diff --git a/lsm/Makefile b/lsm/Makefile
new file mode 100644
index 0000000..5352623
--- /dev/null
+++ b/lsm/Makefile
@@ -0,0 +1,95 @@
+# https://spin.atomicobject.com/2016/08/26/makefile-c-projects/ was a great
+# base for this Makefile
+
+-include config.mk
+
+LIB := $(BUILD_DIR)/$(LIB_FILENAME)
+
+SRCS != find '$(SRC_DIR)' -iname '*.c'
+SRCS_H != find $(INC_DIRS) -iname '*.h'
+SRCS_H_INTERNAL != find $(SRC_DIR) -iname '*.h'
+SRCS_TEST != find '$(TEST_DIR)' -iname '*.c'
+
+OBJS := $(SRCS:%=$(BUILD_DIR)/%.o)
+OBJS_TEST := $(SRCS_TEST:%=$(BUILD_DIR)/%.o)
+DEPS := $(SRCS:%=$(BUILD_DIR)/%.d) $(SRCS_TEST:%=$(BUILD_DIR)/%.d)
+
+BINS_TEST := $(OBJS_TEST:%.c.o=%)
+TARGETS_TEST := $(BINS_TEST:%=test-%)
+TARGETS_MEM_TEST := $(BINS_TEST:%=test-mem-%)
+
+_CFLAGS := $(addprefix -I,$(INC_DIRS)) $(CFLAGS) -Wall -Wextra
+
+.PHONY: all
+all: lib
+
+
+# =====COMPILATION=====
+# Utility used by the CI to lint
+.PHONY: objs
+objs: $(OBJS)
+
+.PHONY: lib
+lib: $(LIB)
+$(LIB): $(OBJS)
+	ar -rcs $@ $(OBJS)
+
+$(BUILD_DIR)/$(SRC_DIR)/%.c.o: $(SRC_DIR)/%.c
+	mkdir -p $(dir $@)
+	$(CC) -c $(_CFLAGS) $< -o $@
+
+
+# =====TESTING=====
+.PHONY: test
+test: $(TARGETS_TEST)
+
+.PHONY: test-mem
+test-mem: $(TARGETS_MEM_TEST)
+
+.PHONY: $(TARGETS_TEST)
+$(TARGETS_TEST): test-%: %
+	./$^
+
+.PHONY: $(TARGETS_MEM_TEST)
+$(TARGETS_MEM_TEST): test-mem-%: %
+	valgrind --tool=memcheck --error-exitcode=1 --track-origins=yes --leak-check=full ./$^
+
+.PHONY: build-test
+build-test: $(BINS_TEST)
+
+$(BINS_TEST): %: %.c.o $(LIB)
+	$(CC) \
+		$^ -o $@
+
+# Along with the include directory, each test includes $(TEST_DIR) (which
+# contains the acutest.h header file), and the src directory of the module it's
+# testing. This allows tests to access internal methods, which aren't publicly
+# exposed.
+$(BUILD_DIR)/$(TEST_DIR)/%.c.o: $(TEST_DIR)/%.c
+	mkdir -p $(dir $@)
+	$(CC) $(_CFLAGS) -I$(TEST_DIR) \
+		-I$(dir $(@:$(BUILD_DIR)/$(TEST_DIR)/%=$(SRC_DIR)/%)) \
+		-c $< -o $@
+
+# =====MAINTENANCE=====
+.PHONY: lint
+lint:
+	clang-format -n --Werror $(SRCS) $(SRCS_H) $(SRCS_H_INTERNAL)
+
+.PHONY: fmt
+fmt:
+	clang-format -i $(SRCS) $(SRCS_H) $(SRCS_H_INTERNAL)
+
+.PHONY: clean
+clean:
+	rm -rf $(BUILD_DIR)
+
+
+.PHONY: bear
+bear: clean
+	bear -- make
+	bear --append -- make build-test
+
+
+# Make make aware of the .d files
+-include $(DEPS)
diff --git a/lsm/config.mk b/lsm/config.mk
new file mode 100644
index 0000000..c453c6a
--- /dev/null
+++ b/lsm/config.mk
@@ -0,0 +1,13 @@
+LIB_FILENAME = liblsm.a
+
+BUILD_DIR = build
+SRC_DIR = src
+TEST_DIR = test
+INC_DIRS = include
+
+# -MMD: generate a .d file for every source file. This file can be imported by
+#  make and makes make aware that a header file has been changed, ensuring an
+#  object file is also recompiled if only a header is changed.
