Unclear The finding does not say how or where resume_reason values are used or surfaced beyond internal telemetry.
What
When Claude Code sends a query, if the event that triggered it carries a resumeReason (a note explaining why a session was resumed), that reason is now attached as resume_reason in the telemetry data recorded for the query.
Why
This gives internal telemetry more context about why a given query happened, specifically when it follows a session resume, which can help with diagnosing and understanding usage patterns.
Names in the bundleresume_reason
Documented inclaude-code/agent-sdk/typescript
The entry above is what we published on the day. These lines were added later, as Anthropic's own pages caught up, and they sit beside the original rather than replacing it.
Added since
A small documentation edit on Agent SDK reference - TypeScript touched a line naming resume_reason after this was published.
* `resume_reason`: why Claude Code re-ran this turn after a restart interrupted it. Present on both arms. See [`resume_reason`](#resume_reason).agent-sdk/typescript see the edit
Confirmed since
Anthropic's documentation has since written up resume_reason, on Agent SDK reference - TypeScript.
resume_reason?: string;agent-sdk/typescript see the edit
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubt
The finding does not say how or where resume_reason values are used or surfaced beyond internal telemetry.
Anthropic's documentation agrees
Anthropic's documentation has since written up resume_reason, on Agent SDK reference - TypeScript.