diff --git a/README.md b/README.md
index 3fab05d..ef354f4 100644
--- a/README.md
+++ b/README.md
@@ -53,7 +53,7 @@ Candidate trace note: candidate-level `sourceItemId` / `traceId`, `sourceTitle`
 
 Soft Scattermind labels are accepted at the bridge boundary so Scattermind does not need to use harsh verdict copy in its own product surface. Lens text can say `Continue first`, `Make tangible`, `Try next`, `Evidence next`, `Hold for later`, or `Set aside`; Build Order objects and direct bridge/envelope sections can use matching camel/snake-case keys such as `continueFirst`, `evidenceNext`, `holdForLater`, and `setAside`. Ranker maps those to `doFirst / validateNext / defer / park` while preserving the softer original label in `sourceQuote` or candidate source trace.
 
-Lane safety note: explicit Scattermind `defer` / `park` hints are hard rails, not mild suggestions. Source `nonGoals` / `avoid` guardrails are also hard enough to keep conflicting candidates out of Do first / Validate next even when their local scoring hints look attractive; the result will mark the lane source as `source-non-goal` so the handoff can explain that the candidate needs guardrail resolution before active work. Handoff `source.requiresSourceTrace` is true only when a real source artifact/title is present; plain idea-only ranking still warns about a missing artifact ID when it carries prompt provenance, but it does not spam source-section/evidence warnings meant for Scattermind artifacts. Handoff `readiness` now gives downstream bridge consumers a deterministic gate: `ready`, `usable-with-warnings`, `needs-source-context`, or `blocked`, with blockers and next checks for missing evidence, source trace, duplicate IDs, or active source-non-goal conflicts. For tired first-screen users, `brief.decisionReceipt` repeats the one active move, first proof step, evidence question, held-back items, source anchor, and the handoff rule that only Do first is active; use it as the compact result strip before showing the full lane board. For low-friction handoff, `/api/rank-feedback` also detects a raw Scattermind/Concept Map JSON object pasted into `idea`, `ideaText`, `optionsText`, or wrapper keys such as `payload`; it expands that object before ranking and reports `input.embeddedPayloadSource` so the public form can accept copy/paste exports without a custom import screen.
+Lane safety note: explicit Scattermind `defer` / `park` hints are hard rails, not mild suggestions. Source `nonGoals` / `avoid` guardrails are also hard enough to keep conflicting candidates out of Do first / Validate next even when their local scoring hints look attractive; the result will mark the lane source as `source-non-goal` so the handoff can explain that the candidate needs guardrail resolution before active work. Handoff `source.requiresSourceTrace` is true only when a real source artifact/title is present; plain idea-only ranking still warns about a missing artifact ID when it carries prompt provenance, but it does not spam source-section/evidence warnings meant for Scattermind artifacts. Handoff `readiness` now gives downstream bridge consumers a deterministic gate: `ready`, `usable-with-warnings`, `needs-source-context`, or `blocked`, with blockers and next checks for missing evidence, source trace, duplicate IDs, or active source-non-goal conflicts. Handoff `activeSlice` (`ranker-active-slice-v1`) is the compact machine-readable continuation unit: one active item, its proof/evidence/success/kill signals, source anchor, held-back items, readiness status, and the rule that only this slice is build-ready. For tired first-screen users, `brief.decisionReceipt` repeats the one active move, first proof step, evidence question, held-back items, source anchor, and the handoff rule that only Do first is active; use it as the compact result strip before showing the full lane board. For low-friction handoff, `/api/rank-feedback` also detects a raw Scattermind/Concept Map JSON object pasted into `idea`, `ideaText`, `optionsText`, or wrapper keys such as `payload`; it expands that object before ranking and reports `input.embeddedPayloadSource` so the public form can accept copy/paste exports without a custom import screen.
 
 Recommended payload shape:
 
diff --git a/scripts/check-rank-feedback.mjs b/scripts/check-rank-feedback.mjs
index 3d7130f..50f17c3 100644
--- a/scripts/check-rank-feedback.mjs
+++ b/scripts/check-rank-feedback.mjs
@@ -105,6 +105,15 @@ try {
   assert.ok(data.brief.whatWouldChangeRanking.some(item => /evidence fails|re-run the order/i.test(item)));
   assert.ok(Array.isArray(data.brief.assumptions));
   assert.equal(data.handoff.readiness.status, 'ready');
+  assert.equal(data.handoff.activeSlice.schema, 'ranker-active-slice-v1');
+  assert.equal(data.handoff.activeSlice.item.id, data.buildOrder.doFirst[0]);
+  assert.match(data.handoff.activeSlice.proof.nextStep, /manual proof/i);
+  assert.equal(data.handoff.activeSlice.source.artifactId, 'snapshot_123');
+  assert.equal(data.handoff.activeSlice.source.sourceSection, 'concept-map.nextMoves');
+  assert.ok(data.handoff.activeSlice.notNow.some(item => item.id === 'export'));
+  assert.match(data.handoff.activeSlice.rule, /Only this active slice is build-ready/);
+  assert.match(data.handoff.copyableText, /## Active slice/);
+  assert.match(data.handoff.copyableText, /- Do not start yet:/);
   assert.equal(data.handoff.readiness.sourceComplete, true);
   assert.ok(data.handoff.readiness.nextChecks.some(item => /Do first item/i.test(item)));
   assert.match(data.handoff.copyableText, /# Ranker build-order handoff/);
diff --git a/server.js b/server.js
index 93bed4f..919cd03 100644
--- a/server.js
+++ b/server.js
@@ -1396,7 +1396,41 @@ function handoffReadinessFor({ ranked = [], provenance = {}, warnings = [], expe
   };
 }
 
