The first point of divergence between this request and the one referenced
by cacheDiagnostics.previousMessageId, as reported by Anthropic's
cache-diagnostics beta. type is one of the API's discriminants
(model_changed | system_changed | tools_changed | messages_changed
| previous_message_not_found | unavailable) — kept as an open string so
new discriminants pass through without a library update. The *_changed
types also carry cacheMissedInputTokens, an estimate of how many input
tokens fell after the divergence point (magnitude indicator, not a billing
number).
The first point of divergence between this request and the one referenced by
cacheDiagnostics.previousMessageId, as reported by Anthropic's cache-diagnostics beta.typeis one of the API's discriminants (model_changed|system_changed|tools_changed|messages_changed|previous_message_not_found|unavailable) — kept as an open string so new discriminants pass through without a library update. The*_changedtypes also carrycacheMissedInputTokens, an estimate of how many input tokens fell after the divergence point (magnitude indicator, not a billing number).