diff --git a/understand-anything-plugin/packages/core/src/__tests__/normalize-graph.test.ts b/understand-anything-plugin/packages/core/src/__tests__/normalize-graph.test.ts
new file mode 100644
index 0000000..fa150c2
--- /dev/null
+++ b/understand-anything-plugin/packages/core/src/__tests__/normalize-graph.test.ts
@@ -0,0 +1,498 @@
+import { describe, it, expect } from "vitest";
+import {
+  normalizeNodeId,
+  normalizeComplexity,
+  normalizeBatchOutput,
+} from "../analyzer/normalize-graph.js";
+import { validateGraph } from "../schema.js";
+
+describe("normalizeNodeId", () => {
+  it("passes through a correct file ID unchanged", () => {
+    expect(
+      normalizeNodeId("file:src/index.ts", { type: "file" }),
+    ).toBe("file:src/index.ts");
+  });
+
+  it("passes through a correct func ID unchanged", () => {
+    expect(
+      normalizeNodeId("func:src/utils.ts:formatDate", { type: "function" }),
+    ).toBe("func:src/utils.ts:formatDate");
+  });
+
+  it("passes through a correct class ID unchanged", () => {
+    expect(
+      normalizeNodeId("class:src/models/User.ts:User", { type: "class" }),
+    ).toBe("class:src/models/User.ts:User");
+  });
+
+  it("fixes double-prefixed IDs", () => {
+    expect(
+      normalizeNodeId("file:file:src/foo.ts", { type: "file" }),
+    ).toBe("file:src/foo.ts");
+  });
+
+  it("strips project-name prefix when valid prefix follows", () => {
+    expect(
+      normalizeNodeId("my-project:file:src/foo.ts", { type: "file" }),
+    ).toBe("file:src/foo.ts");
+  });
+
+  it("strips project-name prefix and adds correct prefix for bare path", () => {
+    expect(
+      normalizeNodeId("my-project:src/foo.ts", { type: "file" }),
+    ).toBe("file:src/foo.ts");
+  });
+
+  it("adds file: prefix to bare paths", () => {
+    expect(
+      normalizeNodeId("frontend/src/utils/constants.ts", { type: "file" }),
+    ).toBe("file:frontend/src/utils/constants.ts");
+  });
+
+  it("reconstructs func ID from filePath and name for bare paths", () => {
+    expect(
+      normalizeNodeId("formatDate", {
+        type: "function",
+        filePath: "src/utils.ts",
+        name: "formatDate",
+      }),
+    ).toBe("func:src/utils.ts:formatDate");
+  });
+
+  it("reconstructs class ID from filePath and name for bare paths", () => {
+    expect(
+      normalizeNodeId("User", {
+        type: "class",
+        filePath: "src/models/User.ts",
+        name: "User",
+      }),
+    ).toBe("class:src/models/User.ts:User");
+  });
+
+  it("trims whitespace", () => {
+    expect(
+      normalizeNodeId("  file:src/foo.ts  ", { type: "file" }),
+    ).toBe("file:src/foo.ts");
+  });
+
+  it("handles module: and concept: prefixes", () => {
+    expect(
+      normalizeNodeId("module:auth", { type: "module" }),
+    ).toBe("module:auth");
+    expect(
+      normalizeNodeId("concept:caching", { type: "concept" }),
+    ).toBe("concept:caching");
+  });
+
+  it("handles project-name prefix before a valid non-code prefix", () => {
+    expect(
+      normalizeNodeId("my-project:service:docker-compose.yml", {
+        type: "file",
+      }),
+    ).toBe("service:docker-compose.yml");
+  });
+
+  it("returns empty string for empty input", () => {
+    expect(normalizeNodeId("", { type: "file" })).toBe("");
+  });
+
+  it("falls back to untouched ID for unknown node type", () => {
+    expect(normalizeNodeId("some-id", { type: "widget" as any })).toBe("some-id");
+  });
+
+  it("passes through non-code type IDs unchanged", () => {
+    expect(normalizeNodeId("config:tsconfig.json", { type: "config" })).toBe("config:tsconfig.json");
+    expect(normalizeNodeId("document:README.md", { type: "document" })).toBe("document:README.md");
