handoff

/threadhop:handoff

You have been invoked to produce a handoff brief for a prior Claude Code session, so the current conversation can carry its context forward.

The user invokes this skill as:

/threadhop:handoff <session_id> [--full]

<session_id> — required. The Claude Code session UUID (or the first unambiguous prefix) the user wants to hand off from. Usually lifted from the ThreadHop TUI or ~/.claude/projects/.
--full — optional. Request a comprehensive brief with rationale, file/code references, and verbatim transcript excerpts. Without it, you get a short brief (~30-50 lines).

Parse those from $ARGUMENTS exactly. If <session_id> is missing, stop and ask the user for it — do not guess.

Run the ThreadHop handoff subcommand with the parsed arguments. It already handles every observer/observation detail per ADR-018:
- Seeds the sessions row if the transcript exists.
- Runs the observer to catch up incrementally (or extract from byte 0 if this session was never observed).
- Reads the per-session unified observation JSONL (observer + reflector conflict entries, ADR-020).
- Formats short sets directly; polishes large sets / --full through a Haiku sub-agent.
```
threadhop handoff <session_id>          # short brief
threadhop handoff <session_id> --full   # comprehensive brief
```
The command prints the markdown brief to stdout. Status and diagnostic lines (e.g. "Polished 12 observations via Haiku", or the fallback reason if Haiku polish failed) go to stderr — surface those only if something noteworthy happened (fallback, error).
Present the brief to the user inside a clearly bounded context block so it's visually distinct from your own reasoning. Start with a one-line preface that names the session id and mode, then render the markdown the command emitted verbatim (do not paraphrase, truncate, or reflow).

Example layout:
```
Handoff brief for session abc12345 (short):

<markdown stdout from `threadhop handoff`>
```
After the brief, do NOT automatically start acting on any TODOs it lists. Wait for the user to tell you what to do with the handed-off context. This skill only loads context; it does not execute on it.

Exit code 1 (no_source — transcript not found): tell the user the session id couldn't be located and suggest they confirm it via the ThreadHop TUI or ls ~/.claude/projects/. Do not retry with a different id unless the user provides one.
Exit code 0 with empty stdout (no_observations): the stderr message explains — usually the target session is too short or routine for the observer to find decisions/TODOs. Pass that message through to the user; do not fabricate a brief.
Any other non-zero exit: show the stderr message verbatim. Do not retry silently.

Do NOT try to read the raw JSONL transcript yourself. Always go through threadhop handoff — it owns the observer invocation, prompt template, and state tracking.
Do NOT re-run the subcommand multiple times hoping for a better brief. The observer is deterministic-enough that a retry at the same state returns the same output.
Do NOT edit ~/.config/threadhop/observations/*.jsonl or the ThreadHop SQLite DB yourself. Those files are append-only and maintained by the observer/reflector (ADR-020).