Anthropic is retiring the legacy Claude Workbench and three experimental prompt API endpoints on 17 August 2026
The legacy Workbench and three /v1/experimental/ prompt endpoints shut down 17 August 2026. Here's what to export and what replaces them.
If you use the Claude Console to store and iterate on prompts, or if your codebase calls any of Anthropic’s experimental prompt-generation endpoints, you have a firm deadline to work with: 17 August 2026. After that date, the legacy Workbench disappears entirely, and three API endpoints stop responding.
Announced on 17 July 2026 in Anthropic’s platform release notes, this is a straightforward deprecation with a clear replacement already in place. The main risk is inaction: if you do not export your data and migrate your code before the deadline, you will lose access to both.
What exactly is being retired
The legacy Workbench at platform.claude.com/workbench has been a long-standing feature of the Claude Console, offering server-side storage for saved prompts, prompt versions, variables, and evaluation configurations. It stopped being available to new users before the announcement, and on 17 August 2026 it goes away for everyone.
Three experimental API endpoints are being retired on the same date:
POST /v1/experimental/generate_promptPOST /v1/experimental/improve_promptPOST /v1/experimental/templatize_prompt
These endpoints powered the prompt-generation tools baked into the legacy Workbench. After 17 August 2026, any request to these endpoints will return an error. There is no grace period after the deadline.
What you need to do before 17 August 2026
If you used the legacy Workbench: Your prompts, prompt versions, variables, and evals are stored server-side and will not carry over automatically. They will be permanently inaccessible after the deadline. To export them, use the banner shown inside the Console or go to your Organisational Settings and use the Export option there. Do this now rather than closer to the date.
If your code calls any of the three experimental endpoints: You need to replace those calls before 17 August 2026. Anthropic has not announced a direct like-for-like API replacement for these endpoints. The practical path forward is to handle prompt generation, improvement, and templatisation yourself using the standard Messages API directly, for example by writing system prompts that instruct Claude to improve or templatise a given prompt. It is more manual, but it gives you full control and avoids relying on experimental infrastructure.
What replaces the legacy Workbench
The new Workbench lives at platform.claude.com/playground and takes a fundamentally different approach. Rather than storing your prompts and conversations on Anthropic’s servers, it operates statelessly. Your current draft lives in your browser only, and nothing is persisted server-side.
The key design decision behind the new Workbench is worth understanding: it is built directly on the public Messages API. What you construct in the Playground is exactly the request your code will send. There is a “code” tab that shows you the equivalent API call, which you can copy and store yourself. This makes it a transparent debugging and prototyping tool rather than a proprietary layer on top of the API.
The trade-off is obvious: if you relied on the legacy Workbench as a shared library of saved prompts for your team, you will need to find another home for that. Options include version-controlled prompt files in your repository, a dedicated prompt management tool, or a shared document your team maintains. The Playground itself is not designed to replace that organisational function.
What this means for you
For most developers, the immediate priority is the export step. If there is any chance prompts saved in the legacy Workbench are being used in production, export them now and verify what you have before the deadline removes your ability to do so.
For teams with code calling the experimental endpoints, audit your codebase for calls to /v1/experimental/generate_prompt, /v1/experimental/improve_prompt, or /v1/experimental/templatize_prompt and replace them before 17 August 2026. These were always marked experimental, so their removal is not a surprise, but the deadline makes it urgent.
The new Playground at platform.claude.com/playground is worth spending time with even if you are not currently affected by the deprecation. The direct API mirroring means you can prototype and debug without any translation layer between what you see in the UI and what your code sends, which is genuinely useful for integration work.
For more detail on using the new Workbench, Anthropic’s help centre has a dedicated article at support.claude.com.