Claude Code v2.1.239: Bedrock二重課金バグ修正とPython SDK移行コマンド追加Claude Code v2.1.239 fixes a silent double-billing bug affecting Amazon Bedrock…

Anthropic has shipped Claude Code v2.1.239, a maintenance-focused release whose headline change is not a new capability but a fix for a billing defect that could quietly inflate costs. According to the source, the update corrects a bug in which API calls were silently charged twice for users running Claude Code against Amazon Bedrock through a proxy setup. For teams paying per token, a defect that doubles usage without any visible error is the kind of problem that can go unnoticed until an invoice arrives, which is what makes this release worth attention despite its modest feature list.

Claude Code is Anthropic's command-line coding agent, designed to read, edit, and run code from the terminal while calling a Claude model in the background. It can be pointed at different model backends, and one common enterprise configuration routes requests to Claude models hosted on Amazon Bedrock, AWS's managed service for foundation models. Many organizations place a proxy between the tool and the model endpoint, whether a corporate egress proxy or a request-routing layer, to centralize authentication, logging, rate limiting, or cost tracking. The double-billing issue described in the source appears to have been specific to that proxy path rather than to direct Bedrock access, though the exact trigger conditions are not fully detailed in the excerpt.

The practical impact of a silent double-billing bug is worth spelling out. Because the extra charge reportedly occurred without a visible failure, workflows would continue to function normally while consuming twice the expected token volume on Bedrock. That combination is particularly awkward for usage-based billing, where there is no fixed subscription ceiling to absorb the overage. Affected teams are likely to want to review recent Bedrock usage and cost reports to gauge exposure, since the discrepancy would not have surfaced through ordinary error handling. Anyone running Claude Code on Bedrock via a proxy is the group most directly concerned, and upgrading to v2.1.239 is the straightforward remediation.

Alongside the fix, the release adds a new command intended to assist with migrating to the Python SDK. Anthropic maintains official client libraries in several languages, and the Python SDK is a common way to integrate Claude programmatically outside of the Claude Code CLI itself. A dedicated migration command suggests an effort to smooth the path for developers moving existing scripts or automation onto the current SDK surface, likely reducing manual rewrites when interfaces or import paths change. The source does not enumerate exactly what the command generates or transforms, so the precise scope of the assistance is best confirmed against the release notes and the tool's own help output.

For context, billing correctness in agentic coding tools has become a recurring concern as these systems make many model calls per task. Unlike a single chat request, an agent may issue numerous background calls to plan, read files, and iterate, so a per-call charging error is magnified across a session. This is one reason organizations layer proxies and gateways in front of model APIs in the first place, both to observe consumption and to enforce guardrails. The trade-off is added complexity: each intermediary is another place where request handling can diverge from the direct path, as this Bedrock case appears to illustrate.

The broader ecosystem around Claude Code includes competing and complementary tooling. Amazon Bedrock is one of three main ways to reach Claude models, alongside Anthropic's own API and Google Cloud's Vertex AI, and enterprises often choose Bedrock to keep model traffic within an existing AWS account and its security controls. Proxy layers such as open-source LLM gateways are frequently used to unify access across these backends. Against that backdrop, a fix that ensures calls are counted once rather than twice reinforces the importance of validating cost telemetry whenever a proxy sits in the request chain.

As always with a point release, the recommended action is to update and verify. Teams on affected configurations should install v2.1.239, confirm that Bedrock call volumes return to expected levels, and consult the official changelog for the specific behavior of the new Python SDK migration command. Because the finer details of the trigger conditions and the command's exact output are not spelled out in the available excerpt, treating the release notes as the authoritative reference is the safest approach.