+    expect(normalizeNodeId("service:docker-compose.yml", { type: "service" })).toBe("service:docker-compose.yml");
+    expect(normalizeNodeId("table:migrations/001.sql:users", { type: "table" })).toBe("table:migrations/001.sql:users");
+    expect(normalizeNodeId("endpoint:src/routes.ts:GET /api/users", { type: "endpoint" })).toBe("endpoint:src/routes.ts:GET /api/users");
+    expect(normalizeNodeId("pipeline:.github/workflows/ci.yml", { type: "pipeline" })).toBe("pipeline:.github/workflows/ci.yml");
+    expect(normalizeNodeId("schema:schema.graphql", { type: "schema" })).toBe("schema:schema.graphql");
+    expect(normalizeNodeId("resource:main.tf", { type: "resource" })).toBe("resource:main.tf");
+  });
+
+  it("adds prefix for bare paths with non-code types", () => {
+    expect(normalizeNodeId("tsconfig.json", { type: "config" })).toBe("config:tsconfig.json");
+    expect(normalizeNodeId("README.md", { type: "document" })).toBe("document:README.md");
+  });
+
+  it("strips project-name prefix from non-code type IDs", () => {
+    expect(normalizeNodeId("my-project:config:tsconfig.json", { type: "config" })).toBe("config:tsconfig.json");
+  });
+});
+
+describe("normalizeComplexity", () => {
+  it("passes through valid values unchanged", () => {
+    expect(normalizeComplexity("simple")).toBe("simple");
+    expect(normalizeComplexity("moderate")).toBe("moderate");
+    expect(normalizeComplexity("complex")).toBe("complex");
+  });
+
+  it("maps 'low' to 'simple'", () => {
+    expect(normalizeComplexity("low")).toBe("simple");
+  });
+
+  it("maps 'high' to 'complex'", () => {
+    expect(normalizeComplexity("high")).toBe("complex");
+  });
+
+  it("maps 'medium' to 'moderate'", () => {
+    expect(normalizeComplexity("medium")).toBe("moderate");
+  });
+
+  it("maps other aliases from upstream COMPLEXITY_ALIASES", () => {
+    expect(normalizeComplexity("easy")).toBe("simple");
+    expect(normalizeComplexity("hard")).toBe("complex");
+    expect(normalizeComplexity("difficult")).toBe("complex");
+    expect(normalizeComplexity("intermediate")).toBe("moderate");
+  });
+
+  it("is case-insensitive", () => {
+    expect(normalizeComplexity("LOW")).toBe("simple");
+    expect(normalizeComplexity("High")).toBe("complex");
+    expect(normalizeComplexity("MODERATE")).toBe("moderate");
+  });
+
+  it("maps numeric 1-3 to simple", () => {
+    expect(normalizeComplexity(1)).toBe("simple");
+    expect(normalizeComplexity(3)).toBe("simple");
+  });
+
+  it("maps numeric 4-6 to moderate", () => {
+    expect(normalizeComplexity(4)).toBe("moderate");
+    expect(normalizeComplexity(6)).toBe("moderate");
+  });
+
+  it("maps numeric 7-10 to complex", () => {
+    expect(normalizeComplexity(7)).toBe("complex");
+    expect(normalizeComplexity(10)).toBe("complex");
+  });
+
+  it("defaults free-text to moderate", () => {
+    expect(normalizeComplexity("detailed")).toBe("moderate");
+    expect(normalizeComplexity("very complex with many deps")).toBe("moderate");
+  });
+
+  it("defaults undefined/null to moderate", () => {
+    expect(normalizeComplexity(undefined)).toBe("moderate");
+    expect(normalizeComplexity(null)).toBe("moderate");
+  });
+
+  it("defaults zero and negative numbers to moderate", () => {
+    expect(normalizeComplexity(0)).toBe("moderate");
+    expect(normalizeComplexity(-5)).toBe("moderate");
+  });
+});
+
+describe("normalizeBatchOutput", () => {
+  it("normalizes IDs and numeric complexity, rewrites edges", () => {
+    const result = normalizeBatchOutput({
+      nodes: [
+        {
+          id: "file:src/good.ts",
+          type: "file",
+          name: "good.ts",
