diff --git a/apps/cli/src/commands/tree/export-graph.ts b/apps/cli/src/commands/tree/export-graph.ts
new file mode 100644
index 0000000..b0a884b
Binary files /dev/null and b/apps/cli/src/commands/tree/export-graph.ts differ
diff --git a/apps/cli/src/commands/tree/index.ts b/apps/cli/src/commands/tree/index.ts
index ee38fb0..057290e 100644
--- a/apps/cli/src/commands/tree/index.ts
+++ b/apps/cli/src/commands/tree/index.ts
@@ -4,6 +4,7 @@ import type { CommandModule, SubcommandModule } from "../types.js";
 import { registerCommandGroup, registerSubcommands } from "../groups.js";
 import { bindCommand } from "./bind.js";
 import { bootstrapCommand } from "./bootstrap.js";
+import { exportGraphCommand } from "./export-graph.js";
 import { generateCodeownersCommand } from "./generate-codeowners.js";
 import { inspectCommand } from "./inspect.js";
 import { injectContextCommand } from "./inject-context.js";
@@ -43,6 +44,7 @@ const treeSubcommands: SubcommandModule[] = [
   verifyCommand,
   upgradeCommand,
   publishCommand,
+  exportGraphCommand,
   generateCodeownersCommand,
   installClaudeCodeHookCommand,
   injectContextCommand,
diff --git a/apps/cli/tests/export-graph.test.ts b/apps/cli/tests/export-graph.test.ts
new file mode 100644
index 0000000..e1ef6a5
--- /dev/null
+++ b/apps/cli/tests/export-graph.test.ts
@@ -0,0 +1,201 @@
+import { mkdirSync, mkdtempSync, readFileSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+
+import { afterEach, describe, expect, it } from "vitest";
+
+import {
+  buildGraph,
+  extractSummary,
+  parseFrontmatter,
+  runExportGraph,
+} from "../src/commands/tree/export-graph.js";
+
+const tempDirs: string[] = [];
+
+function makeTempDir(prefix: string): string {
+  const dir = mkdtempSync(join(tmpdir(), prefix));
+  tempDirs.push(dir);
+  return dir;
+}
+
+function write(root: string, relPath: string, content: string): void {
+  const full = join(root, relPath);
+  mkdirSync(join(full, ".."), { recursive: true });
+  writeFileSync(full, content);
+}
+
+afterEach(() => {
+  while (tempDirs.length > 0) {
+    const dir = tempDirs.pop();
+    if (dir) {
+      rmSync(dir, { recursive: true, force: true });
+    }
+  }
+});
+
+describe("parseFrontmatter", () => {
+  it("parses inline-list owners and tags", () => {
+    const result = parseFrontmatter(
+      `---\ntitle: Alice\nowners: [alice, "bob"]\ntags: [pm, design]\n---\n\nbody\n`,
+    );
+
+    expect(result.title).toBe("Alice");
+    expect(result.owners).toEqual(["alice", "bob"]);
+    expect(result.tags).toEqual(["pm", "design"]);
+    expect(result.links).toEqual([]);
+  });
+
+  it("parses block-style lists", () => {
+    const result = parseFrontmatter(
+      `---\ntitle: Node\nowners:\n  - alice\n  - bob\nlinks:\n  - "domains/design"\n---\n`,
+    );
+
+    expect(result.owners).toEqual(["alice", "bob"]);
+    expect(result.links).toEqual(["domains/design"]);
+  });
+
+  it("returns empty defaults on missing frontmatter", () => {
+    const result = parseFrontmatter("just markdown, no frontmatter\n");
+    expect(result.title).toBeUndefined();
+    expect(result.owners).toEqual([]);
+    expect(result.tags).toEqual([]);
+    expect(result.links).toEqual([]);
+  });
+});
+
+describe("extractSummary", () => {
+  it("strips frontmatter and headings and collapses whitespace", () => {
+    const summary = extractSummary(
+      `---\ntitle: X\n---\n\n# Heading\n\nThis is the   body of  the doc.\n\nSecond paragraph.\n`,
+    );
+    expect(summary).toBe("This is the body of the doc. Second paragraph.");
+  });
+
+  it("truncates long summaries with an ellipsis", () => {
+    const body = "word ".repeat(200).trim();
+    const summary = extractSummary(body);
+    expect(summary.endsWith("…")).toBe(true);
+    expect(summary.length).toBeLessThanOrEqual(240);
+  });
+});
+
+describe("buildGraph", () => {
+  it("emits nodes for every markdown file with parent edges", () => {
+    const root = makeTempDir("export-graph-");
+    write(root, "NODE.md", "---\ntitle: Root\nowners: [serena]\n---\n\nroot body\n");
+    write(
+      root,
+      "members/serena.md",
+      "---\ntitle: Serena Tan\nowners: [serena]\ntags: [pm]\n---\n\nfounder bio\n",
+    );
+    write(root, "members/NODE.md", "---\ntitle: Members\nowners: [serena]\n---\n\n");
+    write(root, "domains/design/NODE.md", "---\ntitle: Design\nowners: [serena]\n---\n\n");
+
+    const graph = buildGraph(root, {