+# -MP: generate a dummy target for every header file (according to the  docs it
+#  prevents some errors when removing header files)
+CFLAGS = -MMD -MP -g
diff --git a/lsm/include/lsm.h b/lsm/include/lsm.h
new file mode 100644
index 0000000..6eb7fd0
--- /dev/null
+++ b/lsm/include/lsm.h
@@ -0,0 +1,67 @@
+#ifndef LSM
+#define LSM
+
+#include <stdint.h>
+
+#define LSM_MAX_SKIP_SIZE 8
+
+typedef enum lsm_error {
+   lsm_error_ok = 0,
+   lsm_error_failed_alloc = 1,
+   lsm_error_not_found = 2
+} lsm_error;
+
+/**
+ * Represents a string (or really any kind of data) with a known length. Data
+ * with length 8 or less is stored inside the pointer, and does not allocate
+ * additional memory.
+ */
+typedef struct lsm_string {
+  uint64_t len;
+  union {
+    void *ptr;
+    char val[8];
+  } str;
+} lsm_string;
+
+/**
+ * The type of an attribute. Each type is represented as a single bit of a
+ * 32-bit integer, so they can be easily combined into a bitmap.
+ */
+typedef enum lsm_attr_type {
+  lsm_attr_type_entry_type = 1 << 0
+} lsm_attr_type;
+
+/**
+ * A single attribute associated with an entry
+ */
+typedef struct lsm_attr {
+  lsm_attr_type type;
+  lsm_string str;
+} lsm_attr;
+
+/**
+ * Represents a collection of attributes for an entry. A collection can only
+ * contain one of each attribute.
+ */
+typedef struct lsm_attr_list {
+  uint64_t count;
+  lsm_attr *items;
+  uint32_t bitmap;
+} lsm_attr_list;
+
+/**
+ * An entry inside an LSM store
+ */
+typedef struct lsm_entry {
+  lsm_string key;
+  lsm_attr_list attrs;
+  lsm_string data;
+} lsm_entry;
+
+/**
+ * A store of entries, which manages its data both in-memory and on disk.
+ */
+typedef struct lsm_store lsm_store;
+
+#endif
diff --git a/lsm/src/lsm_store.c b/lsm/src/lsm_store.c
new file mode 100644
index 0000000..e167836
--- /dev/null
+++ b/lsm/src/lsm_store.c
@@ -0,0 +1,22 @@
+#include <stdlib.h>
+
+#include "lsm.h"
+#include "lsm_store.h"
+
+/**
+ * Initialize a new lsm_store struct.