+          filePath: "src/good.ts",
+          summary: "A good file",
+          tags: ["util"],
+          complexity: "simple",
+        },
+        {
+          id: "my-project:file:src/bad.ts",
+          type: "file",
+          name: "bad.ts",
+          filePath: "src/bad.ts",
+          summary: "Project-prefixed",
+          tags: ["api"],
+          complexity: "simple",
+        },
+        {
+          id: "src/bare.ts",
+          type: "file",
+          name: "bare.ts",
+          filePath: "src/bare.ts",
+          summary: "Bare path",
+          tags: [],
+          complexity: 4,
+        },
+      ],
+      edges: [
+        {
+          source: "file:src/good.ts",
+          target: "my-project:file:src/bad.ts",
+          type: "imports",
+          direction: "forward",
+          weight: 0.7,
+        },
+        {
+          source: "src/bare.ts",
+          target: "file:src/good.ts",
+          type: "imports",
+          direction: "forward",
+          weight: 0.7,
+        },
+      ],
+    });
+
+    expect(result.nodes).toHaveLength(3);
+    expect(result.nodes[0].id).toBe("file:src/good.ts");
+    expect(result.nodes[1].id).toBe("file:src/bad.ts");
+    expect(result.nodes[2].id).toBe("file:src/bare.ts");
+    // Only numeric complexity is fixed here; string aliases are upstream's job
+    expect(result.nodes[2].complexity).toBe("moderate");
+
+    // Edges should be rewritten through the ID map
+    expect(result.edges).toHaveLength(2);
+    expect(result.edges[0].source).toBe("file:src/good.ts");
+    expect(result.edges[0].target).toBe("file:src/bad.ts");
+    expect(result.edges[1].source).toBe("file:src/bare.ts");
+
+    expect(result.stats.idsFixed).toBe(2);
+    expect(result.stats.complexityFixed).toBe(1); // only the numeric one
+    expect(result.stats.edgesRewritten).toBe(2);
+    expect(result.stats.danglingEdgesDropped).toBe(0);
+  });
+
+  it("drops dangling edges after normalization", () => {
+    const result = normalizeBatchOutput({
+      nodes: [
+        {
+          id: "file:src/a.ts",
+          type: "file",
+          name: "a.ts",
+          summary: "File A",
+          tags: [],
+          complexity: "simple",
+        },
+      ],
+      edges: [
+        {
+          source: "file:src/a.ts",
+          target: "file:src/nonexistent.ts",
+          type: "imports",
+          direction: "forward",
+          weight: 0.7,
+        },
+      ],
+    });
+
+    expect(result.edges).toHaveLength(0);
+    expect(result.stats.danglingEdgesDropped).toBe(1);
+    expect(result.stats.droppedEdges).toHaveLength(1);
+    expect(result.stats.droppedEdges[0]).toEqual({
+      source: "file:src/a.ts",
+      target: "file:src/nonexistent.ts",
+      type: "imports",
+      reason: "missing-target",
+    });
+  });
+
+  it("deduplicates nodes keeping last occurrence", () => {
+    const result = normalizeBatchOutput({
+      nodes: [
+        {
+          id: "file:src/a.ts",
+          type: "file",
+          name: "a.ts",
+          summary: "First version",
+          tags: [],
+          complexity: "simple",
+        },
+        {
+          id: "file:src/a.ts",
+          type: "file",
+          name: "a.ts",
+          summary: "Second version",
+          tags: ["updated"],
+          complexity: "complex",
+        },
+      ],
+      edges: [],
+    });
+
+    expect(result.nodes).toHaveLength(1);
+    expect(result.nodes[0].summary).toBe("Second version");
+  });
+
+  it("deduplicates edges after ID rewriting", () => {
+    const result = normalizeBatchOutput({
+      nodes: [
+        {
+          id: "file:src/a.ts",
+          type: "file",
+          name: "a.ts",
