Claude Code 2.1.273 ships opt-in gateway hint headers exposing request class, agent type, and compaction state to any LLM proxy. It also flips the auto mode classifier to local-only on Bedrock, Vertex AI, and Foundry — only one change has a revert path.
Since 2.1.265, every turn through a third-party Anthropic-compatible endpoint failed with HTTP 400. Version 2.1.268 fixes it and adds gatewayInternalNetworks CIDR policy, pricing sync to gateway.yaml, and byte-stable prompt caches for Bedrock, Vertex, and Foundry.
Three operator-facing changes land in 2.1.267: a new maxEffortLevel cap across Bedrock, Vertex, and Foundry; a flag to stop prompt-snapshot reuse during iteration; and a marketplace containment bypass fix. Plus twelve prompt-cache stability improvements.
Claude Code 2.1.237 silently fixed a bug that invalidated prompt caching for every session routed through a custom base URL. If you've been routing Claude Code through a gateway, you've been paying full context-window cost on every turn since at least 2.1.229.
Anthropic shipped claude-opus-5 yesterday with adaptive thinking on by default — which means thinking tokens bill as output tokens even when you never see them. Here is the routing policy update for teams coming from Opus 4.8 on Claude API, Bedrock, and Vertex.
