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.
A stripped Content-Type response header from proxies, API gateways, or load balancers caused Claude Code to re-run every Bedrock turn in non-streaming mode — billing you twice per request. Here is how to verify exposure and what else 2.1.239 fixes for gateway operators.
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.
Claude Code 2.1.229 injects SSE keepalive pings into gateway streaming responses during long thinking pauses, preventing silent idle-timeout disconnects on Vertex AI and Bedrock. Plus: /commit-push-pr now blocks dangerous git flags and the sandbox enforces IPv6 fail-closed.
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.
Claude Code misattributed all Bedrock application-inference-profile ARN traffic to the same model ID since February 2026, collapsing Haiku and Opus costs to ~$0.23 per call. Version 2.1.218 fixes ARN resolution — but your historical gateway spend logs are wrong.
Claude Code 2.1.211 fixes a prompt-caching billing regression that silently billed the trailing system context block as fresh input tokens on every request across Bedrock, Vertex AI, Mantle, and Foundry. Gateway operators have overcharges to investigate.
Claude Code 2.1.207 removes the CLAUDE_CODE_ENABLE_AUTO_MODE opt-in requirement on Bedrock, Vertex AI, and Foundry. Auto mode is now on by default for all managed-provider sessions — operators must add disableAutoMode to maintain prior behavior.
Before rolling Claude Code 2.1.177 across a managed fleet, verify the 2.1.176 fixes: availableModels now catches ANTHROPIC_DEFAULT_*_MODEL aliases, Bedrock awsCredentialExport follows STS Expiration, and Remote Control no longer swaps session models silently.
Anthropic Bedrock Mantle adds Claude Messages API compatibility on Amazon Bedrock, including SigV4 auth, SSE streaming, bedrock-2023-05-31 semantics, and routing tradeoffs for Claude Code teams.
Claude Code auto mode now runs on AWS Bedrock, Google Vertex AI, and Microsoft Foundry — set CLAUDE_CODE_ENABLE_AUTO_MODE=1 and your coding agent runs inside your VPC. Here's what changes for billing, latency, and fallback routing when you switch from the Anthropic API.
