| name | extract-build-log |
| description | Extracts the build conversation for a recorded run in the spec-build-lab and writes it to evals/<run>/session-log.md. Use this skill ANY time the user wants to capture, save, snapshot, extract, export, or render the conversation for a specific build run — including phrasings like "extract the build log", "save the conversation for run-02", "snapshot run-02", "export the build log", "render the session log", "log this build", "produce the session log for run-NN", or "/extract-build-log run-NN". Reads the transcript recorded by Claude Code (located via the .session breadcrumb at evals/<run>/.session) and slices it between an opening bookend (the /prepare-build announcement) and a closing bookend (a fuzzy diagram/structure phrase by default, or a user-supplied --until pattern). Idempotent — re-runnable with different bookends. Requires an explicit run-NN; if none is given, list the runs in builds/ and ASK which one — never default. Do NOT use this skill to evaluate the run — that's /eval-spec-vs-build or /eval-materials-vs-build.
|
| argument-hint | <run-NN> [--until="phrase"] |
| allowed-tools | ["Read","Write","Bash","Grep"] |
extract-build-log
Slice the build conversation out of Claude Code's session transcript and
render it as a markdown log at evals/<run>/session-log.md.
Steps
- Verify cwd is a course folder. Confirm
spec.md, materials/,
builds/, evals/ exist. Refuse otherwise: "Run /extract-build-log
from inside a course folder — cd courses/<name> first." Stop.
- Require a run. If
$ARGUMENTS (or its first whitespace-separated
token) is empty:
ls -1 builds/ 2>/dev/null | grep -E '^run-[0-9]+$' | sort
List those runs and ask: "Which run should I extract? Pick one — I
won't default to the latest." Stop until they answer.
- Validate the run. Confirm
evals/$ARGUMENTS/.session exists.
Refuse otherwise: "evals/$ARGUMENTS/.session is missing — this run
wasn't allocated by /prepare-build, so I can't locate its
transcript." Stop.
- Run the extractor. From the project root:
python3 "$CLAUDE_PROJECT_DIR/.claude/skills/extract-build-log/scripts/extract.py" \
"evals/$ARGUMENTS" \
[--until="<user-supplied phrase>"]
Pass --until only if the user gave one. The script:
- Reads
evals/$ARGUMENTS/.session to find the transcript
- Slices between the opening bookend (the
/prepare-build
announcement matching this run number) and the closing bookend
(--until regex if given, else a fuzzy default, else end of
transcript)
- Writes
evals/$ARGUMENTS/session-log.md (overwrites if present —
re-run freely with different bookends)
- Report. Echo the script's stdout — it prints the path written
plus a one-line summary of how many turns were extracted and which
bookends were used.
- Hand off. Tell the user: "Ready to evaluate run-$ARGUMENTS — I
can run /eval-spec-vs-build $ARGUMENTS and /eval-materials-vs-build
$ARGUMENTS next. Say 'go ahead' to proceed, or pick one if you only
want to run one of them."
Don't
- Don't generate or judge content — this skill is a transcript slicer,
not an analyst.
- Don't read or write to
builds/<run>/ — that's the build artifact,
out of scope.
- Don't pick a default run. List the runs in
builds/ and ask.
- Don't fabricate a
.session file if it's missing — that means the
run wasn't allocated normally; refuse and ask the user to investigate.