+          summary: "A",
+          tags: [],
+          complexity: "simple",
+        },
+        {
+          id: "file:src/b.ts",
+          type: "file",
+          name: "b.ts",
+          summary: "B",
+          tags: [],
+          complexity: "simple",
+        },
+      ],
+      edges: [
+        {
+          source: "file:src/a.ts",
+          target: "file:src/b.ts",
+          type: "imports",
+          direction: "forward",
+          weight: 0.7,
+        },
+        {
+          source: "proj:file:src/a.ts",
+          target: "file:src/b.ts",
+          type: "imports",
+          direction: "forward",
+          weight: 0.7,
+        },
+      ],
+    });
+
+    // Both edges resolve to the same source after normalization — deduplicated
+    expect(result.edges).toHaveLength(1);
+  });
+
+  it("returns accurate stats", () => {
+    const result = normalizeBatchOutput({
+      nodes: [
+        {
+          id: "file:src/ok.ts",
+          type: "file",
+          name: "ok.ts",
+          summary: "OK",
+          tags: [],
+          complexity: "simple",
+        },
+        {
+          id: "proj:file:src/fix.ts",
+          type: "file",
+          name: "fix.ts",
+          summary: "Needs fix",
+          tags: [],
+          complexity: 2,
+        },
+      ],
+      edges: [
+        {
+          source: "proj:file:src/fix.ts",
+          target: "file:src/ok.ts",
+          type: "imports",
+          direction: "forward",
+          weight: 0.7,
+        },
+        {
+          source: "file:src/ok.ts",
+          target: "file:src/gone.ts",
+          type: "imports",
+          direction: "forward",
+          weight: 0.7,
+        },
+      ],
+    });
+
+    expect(result.stats.idsFixed).toBe(1);
+    expect(result.stats.complexityFixed).toBe(1);
+    expect(result.stats.edgesRewritten).toBe(1);
+    expect(result.stats.danglingEdgesDropped).toBe(1);
+    expect(result.edges).toHaveLength(1);
+  });
+
+  it("resolves edge endpoints with different malformed variants than node IDs", () => {
+    const result = normalizeBatchOutput({
+      nodes: [
+        {
+          id: "src/bare.ts",
+          type: "file",
+          name: "bare.ts",
+          filePath: "src/bare.ts",
+          summary: "Bare",
+          tags: [],
+          complexity: "simple",
+        },
+        {
+          id: "file:src/target.ts",
+          type: "file",
+          name: "target.ts",
+          filePath: "src/target.ts",
+          summary: "Target",
+          tags: [],
+          complexity: "simple",
+        },
+      ],
+      edges: [
+        {
+          source: "my-project:file:src/bare.ts",
+          target: "file:src/target.ts",
+          type: "imports",
+          direction: "forward",
+          weight: 0.7,
+        },
+      ],
+    });
+
+    expect(result.edges).toHaveLength(1);
+    expect(result.edges[0].source).toBe("file:src/bare.ts");
+    expect(result.edges[0].target).toBe("file:src/target.ts");
+  });
+});
+
+describe("normalizeBatchOutput integration", () => {
+  it("produces output that passes validateGraph after wrapping", () => {
+    const result = normalizeBatchOutput({
+      nodes: [
+        {
+          id: "my-project:file:src/index.ts",
+          type: "file",
+          name: "index.ts",
+          filePath: "src/index.ts",
+          summary: "Entry point",
+          tags: ["entry"],
+          complexity: 3,
+        },
+        {
+          id: "src/utils.ts",
+          type: "file",
+          name: "utils.ts",
+          filePath: "src/utils.ts",
+          summary: "Utilities",
+          tags: [],
+          complexity: "simple",
+        },
