Claude Code 2.1.239 migrates your Python SDK to anthropic 1.x
It also kills a Bedrock proxy bug that silently doubled billed calls, surfaces the US-inference cost premium, and brings cross-session messaging to Windows.
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One command upgrades your Python SDK to 1.x
`/claude-api upgrade` migrates a project from the `anthropic` 0.x SDK to 1.x and refreshes the skill's Python reference — note that timeouts now use `anthropic.Timeout`, not `httpx.Timeout`. If you've put off the 1.x jump, it's now a single command.
A Bedrock proxy bug was doubling your billed calls
The release fixes Bedrock streaming behind proxies that strip the response Content-Type header — a bug that silently re-ran every turn non-streaming, doubling your billed API calls. It also fixes startup hangs behind an HTTPS proxy using Bedrock with an SSO profile and `awsAuthRefresh`.
Cost estimates now include the US-inference premium
`/cost`, the status line, and `--max-budget-usd` now fold in the 1.1× US-only-inference premium for data-residency workspaces, so budgets match your real charges. The "spend limit used up" message now also tells you when your session or weekly limit resets.
Windows gets cross-session messaging; cloud plugins go @synced
Windows can finally use `SendMessage` and `ListAgents` across sessions and machines, matching macOS and Linux. Plugins synced from claude.ai now appear as `name@synced`, toggle via `claude plugin enable/disable <name>@synced`, and won't clobber a same-named plugin you installed.
Elsewhere: Slack Code puts coding agents in shared channels
Salesforce launched Slack Code on any Slack plan: tag an agent to spin up a dedicated code channel with inline diffs and live HTML previews, turning agent coding into an auditable team activity. Founding agents include Claude, Devin, Copilot, ChatGPT, and Vercel.