What CMEK covers on Claude Platform
Look up which Claude Platform data your key encrypts, what turns off or changes, and what stays under Anthropic's key.
For Claude Enterprise, see What CMEK covers on Claude Enterprise. Beta and research preview features that aren't listed here might not be covered by customer-managed encryption keys (CMEK).
Encrypted with your key
- Message content.
- Files and attachments, whether sent inline with a request or uploaded with the Files API.
- MCP and tool configuration.
- Claude Managed Agents (beta) data, including agent configurations, environments, webhooks, sessions and their events, memory stores (beta) and their memories and memory versions, and dreams (research preview).
- Batch API and Skills API data stored at rest.
- Tool data stored at rest by web search, web fetch, code execution, bash, text editor, MCP connector (beta), structured outputs, advisor tool (beta), computer use, browser use, and context management.
- Backups and snapshots, which inherit the key.
Turned off or changed
This list is not exhaustive. Review it with your team before you set up CMEK.
| Feature | What changes |
|---|---|
| Playground in the Claude Console | Turned off. |
Structured outputs, including strict: true on tools, with Claude Fable or Claude Mythos models | Turned off in CMEK organizations. With other models, data that structured outputs store at rest is encrypted with your key. |
| Organization webhooks (beta) | Turned off for an organization whose default workspace uses a key. Requests return a 400 error. |
| Zero data retention (ZDR) | A workspace with your key retains data. See CMEK, data retention, and ZDR. |
Encrypted with Anthropic's key
The features that store this data stay available, but the data isn't encrypted with your key. You can turn off some of these features in Settings.
| Data | Details |
|---|---|
| Existing data | Written before your key takes effect. |
| Data that isn't at rest, and data with a TTL shorter than 24 hours | For example, cache. |
| Activity Feed, audit logs, and telemetry network traffic such as OpenTelemetry | Kept under Anthropic's key so that you can maintain compliance even if your key can't be used. |
| Claude Managed Agents vault credential values, such as OAuth tokens and client secrets | Write-only and never returned in API responses. |
| User profiles | Profile fields such as name and metadata. Don't store sensitive personal data in profile metadata. |
| Claude Console feedback | Ratings and comments that members choose to send with the Feedback option. No setting turns it off. |
| OpenTelemetry destination request headers, such as the API key header of your observability platform | Write-only and never returned in API responses. |
| Account data for users in your organization | Includes names, email addresses, and profile pictures. |
| Preserved records | Anthropic can preserve specific records in three narrow cases. |
Where CMEK does not apply: Claude Code telemetry
When Claude Code connects through an LLM gateway or proxy (a custom ANTHROPIC_BASE_URL), CMEK does not apply to Claude Code's operational telemetry. To turn this telemetry off, set the DISABLE_TELEMETRY environment variable to 1, as described under Telemetry services in the Claude Code documentation.
Was this page helpful?