lean-ctx session review

Upstream repo: yvgude/lean-ctx (https://github.com/yvgude/lean-ctx).

Reads a Claude Code session transcript, so it applies to agents that write ~/.claude/projects/*/*.jsonl. Other harnesses need their own extractor; the triage rules below are harness-independent.

1. Extract

Run from this skill's directory (needs python3):

python3 scripts/scan_session.py

Defaults to the newest transcript under ~/.claude/projects/*/, the live Claude Code session. Pass a path to review a different one. -d N dumps call #N in full.

The script reports facts, not verdicts: every ctx_* call in order, which results the harness flagged is_error, which calls repeated identical arguments, which asked for raw/fresh output, and how many native Read/Grep/Bash calls happened. It deliberately does not guess which of those is a problem, that judgment is yours, below.

Transcripts run to megabytes, so read the table, not the raw JSONL.

2. Triage

Start from is_error. In practice every genuine tool failure carries it. Then read the call list for the softer signals: identical retries, raw/fresh re-reads, native calls clustered right after a ctx_* call, or a sequence that only completed once ctx_* was abandoned.

Before absolving anything, do these two things

Skipping them is how this review returns a false "nothing to report". Both cost one command each.

Search the tracker for the guard or tool you are about to excuse. Do this during triage, not at step 4. A closed issue defines intended behaviour: if a shipped fix says a form is supported and you just watched it fail, that is a regression and one of the most valuable things this review finds. It also stops you re-filing a settled design decision.

gh issue list --repo yvgude/lean-ctx --search "<guard or tool keyword>" --state all