diff --git a/lib/graph/update-proposal.js b/lib/graph/update-proposal.js
index 8e462ea..95d01d5 100644
--- a/lib/graph/update-proposal.js
+++ b/lib/graph/update-proposal.js
@@ -62,6 +62,19 @@ function applyKnownEnumAliases(proposal, normalisationsApplied) {
     });
   }
 
+  if (Array.isArray(proposal.addedEdges)) {
+    proposal.addedEdges = proposal.addedEdges.map((edge, index) => {
+      if (edge?.relationship === "affects") {
+        normalisationsApplied.push({
+          path: ["addedEdges", index, "relationship"],
+          change: "Converted affects to other",
+        });
+        return { ...edge, relationship: "other" };
+      }
+      return edge;
+    });
+  }
+
   return proposal;
 }
 
diff --git a/tests/graph/apply-proposal.test.js b/tests/graph/apply-proposal.test.js
index cb245a7..0b22293 100644
--- a/tests/graph/apply-proposal.test.js
+++ b/tests/graph/apply-proposal.test.js
@@ -401,6 +401,35 @@ describe("applyValidatedProposal", () => {
     expect(result.stage).toBe("proposal_compatibility");
   });
 
+  it("accepts a proposal edge normalised from affects to canonical other before application", () => {
+    const { graph, proposal } = makeApplicationFixture();
+
+    const result = applyValidatedProposal({
+      situationGraph: graph,
+      proposal: {
+        ...proposal,
+        addedEdges: [
+          makeEdge({
+            id: "e-other-edge",
+            fromNodeId: "n-complaint-count",
+            toNodeId: "n-quality-deterioration",
+            relationship: "other",
+            confidence: "medium",
+            description:
+              "Canonical generic relationship after proposal-boundary normalisation.",
+          }),
+        ],
+      },
+    });
+
+    expect(result.success).toBe(true);
+    expect(
+      result.updatedSituationGraph.edges.some(
+        (edge) => edge.id === "e-other-edge" && edge.relationship === "other",
+      ),
+    ).toBe(true);
+  });
+
   it("rejects duplicate IDs", () => {
     const { graph, proposal, ids } = makeApplicationFixture();
 
diff --git a/tests/graph/update-proposal.test.js b/tests/graph/update-proposal.test.js
index 82d571c..b8bb8cc 100644
--- a/tests/graph/update-proposal.test.js
+++ b/tests/graph/update-proposal.test.js
@@ -1,5 +1,7 @@
 import { describe, expect, it } from "vitest";
 import { parseGraphUpdateProposal } from "@/lib/graph/update-proposal.js";
+import { applyGraphUpdate } from "@/lib/graph/utils.js";
+import { makeEdge, makeGraph, makeNode } from "@/lib/graph/schema.js";
 
 function makeValidProposal(overrides = {}) {
   return {
@@ -144,6 +146,125 @@ describe("parseGraphUpdateProposal", () => {
     });
   });
 
+  it("normalises the observed external relationship wording affects to canonical other at the proposal boundary", () => {
+    const result = parseGraphUpdateProposal({
+      ...makeValidProposal(),
+      addedEdges: [
+        {
+          id: "e-affects",
+          fromNodeId: "n-driver",
+          toNodeId: "n-unknown",
+          relationship: "affects",
+          confidence: "medium",
+          description: "Model-style relationship wording from live output.",
+        },
+      ],
+    });
+
+    expect(result.success).toBe(true);
+    expect(result.proposal.addedEdges[0].relationship).toBe("other");
+    expect(result.normalisationsApplied).toEqual(
+      expect.arrayContaining([
+        expect.objectContaining({ change: "Converted affects to other" }),
+      ]),
+    );
+  });
+
+  it("leaves already-valid canonical relationship values unchanged", () => {
+    const canonicalRelationships = [
+      "supports",
+      "weakens",
+      "contradicts",
+      "depends_on",
+      "causes",
+      "may_cause",
+      "measures",
+      "compares_with",
+      "updates",
+      "other",
+    ];
+
+    for (const relationship of canonicalRelationships) {
+      const result = parseGraphUpdateProposal({
+        ...makeValidProposal(),
+        addedEdges: [
+          {
+            id: `e-${relationship}`,
+            fromNodeId: "n-driver",
+            toNodeId: "n-unknown",
+            relationship,
+            confidence: "medium",
+            description: `Canonical relationship ${relationship}`,
+          },
+        ],
+      });
+
+      expect(result.success).toBe(true);
+      expect(result.proposal.addedEdges[0].relationship).toBe(relationship);
+    }
+  });
+
+  it("still rejects unsupported arbitrary relationship values", () => {
+    const result = parseGraphUpdateProposal({
+      ...makeValidProposal(),
+      addedEdges: [
+        {
+          id: "e-unsupported",
+          fromNodeId: "n-driver",
+          toNodeId: "n-unknown",
+          relationship: "influences_decisively",
+          confidence: "medium",
+          description: "Unsupported relationship wording.",
+        },
+      ],
+    });
+
+    expect(result.success).toBe(false);
+  });
+
+  it("applies only the canonical internal relationship after normalisation", () => {
+    const parsed = parseGraphUpdateProposal({
+      ...makeValidProposal({
+        updatedNodes: [],
+        resolvedUnknownNodeIds: [],
+      }),
+      addedEdges: [
+        {
+          id: "e-affects",
+          fromNodeId: "n-driver",
+          toNodeId: "n-unknown",
+          relationship: "affects",
+          confidence: "medium",
+          description: "Model-style relationship wording from live output.",
+        },
+      ],
+    });
+
+    expect(parsed.success).toBe(true);
+
+    const graph = makeGraph({
+      centralStatement: "Relationship application fixture",
+      nodes: [
+        makeNode({ id: "n-driver", label: "Driver", status: "known" }),
+        makeNode({ id: "n-unknown", label: "Unknown" }),
+      ],
+      edges: [],
+      currentSummary: "Initial summary",
+    });
+
+    const applied = applyGraphUpdate(graph, parsed.proposal);
+
+    expect(applied.success).toBe(true);
+    expect(applied.edges).toEqual(
+      expect.arrayContaining([
+        expect.objectContaining({ relationship: "other" }),
+      ]),
+    );
+    expect(applied.edges.some((edge) => edge.relationship === "affects")).toBe(
+      false,
+    );
+  });
+
   it("unknown node enum values still fail", () => {
     const result = parseGraphUpdateProposal({
       ...makeValidProposal(),