Initialize a new CogSession for the current project. Call this at the START of a Claude Code session. Provide parent_session_id to continue from a previous session (tree structure). Provide focus to describe what this session is about.

Save the current session state to disk. CALL THIS at 70-80% context. Writes: handoff.md, tasks.json, dead_ends.md, assumptions.md, environment.json, architecture.mermaid, session_log.jsonl. Also auto-writes handoff.md to CLAUDE.md so next session loads it.

Load the handoff from a previous session. Call at the START of a new session to get context from the last one. Returns the handoff brief (~250 tokens) — exactly what the new session needs.

Add information to the current session. Use this throughout the session to record: decisions made, dead ends found, assumptions made, tasks completed/added, danger zones discovered, errors seen.

Show the full session tree for this project. Like 'git log --graph' but for CogSession work history. Shows all sessions, their relationships, and their status.

Search across ALL sessions for a query. Useful for: 'when did we decide X?', 'what errors have we seen?', 'which session touched file Y?', 'what dead ends are there?'

Get the current session's status: what's been recorded, how many dead ends, task progress, context warning level.

A git log for this project's sessions: one line per recorded event, newest first, with local timestamp, event type and the repo state (branch@commit+dirty) it happened at. Use it to scan history fast, then grep the session's own session.md for the entry that matters. Filter by type to answer 'what has already failed here' in one call.

Record a claim together with the command that PROVES it, so a later session is told when it stops being true. Use this for any factual statement you write somewhere durable — a PR description, a code comment, a doc, a status report. The proof must be a cheap read-only shell command whose output can be compared.

Re-run recorded claims and report only the ones that no longer hold. Silence means everything still checks out.

Show or regenerate the architecture diagram (Mermaid format). Auto-scans the project files to build a dependency graph. Pass to a Mermaid renderer to visualize.