datalad-log

name	datalad-log
description	Auto-invoke when the user wants to browse dataset history, find what command produced a specific output, inspect recorded run provenance, or audit past analyses. Trigger on "show run history", "what command produced this", "browse dataset history", "find the run that made this file", "show provenance", "list recorded runs", "what was the last run", or /datalad-log. Do NOT trigger for running new commands (use datalad-run) or replaying existing runs (use datalad-run's rerun section).
argument-hint	["path-or-commit"]
user-invocable	true
disable-model-invocation	false
allowed-tools	Read, Bash, Glob

Skill: datalad-log

Browse the recorded history of a DataLad dataset: list run commits, inspect what a specific run recorded, and trace which command produced a given output file.

Steps

Browsing run history

1. Verify DataLad context — check for .datalad/ in the current directory:

   ls .datalad/ 2>/dev/null
   

   If not in a dataset, stop and inform the user.

2. List recorded runs — show the run history with:

   datalad log --oneline
   

   Or to show only datalad run commits (excludes saves, checkpoints, manual commits):

   git log --oneline --grep="datalad run"
   

   Present the output as a numbered list showing commit SHA and message.

3. Inspect a specific run — when the user wants detail on a particular commit:

   datalad rerun --report <sha>
   

   This shows the run record (command, inputs, outputs, message) without re-executing. Report:

   • The original command
   • Declared inputs (-i)
   • Declared outputs (-o)
   • Commit message
   • Timestamp

Tracing output provenance

When the user asks "what command produced <file>":

1. Find commits that touched the file:

   git log --oneline -- <path>
   

2. Check each commit for a run record:

   datalad rerun --report <sha>
   

   If the commit is a datalad run commit, this shows the full run metadata. If it is a plain save or checkpoint, report that instead.

3. Report the full provenance chain — if the file was produced by a run, show:

   • Which commit recorded it
   • The command that produced it
   • The declared inputs to that command

Identifying checkpoint commits

The auto-checkpoint hook creates commits with messages like:

[datalad] checkpoint 2026-03-12T14:05:22Z: code/analysis.py outputs/result.csv

These are not run records — they are auto-saves. They will appear in git log and datalad log output. To show only datalad run commits (excludes checkpoints and saves):

git log --oneline --grep="\[datalad run\]"

Note: using --invert-grep with multiple --grep flags uses OR logic and will not correctly exclude checkpoints — use the single --grep="\[datalad run\]" form instead.

Constraints

• Never re-execute a run when the user only wants to inspect it — always use datalad rerun --report for inspection, not datalad rerun alone.
• Always distinguish between datalad run commits (provenance records) and plain save commits or checkpoint commits in your report.
• If datalad log is not available (older DataLad), fall back to git log --oneline --grep="datalad run" and explain the fallback.
• For file-level differences between two commits, direct the user to /datalad-diff.