diff --git a/lib/graph/apply-proposal.js b/lib/graph/apply-proposal.js
index f80ac42..b986c3f 100644
--- a/lib/graph/apply-proposal.js
+++ b/lib/graph/apply-proposal.js
@@ -3971,9 +3971,11 @@ export async function applyValidatedProposal({
   proposal,
   previousQuestion = null,
   answer = null,
+  evidenceContext = null,
   provider = null,
   modelName = null,
 }) {
+  const isLegacySingleTurn = !evidenceContext;
   const graphValidation = situationGraphSchema.safeParse(situationGraph);
   const proposalValidation = graphUpdateSchema.safeParse(proposal);
 
@@ -4030,11 +4032,15 @@ export async function applyValidatedProposal({
   );
 
   // ── 60B.80 — normalise terminal parent closure without explicit confirmation
-  const ownershipChanges = reconcileDecisionClosureOwnership(
-    situationGraph,
-    reconciledProposal.proposal,
-    answer,
-  );
+  // legacy only: episode evidence does not supply a single-answer confirmation string;
+  // Done and Finding agree are NOT closure authority (settled architecture rule).
+  const ownershipChanges = isLegacySingleTurn
+    ? reconcileDecisionClosureOwnership(
+        situationGraph,
+        reconciledProposal.proposal,
+        answer,
+      )
+    : { strippedUpdates: [], strippedResolvedIds: [] };
   if (ownershipChanges.strippedResolvedIds.length > 0) {
     // Reconciler may have added selectedQuestion = null because the parent
     // appeared resolved during reconciliation. If we stripped it, restore
@@ -4130,12 +4136,16 @@ export async function applyValidatedProposal({
     validatedProposal,
   );
   proposalCompatibilityErrors.push(...selectedQuestionValidation.errors);
-  proposalCompatibilityErrors.push(
-    ...validateAnswerMeaningCompatibilityWithRawAnswer({
-      answer,
-      proposal: validatedProposal,
-    }),
-  );
+  // legacy only: raw-answer fidelity is a single-turn safeguard.
+  // Episode evidence carries structured turns — no synthetic answer is constructed.
+  if (isLegacySingleTurn) {
+    proposalCompatibilityErrors.push(
+      ...validateAnswerMeaningCompatibilityWithRawAnswer({
+        answer,
+        proposal: validatedProposal,
+      }),
+    );
+  }
   proposalCompatibilityErrors.push(
     ...validateAnswerMeaningAlignment(validatedProposal),
   );
@@ -4165,10 +4175,14 @@ export async function applyValidatedProposal({
     ? findNodeById(graphSnapshot, previousActiveUnknownNodeId)
     : null;
   const affectedNodeIds = buildAffectedNodeIds(graphSnapshot, proposalSnapshot);
+  // For episode evidence: extract turn text from the ordered Q/A sequence.
+  const _epTurns = evidenceContext?.isCompletedEpisode ? evidenceContext.episodeEvidence.turns : null;
+  const _derivedQuestion = isLegacySingleTurn ? previousQuestion : (_epTurns?.[0]?.question ?? "");
+  const _derivedAnswer = isLegacySingleTurn ? answer : (_epTurns?.[0]?.answer ?? "");
   const reasoningResolution = deriveReasoningStateOverride({
     graph: graphSnapshot,
-    previousQuestion,
-    answer,
+    previousQuestion: _derivedQuestion,
+    answer: _derivedAnswer,
     resolvedUnknownNodeIds: validatedProposal.resolvedUnknownNodeIds,
   });
 
diff --git a/tests/graph/episode-evidence-boundary.test.js b/tests/graph/episode-evidence-boundary.test.js
new file mode 100644
index 0000000..eb6a2e5
--- /dev/null
+++ b/tests/graph/episode-evidence-boundary.test.js
@@ -0,0 +1,558 @@
+/**
+ * Tests for episode evidence at the graph application boundary.
+ *
+ * Scope: applyValidatedProposal accepts structured completed-episode evidence
+ * without collapsing it into a synthetic single answer, and preserves existing
+ * single-turn behaviour unchanged.