+ *
+ * @param lsm_store pointer to where to store the newly allocated object's pointer
+ * @return success of the function
+ */
+lsm_error lsm_store_init(lsm_store **ptr) {
+  lsm_store *store = calloc(1, sizeof(lsm_store));
+
+  if (store == NULL) {
+    return lsm_error_failed_alloc;
+  }
+
+  *ptr = store;
+
+  return lsm_error_ok;
+}
diff --git a/lsm/src/lsm_store.h b/lsm/src/lsm_store.h
new file mode 100644
index 0000000..c73b2e9
--- /dev/null
+++ b/lsm/src/lsm_store.h
@@ -0,0 +1,12 @@
+#ifndef LSM_STORE_INTERNAL
+#define LSM_STORE_INTERNAL
+
+#include "lsm.h"
+#include "lsm_store_node.h"
+
+struct lsm_store {
+  lsm_store_node *root;
+  uint64_t size;
+};
+
+#endif
diff --git a/lsm/src/lsm_store_node.c b/lsm/src/lsm_store_node.c
new file mode 100644
index 0000000..63bc238
--- /dev/null
+++ b/lsm/src/lsm_store_node.c
@@ -0,0 +1,62 @@
+#include <stdlib.h>
+
+#include "lsm_store_node.h"
+#include "lsm.h"
+
+lsm_error lsm_store_inode_init(lsm_store_inode **ptr, const char c) {
+  lsm_store_inode *node = calloc(1, sizeof(lsm_store_inode));
+
+  if (node == NULL) {
+    return lsm_error_failed_alloc;
+  }
+
+  node->key = c;
+  *ptr = node;
+
+  return lsm_error_ok;
+}
+
+lsm_error lsm_store_node_init(lsm_store_node **ptr) {
+  lsm_store_node *node = calloc(1, sizeof(lsm_store_node));
+
+  if (node == NULL) {
+    return lsm_error_failed_alloc;
+  }
+
+  *ptr = node;
+
+  return lsm_error_ok;
+}
+
+lsm_error lsm_store_node_search(lsm_store_node **out_ptr, lsm_store_node *node, const char c) {
+  if (node->size == 0) {
+    return lsm_error_not_found;
+  }
+
+  lsm_store_inode *parent = node->root;
+  lsm_store_inode *child;
+  lsm_store_node *out = NULL;
+
+  while (1) {
+    if (parent->key == c) {
+      out = parent->next;
+      break;
+    }
+
+    child = (c < parent->key) ? parent->left : parent->right;
+
+    if (child == NULL) {
+      break;
+    }
+
+    parent = child;
+  };
+
+  if (out == NULL) {
+    return lsm_error_not_found;
+  }
+
+  *out_ptr = out;
+
+  return lsm_error_ok;
+}
diff --git a/lsm/src/lsm_store_node.h b/lsm/src/lsm_store_node.h
new file mode 100644
index 0000000..7fbcff3
--- /dev/null
+++ b/lsm/src/lsm_store_node.h
@@ -0,0 +1,42 @@
+#ifndef LSM_STORE_NODE_INTERNAL
+#define LSM_STORE_NODE_INTERNAL
+
+#include "lsm.h"
+
+/**
+ * A node inside a store node's internal binary tree.
+ */
+typedef struct lsm_store_inode {
+  struct lsm_store_inode *left;
+  struct lsm_store_inode *right;
+  struct lsm_store_node *next;
+  char key;
+} lsm_store_inode;
+
+/**
+ * Initialize a new lsm_store_inode.
+ */
+lsm_error lsm_store_inode_init(lsm_store_inode **ptr, const char c);
+
+/**
+ * A node inside the store's trie structure. Internally, each node manages a
+ * binary tree.
+ */
+typedef struct lsm_store_node {
+  lsm_entry *entry;
+  lsm_store_inode *root;
+  uint8_t size;
+  lsm_string skip;
+} lsm_store_node;
+
+/**
+ * Initialize a new lsm_store_node.
+ */
+lsm_error lsm_store_node_init(lsm_store_node **out);
+
+/**
+ * Search for the next node following the given character, if present.
+ */
+lsm_error lsm_store_node_search(lsm_store_node **out, lsm_store_node *node, const char c);
+
+#endif
diff --git a/src/main.c b/src/main.c
index fa9d95e..f32f83f 100644
--- a/src/main.c
+++ b/src/main.c
@@ -27,7 +27,7 @@ int main() {
 
   int port = atoi(port_str);
 
-  if (port <= 0 || port >= 2 << 16) {
+  if (port <= 0 || port >= 1 << 16) {
     critical(1, "Invalid TCP port %s", port_str);
   }