diff --git a/.changeset/replace-fast-glob-with-tinyglobby.md b/.changeset/replace-fast-glob-with-tinyglobby.md
new file mode 100644
index 0000000..9783b07
--- /dev/null
+++ b/.changeset/replace-fast-glob-with-tinyglobby.md
@@ -0,0 +1,5 @@
+---
+"leadtype": patch
+---
+
+Replace `fast-glob` with `tinyglobby` to shrink the dependency tree (16 transitive deps → 3) and reduce install footprint (~1.2 MB → ~240 KB). Globbing behavior and call-site options are unchanged.
diff --git a/bun.lock b/bun.lock
index ef633ae..7a03cd5 100644
--- a/bun.lock
+++ b/bun.lock
@@ -73,19 +73,18 @@
       "version": "0.0.0",
       "devDependencies": {
         "ai": "^6.0.168",
-        "fast-glob": "3.3.3",
+        "tinyglobby": "0.2.16",
         "vitest": "^2.1.8",
         "zod": "^3.23.8",
       },
     },
     "packages/leadtype": {
       "name": "leadtype",
-      "version": "0.0.0",
+      "version": "0.1.0",
       "bin": "./dist/cli.js",
       "dependencies": {
         "@types/mdast": "4.0.4",
         "decode-named-character-reference": "1.3.0",
-        "fast-glob": "3.3.3",
         "gray-matter": "4.0.3",
         "jiti": "^2.7.0",
         "json5": "2.2.3",
@@ -95,6 +94,7 @@
         "remark": "15.0.1",
         "remark-gfm": "4.0.1",
         "remark-mdx": "3.1.1",
+        "tinyglobby": "0.2.16",
         "unified": "11.0.5",
         "unist-builder": "4.0.0",
         "unist-util-is": "6.0.1",
diff --git a/evals/lib/tools.ts b/evals/lib/tools.ts
index 5f1917c..445107d 100644
--- a/evals/lib/tools.ts
+++ b/evals/lib/tools.ts
@@ -2,7 +2,7 @@ import { spawn } from "node:child_process";
 import { mkdir, readdir, readFile, writeFile } from "node:fs/promises";
 import path from "node:path";
 import { tool } from "ai";
-import fg from "fast-glob";
+import { glob as fg } from "tinyglobby";
 import { z } from "zod";
 import type { ToolCall } from "./transcript";
 
@@ -235,6 +235,9 @@ export function scopedTools(ctx: ToolCtx) {
               absolute: false,
               dot: false,
               followSymbolicLinks: false,
+              // Agent supplies the pattern; keep fast-glob semantics so a
+              // bare directory name doesn't silently expand to `dir/**`.
+              expandDirectories: false,
             });
             return matches.join("\n");
           },
diff --git a/evals/package.json b/evals/package.json
index 2b10dcd..e7413a4 100644
--- a/evals/package.json
+++ b/evals/package.json
@@ -12,7 +12,7 @@
   },
   "devDependencies": {
     "ai": "^6.0.168",
-    "fast-glob": "3.3.3",
+    "tinyglobby": "0.2.16",
     "vitest": "^2.1.8",
     "zod": "^3.23.8"
   }
diff --git a/packages/leadtype/package.json b/packages/leadtype/package.json
index 55a53cf..9351256 100644
--- a/packages/leadtype/package.json
+++ b/packages/leadtype/package.json
@@ -92,7 +92,6 @@
   "dependencies": {
     "@types/mdast": "4.0.4",
     "decode-named-character-reference": "1.3.0",
-    "fast-glob": "3.3.3",
     "gray-matter": "4.0.3",
     "jiti": "^2.7.0",
     "json5": "2.2.3",
@@ -102,6 +101,7 @@
     "remark": "15.0.1",
     "remark-gfm": "4.0.1",
     "remark-mdx": "3.1.1",
+    "tinyglobby": "0.2.16",
     "unified": "11.0.5",
     "unist-builder": "4.0.0",
     "unist-util-is": "6.0.1",
diff --git a/packages/leadtype/src/cli.test.ts b/packages/leadtype/src/cli.test.ts
index da6b774..4774b1a 100644
--- a/packages/leadtype/src/cli.test.ts
+++ b/packages/leadtype/src/cli.test.ts
@@ -3,7 +3,7 @@ import { mkdir, mkdtemp, readFile, rm, writeFile } from "node:fs/promises";
 import { tmpdir } from "node:os";
 import path from "node:path";
 import { fileURLToPath } from "node:url";
-import fg from "fast-glob";
+import { glob as fg } from "tinyglobby";
 import { afterEach, describe, expect, it } from "vitest";
 import { runCli } from "./cli";
 
