context/

runtime/context

Session persistence for global and thread context modes.

Format: tree-structured JSONL per spec §2.6 — every entry carries id + parentId; active branch defined by head pointer in a sidecar file.

Layout

• tree/ — tree operations (§4.6): rewind, fork, branch-summary, replay-from-head, compaction application.
• (flat entry I/O lives at this level once implemented — append, read-by-id, walk-parents, token-count-active-branch.)

Compaction

Per spec §2.7. shouldCompact(tokens, window, reserve) := tokens > window - reserve. Runtime-driven, not provider-driven. Produces compaction entries with firstKeptEntryId so pre-compact history is preserved in-tree.

Modes

• global — one tree per aspect at <home>/session/global.jsonl + global.head.
• thread — one tree per thread at <home>/session/threads/<thread_id>.jsonl + <thread_id>.head.
• stateless — no persistence, no code paths here.