feat(core): can use now approximate alias inplace of count_tokens_approximately, any of it works now

[Davda-James]

Description:

earlier we have to use like below:

from langchain_core.messages import trim_messages
from langchain_core.messages.utils import count_tokens_approximately

trim_messages(..., token_counter=count_tokens_approximately)

Now can be used as like this also

from langchain_core.messages import trim_messages

trim_messages(..., token_counter="approximate")

• Added tests
• Lint and test: Run this as I made change in langchain/core, uv run --group test pytest tests/unit_tests/messages/test_utils.py -v

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

1 Skipped Deployment

Project	Deployment	Preview	Comments	Updated (UTC)
langchain	Ignored	Preview		Sep 26, 2025 7:37pm

[codspeed-hq]

CodSpeed WallTime Performance Report

Merging #33045 will not alter performance

_{Comparing Davda-James:feat/trim_messages-support-approx-alias (0048bc8) with master (9863023)}

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

Summary

✅ 13 untouched

[eyurtsev]

@Davda-James could you undo the changes in the lock file? And we can merge then?

[Davda-James]

@eyurtsev reverted the lock file changes in new commit.

[Davda-James]

Hey @eyurtsev any further changes needed or anything to add ?