diff --git a/src/numex.h b/src/numex.h
new file mode 100644
index 00000000..a2640845
--- /dev/null
+++ b/src/numex.h
@@ -0,0 +1,107 @@
+#ifndef NUMEX_H
+#define NUMEX_H
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+
+#include "string_utils.h"
+#include "tokens.h"
+#include "collections.h"
+
+#define DEFAULT_NUMEX_PATH LIBPOSTAL_DATA_DIR "/numex/numex.dat"
+
+typedef enum {
+    GENDER_MASCULINE,
+    GENDER_FEMININE,
+    GENDER_NEUTER,
+    GENDER_NONE
+} gender_t;
+
+typedef enum {
+    NUMEX_LEFT_CONTEXT_NONE,
+    NUMEX_LEFT_CONTEXT_ADD,
+    NUMEX_LEFT_CONTEXT_MULTIPLY
+} numex_left_context;
+
+typedef enum {
+    NUMEX_RIGHT_CONTEXT_NONE,
+    NUMEX_RIGHT_CONTEXT_ADD
+} numex_right_context;
+
+typedef enum {
+    NUMEX_CARDINAL_RULE,
+    NUMEX_ORDINAL_RULE,
+    NUMEX_DECIMAL_RULE,
+    NUMEX_NEGATION_RULE,
+    NUMEX_STOPWORD
+} numex_rule_type;
+
+typedef struct numex_rule {
+    numex_left_context_type left_context_type;
+    numex_right_context_type right_context_type;
+    numex_rule_type rule_type;
+    gender_t gender;
+    uint32_t radix;
+    int64_t value;
+} numex_rule_t;
+
+#define NUMEX_STOPWORD_RULE (numex_rule_t) {NUMEX_LEFT_CONTEXT_NONE, NUMEX_RIGHT_CONTEXT_NONE, NUMEX_STOPWORD, GENDER_NONE, 0, 0};
+
+VECTOR_INIT(numex_rule_array, numex_rule_t)
+
+typedef struct ordinal_indicator {
+    uint8_t number;
+    gender_t gender;
+    char *indicator;
+} ordinal_indicator_t;
+
+void ordinal_indicator_destroy(ordinal_indicator_t *self);
+
+VECTOR_INIT_FREE_DATA(ordinal_indicator_array, ordinal_indicator_t *, ordinal_indicator_destroy)
+
+typedef struct numex_language {
+    char *name;
+    bool concatenated;
+    size_t rules_index;
+    size_t num_rules;
+    size_t ordinals_index;
+    size_t num_ordinals;
+} numex_language_t;
+
+KHASH_MAP_INIT_STR(str_numex_language, numex_language_t *)
+
+typedef struct {
+    khash_t(str_numex_language) *languages;
+    trie_t *trie;
+    numex_rule_array *rules;
+    ordinal_indicator_array *ordinal_indicators;
+} numex_table_t;
+
+numex_table_t *get_numex_table(void);
+
+numex_language_t *numex_language_new(char *name, bool concatenated, size_t rules_index, size_t num_rules, size_t ordinals_index, size_t num_ordinals)
+void numex_language_destroy(numex_language_t *self);
+
+bool numex_table_add_language(numex_language_t *language);
+
+numex_language_t *get_numex_language(char *name);
+char *convert_numeric_expressions(char *input, token_array *input);
+
+bool numex_table_write(FILE *file);
+bool numex_table_save(char *filename);
+
+void numex_module_setup(char *filename);
+void numex_module_teardown(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
\ No newline at end of file