diff --git a/lsm/include/lsm/store.h b/lsm/include/lsm/store.h
index d0fab21..e542f9d 100644
--- a/lsm/include/lsm/store.h
+++ b/lsm/include/lsm/store.h
@@ -59,6 +59,27 @@ bool lsm_entry_attr_present(lsm_entry *entry, lsm_attr_type type);
 lsm_error lsm_entry_attr_get(lsm_str **out, lsm_entry *entry,
                              lsm_attr_type type);
 
+/**
+ * Add a new attribute to the entry.
+ *
+ * @param entry entry to modify
+ * @param type type of attribute to add
+ * @param data data of attribute; ownership of pointer is taken over
+ */
+lsm_error lsm_entry_attr_insert(lsm_entry *entry, lsm_attr_type type,
+                                lsm_str *data);
+
+/**
+ * Remove an atribute from the given entry, if present.
+ *
+ * @param out pointer to store removed data pointer in. If NULL, data pointer
+ * can get leaked.
+ * @param entry entry to remove attribute from
+ * @param type type of attribute to remove
+ */
+lsm_error lsm_entry_attr_remove(lsm_str **out, lsm_entry *entry,
+                                lsm_attr_type type);
+
 /**
  * A store consisting of LSM entries.
  *
diff --git a/lsm/src/_include/lsm/store_internal.h b/lsm/src/_include/lsm/store_internal.h
index d0aaed0..b4a833c 100644
--- a/lsm/src/_include/lsm/store_internal.h
+++ b/lsm/src/_include/lsm/store_internal.h
@@ -3,10 +3,11 @@
 
 #include "lsm/store.h"
 #include "lsm/str_internal.h"
+#include "lsm/trie.h"
 
 typedef struct lsm_attr {
   lsm_attr_type type;
-  lsm_str str;
+  lsm_str *str;
 } lsm_attr;
 
 struct lsm_entry {
@@ -19,4 +20,8 @@ struct lsm_entry {
   lsm_str data;
 };
 
+struct lsm_store {
+  lsm_trie *trie;
+};
+
 #endif
diff --git a/lsm/src/store/lsm_store.c b/lsm/src/store/lsm_store.c
new file mode 100644
index 0000000..8ba5740
--- /dev/null
+++ b/lsm/src/store/lsm_store.c
@@ -0,0 +1,6 @@
+#include "lsm/store.h"
+#include "lsm/store_internal.h"
+
+/* lsm_error lsm_store_init(lsm_store **ptr) { */
+/*   lsm_store *store = */
+/* } */
diff --git a/lsm/src/store/lsm_store_entry.c b/lsm/src/store/lsm_store_entry.c
index 99a2b30..aa1c7fc 100644
--- a/lsm/src/store/lsm_store_entry.c
+++ b/lsm/src/store/lsm_store_entry.c
@@ -1,4 +1,6 @@
+#include <fcntl.h>
 #include <stdlib.h>
+#include <string.h>
 
 #include "lsm.h"
 #include "lsm/store_internal.h"
@@ -27,7 +29,7 @@ lsm_error lsm_entry_attr_get(lsm_str **out, lsm_entry *entry,
 
   for (uint64_t i = 0; i < entry->attrs.count; i++) {
     if (entry->attrs.items[i].type == type) {
-      *out = &entry->attrs.items[i].str;
+      *out = entry->attrs.items[i].str;
 
       return lsm_error_ok;
     }
@@ -35,3 +37,72 @@ lsm_error lsm_entry_attr_get(lsm_str **out, lsm_entry *entry,
 
   return lsm_error_not_found;
 }
+
+lsm_error lsm_entry_attr_remove(lsm_str **out, lsm_entry *entry,
+                                lsm_attr_type type) {
+  if (!lsm_entry_attr_present(entry, type)) {
+    return lsm_error_not_found;
+  }
+
+  if (entry->attrs.count == 1) {
+    *out = entry->attrs.items[0].str;
+
+    free(entry->attrs.items);
+    entry->attrs.items = NULL;
+    entry->attrs.count = 0;
+    entry->attrs.bitmap = 0;
+
+    return lsm_error_ok;
+  }
+
+  uint64_t i = 0;
+
+  while (entry->attrs.items[i].type != type) {
+    i++;
+  }
+
+  lsm_attr *new_attrs = malloc((entry->attrs.count - 1) * sizeof(lsm_attr));
+
+  if (new_attrs == NULL) {
+    return lsm_error_failed_alloc;
+  }
+
+  if (out != NULL) {
+    *out = entry->attrs.items[i].str;
+  }
+
+  memcpy(new_attrs, entry->attrs.items, i * sizeof(lsm_attr));
+  memcpy(&new_attrs[i], &entry->attrs.items[i + 1],
+         (entry->attrs.count - i - 1) * sizeof(lsm_attr));
+
+  free(entry->attrs.items);
+
+  entry->attrs.items = new_attrs;
+  entry->attrs.count--;
+  entry->attrs.bitmap &= ~type;
+
+  return lsm_error_ok;
+}
+
+lsm_error lsm_entry_attr_insert(lsm_entry *entry, lsm_attr_type type,
+                                lsm_str *data) {
+  if (lsm_entry_attr_present(entry, type)) {
+    return lsm_error_already_present;
+  }
+
+  lsm_attr *new_attrs =
+      realloc(entry->attrs.items, (entry->attrs.count + 1) * sizeof(lsm_attr));
+
+  if (new_attrs == NULL) {
+    return lsm_error_failed_alloc;
+  }
+
+  new_attrs[entry->attrs.count].type = type;
+  new_attrs[entry->attrs.count].str = data;
+
+  entry->attrs.items = new_attrs;
+  entry->attrs.count++;
+  entry->attrs.bitmap |= type;
+
+  return lsm_error_ok;
+}