+      ],
+      edges: [
+        {
+          source: "my-project:file:src/index.ts",
+          target: "src/utils.ts",
+          type: "imports",
+          direction: "forward",
+          weight: 0.7,
+        },
+      ],
+    });
+
+    const graph = {
+      version: "1.0.0",
+      project: {
+        name: "test",
+        languages: ["typescript"],
+        frameworks: [],
+        description: "Test project",
+        analyzedAt: new Date().toISOString(),
+        gitCommitHash: "abc123",
+      },
+      nodes: result.nodes,
+      edges: result.edges,
+      layers: [],
+      tour: [],
+    };
+
+    const validation = validateGraph(graph);
+    expect(validation.success).toBe(true);
+    expect(validation.data?.nodes).toHaveLength(2);
+    expect(validation.data?.edges).toHaveLength(1);
+  });
+});
diff --git a/understand-anything-plugin/packages/core/src/__tests__/schema.test.ts b/understand-anything-plugin/packages/core/src/__tests__/schema.test.ts
index fe5e205..2ea911a 100644
--- a/understand-anything-plugin/packages/core/src/__tests__/schema.test.ts
+++ b/understand-anything-plugin/packages/core/src/__tests__/schema.test.ts
@@ -719,4 +719,12 @@ describe("Extended node/edge types", () => {
       expect(result.data!.edges[0].type).toBe(canonical);
     }
   });
+
+  it("accepts node with bare string ID (schema is lenient on format)", () => {
+    const graph = structuredClone(validGraph);
+    graph.nodes[0].id = "src/foo.ts";
+
+    const result = validateGraph(graph);
+    expect(result.success).toBe(true);
+  });
 });
diff --git a/understand-anything-plugin/packages/core/src/analyzer/normalize-graph.ts b/understand-anything-plugin/packages/core/src/analyzer/normalize-graph.ts
new file mode 100644
index 0000000..9409693
--- /dev/null
+++ b/understand-anything-plugin/packages/core/src/analyzer/normalize-graph.ts
@@ -0,0 +1,257 @@
+const VALID_PREFIXES = new Set([
+  "file", "func", "class", "module", "concept",
+  "config", "document", "service", "table", "endpoint",
+  "pipeline", "schema", "resource",
+]);
+
+const TYPE_TO_PREFIX: Record<string, string> = {
+  file: "file",
+  function: "func",
+  class: "class",
+  module: "module",
+  concept: "concept",
+  config: "config",
+  document: "document",
+  service: "service",
+  table: "table",
+  endpoint: "endpoint",
+  pipeline: "pipeline",
+  schema: "schema",
+  resource: "resource",
+};
+
+/**
+ * Strips all non-valid prefixes from an ID, returning the bare path
+ * and the first valid prefix found (if any).
+ */
+function stripToValidPrefix(id: string): { prefix: string | null; path: string } {
+  let remaining = id;
+
+  // Peel off colon-separated segments until we find a valid prefix or run out
+  while (true) {
+    const colonIdx = remaining.indexOf(":");
+    if (colonIdx <= 0) break;
+
+    const segment = remaining.slice(0, colonIdx);
+    if (VALID_PREFIXES.has(segment)) {
+      // Check for double valid prefix (e.g., "file:file:src/foo.ts")
+      const rest = remaining.slice(colonIdx + 1);
+      const innerColonIdx = rest.indexOf(":");
+      if (innerColonIdx > 0 && VALID_PREFIXES.has(rest.slice(0, innerColonIdx))) {
+        // Double-prefixed — skip the outer, recurse on inner
+        remaining = rest;
+        continue;
+      }
+      return { prefix: segment, path: rest };
+    }
+
+    // Not a valid prefix — strip it and continue
+    remaining = remaining.slice(colonIdx + 1);
+  }
+
+  return { prefix: null, path: remaining };
+}
+
+/**
+ * Normalizes a node ID to the canonical `type:path` format.
+ * Handles: double-prefixed IDs, project-name-prefixed IDs, bare paths.
+ * Idempotent — correct IDs pass through unchanged.