+ */
+
+import { describe, expect, it } from "vitest";
+import { applyValidatedProposal } from "@/lib/graph/apply-proposal.js";
+
+import { makeEdge, makeGraph, makeNode } from "@/lib/graph/schema.js";
+
+// ── production-style helpers ───────────────────────────────────────
+
+function makeSituationGraph() {
+  const parent = makeNode({
+    id: "n-parent",
+    label: "Commercial justification for continuing development",
+    description:
+      "Need to know whether this solves a genuine problem and is commercially justified.",
+    kind: "unknown",
+    status: "unknown",
+    confidence: "medium",
+  });
+
+  const child1 = makeNode({
+    id: "n-child-1",
+    label: "Whether the idea solves a genuine problem",
+    description: "Need evidence about whether there is real user demand.",
+    kind: "unknown",
+    status: "unknown",
+    confidence: "medium",
+    parentId: parent.id,
+  });
+
+  const child2 = makeNode({
+    id: "n-child-2",
+    label: "Whether people would value it enough to pay",
+    description: "Need evidence about willingness to pay.",
+    kind: "unknown",
+    status: "unknown",
+    confidence: "medium",
+    parentId: parent.id,
+  });
+
+  const anchor = makeNode({
+    id: "n-anchor",
+    label: "Market observation anchor",
+    description: "Anchor state introduced by the answer.",
+    kind: "state",
+    status: "known",
+    confidence: "low",
+  });
+
+  return makeGraph({
+    centralStatement:
+      "I have developed a new reasoning method and want to determine whether continuing development is commercially justified.",
+    nodes: [parent, child1, child2, anchor],
+    edges: [
+      makeEdge({
+        id: "e-p-c1",
+        fromNodeId: child1.id,
+        toNodeId: parent.id,
+        relationship: "depends_on",
+        description: "Genuine problem feeds the parent.",
+      }),
+      makeEdge({
+        id: "e-p-c2",
+        fromNodeId: child2.id,
+        toNodeId: parent.id,
+        relationship: "depends_on",
+        description: "Willingness to pay feeds the parent.",
+      }),
+    ],
+    activeUnknownNodeId: "n-child-1",
+    resolvedNodeIds: [],
+    currentSummary: "Episode evidence boundary fixture",
+  });
+}
+
+function makeResolvedProposal(resolvedIds = ["n-child-1"]) {
+  return {
+    addedNodes: [
+      makeNode({
+        id: "n-anchor2",
+        label: "Update anchor 2",
+        description: "Anchor state.",
+        kind: "state",
+        status: "known",
+        confidence: "low",
+      }),
+    ],
+    updatedNodes: resolvedIds.map((id) => ({
+      nodeId: id,
+      previousStatus: "unknown",
+      newStatus: "resolved",
+      previousValue: null,
+      newValue: `answer:${id}`,
+      reason: "resolved child",
+    })),
+    addedEdges: [],
+    removedEdgeIds: [],
+    resolvedUnknownNodeIds: resolvedIds,
+    affectedNodeIds: [],
+    selectedQuestion: null,
+  };
+}
+
+function makeLegacyAnswer() {
+  return "Yes, I confirm there is no further material uncertainty.";
+}
+
+// ── Legacy single-turn regression ──────────────────────────────────
+
+describe("legacy single-turn path", () => {
+  it("continues to work without evidenceContext (backward-compatible signature)", async () => {
+    const graph = makeSituationGraph();
+    const proposal = makeResolvedProposal(["n-child-1"]);
+
+    const result = await applyValidatedProposal({
+      situationGraph: graph,
+      proposal,
+      answer: makeLegacyAnswer(),
+    });
+
+    expect(result.success).toBe(true);
+  });
+
+  it("legacy raw-answer compatibility check still runs (Regression A)", async () => {
+    const graph = makeSituationGraph();
+
+    // Use unstructured answerMeaning (no structured supportCategory/resolutionGuidance)
+    // so that validateAnswerMeaningCompatibilityWithRawAnswer actually executes.
+    // Raw answer states a hard constraint but the proposal weakens it in newValue.
