Bedrock and Vertex model-access checks are cached on disk for 15 minutes

What

When you use Claude through a cloud provider, Claude Code checks at launch whether your account can reach the model. A successful check is now saved in ~/.claude/cache/provider-probe-verdicts.json and reused for up to 15 minutes (900000 ms) on later launches. For Bedrock the log reads [bedrock-probe] <model>: accessible (cached).

• The saved result is keyed on a hash of the region, project, base URL, the skip-auth setting and the names of ANTHROPIC_CUSTOM_HEADERS.
• For Bedrock the key also covers your AWS identity: AWS_PROFILE, AWS_CONFIG_FILE, AWS_SHARED_CREDENTIALS_FILE, AWS_ACCESS_KEY_ID, AWS_ROLE_ARN, the web-identity and container credential variables, and the awsCredentialExport and awsAuthRefresh settings.
• The cache is skipped when short-lived or bearer credentials are in use, such as AWS_BEARER_TOKEN_BEDROCK, CLOUDSDK_AUTH_ACCESS_TOKEN, or CLAUDE_CODE_SKIP_VERTEX_AUTH together with ANTHROPIC_API_KEY, among others.

Why

Before, every launch ran the check again, so startup on Bedrock or Vertex should be faster. Switching AWS profile, role or credentials changes the key, so a stale "accessible" result does not carry over.