Spar Retain

Retain

Turn completed implementation into durable project knowledge.

Retain is closeout, not a retrospective by default. Make the active spec and plan accurate, preserve useful context, update broader docs only with approval, then archive the whole change folder.

Inputs

• specs/active//_spec.md
• specs/active//plan.md
• Completed implementation in the repository
• Optional notes or artifacts in the same change folder
• Relevant repo documentation, such as README, setup, architecture, or product docs

If implementation appears incomplete, stop and ask whether to return to spar-act.

Retention Context

Before editing, review the spec, plan, implementation changes, validation results, and optional notes. Preserve optional artifacts unless the user asked to remove them or they are clearly obsolete.

The retained folder should explain what shipped and why it matters without becoming a noisy build log.

Reconcile the Spec

Update _spec.md so it describes final behavior and durable intent.

• Keep Summary, Problem, Scope, and Out of Scope accurate.
• Update Constraints if implementation revealed durable requirements.
• Update Success Criteria so they reflect the outcomes that shipped and were

validated.

• Update Decisions with important product or technical choices discovered

during implementation.

• Resolve or remove stale Open Questions; keep only questions that materially

affect future implementation or validation.

Do not add step-by-step implementation narrative to the spec.

Reconcile the Plan

Update plan.md so it remains a useful execution record.

• Ensure Tasks are checked or explicitly explained.
• Ensure Validation Strategy reflects what actually ran or what could not be

validated.

• Ensure Risks / Follow-ups captures unresolved risks, deferred work, or

follow-up decisions.

• Ensure Approach and Execution Constraints do not contradict what shipped.
• Remove only scratch notes or duplicate lines that would confuse future readers.

Documentation Updates

Identify broader documentation impact from the final spec, plan, implementation changes, and repo docs.

If broader docs should change, propose concrete edits and ask for approval before applying them. Do not silently edit repo-wide documentation.

If no broader documentation updates are warranted, say so briefly in the final summary so the user knows it was considered.

Archive the Change

Move the entire folder:

specs/active// -> specs/completed//

Create specs/completed/ and specs/completed// if needed. Do not leave a copy under specs/active/. If a destination file already exists, stop and ask how to resolve it; do not overwrite or merge file contents silently.

Stop Conditions

Stop and ask if:

• Implementation appears incomplete.
• Validation is missing and cannot be explained honestly.
• Final behavior contradicts the spec in a way the user has not approved.
• Broader documentation changes are needed but not yet approved.
• A destination file already exists in specs/completed//.

Completion

Retention is complete when:

• The spec matches the implementation.
• The plan reflects completed or explained work.
• Approved documentation updates are applied, or none were needed.
• The change folder exists only under specs/completed//.

Then summarize concisely with genuine enthusiasm for the completed change: final archived path, spec and plan reconciliation, documentation updates made or skipped, and any retained follow-ups. Emphasize that the completed folder is the durable source of truth for what shipped.

Artifact Recap

| Artifact | In this phase | | --- | --- | | _spec.md | Final behavior, durable intent, constraints, success criteria, decisions, and material open questions | | plan.md | Final task state, validation record, risks, and follow-ups | | specs/completed// | Archived source of truth for the shipped change |

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: Jed-Tech
• Source: Jed-Tech/spar-kit
• License: Apache-2.0
• Homepage: https://jed-tech.github.io/spar-kit/

Install and usage instructions live in the source repository linked above.