+ */
+export function normalizeNodeId(
+  id: string,
+  node: { type: string; filePath?: string; name?: string },
+): string {
+  const trimmed = id.trim();
+  if (!trimmed) return trimmed;
+
+  const expectedPrefix = TYPE_TO_PREFIX[node.type];
+  const { prefix, path } = stripToValidPrefix(trimmed);
+
+  if (prefix) {
+    return `${prefix}:${path}`;
+  }
+
+  // No valid prefix found — bare path
+  if (expectedPrefix) {
+    // For func/class, reconstruct from filePath + name if available
+    if (
+      (node.type === "function" || node.type === "class") &&
+      node.filePath &&
+      node.name
+    ) {
+      return `${expectedPrefix}:${node.filePath}:${node.name}`;
+    }
+    return `${expectedPrefix}:${path}`;
+  }
+
+  return trimmed;
+}
+
+const VALID_COMPLEXITIES = new Set(["simple", "moderate", "complex"]);
+
+const COMPLEXITY_STRING_MAP: Record<string, string> = {
+  low: "simple",
+  easy: "simple",
+  medium: "moderate",
+  intermediate: "moderate",
+  high: "complex",
+  hard: "complex",
+  difficult: "complex",
+};
+
+/**
+ * Normalizes a complexity value to one of "simple" | "moderate" | "complex".
+ * Handles both string aliases and numeric scales — defaults to "moderate".
+ */
+export function normalizeComplexity(
+  value: unknown,
+): "simple" | "moderate" | "complex" {
+  if (typeof value === "string") {
+    const lower = value.toLowerCase().trim();
+    if (VALID_COMPLEXITIES.has(lower)) return lower as "simple" | "moderate" | "complex";
+    const aliased = COMPLEXITY_STRING_MAP[lower];
+    if (aliased) return aliased as "simple" | "moderate" | "complex";
+    return "moderate";
+  }
+
+  if (typeof value === "number" && Number.isFinite(value) && value >= 1) {
+    if (value <= 3) return "simple";
+    if (value <= 6) return "moderate";
+    return "complex";
+  }
+
+  return "moderate";
+}
+
+export interface DroppedEdge {
+  source: string;
+  target: string;
+  type: string;
+  reason: "missing-source" | "missing-target" | "missing-both";
+}
+
+export interface NormalizationStats {
+  idsFixed: number;
+  complexityFixed: number;
+  edgesRewritten: number;
+  danglingEdgesDropped: number;
+  droppedEdges: DroppedEdge[];
+}
+
+export interface NormalizeBatchResult {
+  nodes: Record<string, unknown>[];
+  edges: Record<string, unknown>[];
+  idMap: Map<string, string>;
+  stats: NormalizationStats;
+}
+
+/**
+ * Normalizes a merged batch output: fixes node IDs and numeric complexity,
+ * rewrites edge references, deduplicates nodes and edges, and drops dangling edges.
+ *
+ * This runs BEFORE upstream's sanitizeGraph/autoFixGraph/normalizeGraph pipeline,
+ * handling concerns that pipeline does not cover: malformed IDs, numeric complexity,
+ * edge reference rewriting after ID correction, and edge deduplication.
