[Release] langchain-ai/langchain langchain-core==1.5.1: langchain-core==1.5.1

langchain-core version 1.5.1 is released with three key improvements: support for LangSmith gateway configuration via environment variables across Anthropic, Fireworks, and OpenAI integrations, and a fix for BaseTool token counting that leverages tool_call_schema caching in the count_tokens_approximately method. This patch release enhances gateway flexibility and optimizes token counting performance.

Key Points

• •LangSmith gateway now configurable through environment variables for Anthropic, Fireworks, and OpenAI providers
• •BaseTool token counting now uses tool_call_schema cache for improved performance in count_tokens_approximately
• •Environment variable support reduces hardcoded configuration and improves deployment flexibility
• •Token counting optimization reduces redundant schema processing for tool calls
• •Patch release (1.5.1) indicates backward-compatible improvements to langchain-core

Workflow Diagram

Concepts