diff --git a/apps/hook/server/index.ts b/apps/hook/server/index.ts
index 9a4bc628..0f2e6c9a 100644
--- a/apps/hook/server/index.ts
+++ b/apps/hook/server/index.ts
@@ -13,6 +13,7 @@
 import { $ } from "bun";
 import { join } from "path";
 import { mkdirSync, existsSync, statSync } from "fs";
+import { detectProjectName } from "./project";
 
 // --- Obsidian Integration ---
 
@@ -30,10 +31,17 @@ interface BearConfig {
 
 /**
  * Extract tags from markdown content using simple heuristics
+ * Includes project name detection (git repo or directory name)
  */
-function extractTags(markdown: string): string[] {
+async function extractTags(markdown: string): Promise<string[]> {
   const tags = new Set<string>(["plannotator"]);
 
+  // Add project name tag (git repo name or directory fallback)
+  const projectName = await detectProjectName();
+  if (projectName) {
+    tags.add(projectName);
+  }
+
   const stopWords = new Set([
     "the", "and", "for", "with", "this", "that", "from", "into",
     "plan", "implementation", "overview", "phase", "step", "steps",
@@ -64,7 +72,7 @@ function extractTags(markdown: string): string[] {
     }
   }
 
-  return Array.from(tags).slice(0, 6);
+  return Array.from(tags).slice(0, 7);
 }
 
 /**
@@ -205,7 +213,7 @@ async function saveToObsidian(
     const filePath = join(targetFolder, filename);
 
     // Generate content with frontmatter and backlink
-    const tags = extractTags(plan);
+    const tags = await extractTags(plan);
     const frontmatter = generateFrontmatter(tags);
     const content = `${frontmatter}\n\n[[Plannotator Plans]]\n\n${plan}`;
 
@@ -231,7 +239,7 @@ async function saveToBear(
 
     // Extract title and tags
     const title = extractTitle(plan);
-    const tags = extractTags(plan);
+    const tags = await extractTags(plan);
     const hashtags = tags.map(t => `#${t}`).join(' ');
 