+ */
+export function normalizeBatchOutput(data: {
+  nodes: Record<string, unknown>[];
+  edges: Record<string, unknown>[];
+}): NormalizeBatchResult {
+  const stats: NormalizationStats = {
+    idsFixed: 0,
+    complexityFixed: 0,
+    edgesRewritten: 0,
+    danglingEdgesDropped: 0,
+    droppedEdges: [],
+  };
+
+  const idMap = new Map<string, string>();
+
+  // Pass 1: Normalize node IDs and numeric complexity
+  const nodes = data.nodes.map((raw) => {
+    const oldId = String(raw.id ?? "");
+    const nodeType = String(raw.type ?? "file");
+    const newId = normalizeNodeId(oldId, {
+      type: nodeType,
+      filePath: typeof raw.filePath === "string" ? raw.filePath : undefined,
+      name: typeof raw.name === "string" ? raw.name : undefined,
+    });
+
+    if (newId !== oldId) {
+      stats.idsFixed++;
+    }
+    idMap.set(oldId, newId);
+
+    const result: Record<string, unknown> = { ...raw, id: newId };
+
+    // Only fix numeric complexity here — string aliases are handled by upstream's
+    // COMPLEXITY_ALIASES in autoFixGraph
+    if (typeof raw.complexity === "number") {
+      result.complexity = normalizeComplexity(raw.complexity);
+      stats.complexityFixed++;
+    }
+
+    return result;
+  });
+
+  // Deduplicate nodes (keep last occurrence)
+  const seenIds = new Map<string, number>();
+  for (let i = 0; i < nodes.length; i++) {
+    seenIds.set(String(nodes[i].id), i);
+  }
+  const deduped = nodes.filter((_, i) => seenIds.get(String(nodes[i].id)) === i);
+  const validNodeIds = new Set(deduped.map((n) => String(n.id)));
+
+  // Pass 2: Rewrite edge references and deduplicate
+  const edges: Record<string, unknown>[] = [];
+  const seenEdges = new Set<string>();
+  for (const raw of data.edges) {
+    const oldSource = String(raw.source ?? "");
+    const oldTarget = String(raw.target ?? "");
+    let newSource = idMap.get(oldSource) ?? oldSource;
+    let newTarget = idMap.get(oldTarget) ?? oldTarget;
+
+    // Fallback: if endpoint not found in idMap, normalize it directly
+    // (handles cross-variant malformed IDs between nodes and edges)
+    if (!validNodeIds.has(newSource)) {
+      const normalized = normalizeNodeId(newSource, { type: "file" });
+      if (validNodeIds.has(normalized)) newSource = normalized;
+    }
+    if (!validNodeIds.has(newTarget)) {
+      const normalized = normalizeNodeId(newTarget, { type: "file" });
+      if (validNodeIds.has(normalized)) newTarget = normalized;
+    }
+
+    if (newSource !== oldSource || newTarget !== oldTarget) {
+      stats.edgesRewritten++;
+    }
+
+    if (!validNodeIds.has(newSource) || !validNodeIds.has(newTarget)) {
+      const missingSource = !validNodeIds.has(newSource);
+      const missingTarget = !validNodeIds.has(newTarget);
+      stats.danglingEdgesDropped++;
+      stats.droppedEdges.push({
+        source: newSource,
+        target: newTarget,
+        type: String(raw.type ?? ""),
+        reason: missingSource && missingTarget ? "missing-both" : missingSource ? "missing-source" : "missing-target",
+      });
+      continue;
+    }
+
+    // Deduplicate by composite key (source + target + type)
+    const edgeType = String(raw.type ?? "");
+    const edgeKey = `${newSource}|${newTarget}|${edgeType}`;
+    if (seenEdges.has(edgeKey)) continue;
+    seenEdges.add(edgeKey);
+
+    edges.push({ ...raw, source: newSource, target: newTarget });
+  }
+
+  return {
+    nodes: deduped,
+    edges,
+    idMap,
+    stats,
+  };
+}
diff --git a/understand-anything-plugin/packages/core/src/index.ts b/understand-anything-plugin/packages/core/src/index.ts
index 0213ad5..756284d 100644
--- a/understand-anything-plugin/packages/core/src/index.ts
+++ b/understand-anything-plugin/packages/core/src/index.ts
@@ -19,6 +19,14 @@ export {
   parseProjectSummaryResponse,
 } from "./analyzer/llm-analyzer.js";
 export type { LLMFileAnalysis, LLMProjectSummary } from "./analyzer/llm-analyzer.js";
+export {
+  normalizeNodeId,
+  normalizeComplexity,