-function copyableHandoffText({ ranked = [], provenance = {}, decisionContext = {}, readiness = {} }) {
+function activeSliceFor({ ranked = [], provenance = {}, readiness = {} }) {
+  const active = ranked.find(item => item.lane?.id === 'do') || ranked.find(item => item.lane?.id === 'test') || ranked[0] || null;
+  const heldBack = ranked.filter(item => item.id !== active?.id && ['test', 'defer', 'park'].includes(item.lane?.id)).slice(0, 4);
+  if (!active) return null;
+  return {
+    schema: 'ranker-active-slice-v1',
+    item: {
+      id: active.id,
+      title: active.title,
+      lane: active.lane?.id || 'do',
+      laneLabel: active.lane?.label || 'Do first',
+      reason: reasonFor(active),
+    },
+    proof: {
+      nextStep: nextStepFor(active),
+      evidenceQuestion: evidenceQuestionFor(active),
+      successSignal: successSignalFor(active),
+      killSignal: killSignalFor(active),
+    },
+    source: {
+      artifactId: provenance?.artifactId || '',
+      conceptMapId: provenance?.conceptMapId || '',
+      snapshotTitle: provenance?.snapshotTitle || '',
+      sourceSection: active.provenance?.sourceSection || '',
+      sourceId: active.provenance?.sourceId || '',
+      sourceTitle: active.provenance?.sourceTitle || '',
+      sourceQuote: active.provenance?.sourceQuote || '',
+    },
+    notNow: heldBack.map(item => ({ id: item.id, title: item.title, lane: item.lane?.id || 'defer', reason: reasonFor(item) })),
+    readinessStatus: readiness?.status || '',
+    rule: 'Only this active slice is build-ready. Do not promote Validate next / Defer / Park items until evidence changes and Ranker is rerun.',
+  };
+}
+
+function copyableHandoffText({ ranked = [], provenance = {}, decisionContext = {}, readiness = {}, activeSlice = null }) {
   const lanes = [
     ['do', 'Do first'],
     ['test', 'Validate next'],
@@ -1438,11 +1472,20 @@ function copyableHandoffText({ ranked = [], provenance = {}, decisionContext = {
       '',
     ];
   });
+  const activeSliceLines = activeSlice ? [
+    '## Active slice',
+    `- Move: ${activeSlice.item.title}`,
+    `- Proof: ${activeSlice.proof.nextStep}`,
+    `- Evidence question: ${activeSlice.proof.evidenceQuestion}`,
+    activeSlice.source.sourceSection ? `- Source: ${[activeSlice.source.sourceSection, activeSlice.source.sourceId].filter(Boolean).join(' · ')}` : '',
+    activeSlice.notNow.length ? `- Do not start yet: ${activeSlice.notNow.map(item => item.title).join('; ')}` : '',
+  ].filter(Boolean).join('\n') : '';
   return [
     '# Ranker build-order handoff',
     sourceLine ? `Source: ${sourceLine}` : '',
     sourceContextLine,
     readiness?.status ? `Readiness: ${readiness.status} — ${readiness.summary || ''}` : '',
+    activeSliceLines,
     contextLines.length ? ['## Carried context', ...contextLines.map(item => `- ${item}`)].join('\n') : '',
     ...itemLines,
     'Rule: only the Do first item is active. Re-rank after evidence changes; do not quietly turn this into a workspace/dashboard backlog.',
@@ -1479,6 +1522,7 @@ function createHandoffContract({ ranked, provenance, decisionContext }) {
   });
   const uniqueWarnings = [...new Set(warnings)];
   const readiness = handoffReadinessFor({ ranked, provenance, warnings: uniqueWarnings, expectsSourceTrace });
+  const activeSlice = activeSliceFor({ ranked, provenance, readiness });
 
   return {
     schema: 'rank-feedback-result-v1',
@@ -1503,7 +1547,8 @@ function createHandoffContract({ ranked, provenance, decisionContext }) {
     itemTrace,
     warnings: uniqueWarnings,
     readiness,
-    copyableText: copyableHandoffText({ ranked, provenance, decisionContext, readiness }),
+    activeSlice,
+    copyableText: copyableHandoffText({ ranked, provenance, decisionContext, readiness, activeSlice }),
   };
 }