Sessions

Kill-safe persistence. A killed, crashed, or failed session keeps the last good save.

File and shape

Path: ~/.atom/session.json (ATOM_HOME overrides home). 0600 on POSIX, best-effort on Windows. Lives outside the repo, never commit it.

Shape (src/session.ts):

{version:1, savedAt, provider, model, effort, mode, usageTotals, history, turns}

• history: full API history including system plus tool pairs
• turns: display transcript
• Writes are atomic (temp file plus rename) to survive kills mid-write
• Loads never throw: missing file is missing, anything malformed is corrupt. Caller shows a one-line notice and starts fresh

Privacy: the file can contain pasted secrets if typed as chat. Never print its contents.

Save policy

Every completed turn and clean exit writes the file. Failed or cancelled turns roll back and never touch the file, so a bad turn cannot corrupt the last good save. Disk errors propagate to the caller, which ignores them; the in-memory session still applies.

Commands

Model memory across restarts

Your /model, /provider, and /effort picks persist automatically: every completed turn and clean exit saves them, and the next launch restores provider, model, and effort (plus the resolved key/endpoint) with a fresh conversation. The transcript itself only ever restores via an explicit /resume. Explicit config wins: OPENCODE_ZEN_MODEL beats the saved model when set. A saved provider whose key no longer resolves (revoked env/stored key) falls back to the zen default instead of stranding startup. Mode and usage always start fresh (normal, counters reset) — fail-closed, like /new.

/rewind details:

• Every write/edit takes a silent pre-mutation snapshot (src/snapshots.ts, src/tools.ts)
• Restore writes bytes behind the executors and refreshes (or forgets, on deletion) the stale-read fingerprint, so the next edit does not false-refuse
• Scope is file bytes only. Commands already run, packages installed, or external state changed by bash are not undone

Token totals

/clear and compaction keep cumulative spend. The footer NK total keeps growing after compaction; the P% load tracks current context only. See Compaction.