reyn skill

Manage version history and roll back skill definitions. Reads snapshots created by the skill_improver finalize step (FP-0006 Component B), stored under .reyn/skill-versions/<name>/.

Synopsis

reyn skill versions <SKILL_NAME>
reyn skill rollback <SKILL_NAME> [--to vN]

Subcommands

reyn skill versions

List saved version snapshots for a skill.

reyn skill versions <SKILL_NAME>

Positional arguments

Name	Description
SKILL_NAME	Name of the skill to inspect. Resolved via the standard lookup order (project → local → stdlib).

Exit codes

Code	Meaning
0	Success — versions listed, or no versions saved yet (graceful).

Output

my_skill version history:
  v1  2026-05-01 10:00
  v2  2026-05-05 14:30
  v3  2026-05-09 09:15  -> current

If no snapshot directory exists for the skill:

No versions saved for skill 'my_skill'.

---

reyn skill rollback

Restore a skill to a previous saved version.

reyn skill rollback <SKILL_NAME> [--to vN]

Positional arguments

Name	Description
SKILL_NAME	Name of the skill to roll back.

Options

Flag	Description
--to vN	Target version (e.g. v2). When omitted, defaults to the version immediately before the current one (current − 1).

Behavior

1. Reads .reyn/skill-versions/<name>/current for the current version number.
2. Determines target version from --to or defaults to current - 1.
3. Verifies .reyn/skill-versions/<name>/<target>.md exists.
4. Atomically overwrites the skill's skill.md with the snapshot content.
5. Updates .reyn/skill-versions/<name>/current to the restored version.
6. Emits a skill_rolled_back P6 event to .reyn/events/direct/cli/<YYYY-MM-DD>.jsonl.
7. Prints a confirmation line to stdout.

Stdlib restriction

Rolling back a stdlib skill is refused. Stdlib skills are ship-bundled and must remain immutable. To customise a stdlib skill, copy it to reyn/project/<name>/ first, then roll back the project copy.

Exit codes

Code	Meaning
0	Rollback succeeded.
1	Refused — target is a stdlib skill.
2	Error — skill not found, no versions saved, or target version file missing.

Output

Rolled back 'my_skill' from v3 to v2.
skill.md content restored from .reyn/skill-versions/my_skill/v2.md.

Examples

List all saved snapshots:

reyn skill versions my_skill

Check a skill that has no saved snapshots yet (exits 0):

reyn skill versions new_skill
# No versions saved for skill 'new_skill'.

Roll back to the previous version (current − 1):

reyn skill rollback my_skill

Roll back to a specific version:

reyn skill rollback my_skill --to v1

Snapshot directory layout

.reyn/skill-versions/
  my_skill/
    v1.md      # snapshot at first save
    v2.md      # snapshot after first improvement
    v3.md      # snapshot after second improvement
    current    # plain-text file containing "3"

Snapshots are written by skill_improver (FP-0006 Component B). This command reads them; it never creates new snapshots.

See also

• reyn skills — list and inspect all installed skills
• Reference: stdlib/skill_improver — creates snapshots
• Proposal: FP-0006 skill self-improvement — Component B (versioning) and Component E (CLI)
• Reference: events — skill_rolled_back — P6 event payload