Update index.mdx

[Jayanth-sanku]

docs(concepts): add 'Stateful agents' to concepts section for improved clarity

Thank you for contributing to LangChain!

• PR title: "package: description"

  • Where "package" is whichever of langchain, core, etc. is being modified. Use "docs: ..." for purely docs changes, "infra: ..." for CI changes.
  • Example: "core: add foobar LLM"

• PR message: Delete this entire checklist and replace with

  • Description: a description of the change
  • Issue: the issue # it fixes, if applicable
  • Dependencies: any dependencies required for this change
  • Twitter handle: if your PR gets announced, and you'd like a mention, we'll gladly shout you out!

• Add tests and docs: If you're adding a new integration, please include

  1. a test for the integration, preferably unit tests that do not rely on network access,
  2. an example notebook showing its use. It lives in docs/docs/integrations directory.

• Lint and test: Run make format, make lint and make test from the root of the package(s) you've modified. See contribution guidelines for more: https://python.langchain.com/docs/contributing/

Additional guidelines:

• Make sure optional dependencies are imported within a function.
• Please do not add dependencies to pyproject.toml files (even optional ones) unless they are required for unit tests.
• Most PRs should not touch more than one package.
• Changes should be backwards compatible.

If no one reviews your PR within a few days, please @-mention one of baskaryan, eyurtsev, ccurme, vbarda, hwchase17.

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Name	Status	Preview	Comments	Updated (UTC)
langchain	❌ Failed (Inspect)			Jun 5, 2025 6:43am

[codspeed-hq]

CodSpeed Walltime Performance Report

Merging #31494 will improve performances by 13.31%

_{Comparing Jayanth-sanku:patch-1 (9155730) with master (b149cce)}

⚠️ 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

⚡ 11 improvements
✅ 2 untouched benchmarks

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
⚡	test_import_time[CallbackManager]	438 ms	393.7 ms	+11.26%
⚡	test_import_time[ChatPromptTemplate]	409 ms	369 ms	+10.83%
⚡	test_import_time[Document]	166 ms	150.8 ms	+10.07%
⚡	test_import_time[HumanMessage]	169.9 ms	154.2 ms	+10.17%
⚡	test_import_time[InMemoryRateLimiter]	69.3 ms	62.8 ms	+10.4%
⚡	test_import_time[InMemoryVectorStore]	248 ms	219.8 ms	+12.83%
⚡	test_import_time[LangChainTracer]	431.5 ms	383.8 ms	+12.43%
⚡	test_import_time[PydanticOutputParser]	380.9 ms	336.1 ms	+13.31%
⚡	test_import_time[RunnableLambda]	236.5 ms	213.6 ms	+10.69%
⚡	test_import_time[Runnable]	235.5 ms	213 ms	+10.56%
⚡	test_import_time[tool]	493.8 ms	448.7 ms	+10.04%

[codspeed-hq]

CodSpeed Instrumentation Performance Report

Merging #31494 will not alter performance

_{Comparing Jayanth-sanku:patch-1 (9155730) with master (b149cce)}

Summary

✅ 13 untouched benchmarks

[Jayanth-sanku]

@sbusso @baskaryan @deepblue @zeke any one of you can you please review ??

[sbusso]

@Jayanth-sanku random tagging people is no good

[eyurtsev]

@Jayanth-sanku the PR doesn't include the actual concept?

[eyurtsev]

links to a non existent page