diff --git a/Makefile b/Makefile
index 4615429..d99b209 100644
--- a/Makefile
+++ b/Makefile
@@ -6,7 +6,7 @@ LIBWS_LIB=$(LIBWS)lib/libmicrohttpd.a
 LIBSHA=./vendor/sha256/
 LIBSHA_SRC=$(LIBSHA)sha256.c
 
-LDFLAGS=-lm
+LDFLAGS=-lm -luuid
 INCL_FLAGS=-I$(LIBWS)include -I$(LIBSHA)
 
 main: src/main.c $(LIBSHA_SRC) output
diff --git a/src/main.c b/src/main.c
index 841c709..2fe7f9d 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,5 +1,6 @@
 #include <microhttpd.h>
 #include <sha256.h>
+#include <uuid/uuid.h>
 #include <dirent.h>
 #define NOH_IMPLEMENTATION
 #include "noh.h"
@@ -15,6 +16,40 @@ This will ignore any auth headers and always log in with username demo.
 
 Noh_Arena temp;
 
+typedef struct {
+    Noh_String path;
+    Noh_String id;
+} Id;
+
+typedef struct {
+    Id *elems;
+    size_t count;
+    size_t capacity;
+} Id_Store;
+
+Id_Store id_store = {0};
+
+static SV get_id(SV path) {
+    for (size_t i = 0; i < id_store.count; i++) {
+        if (noh_sv_eq(path, noh_sv_from_string(id_store.elems[i].path))) return noh_sv_from_string(id_store.elems[i].id);
+    }
+
+    uuid_t uuid;
+    uuid_generate(uuid);
+    char uuid_str[36];
+    uuid_unparse(uuid, uuid_str);
+
+    Noh_String new_id = {0};
+    noh_string_append_cstr(&new_id, "urn:uuid:");
+    noh_string_append_cstr(&new_id, uuid_str);
+
+    Noh_String stored_path = {0};
+    noh_string_append_sv(&stored_path, path);
+
+    noh_da_append(&id_store, ((Id){ .path = stored_path, .id = new_id }));
+    return noh_sv_from_string(new_id);
+}
+
 static enum MHD_Result send_response(struct MHD_Connection *connection, int status, SV message, bool xml) {
     struct MHD_Response *response = MHD_create_response_from_buffer(
         message.count, (void*)message.elems, MHD_RESPMEM_MUST_COPY);
@@ -111,7 +146,7 @@ static bool create_entry(struct dirent *dir_entry, const char *parent_path, Libr
 
     // Set entry data.
     result->is_dir = type == DT_DIR;
-    result->full_path = noh_sv_from_string(&full_path);
+    result->full_path = noh_sv_from_string(full_path);
     result->name = noh_sv_copy_cstr(&temp, dir_entry->d_name);
     set_modified_time(result);
 
@@ -130,7 +165,7 @@ static char *format_time(Library_Entry entry) {
 
 static void append_entry(Noh_String *response, SV url, Library_Entry entry) {
     noh_string_append_cstr(response, "<entry>");
-    noh_string_append_cstr(response, "<id>TODO</id>");
+    noh_string_append_cstr(response, noh_arena_sprintf(&temp, "<id>"Nsv_Fmt"</id>", Nsv_Arg(get_id(entry.full_path))));
     noh_string_append_cstr(response, noh_arena_sprintf(&temp, "<title>"Nsv_Fmt"</title>", entry.name));
     noh_string_append_cstr(response, noh_arena_sprintf(&temp, "<updated>%s</updated>", format_time(entry)));
     if (entry.is_dir) {
@@ -152,7 +187,7 @@ static Noh_String create_feed_response(Library_Entry self_path, SV url, Library_
     Noh_String response = {0};
 
     noh_string_append_cstr(&response, "<feed>");
-    noh_string_append_cstr(&response, "<id>TODO</id>");
+    noh_string_append_cstr(&response, noh_arena_sprintf(&temp, "<id>"Nsv_Fmt"</id>", Nsv_Arg(get_id(self_path.full_path))));
     noh_string_append_cstr(&response, noh_arena_sprintf(&temp, "<title>"Nsv_Fmt"</title>", self_path.name));
     noh_string_append_cstr(&response, noh_arena_sprintf(&temp, "<updated>%s</updated>", format_time(self_path)));
 
@@ -182,8 +217,8 @@ static enum MHD_Result handle_opds(struct MHD_Connection *connection, SV url, Se
 
     Library_Entry self_entry = {
         .is_dir = true,
-        .full_path = noh_sv_from_string(&fs_path),
-        .name = (url.count == 0) ? settings.library_name : path_to_name(noh_sv_from_string(&fs_path)),
+        .full_path = noh_sv_from_string(fs_path),
+        .name = (url.count == 0) ? settings.library_name : path_to_name(noh_sv_from_string(fs_path)),
         .modified_at = {0},
     };
     set_modified_time(&self_entry);
@@ -205,7 +240,7 @@ static enum MHD_Result handle_opds(struct MHD_Connection *connection, SV url, Se
 
         // Create and send response.
         Noh_String response = create_feed_response(self_entry, url, list);
-        bool result = send_response(connection, 200, noh_sv_from_string(&response), true);
+        bool result = send_response(connection, 200, noh_sv_from_string(response), true);
 
         // Cleanup.
         noh_da_free(&list);
diff --git a/src/noh.h b/src/noh.h
index f57a8ff..66aca74 100644
--- a/src/noh.h
+++ b/src/noh.h
@@ -404,7 +404,7 @@ inline void noh_sv_trim_space(Noh_String_View *sv);
 Noh_String_View noh_sv_from_cstr(const char *cstr);
 
 // Creates a string view from a string.
-Noh_String_View noh_sv_from_string(const Noh_String *string);
+Noh_String_View noh_sv_from_string(const Noh_String string);
 
 // Compares two string views.
 // Returns:
@@ -1009,10 +1009,10 @@ Noh_String_View noh_sv_from_cstr(const char *cstr) {
     return result;
 }
 
-Noh_String_View noh_sv_from_string(const Noh_String *string) {
+Noh_String_View noh_sv_from_string(const Noh_String string) {
     Noh_String_View result = {0};
-    result.elems = string->elems;
-    result.count = string->count;
+    result.elems = string.elems;
+    result.count = string.count;
     return result;
 }