`langchain-classic`, `langchain-text-splitters`, `langchain-tests`,
`langchain-model-profiles`) on every `uv` block — these are editable
installs from local paths and their published constraints are
hand-curated for release, not Dependabot's to bump.
- Restore stripped bounds across all `libs/` packages — runtime
`dependencies` and every dep group (`test`, `dev`, `test_integration`,
`typing`, `lint`) — to `>=1.4.0,<2.0.0` for `langchain-core` and
`>=1.0.0,<2.0.0` for the other internal packages.
## Description
Updates package metadata and README badges so LangChain social links
point to the new `@langchain_oss` X handle. This was completed with
AI-agent assistance.
## Test Plan
- [ ] Validate README badges and package metadata links point to
`https://x.com/langchain_oss`
_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>
CVE-2025-71176 (medium severity)
All are dev-only (test dependency group) — no impact on published
packages.
### Why syrupy was also bumped
syrupy 4.x (`<5.0.0`) constrains pytest to `<9.0.0`, blocking the CVE
fix. Widening to `<6.0.0` allows syrupy 5.x which supports pytest 9.x.
## Summary
Bumps `pygments` to `>=2.20.0` across all 21 affected packages to
address [CVE-2026-4539](https://github.com/advisories/GHSA-XXXX) — ReDoS
via inefficient GUID regex in Pygments.
- **Severity:** Low
- **Fixed in:** 2.20.0 (was 2.19.2)
- **Change:** Added `pygments>=2.20.0` to `constraint-dependencies` in
`[tool.uv]` for each package, then ran `uv lock --upgrade-package
pygments` to regenerate lock files.
Closes Dependabot alerts #3435–#3455.
## Release Note
Patch deps
### Test Plan
- [x] CI Green 🙏
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