     // Append hashtags to content
diff --git a/apps/hook/server/project.test.ts b/apps/hook/server/project.test.ts
new file mode 100644
index 00000000..78e9d4d9
--- /dev/null
+++ b/apps/hook/server/project.test.ts
@@ -0,0 +1,114 @@
+/**
+ * Project Detection Tests
+ *
+ * Run: bun test apps/hook/server/project.test.ts
+ */
+
+import { describe, expect, test } from "bun:test";
+import { sanitizeTag, extractRepoName, extractDirName, detectProjectName } from "./project";
+
+describe("sanitizeTag", () => {
+  test("lowercases input", () => {
+    expect(sanitizeTag("MyProject")).toBe("myproject");
+  });
+
+  test("replaces spaces with hyphens", () => {
+    expect(sanitizeTag("my project")).toBe("my-project");
+  });
+
+  test("replaces underscores with hyphens", () => {
+    expect(sanitizeTag("my_project")).toBe("my-project");
+  });
+
+  test("removes special characters", () => {
+    expect(sanitizeTag("my@project!name")).toBe("myprojectname");
+  });
+
+  test("collapses multiple hyphens", () => {
+    expect(sanitizeTag("my--project")).toBe("my-project");
+  });
+
+  test("trims to 30 chars", () => {
+    const long = "a".repeat(50);
+    expect(sanitizeTag(long)?.length).toBe(30);
+  });
+
+  test("returns null for empty string", () => {
+    expect(sanitizeTag("")).toBeNull();
+  });
+
+  test("returns null for single char", () => {
+    expect(sanitizeTag("a")).toBeNull();
+  });
+
+  test("returns null for null/undefined", () => {
+    expect(sanitizeTag(null as any)).toBeNull();
+    expect(sanitizeTag(undefined as any)).toBeNull();
+  });
+});
+
+describe("extractRepoName", () => {
+  test("extracts name from full path", () => {
+    expect(extractRepoName("/Users/dev/projects/my-app")).toBe("my-app");
+  });
+
+  test("handles trailing slash", () => {
+    expect(extractRepoName("/Users/dev/my-app/")).toBe("my-app");
+  });
+
+  test("handles multiple trailing slashes", () => {
+    expect(extractRepoName("/home/user/repo///")).toBe("repo");
+  });
+
+  test("returns null for empty string", () => {
+    expect(extractRepoName("")).toBeNull();
+  });
+
+  test("returns null for just slash", () => {
+    expect(extractRepoName("/")).toBeNull();
+  });
+});
+
+describe("extractDirName", () => {
+  test("extracts directory name", () => {
+    expect(extractDirName("/home/user/workspace")).toBe("workspace");
+  });
+
+  test("skips generic names", () => {
+    expect(extractDirName("/home")).toBeNull();
+    expect(extractDirName("/Users")).toBeNull();
+    expect(extractDirName("/root")).toBeNull();
+    expect(extractDirName("/tmp")).toBeNull();
+  });
+
+  test("returns null for root path", () => {
+    expect(extractDirName("/")).toBeNull();
+  });
+
+  test("sanitizes the result", () => {
+    expect(extractDirName("/home/user/My Project")).toBe("my-project");
+  });
+});
+
+describe("detectProjectName", () => {
+  test("returns a string or null", async () => {
+    const result = await detectProjectName();
+    expect(result === null || typeof result === "string").toBe(true);
+  });
+
+  test("result is sanitized if not null", async () => {
+    const result = await detectProjectName();
+    if (result) {
+      expect(result).toMatch(/^[a-z0-9-]+$/);
+      expect(result.length).toBeGreaterThanOrEqual(2);
+      expect(result.length).toBeLessThanOrEqual(30);
+    }
+  });
+
+  // This test verifies we get "planning-hook" when run from this repo
+  test("detects current repo name", async () => {
+    const result = await detectProjectName();
+    // We're in the planning-hook repo, so should get that name
+    expect(result).toBe("planning-hook");
+  });
+});
diff --git a/apps/hook/server/project.ts b/apps/hook/server/project.ts
new file mode 100644
index 00000000..53ed58a1
--- /dev/null
+++ b/apps/hook/server/project.ts
@@ -0,0 +1,94 @@
+/**
+ * Project Detection Utility
+ *
+ * Detects the current project name for tagging plans.
+ * Priority: git repo name > directory name > null
+ */
+
+import { $ } from "bun";
+
+/**
+ * Sanitize a string for use as a tag
+ * - lowercase
+ * - replace spaces/underscores with hyphens
+ * - remove special characters
+ * - trim to reasonable length
+ */
+export function sanitizeTag(name: string): string | null {
+  if (!name || typeof name !== "string") return null;
+
+  const sanitized = name
+    .toLowerCase()
+    .trim()
+    .replace(/[\s_]+/g, "-")      // spaces/underscores -> hyphens
+    .replace(/[^a-z0-9-]/g, "")   // remove special chars
+    .replace(/-+/g, "-")          // collapse multiple hyphens
+    .replace(/^-|-$/g, "")        // trim leading/trailing hyphens
+    .slice(0, 30);                // max 30 chars
+
+  return sanitized.length >= 2 ? sanitized : null;
+}
+
+/**
+ * Extract repo name from a git root path
+ */
+export function extractRepoName(gitRootPath: string): string | null {
+  if (!gitRootPath || typeof gitRootPath !== "string") return null;
+
+  const trimmed = gitRootPath.trim().replace(/\/+$/, ""); // remove trailing slashes
+  const parts = trimmed.split("/");
+  const name = parts[parts.length - 1];
+
+  return sanitizeTag(name);
+}
+
+/**
+ * Extract directory name from a path
+ */
+export function extractDirName(path: string): string | null {
+  if (!path || typeof path !== "string") return null;
+
+  const trimmed = path.trim().replace(/\/+$/, "");
+  if (trimmed === "" || trimmed === "/") return null;
+
+  const parts = trimmed.split("/");
+  const name = parts[parts.length - 1];
+
+  // Skip generic names
+  const skipNames = new Set(["home", "users", "user", "root", "tmp", "var"]);
+  if (skipNames.has(name.toLowerCase())) return null;
+
+  return sanitizeTag(name);
+}
+
+/**
+ * Detect project name from current context
+ *
+ * Priority:
+ * 1. Git repository name (most reliable)
+ * 2. Current directory name (fallback)
+ * 3. null (if nothing useful found)
+ */
+export async function detectProjectName(): Promise<string | null> {
+  // Try git repo name first
+  try {
+    const result = await $`git rev-parse --show-toplevel`.quiet().nothrow();
+    if (result.exitCode === 0) {
+      const repoName = extractRepoName(result.stdout.toString());
+      if (repoName) return repoName;
+    }
+  } catch {
+    // Git not available or not in a repo - continue to fallback
+  }
+
+  // Fallback to current directory name
+  try {
+    const cwd = process.cwd();
+    const dirName = extractDirName(cwd);
+    if (dirName) return dirName;
+  } catch {
+    // process.cwd() failed (rare)
+  }
+
+  return null;
+}
diff --git a/package.json b/package.json
index 4640a81a..8070fcbb 100644
--- a/package.json
+++ b/package.json
@@ -22,6 +22,7 @@
     "build:portal": "bun run --cwd apps/portal build",
     "build:marketing": "bun run --cwd apps/marketing build",
     "build:opencode": "bun run --cwd apps/opencode-plugin build",
-    "build": "bun run build:hook && bun run build:opencode"
+    "build": "bun run build:hook && bun run build:opencode",
+    "test": "bun test"
   }
 }