Individual skill
langchain-sdk-patterns
Compose LangChain 1.0 Python runnables with the production defaults the docs do not warn about: parallel batching, narrow fallbacks, and brace-safe prompts. Use when building an LCEL chain with RunnableSequence / RunnableParallel, adding resilience via .with_fallbacks(), tuning throughput with .batch() or .abatch(), or wrapping user input in a prompt template. Trigger with "langchain runnable", "with_fallbacks", "langchain batch", "runnable sequence", "lcel", "runnableparallel", "chain composition".
plugins/saas-packs/langchain-py-pack/skills/langchain-sdk-patterns/SKILL.md
Source commit 0500b275e963c027f6b410e8c49c0446945c574e
What was checked
- Matches the observed repository HEAD
- Yes
- Scanner rules are current
- No
- Repository scan complete
- No
- Skill scan complete
- No
- Observed behavior
- Not checked yet
- Last checked
- Nov 12, 2026
These are observations at the recorded commit, not a guarantee of safety. Review the source before running it.
Install this skill
Choose an agent in your Stack or copy a command below. Commands fetch the pinned commit and copy only this skill directory. Existing destinations are refused. Copying a command does not install anything.
An install command is unavailable: current rules, complete repository and skill scans, an eligible behavior level and a permitted license are required.
Repository context
- Repository stars (not skill ratings)
- 2,916
- Repository last updated
- Nov 12, 2026
- License
- MIT
Observed agent integration: No specific integration evidence. Standard SKILL.md installation does not imply verified compatibility.
- ai Repository topic
- automation Repository topic
- claude-code Repository topic
- devops Repository topic
- mcp Repository topic
- ai-agents Repository topic
- anthropic Repository topic
- claude-code-plugins Repository topic
- developer-tools Repository topic
- llm Repository topic
- saas Declared skill tag
- langchain Declared skill tag
- langgraph Declared skill tag
- python Declared skill tag
- langchain-1.0 Declared skill tag
- lcel Declared skill tag
- runnables Declared skill tag
- docs Derived category
Files and excerpt
File metadata and permitted, redacted excerpts come from the recorded scan. Source links are pinned to that commit.
Browse files
SKILL.mdcore · 13,615 bytesSKILL.mdcore · 13,615 bytesSKILL.mdcore · 13,615 bytesSKILL.mdcore · 13,615 bytesSKILL.mdcore · 13,615 bytesSKILL.mdcore · 13,615 bytesSKILL.mdcore · 13,615 bytesreferences/batch-concurrency-tuning.mddoc · 4,769 bytesreferences/fallback-exception-list.mddoc · 5,564 bytesreferences/one-pager.mddoc · 2,477 bytesreferences/prompt-template-escaping.mddoc · 4,299 bytesreferences/runnable-composition-matrix.mddoc · 4,183 bytes
Read excerpt
# LangChain SDK Patterns (Python)
## Overview
`chain.batch(inputs)` in LangChain 1.0 does **not** parallelize by default. The
`max_concurrency` parameter defaults to **1** in several provider packages
(notably older `langchain-openai`), so a call like `chain.batch(inputs_1000)`
runs 1,000 sequential round-trips — same wall-clock time as a `for` loop, plus
the overhead of the batch machinery. Users file "batch is slow" tickets,
benchmark it against asyncio, and move to a different framework — when the fix
is two lines:
```python
# BAD — silently serializes (P08)
chain.batch(inputs_1000)