plastic-intent-savepoint

Savepoint

savepoint.md is a deterministic, append-only ledger of an intent's cycle steps, one line per lifecycle milestone, newest at the bottom:

2026-06-16T14:02Z  What  34--cycle-step-savepoints.md
2026-06-16T14:20Z  Why   spec.md created
2026-06-16T15:10Z  How   plan.md created
2026-06-16T15:11Z  How   checklist.md created
2026-06-16T16:40Z  Exec  outcome.md created

It is sugar on top of the conventions, not a source of truth. The gate hook (hook-gate-check) writes each line automatically when a stage file is created, so there is nothing to save by hand. State is always derivable from files-on-disk; the ledger just lets a resuming agent read the cycle's succession from one glance (last line = where we are).

Read ../plastic-conventions/references/lifecycle-and-savepoints.md for the subagent report-home contract that this ledger feeds. This path resolves relative to this skill's own installed directory.

When to Use

• A PreCompact hook fires, or the user says "save" / "savepoint": verify the ledger is current.
• Resuming an intent: read the ledger to learn the cycle's succession quickly.
• The ledger looks stale, empty, or missing: rebuild it from the filesystem.

What this skill does NOT do

• It does not write prose, "in progress", "next step", or "blockers". The old 50%-context prose savepoint is retired. The semantic trace lives in ## Insights (append-only, newest at the bottom); the byte history lives in git.

Workflow

1. Find Active Intent(s)

Read the active store's INDEX.md and extract intents under ## Active.

2. For Each Active Intent — verify the ledger

• Read savepoint.md. Confirm it exists and is non-empty.
• Confirm the last line's stage matches the stage derived from files-on-disk (Bridge.derive_stage). If they disagree, or the file is missing/empty, the ledger has drifted.
• Run Bridge.savepoint_phantom_lines(intent_dir) (pure, disk-only, no bridge or session resolution; intent 134). It flags a line disk evidence contradicts: a file-landing milestone whose file is absent or still a sentinel placeholder, a duplicate (stage, milestone) pair, or a state line (How started / Exec started) whose stage prerequisites are absent. If it returns any lines:
  • LIVE intent (INDEX ## Active): rebuild via step 3 below.
  • INDEX ## Completed/## Abandoned intent: REPORT the phantom lines and STOP. Do not rewrite. Completed intents are immutable. A repair is available only under an explicit human grant, following the 124a precedent: rebuild the file-landing skeleton (step 3), then re-append the terminal Done <disposition> bookend with the disposition read from outcome.md's disposition: frontmatter and the timestamp recovered from the merge commit or the file's mtime, never invented.