+  normalizeBatchOutput,
+  type DroppedEdge,
+  type NormalizationStats,
+  type NormalizeBatchResult,
+} from "./analyzer/normalize-graph.js";
 export { SearchEngine, type SearchResult, type SearchOptions } from "./search.js";
 export {
   getChangedFiles,
diff --git a/understand-anything-plugin/skills/understand/SKILL.md b/understand-anything-plugin/skills/understand/SKILL.md
index b6503dc..64c8cba 100644
--- a/understand-anything-plugin/skills/understand/SKILL.md
+++ b/understand-anything-plugin/skills/understand/SKILL.md
@@ -174,11 +174,28 @@ After batches complete, merge with the existing graph:
 
 ## Phase 3 — ASSEMBLE
 
-Merge all file-analyzer results into a single set of nodes and edges. Then perform basic integrity cleanup:
+Merge all file-analyzer results into a single set of nodes and edges. Then perform normalization and integrity cleanup **in this order**:
 
-- Remove any edge whose `source` or `target` references a node ID that does not exist in the merged node set
-- Remove duplicate node IDs (keep the last occurrence)
-- Log any removed edges or nodes for the final summary
+1. **Normalize node IDs:** For every node, verify the `id` field follows the convention `<type-prefix>:<path>` where type-prefix is one of `file`, `func`, `class`, `module`, `concept`, `config`, `document`, `service`, `table`, `endpoint`, `pipeline`, `schema`, `resource`. Apply these fixes:
+   - If the ID has a double prefix (e.g., `file:file:src/foo.ts`), strip the duplicate prefix.
+   - If the ID has a project-name prefix (e.g., `my-project:file:src/foo.ts`), strip the project-name portion.
+   - If the ID is a bare file path with no prefix, add the appropriate prefix based on the node's `type` field: `file` → `file:<path>`, `function` → `func:<filePath>:<name>`, `class` → `class:<filePath>:<name>`.
+   - Build a mapping of original IDs → corrected IDs.
+
+2. **Normalize complexity values:** For every node, verify `complexity` is one of `"simple"`, `"moderate"`, `"complex"`. Apply these mappings for invalid values:
+   - `"low"`, `"easy"` → `"simple"`
+   - `"medium"`, `"intermediate"` → `"moderate"`
+   - `"high"`, `"hard"`, `"difficult"` → `"complex"`
+   - Numeric 1-3 → `"simple"`, 4-6 → `"moderate"`, 7-10 → `"complex"`
+   - Any other value → `"moderate"`
+
+3. **Rewrite edge references:** Using the ID mapping from step 1, update every edge's `source` and `target` fields. This prevents cascading edge drops when only the ID format was wrong.
+
+4. **Remove duplicate node IDs:** If duplicate node IDs exist after normalization, keep the last occurrence.
+
+5. **Remove dangling edges:** Remove any edge whose `source` or `target` references a node ID that does not exist in the merged node set.
+
+6. **Log changes:** Record counts of IDs corrected, complexity values fixed, edges rewritten, duplicates removed, and dangling edges dropped. Include these counts in the Phase warnings list passed to the reviewer.
 
 ---
 
diff --git a/understand-anything-plugin/skills/understand/file-analyzer-prompt.md b/understand-anything-plugin/skills/understand/file-analyzer-prompt.md
index 974d0a0..1177b16 100644
--- a/understand-anything-plugin/skills/understand/file-analyzer-prompt.md
+++ b/understand-anything-plugin/skills/understand/file-analyzer-prompt.md
@@ -444,6 +444,8 @@ You MUST use these exact prefixes for node IDs:
 
 **Scope restriction:** Only produce node types listed above. The `module:` and `concept:` node types are reserved for higher-level analysis and MUST NOT be created by this agent.
 
+> **WARNING:** Node IDs MUST use the exact prefix formats shown above. Do NOT prefix IDs with the project name (e.g., `my-project:file:src/foo.ts` is WRONG). Do NOT use bare file paths without a type prefix (e.g., `src/foo.ts` is WRONG). Invalid IDs will be auto-corrected during assembly, which may cause unexpected edge rewiring.
+
 ## Output Format
 
 Produce a single, valid JSON block. Validate it mentally before writing -- malformed JSON breaks the entire pipeline.