+    const proposalWithWeakening = {
+      addedNodes: [
+        makeNode({
+          id: "n-anchor-lr",
+          label: "Update anchor",
+          description: "Anchor state.",
+          kind: "state",
+          status: "known",
+          confidence: "low",
+        }),
+      ],
+      updatedNodes: [
+        {
+          nodeId: "n-child-1",
+          previousStatus: "unknown",
+          newStatus: "resolved",
+          previousValue: null,
+          newValue: "It would be good to proceed.", // weaker than raw constraint
+          reason: "Evidence supports proceeding.",
+        },
+      ],
+      addedEdges: [],
+      removedEdgeIds: [],
+      resolvedUnknownNodeIds: ["n-child-1"],
+      affectedNodeIds: [],
+      selectedQuestion: null,
+      answerMeaning: {
+        userSupportedMeaning: "It would be good to proceed.",
+        supportCategory: null,
+        resolutionGuidance: null,
+      },
+    };
+
+    const result = await applyValidatedProposal({
+      situationGraph: graph,
+      proposal: proposalWithWeakening,
+      answer: "We MUST proceed — no exceptions.", // explicit hard constraint in raw answer
+    });
+
+    // legacy path: raw-answer compatibility check rejects weakening
+    expect(result.success).toBe(false);
+    expect(result.stage).toBe("proposal_compatibility");
+  });
+});
+
+// ── Episode evidence path ──────────────────────────────────────────
+
+describe("episode evidence at application boundary", () => {
+  it("accepts structured completed-episode evidence without collapsing to synthetic answer", async () => {
+    const graph = makeSituationGraph();
+    const proposal = makeResolvedProposal(["n-child-1"]);
+
+    const episodeEvidence = {
+      isCompletedEpisode: true,
+      episodeEvidence: {
+        situationGraph: graph,
+        targetNodeId: "n-parent",
+        turns: [
+          {
+            contributionId: "c-1",
+            sequence: 1,
+            question: "Should we proceed with the investment?",
+            answer: "Yes, the risk assessment is complete.",
+          },
+          {
+            contributionId: "c-2",
+            sequence: 2,
+            question: "Any remaining material uncertainties?",
+            answer: "No, all findings are aligned.",
+          },
+        ],
+        eligibleCanonicalFindings: [
+          {
+            findingId: "f-1",
+            contributionId: "c-1",
+            proposition: "Risk assessment confirms go/no-go criteria met.",
+            sourceObservation: "Risk analysis document v3.",
+            endorsement: "agree",
+          },
+          {
+            findingId: "f-2",
+            contributionId: "c-2",
+            proposition: "No remaining material uncertainties identified.",
+            sourceObservation: "User confirmation response.",
+            endorsement: null,
+          },
+        ],
+        excludedFindingProvenance: [
+          {
+            findingId: "f-3",
+            contributionId: "c-1",
+            proposition: "Minor budget variance noted.",
+            sourceObservation: "Budget report.",
+            disposition: "not_relevant",
+          },
+        ],
+      },
+    };
+
+    const result = await applyValidatedProposal({
+      situationGraph: graph,
+      proposal,
+      evidenceContext: episodeEvidence,
+    });
+
+    expect(result.success).toBe(true);
+  });
+
+  it("ordered turns remain distinct (no aggregation)", async () => {
+    const graph = makeSituationGraph();
+    const proposal = makeResolvedProposal(["n-child-1"]);
+
+    const episodeEvidence = {
+      isCompletedEpisode: true,
+      episodeEvidence: {
+        situationGraph: graph,
+        targetNodeId: "n-parent",
+        turns: [
+          {
+            contributionId: "c-10",
+            sequence: 1,
+            question: "Q1 distinct text?",
+            answer: "A1 distinct text.",
+          },
+          {
+            contributionId: "c-11",
+            sequence: 2,
+            question: "Q2 distinct text?",
+            answer: "A2 distinct text.",
+          },
+          {
+            contributionId: "c-12",
+            sequence: 3,
+            question: "Q3 distinct text?",
+            answer: "A3 distinct text.",
+          },
+        ],
+        eligibleCanonicalFindings: [],
+        excludedFindingProvenance: [],
+      },
+    };
+
+    const result = await applyValidatedProposal({
+      situationGraph: graph,
+      proposal,
+      evidenceContext: episodeEvidence,
+    });
+
+    expect(result.success).toBe(true);
+  });
+
+  it("eligible Findings remain structured evidence", async () => {
+    const graph = makeSituationGraph();
+    const proposal = makeResolvedProposal(["n-child-1"]);
+
+    const eligibleFindings = [
+      {
+        findingId: "f-aggree",
+        contributionId: "c-a",
+        proposition: "Confirmed proposition A.",
+        sourceObservation: "Source A.",
+        endorsement: "agree",
+      },
+      {
+        findingId: "f-agenull",
+        contributionId: "c-b",
+        proposition: "Working premise B.",
+        sourceObservation: "Source B.",
+        endorsement: null,
+      },
+    ];
+
+    const episodeEvidence = {
+      isCompletedEpisode: true,
+      episodeEvidence: {
+        situationGraph: graph,
+        targetNodeId: "n-parent",
+        turns: [
+          { contributionId: "c-a", sequence: 1, question: "Q?", answer: "A." },
+          { contributionId: "c-b", sequence: 2, question: "Q?", answer: "A." },
+        ],
+        eligibleCanonicalFindings: eligibleFindings,
+        excludedFindingProvenance: [],
+      },
+    };
+
+    const result = await applyValidatedProposal({
+      situationGraph: graph,
+      proposal,
+      evidenceContext: episodeEvidence,
+    });
+
+    expect(result.success).toBe(true);
+  });
+
+  it("no synthetic answer is constructed for episode path", async () => {
+    // In episode mode, the `answer` parameter is omitted and structured turns
+    // are provided via evidenceContext. Since no raw `answer` is passed,
+    // validateAnswerMeaningCompatibilityWithRawAnswer returns [] immediately
+    // (requires a truthy answer to execute), proving no synthetic/combined
+    // answer is constructed from the episode turns.
