Module hook 

The hook: every harness’s events, one canonical, Claude-shaped event each (session_id, cwd, prompt, tool_name, tool_input, error, last_assistant_message, transcript_path, stop_hook_active), answered Claude-shaped ({“decision”:“block”,“reason”} at stop, hookSpecificOutput with context at a prompt or tool call); adapters translate both ways (harness/). What differs per harness comes from its Harness: capabilities, the turn’s work and the drone’s last message, never its name.

main routes and records presence; dispatch has one function per event. Hooks always fail open: any error lets the drone continue untouched.

Functions

dispatch

One hook event, canonical already (harness normalise), for the drone h runs: what borg answers (Claude-shaped), or None. One function per event.

judge_session

The session-end judge (0.7.6), run by borg learn --session before it learns (main.rs learn_cmd): every delivery of session (any channel) whose latest delivery no verdict settled yet (none came, or only unclear, consequence_remains or missing ones, its tries spent or not) is judged, beside as much of the session’s work as the prompt’s budget leaves (end_budget, session_sources, within). The lessons go in batches by delivery order, each prompt within the budget (batches), each batch its own model call, runner::JOBS at a time, each within end_timeout, under the session lock, renewed before each call (live.rs Guard::renew). Each batch records as soon as its call returns, while the others still run, so a pass stopped partway keeps what it was already told (and paid for). An answered batch records as a check’s judge does (record_verdicts, at outcome.rs AT_END, its cost line naming batch=<i>/<n>, budget= and cut=) and writes the state lines #borg-judged, then its own END_JUDGED: what it judged settles there, and borg learn then settles the rest as asked_not_corrected with its reason (unjudged). Each call is counted as a model_call with why judge. A failed batch is no try, for its own lessons alone (#borg-unjudged … why=failed), and its cost line judge-failed keeps its lessons as sent and unanswered for the judge’s effective length (judge_length.rs); after runner::MAX_FAILURES failed calls before the first answer the judge is unavailable, and the batches not yet asked fail alike, without a call. A pass whose lock was taken over asks nothing more; what it did not ask stays open for the lock’s new holder, and borg learn settles no session whose lock another holds (learn.rs). A lock held by another (a stop, or an earlier pass of a resumed session) is waited for, as long as it is renewed: it reads stale live::stale_ms after its holder stops. Nothing runs, and nothing is written, without learning (BORG_LEARN=off), without a runner for the consequence model (BORG_PREDICT_MODEL=off, none installed), or with nothing open. Returns how many lessons it judged.

main

borg hook <harness> <event>, the event on stdin: routes the repo to its collective (an off repo leaves no trace), records presence, then answers through steering, the experts and dispatch, with the messages from other sessions (msg.rs). An unknown harness, like any failure here, lets the drone continue untouched.

stripped

Whether the judge sees question lesson of check without the drone’s <id>: applies|skip: a fair coin from blake3 over both, so a retry strips alike and a replay knows it (outcome.rs stripped; a test predicts a judge prompt by it). Method: a random half, to measure what the declaration adds to a verdict.