@@ -524,6 +524,38 @@ describe("leadtype CLI", () => {
     expect(error.filters.include).toEqual(["nope/**"]);
   });
 
+  it("treats a bare directory in --include as matching no MDX files", async () => {
+    // tinyglobby expands bare directory names to `dir/**` by default; fast-glob
+    // didn't. With expandDirectories disabled at the call site, `--include build`
+    // should fail the same way `--include nope` does — not silently include
+    // every file under `docs/build/`.
+    const outDir = await createTempDir();
+    const capture = createCapture();
+
+    const code = await runCli(
+      [
+        "generate",
+        "--src",
+        repoRoot,
+        "--out",
+        outDir,
+        "--include",
+        "build",
+        "--format",
+        "json",
+      ],
+      capture.io
+    );
+
+    expect(code).toBe(1);
+    const error = JSON.parse(capture.stderr) as {
+      error: string;
+      filters: { include: string[] };
+    };
+    expect(error.error).toContain("No MDX files matched");
+    expect(error.filters.include).toEqual(["build"]);
+  });
+
   it("rejects invalid generate formats as usage errors", async () => {
     const capture = createCapture();
 
diff --git a/packages/leadtype/src/cli/generate.ts b/packages/leadtype/src/cli/generate.ts
index f421414..16372b2 100644
--- a/packages/leadtype/src/cli/generate.ts
+++ b/packages/leadtype/src/cli/generate.ts
@@ -2,9 +2,9 @@ import { existsSync } from "node:fs";
 import { cp, mkdir, mkdtemp, readFile, rm } from "node:fs/promises";
 import { tmpdir } from "node:os";
 import path from "node:path";
-import fg from "fast-glob";
 import matter from "gray-matter";
 import { createJiti } from "jiti";
+import { glob as fg } from "tinyglobby";
 import { convertAllMdx } from "../convert";
 import {
   logger,
@@ -436,6 +436,11 @@ async function createSourceMirror(
     const files = await fg(patterns, {
       absolute: false,
       cwd: docsDir,
+      // tinyglobby expands bare directory names (`build` → `build/**`) by
+      // default; fast-glob did not. Disable it so `--include build` still
+      // reports "No MDX files matched" instead of silently slurping everything
+      // under `build/`.
+      expandDirectories: false,
       ignore: filters.exclude,
       onlyFiles: true,
     });
diff --git a/packages/leadtype/src/convert/convert.ts b/packages/leadtype/src/convert/convert.ts
index 5767013..9d5e28d 100644
--- a/packages/leadtype/src/convert/convert.ts
+++ b/packages/leadtype/src/convert/convert.ts
@@ -4,11 +4,11 @@ import { mkdir, readFile, writeFile } from "node:fs/promises";
 import { cpus } from "node:os";
 import { basename, dirname, join, relative, resolve, sep } from "node:path";
 import { promisify } from "node:util";
-import fg from "fast-glob";
 import matter from "gray-matter";
 import { remark } from "remark";
 import remarkGfm from "remark-gfm";
 import remarkMdx from "remark-mdx";
+import { glob as fg } from "tinyglobby";
 import type { Pluggable, PluggableList } from "unified";
 import {
   deriveDocContext,
diff --git a/packages/leadtype/src/lint/runner.ts b/packages/leadtype/src/lint/runner.ts
index 8b14f17..84fc211 100644
--- a/packages/leadtype/src/lint/runner.ts
+++ b/packages/leadtype/src/lint/runner.ts
@@ -1,10 +1,10 @@
 import { existsSync } from "node:fs";
 import { readFile } from "node:fs/promises";
 import { relative, resolve, sep } from "node:path";
-import fg from "fast-glob";
 import matter from "gray-matter";
 import { remark } from "remark";
 import remarkGfm from "remark-gfm";
+import { glob as fg } from "tinyglobby";
 import { visit } from "unist-util-visit";
 import * as v from "valibot";
 import { convertMdxToMarkdown } from "../convert";
@@ -97,6 +97,9 @@ async function glob(
     onlyFiles: true,
     ignore,
     dot: false,
+    // Preserve fast-glob semantics: callers can pass user-supplied ignores,
+    // and bare directory entries should not auto-expand to `dir/**`.
+    expandDirectories: false,
   });
 }