Live capture only sees sessions that happen after you connect. Backfill is the one-time import of the history from before — it re-sends your existing local sessions through the exact same path, and with the same metadata-only privacy guarantee, as live capture.
Running a backfill
attribut connect offers it automatically right after it installs the hooks: it shows how many prior sessions it found and how far back they reach, then lets you pick Last 90 days (default), All history, or Skip.
Run it yourself anytime:
attribut backfill # interactive: confirm, then pick a window attribut backfill --all --yes # everything still on disk, no prompts attribut backfill --since=30d # a specific window
It is safe to re-run. The server reconciles by session id (latest non-partial wins), so a session already captured live — or backfilled twice — just overwrites in place. It never double-counts. --dry-run shows what it would send without posting anything.
How far back it can reach
Backfill can only send sessions the tool still keeps on disk, and each tool manages its own local history — how far back you can reach is set by the tool, not by ATTRIBUT.
Tool | Local session store | How far back backfill reaches |
Claude Code |
| ~30 days by default — Claude Code deletes transcripts older than |
Cursor |
| Long — typically many months |
OpenAI Codex |
| As far back as you've used it |
Google Antigravity |
| As far back as you've used it |
"Why did --all only import the last month of Claude Code?"
This is expected, not a bug. Claude Code automatically deletes chat transcripts older than cleanupPeriodDays (default 30 days), so those older sessions are already gone from disk before backfill runs. A result like Claude Code: 76 sessions (last 30 days) is faithfully sending everything that still exists.
To keep more history going forward, raise the setting in ~/.claude/settings.json:
{ "cleanupPeriodDays": 365 }
This affects only new sessions — transcripts Claude Code has already deleted cannot be recovered.
Bottom line
Live capture is never affected — every new session is captured at session-end regardless of how a tool prunes old history.
Backfill only matters for the window before you connected, and only as far back as the tool still has the data.
If long Claude Code history matters to you, raise
cleanupPeriodDaysearly.
Related
Connect your AI tools to ATTRIBUT
Supported tools & setup notes
What ATTRIBUT captures — and what it never sends
Troubleshooting & configuration