diff --git a/include/chardefs.h b/include/chardefs.h
new file mode 100644
index 0000000..f56477c
--- /dev/null
+++ b/include/chardefs.h
@@ -0,0 +1,20 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   chardefs.h                                         :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: sede-san <sede-san@student.42madrid.com    +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2025/10/23 13:23:25 by sede-san          #+#    #+#             */
+/*   Updated: 2025/10/23 13:24:41 by sede-san         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#ifndef CHARDEFS_H
+# define CHARDEFS_H
+
+# define DOLLAR '$'
+# define SINGLE_QUOTE '\''
+# define DOUBLE_QUOTE '\"'
+
+#endif /* CHARDEFS_H */
diff --git a/include/minishell.h b/include/minishell.h
index 44a6e83..87cbbcb 100644
--- a/include/minishell.h
+++ b/include/minishell.h
@@ -6,7 +6,7 @@
 /*   By: sede-san <sede-san@student.42madrid.com    +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2025/10/20 16:35:10 by sede-san          #+#    #+#             */
-/*   Updated: 2025/10/22 19:19:46 by sede-san         ###   ########.fr       */
+/*   Updated: 2025/10/23 13:25:25 by sede-san         ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -15,6 +15,8 @@
 
 # include "libft.h"
 # include "core.h"
+# include "parser.h"
+# include "chardefs.h"
 # include <readline/readline.h>	// readline(3), rl_clear_history(),
 								// rl_on_new_line(), rl_replace_line(),
 								// rl_redisplay()
diff --git a/include/parser.h b/include/parser.h
new file mode 100644
index 0000000..61fd6c7
--- /dev/null
+++ b/include/parser.h
@@ -0,0 +1,38 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   parser.h                                           :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: sede-san <sede-san@student.42madrid.com    +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2025/10/22 19:03:51 by sede-san          #+#    #+#             */
+/*   Updated: 2025/10/23 13:31:09 by sede-san         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#ifndef PARSER_H
+# define PARSER_H
+
+# include "minishell.h"
+
+/******************************************************************************/
+/*                           Structures & Data Types                          */
+/******************************************************************************/
+
+typedef struct s_command	t_command;
+
+typedef struct s_command
+{
+	int		argc;
+	char	**argv;
+}	t_command;
+
+/******************************************************************************/
+/*                                 Functions                                  */
+/******************************************************************************/
+
+// parser.c
+
+extern char	*parse(char *line, t_minishell *minishell);
+
+#endif /* PARSER_H */
diff --git a/src/main.c b/src/main.c
index 175ac78..f5c19a3 100644
--- a/src/main.c
+++ b/src/main.c
@@ -3,10 +3,10 @@
 /*                                                        :::      ::::::::   */
 /*   main.c                                             :+:      :+:    :+:   */
 /*                                                    +:+ +:+         +:+     */
-/*   By: sede-san <sede-san@student.42madrid.com    +#+  +:+       +#+        */
+/*   By: padan-pe <padan-pe@student.42.fr>          +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2025/10/20 16:34:42 by sede-san          #+#    #+#             */
-/*   Updated: 2025/10/22 16:58:08 by sede-san         ###   ########.fr       */
+/*   Updated: 2025/10/23 17:10:17 by padan-pe         ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
diff --git a/src/parser/parser.c b/src/parser/parser.c
new file mode 100644
index 0000000..5fb39e8
--- /dev/null
+++ b/src/parser/parser.c
@@ -0,0 +1,88 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   parser.c                                           :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: sede-san <sede-san@student.42madrid.com    +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2025/10/22 18:37:38 by sede-san          #+#    #+#             */
+/*   Updated: 2025/10/23 14:07:20 by sede-san         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "minishell.h"
+
+static char	**expand_paths(char **argv);
+static char	**expand_envs(char **argv);
+static int	count_argv(char **argv);
+
+char	*parse(
+	char *line,
+	t_minishell *minishell
+){
+	t_command	command;
+
+	if (!line || !*line)
+		return (NULL);
+	command.argv = expand_envs(ft_split(line, SPACE));
+	command.argc = count_argv(command.argv);
+	if (!command.argc)
+		return (NULL);
+////////////////////////////////////////////////////////////////////////////////
+	//* DEBUG
+	int	i = -1;
+	while (command.argv[++i])
+		printf("argv[%i]: %s\n", i, command.argv[i]);
+	ft_free_split(command.argv);
+////////////////////////////////////////////////////////////////////////////////
+	return (NULL);
+}
+
+// not sure of this step here
+static char	**expand_paths(
+	char **argv
+){
+	if (!argv)
+		return (NULL);
+	return (argv);
+}
+
+static char	**expand_envs(
+	char **argv
+){
+	int		i;
+	char	*env;
+
+	if (!argv)
+		return (NULL);
+	else if (!*argv) // check if ft_split returned and empty matrix
+	{
+		ft_free_split(argv);
+		return (NULL);
+	}
+	i = -1;
+	while (argv[++i])
+	{
+		if (!ft_strchr(argv[i], DOLLAR)
+			|| (ft_strchr(argv[i], DOLLAR) && ft_strchr(argv[i], SINGLE_QUOTE) && ft_strchr(argv[i] + (ft_strchr(argv[i], SINGLE_QUOTE) + 1 - argv[i]), SINGLE_QUOTE))) // env is surrounded by single quote
+			continue ;
+		env = getenv(ft_strchr(argv[i], DOLLAR) + 1);
+		free(argv[i]);
+		if (env)
+			argv[i] = ft_strdup(env);
+		else
+			argv[i] = ft_strdup("");
+	}
+	return (argv);
+}
+
+static int	count_argv(
+	char **argv
+){
+	int	i;
+
+	i = 0;
+	while (argv[i])
+		i++;
+	return (i);
+}