+    const graph = makeSituationGraph();
+
+    // Use structured meaning (bypasses raw-answer compatibility) with valid alignment
+    const proposalWithMeaning = {
+      addedNodes: [
+        makeNode({
+          id: "n-anchor-na",
+          label: "Update anchor",
+          description: "Anchor state.",
+          kind: "state",
+          status: "known",
+          confidence: "low",
+        }),
+      ],
+      updatedNodes: [
+        {
+          nodeId: "n-child-1",
+          previousStatus: "unknown",
+          newStatus: "resolved",
+          previousValue: null,
+          newValue: "Proceed with full commitment.",
+          reason: "Evidence supports it.",
+        },
+      ],
+      addedEdges: [],
+      removedEdgeIds: [],
+      resolvedUnknownNodeIds: ["n-child-1"],
+      affectedNodeIds: [],
+      selectedQuestion: null,
+      structuralActionRequired: true,
+      answerMeaning: {
+        supportCategory: "explicit_hard_constraint",
+        resolutionGuidance: "must_resolve",
+        userSupportedMeaning: "Proceed with full commitment.",
+      },
+    };
+
+    const episodeEvidence = {
+      isCompletedEpisode: true,
+      episodeEvidence: {
+        situationGraph: graph,
+        targetNodeId: "n-parent",
+        turns: [
+          { contributionId: "c-1", sequence: 1, question: "Go?", answer: "Absolutely yes." },
+          { contributionId: "c-2", sequence: 2, question: "Any remaining material uncertainties?", answer: "No." },
+        ],
+        eligibleCanonicalFindings: [],
+        excludedFindingProvenance: [],
+      },
+    };
+
+    // No `answer` parameter — evidenceContext drives the episode branch.
+    const result = await applyValidatedProposal({
+      situationGraph: graph,
+      proposal: proposalWithMeaning,
+      evidenceContext: episodeEvidence,
+    });
+
+    expect(result.success).toBe(true);
+  });
+
+  it("proposal-internal validation still runs in episode mode", async () => {
+    const graph = makeSituationGraph();
+
+    // Duplicate node ID — structural violation that proposal-internal validation catches.
+    const proposalWithDuplicateNodes = {
+      addedNodes: [
+        {
+          id: "n-child-1", // duplicates existing node ID
+          kind: "unknown",
+          status: "unknown",
+          confidence: "medium",
+          label: "Duplicate unknown",
+          value: null,
+          dependsOn: [],
+        },
+      ],
+      updatedNodes: [],
+      addedEdges: [],
+      removedEdgeIds: [],
+      resolvedUnknownNodeIds: [],
+      affectedNodeIds: [],
+      selectedQuestion: null,
+    };
+
+    const episodeEvidence = {
+      isCompletedEpisode: true,
+      episodeEvidence: {
+        situationGraph: graph,
+        targetNodeId: "n-parent",
+        turns: [
+          { contributionId: "c-1", sequence: 1, question: "Q?", answer: "A." },
+        ],
+        eligibleCanonicalFindings: [],
+        excludedFindingProvenance: [],
+      },
+    };
+
+    const result = await applyValidatedProposal({
+      situationGraph: graph,
+      proposal: proposalWithDuplicateNodes,
+      evidenceContext: episodeEvidence,
+    });
+
+    // Proposal-internal validation (structural) still runs and rejects.
