Claude Code deleted my sessions.

Claude Code deletes session transcripts older than cleanupPeriodDays when it starts. The default is 30 days. It is documented behaviour, not a bug — and nothing announces it, so the first sign is usually a --resume that cannot find the conversation.

In ~/.claude/projects/, one folder per working directory. Each session is a <session-id>.jsonl transcript, often with a folder of the same name beside it holding subagent transcripts and saved tool output. See the oldest one you still have:

Only if something copied it before the deletion. Claude Code keeps no trash. brain-mcp exists for exactly this: it records every session — transcript and folder — byte-exact as you work, and brain-mcp restore <id> writes a deleted one back where claude --resume <id> finds it. A session deleted before brain-mcp was installed cannot be recovered by it.

Two independent ways. Raise cleanupPeriodDays in your Claude Code settings so fewer sessions age out — that changes the clock but keeps one copy, on one machine. Or record them somewhere you control: brain-mcp keeps an append-only, sha256-manifested copy under ~/.brain, searchable from any MCP client, with no network and no account.

brain-mcp health carries a receipt: which sessions are gone from where Claude Code kept them, and that the recorded copy still matches the hashes taken when it was captured. A copy that no longer matches is reported as unverified, never as fine.