Capture

The best notes are the ones you never got around to writing. Capture is the pad writing them for you: what happened in a session becomes durable notes, without slowing anything down and without dumping raw noise into the pad.

The rest of this section is how that's kept honest.

A two-tier write. Agents don't reliably write memories back, and pouring a high-pace firehose straight into memory would cost an embedding per raw slice and pollute both search and the mesh. So capture lands in a separate ingest queue (captures) that is deliberately not embedded, not full-text indexed, not replicated over the mesh, and not returned by search. Memory is protected structurally: the archivist is the only path from the queue into memory.

Off the hot path. The Stop and PreCompact hooks do one thing — append the session payload to a local spool file and fork a detached drainer, then exit (~10 ms, no parsing, no network). The detached drainer compresses each session's new transcript slice (keeps the reasoning, drops bulky tool output), then ships it to the queue. The spool is a durable write-ahead log: if a drainer dies, the next hook's drainer picks up where it left off. Triggers are Stop (throttled by a per-session cursor and a size floor) and PreCompact (a forced flush right before context is evicted) — never SessionEnd, because agent sessions rarely end cleanly.

Leveled compaction (LSM-style). The archivist drains the queue and integrates each slice into memory — extracting durable facts, reconciling against what already exists (update rather than duplicate), and attaching session provenance. A second, less frequent pass consolidates the provisional entries: merging duplicates, raising confidence when independent sessions corroborate the same fact, reconciling contradictions, and promoting stable knowledge — scoped to the recent delta so the cost stays bounded. Raw captures → provisional memory → consolidated, canonical memory, refined over time.

The net effect: memory quality is decoupled from write volume. Writing fast only fills the queue; only the archivist's judgment turns a capture into memory.