artifact-path

# Artifact Path `.lets/` is ONE directory shared by every worktree of the repo (whole-dir symlink). Two sessions writing the same artifact kind on the same day used to overwrite each other (lets-05c4s - a plan review was lost). This skill is the single place that names an artifact and guarantees the path is free. **Contract:** args `kind=<kind> ext=<md|json> [task=<task-id>]`. Output: ONE echoed line `ARTIFACT_FILE=<absolute path>`. The caller writes to that path VERBATIM - never recomputes the stamp, never strips the `-vN` suffix, never writes anywhere else. ## Name shape `{YYYY-MM-DD}-{HHMM}-{ID}-{KIND}[-vN].{EXT}` under the kind's directory: | kind | directory | |------|-----------| | `plan` | `.lets/plans/` | | `idea` | `.lets/plans/` | | `review-local`, `review-branch`, `review-pr-<n>`, `review-plan` | `.lets/reviews/` | | `snapshot` | `.lets/sessions/` | `ID` is the task id when one is active (MANDATORY whenever a task exists - same rule as the branch named by the active tracker convention). With no task: `{branch-slug}-{6hex}`, 6hex = first 6 chars of `$CLAUDE_CODE_SESSION_ID`, so two taskless sessions on `main` still get distinct names. `-vN` (v2, v3, ...) is appended whenever the path already exists - for task and taskless alike. ## Step 1: Resolve the task id If the caller passed `task=`, use it. Otherwise invoke `Skill(skill: "lets:detect-task", args: "fallback=no")` and use its result (may be empty). `fallback=no` is mandatory: the searched fallback asks a question, and a taskless snapshot on `/lets:end` must stay silent. ## Step 2: Compute the path ```bash LETS_PROJECT_ROOT=$(git rev-parse --show-toplevel) KIND="{kind}"; EXT="{ext}"; TASK_ID="{task-id or empty}" case "$KIND" in plan|idea) DIR=plans ;; review-*) DIR=reviews ;; snapshot*) DIR=sessions ;; *) echo "artifact-path: unknown kind '$KIND'"; exit 1 ;; esac mkdir -p "$LETS_PROJECT_ROOT/.lets/$DIR" STAMP=$(date +%Y-%m-%d-%H%M) if [ -n "$TASK_ID" ]; then ID="$TASK_ID" else HEX=$(printf '%s' "${CLAUDE_CODE_SESSION_ID:-$$}" | cut -c1-6) # session-id prefix; PID outside Claude Code ID="$(git branch --show-current | tr '/' '-')-${HEX}" fi BASE="$LETS_PROJECT_ROOT/.lets/$DIR/${STAMP}-${ID}-${KIND}" ARTIFACT_FILE="${BASE}.${EXT}"; N=2 while [ -e "$ARTIFACT_FILE" ]; do ARTIFACT_FILE="${BASE}-v${N}.${EXT}"; N=$((N+1)); done echo "ARTIFACT_FILE=$ARTIFACT_FILE" ``` ## Return Return the echoed `ARTIFACT_FILE` to the caller. If the echo is missing or `exit 1` fired, the caller MUST NOT write anything - surface the error. ## Rules - NEVER overwrite: the loop is the guard; the caller never "fixes" a path by hand. - NEVER compute a second `date` in the caller - the stamp is captured here once. - Task id in the name is mandatory when a task is active. - No tracker calls here beyond `detect-task`. - Go-owned state files are NOT artifacts and never come through here: `.lets/sessions/.task-*` (`lets worktree task-state`), `.lets/sessions/peers/*.role` (`lets peers role`), `.lets/cache/released-*` (`lets worktree release`), and transient `.lets/cache/peer-msg/<msgid>.txt` handoffs (0700 directory, created by `lets peers frame`, written by the orc skill or `/lets:hub`, deleted by Go when the message is sent), and `.lets/cache/ask-ro-mcp-empty.json` - their owner writes them.