What changed: On the Capabilities page in Claude Console, admins gained a toggle to switch off the web fetch tool entirely for their organization. Once disabled, any Messages API call that includes the web fetch tool gets rejected with a 400 error, and in Claude Managed Agents sessions the web_fetch tool returns an error to the agent rather than running. When the tool stays enabled, the same Capabilities page also lets admins define which domains are allowed or blocked for web fetch.
Who is affected
The source refers to admins of organizations using Claude Console (Claude Platform) with the web fetch tool enabled; Claude Managed Agents sessions are also subject to these restrictions.
What it means for your business
For businesses using Claude API's web fetch tool, this means admins can now fully disable the feature or limit it to a specific list of allowed or blocked domains.
What to do
Check the Capabilities page in Claude Console, decide whether to keep web fetch enabled based on your needs, and update your allowed/blocked domain lists to match your organization's security policy.
When it takes effect
The source does not give a separate effective date; the change is described as now available in the October 20, 2026 release notes.
Source: https://platform.claude.com/docs/en/release-notes/overview#october-20-2026
