LangChain Model Inference (Python) Overview is a on simple OpenAI calls and a on Claude the instant any , , or block enters the response. Code that does crashes with — the #1 first-production-call LangChain 1.0 bug on Anthropic. And that is one of four separate "content shape" pitfalls in this skill: - P02 — list-vs-string divergence - P03 — silently drops fields on 40% of real schemas - P05 — is not deterministic on Anthropic even though it is on OpenAI - P58 — Claude expects the system message at position 0; middleware that reorders messages makes it silently ignored This skill walks throug…