diff --git a/.changeset/quiet-states-rest.md b/.changeset/quiet-states-rest.md
new file mode 100644
index 000000000..5a04b4089
--- /dev/null
+++ b/.changeset/quiet-states-rest.md
@@ -0,0 +1,5 @@
+---
+"hunkdiff": patch
+---
+
+Store Hunk state and globally installed extensions under the XDG state directory.
diff --git a/src/core/run/paths.test.ts b/src/core/run/paths.test.ts
index 0c24bc347..7b1786530 100644
--- a/src/core/run/paths.test.ts
+++ b/src/core/run/paths.test.ts
@@ -9,6 +9,7 @@ import {
   resolveCanonicalPath,
   resolveGlobalConfigPath,
   resolveAppStatePath,
+  resolveGlobalExtensionsDir,
 } from "./paths";
 
 function createTempRoot(prefix: string) {
@@ -17,10 +18,25 @@ function createTempRoot(prefix: string) {
 
 describe("paths", () => {
   test("resolves XDG config and state paths", () => {
-    const env = { XDG_CONFIG_HOME: join("/tmp", "xdg-home") } as NodeJS.ProcessEnv;
+    const env = {
+      XDG_CONFIG_HOME: join("/tmp", "xdg-config"),
+      XDG_STATE_HOME: join("/tmp", "xdg-state"),
+    } as NodeJS.ProcessEnv;
+
+    expect(resolveGlobalConfigPath(env)).toBe(join("/tmp", "xdg-config", "hunk", "config.toml"));
+    expect(resolveAppStatePath(env)).toBe(join("/tmp", "xdg-state", "hunk", "state.json"));
+    expect(resolveGlobalExtensionsDir(env)).toBe(join("/tmp", "xdg-state", "hunk", "extensions"));
+  });
+
+  test("falls back to the platform-independent XDG state location", () => {
+    const env = { HOME: join("/tmp", "home") } as NodeJS.ProcessEnv;
 
-    expect(resolveGlobalConfigPath(env)).toBe(join("/tmp", "xdg-home", "hunk", "config.toml"));
-    expect(resolveAppStatePath(env)).toBe(join("/tmp", "xdg-home", "hunk", "state.json"));
+    expect(resolveAppStatePath(env)).toBe(
+      join("/tmp", "home", ".local", "state", "hunk", "state.json"),
+    );
+    expect(resolveGlobalExtensionsDir(env)).toBe(
+      join("/tmp", "home", ".local", "state", "hunk", "extensions"),
+    );
   });
 
   test("falls back to HOME for config and state paths", () => {
@@ -29,7 +45,9 @@ describe("paths", () => {
     expect(resolveGlobalConfigPath(env)).toBe(
       join("/tmp", "home", ".config", "hunk", "config.toml"),
     );
-    expect(resolveAppStatePath(env)).toBe(join("/tmp", "home", ".config", "hunk", "state.json"));
+    expect(resolveAppStatePath(env)).toBe(
+      join("/tmp", "home", ".local", "state", "hunk", "state.json"),
+    );
   });
 
   test("falls back to USERPROFILE when HOME is unavailable", () => {
@@ -39,7 +57,7 @@ describe("paths", () => {
       join("/tmp", "windows-profile", ".config", "hunk", "config.toml"),
     );
     expect(resolveAppStatePath(env)).toBe(
-      join("/tmp", "windows-profile", ".config", "hunk", "state.json"),
+      join("/tmp", "windows-profile", ".local", "state", "hunk", "state.json"),
     );
   });
 
diff --git a/src/core/run/paths.ts b/src/core/run/paths.ts
index 7ded9f11c..bb17347d1 100644
--- a/src/core/run/paths.ts
+++ b/src/core/run/paths.ts
@@ -86,6 +86,16 @@ export function resolveUserConfigDir(env: NodeJS.ProcessEnv = process.env) {
   return undefined;
 }
 
+/** Resolve the base state directory Hunk should use for user-scoped files. */
+export function resolveUserStateDir(env: NodeJS.ProcessEnv = process.env) {
+  if (env.XDG_STATE_HOME) {
+    return env.XDG_STATE_HOME;
+  }
+
+  const home = env.HOME || env.USERPROFILE;
+  return home ? join(home, ".local", "state") : undefined;
+}
+
 /** Resolve the global Hunk config file path from the current environment. */
 export function resolveGlobalConfigPath(env: NodeJS.ProcessEnv = process.env) {
   const configDir = resolveUserConfigDir(env);
@@ -94,14 +104,14 @@ export function resolveGlobalConfigPath(env: NodeJS.ProcessEnv = process.env) {
 
 /** Resolve the persisted Hunk state file path from the current environment. */
 export function resolveAppStatePath(env: NodeJS.ProcessEnv = process.env) {
-  const configDir = resolveUserConfigDir(env);
-  return configDir ? join(configDir, "hunk", "state.json") : undefined;
+  const stateDir = resolveUserStateDir(env);
+  return stateDir ? join(stateDir, "hunk", "state.json") : undefined;
 }
 