+      repo: "agent-team-foundation/demo-tree",
+      now: () => new Date("2026-05-12T22:45:00Z"),
+    });
+
+    expect(graph.version).toBe(1);
+    expect(graph.repo).toBe("agent-team-foundation/demo-tree");
+    expect(graph.generated_at).toBe("2026-05-12T22:45:00.000Z");
+
+    const ids = graph.nodes.map((node) => node.id).sort();
+    expect(ids).toEqual(["NODE", "domains/design/NODE", "members/NODE", "members/serena"]);
+
+    const serena = graph.nodes.find((node) => node.id === "members/serena");
+    expect(serena).toBeDefined();
+    expect(serena?.kind).toBe("member");
+    expect(serena?.owner).toBe("serena");
+    expect(serena?.tags).toEqual(["pm"]);
+    expect(serena?.size).toBeGreaterThan(0);
+
+    const parentEdges = graph.edges.filter((edge) => edge.kind === "parent");
+    const edgeKeys = parentEdges.map((edge) => `${edge.source}->${edge.target}`).sort();
+    expect(edgeKeys).toContain("members/NODE->members/serena");
+  });
+
+  it("emits link edges only when the target node exists", () => {
+    const root = makeTempDir("export-graph-");
+    write(root, "NODE.md", "---\ntitle: Root\nowners: [serena]\n---\n");
+    write(
+      root,
+      "members/serena.md",
+      `---\ntitle: Serena\nowners: [serena]\nlinks:\n  - domains/design\n  - domains/nonexistent\n---\n`,
+    );
+    write(root, "domains/design/NODE.md", "---\ntitle: Design\nowners: [serena]\n---\n");
+
+    const graph = buildGraph(root);
+    const linkEdges = graph.edges.filter((edge) => edge.kind === "link");
+
+    expect(linkEdges).toHaveLength(1);
+    expect(linkEdges[0]).toMatchObject({
+      source: "members/serena",
+      target: "domains/design/NODE",
+      kind: "link",
+    });
+  });
+
+  it("skips hidden directories and node_modules", () => {
+    const root = makeTempDir("export-graph-");
+    write(root, "NODE.md", "---\ntitle: Root\nowners: [serena]\n---\n");
+    write(root, ".hidden/secret.md", "---\ntitle: secret\n---\n");
+    write(root, "node_modules/pkg/README.md", "noise\n");
+    write(root, "domains/design/NODE.md", "---\ntitle: Design\nowners: [serena]\n---\n");
+
+    const graph = buildGraph(root);
+    const ids = graph.nodes.map((node) => node.id);
+
+    expect(ids).toContain("NODE");
+    expect(ids).toContain("domains/design/NODE");
+    expect(ids.some((id) => id.startsWith(".hidden"))).toBe(false);
+    expect(ids.some((id) => id.startsWith("node_modules"))).toBe(false);
+  });
+
+  it("classifies node kinds from top-level folder when frontmatter is silent", () => {
+    const root = makeTempDir("export-graph-");
+    write(root, "NODE.md", "---\ntitle: Root\nowners: [serena]\n---\n");
+    write(root, "members/alice.md", "---\ntitle: Alice\nowners: [alice]\n---\n");
+    write(root, "decisions/2026-04-pivot.md", "---\ntitle: Pivot\nowners: [serena]\n---\n");
+    write(root, "constraints/legal.md", "---\ntitle: Legal\nowners: [serena]\n---\n");
+    write(root, "domains/design/NODE.md", "---\ntitle: Design\nowners: [serena]\n---\n");
+    write(root, "freeform/notes.md", "---\ntitle: Notes\nowners: [serena]\n---\n");
+
+    const graph = buildGraph(root);
+    const kindById = Object.fromEntries(graph.nodes.map((node) => [node.id, node.kind]));
+
+    expect(kindById["members/alice"]).toBe("member");
+    expect(kindById["decisions/2026-04-pivot"]).toBe("decision");
+    expect(kindById["constraints/legal"]).toBe("constraint");
+    expect(kindById["domains/design/NODE"]).toBe("domain");
+    expect(kindById["freeform/notes"]).toBe("node");
+  });
+});
+
+describe("runExportGraph", () => {
+  it("writes the graph to disk when --out is given", () => {
+    const root = makeTempDir("export-graph-");
+    write(root, "NODE.md", "---\ntitle: Root\nowners: [serena]\n---\n");
+    write(root, "members/serena.md", "---\ntitle: Serena\nowners: [serena]\n---\n");
+
+    const outPath = join(root, "graph.json");
+    const result = runExportGraph({
+      cwd: root,
+      out: "graph.json",
+      repo: "demo/tree",
+      now: () => new Date("2026-05-12T22:45:00Z"),
+    });
+
+    expect(result.exitCode).toBe(0);
+    expect(result.outputPath).toBe(outPath);
+
+    const written = JSON.parse(readFileSync(outPath, "utf-8")) as {
+      repo: string;
+      nodes: unknown[];
+    };
+    expect(written.repo).toBe("demo/tree");
+    expect(Array.isArray(written.nodes)).toBe(true);
+    expect(written.nodes.length).toBeGreaterThan(0);
+  });
+});