+    expect(result.success).toBe(false);
+    expect(result.stage).toBe("proposal_compatibility");
+  });
+
+  it("structured episode is available for subsequent safeguard adaptation", async () => {
+    const graph = makeSituationGraph();
+    const proposal = makeResolvedProposal(["n-child-1"]);
+
+    const turns = [
+      { contributionId: "c-1", sequence: 1, question: "First turn?", answer: "First answer." },
+      { contributionId: "c-2", sequence: 2, question: "Second turn?", answer: "Second answer." },
+    ];
+
+    const episodeEvidence = {
+      isCompletedEpisode: true,
+      episodeEvidence: {
+        situationGraph: graph,
+        targetNodeId: "n-parent",
+        turns,
+        eligibleCanonicalFindings: [],
+        excludedFindingProvenance: [],
+      },
+    };
+
+    const result = await applyValidatedProposal({
+      situationGraph: graph,
+      proposal,
+      evidenceContext: episodeEvidence,
+    });
+
+    expect(result.success).toBe(true);
+    expect(result.updatedSituationGraph.nodes.find((n) => n.id === "n-child-1")?.status).toBe("resolved");
+  });
+
+  it("preserves existing graph mutation behaviour in episode mode", async () => {
+    const graph = makeSituationGraph();
+    const proposal = makeResolvedProposal(["n-child-1"]);
+    const originalParentStatus = graph.nodes.find((n) => n.id === "n-parent")?.status;
+
+    const episodeEvidence = {
+      isCompletedEpisode: true,
+      episodeEvidence: {
+        situationGraph: graph,
+        targetNodeId: "n-parent",
+        turns: [
+          { contributionId: "c-1", sequence: 1, question: "Q?", answer: "A." },
+        ],
+        eligibleCanonicalFindings: [],
+        excludedFindingProvenance: [],
+      },
+    };
+
+    const result = await applyValidatedProposal({
+      situationGraph: graph,
+      proposal,
+      evidenceContext: episodeEvidence,
+    });
+
+    expect(result.success).toBe(true);
+    // Graph was mutated (expected)
+    expect(result.updatedSituationGraph.nodes.find((n) => n.id === "n-child-1")?.status).toBe("resolved");
+    // Original graph not mutated (atomicity test)
+    expect(graph.nodes.find((n) => n.id === "n-parent")?.status).toBe(originalParentStatus);
+  });
+});
+
+
+// ── Signature compatibility ────────────────────────────────────────
+
+describe("applyValidatedProposal signature", () => {
+  it("works with minimal legacy call (situationGraph + proposal only)", async () => {
+    const graph = makeSituationGraph();
+    const result = await applyValidatedProposal({
+      situationGraph: graph,
+      proposal: makeResolvedProposal(["n-child-1"]),
+    });
+    expect(result.success).toBe(true);
+  });
+
+  it("works with legacy answer parameter still passed", async () => {
+    const graph = makeSituationGraph();
+    const result = await applyValidatedProposal({
+      situationGraph: graph,
+      proposal: makeResolvedProposal(["n-child-1"]),
+      answer: "Yes.",
+    });
+    expect(result.success).toBe(true);
+  });
+
+  it("works with both evidenceContext and legacy parameters (evidenceContext takes precedence)", async () => {
+    const graph = makeSituationGraph();
+    const proposal = makeResolvedProposal(["n-child-1"]);
+
+    const episodeEvidence = {
+      isCompletedEpisode: true,
+      episodeEvidence: {
+        situationGraph: graph,
+        targetNodeId: "n-parent",
+        turns: [
+          { contributionId: "c-1", sequence: 1, question: "Q?", answer: "A." },
+        ],
+        eligibleCanonicalFindings: [],
+        excludedFindingProvenance: [],
+      },
+    };
+
+    const result = await applyValidatedProposal({
+      situationGraph: graph,
+      proposal,
+      previousQuestion: "Legacy question?",
+      answer: "Legacy answer.", // should be ignored — evidenceContext present
+      evidenceContext: episodeEvidence,
+    });
+
+    expect(result.success).toBe(true);
+  });
+});