 /** Resolve the user-scoped directory Hunk scans for globally installed extensions. */
 export function resolveGlobalExtensionsDir(env: NodeJS.ProcessEnv = process.env) {
-  const configDir = resolveUserConfigDir(env);
-  return configDir ? join(configDir, "hunk", "extensions") : undefined;
+  const stateDir = resolveUserStateDir(env);
+  return stateDir ? join(stateDir, "hunk", "extensions") : undefined;
 }
 
 /**
diff --git a/src/extensions/discovery.test.ts b/src/extensions/discovery.test.ts
index 479ef52c8..429fd7420 100644
--- a/src/extensions/discovery.test.ts
+++ b/src/extensions/discovery.test.ts
@@ -264,7 +264,7 @@ describe("extension discovery", () => {
     const candidates = discoverExtensions({
       cwd: home,
       repoRoot: undefined,
-      env: { XDG_CONFIG_HOME: home } as NodeJS.ProcessEnv,
+      env: { XDG_STATE_HOME: home } as NodeJS.ProcessEnv,
     });
 
     expect(candidates).toEqual([{ id: "themed", path: globalPath, origin: "global" }]);
diff --git a/src/extensions/manage/install.test.ts b/src/extensions/manage/install.test.ts
index e5135ec64..823fa5c2e 100644
--- a/src/extensions/manage/install.test.ts
+++ b/src/extensions/manage/install.test.ts
@@ -229,7 +229,7 @@ describe("hunk extension command runner", () => {
         stdout: (text: string) => out.push(text),
         stderr: (text: string) => err.push(text),
         ...(confirmAnswer !== undefined ? { confirm: async () => confirmAnswer } : {}),
-        env: { XDG_CONFIG_HOME: configDir } as NodeJS.ProcessEnv,
+        env: { XDG_STATE_HOME: configDir } as NodeJS.ProcessEnv,
       },
     };
   }
diff --git a/src/extensions/startup.test.ts b/src/extensions/startup.test.ts
index 1e12af04c..9d0d74ea3 100644
--- a/src/extensions/startup.test.ts
+++ b/src/extensions/startup.test.ts
@@ -44,7 +44,7 @@ describe("extension startup", () => {
     const result = await loadStartupExtensions({
       extensions: createExtensionsConfig({ enabled: false }),
       cwd: home,
-      env: { XDG_CONFIG_HOME: home } as NodeJS.ProcessEnv,
+      env: { XDG_STATE_HOME: home } as NodeJS.ProcessEnv,
     });
 
     const empty = createEmptyExtensionLoadResult(home);
@@ -71,7 +71,7 @@ describe("extension startup", () => {
         extensionConfigs: { themed: { themeId: "midnight" } },
       }),
       cwd: home,
-      env: { XDG_CONFIG_HOME: home } as NodeJS.ProcessEnv,
+      env: { XDG_STATE_HOME: home } as NodeJS.ProcessEnv,
       hostOverrides: { repoRoot: undefined },
     });
 
@@ -100,7 +100,7 @@ export default function (hunk) {
     const provisional = await loadStartupExtensions({
       extensions: createExtensionsConfig(),
       cwd: repo,
-      env: { XDG_CONFIG_HOME: configHome } as NodeJS.ProcessEnv,
+      env: { XDG_STATE_HOME: configHome } as NodeJS.ProcessEnv,
       deferEventBusBinding: true,
     });
     const repoExtensions = join(repo, ".hunk", "extensions");
@@ -118,7 +118,7 @@ export default function (hunk) {
     const final = await loadStartupExtensions({
       extensions: createExtensionsConfig(),
       cwd: repo,
-      env: { XDG_CONFIG_HOME: configHome } as NodeJS.ProcessEnv,
+      env: { XDG_STATE_HOME: configHome } as NodeJS.ProcessEnv,
       projectRoot: repo,
       previousLoad: provisional,
       hostOverrides: { resolveRepoTrustImpl: () => "trusted" },
@@ -145,12 +145,12 @@ export default function (hunk) {
     const provisional = await loadStartupExtensions({
       extensions: createExtensionsConfig({ extensionConfigs: { configured: { value: 1 } } }),
       cwd: home,
-      env: { XDG_CONFIG_HOME: home } as NodeJS.ProcessEnv,
+      env: { XDG_STATE_HOME: home } as NodeJS.ProcessEnv,
     });
     await loadStartupExtensions({
       extensions: createExtensionsConfig({ extensionConfigs: { configured: { value: 2 } } }),
       cwd: home,
-      env: { XDG_CONFIG_HOME: home } as NodeJS.ProcessEnv,
+      env: { XDG_STATE_HOME: home } as NodeJS.ProcessEnv,
       previousLoad: provisional,
     });