diff --git a/Cargo.lock b/Cargo.lock
index 0b44e3c..4411f41 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,22 +2,90 @@
 # It is not intended for manual editing.
 version = 4
 
+[[package]]
+name = "aho-corasick"
+version = "1.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e60d3430d3a69478ad0993f19238d2df97c507009a52b3c10addcd7f6bcb916"
+dependencies = [
+ "memchr",
+]
+
+[[package]]
+name = "allocator-api2"
+version = "0.2.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "683d7910e743518b0e34f1186f92494becacb047c7b6bf616c96772180fef923"
+
 [[package]]
 name = "beef"
 version = "0.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3a8241f3ebb85c056b509d4327ad0358fbbba6ffb340bf388f26350aeda225b1"
 
+[[package]]
+name = "cc"
+version = "1.2.31"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3a42d84bb6b69d3a8b3eaacf0d88f179e1929695e1ad012b6cf64d9caaa5fd2"
+dependencies = [
+ "shlex",
+]
+
+[[package]]
+name = "cfg-if"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9555578bc9e57714c812a1f84e4fc5b4d21fcb063490c624de019f7464c91268"
+
+[[package]]
+name = "chumsky"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "14377e276b2c8300513dff55ba4cc4142b44e5d6de6d00eb5b2307d650bb4ec1"
+dependencies = [
+ "hashbrown",
+ "regex-automata",
+ "serde",
+ "stacker",
+ "unicode-ident",
+ "unicode-segmentation",
+]
+
+[[package]]
+name = "equivalent"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "877a4ace8713b0bcf2a4e7eec82529c029f1d0619886d18145fea96c3ffe5c0f"
+
 [[package]]
 name = "fnv"
 version = "1.0.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3f9eec918d3f24069decb9af1554cad7c880e2da24a9afd88aca000531ab82c1"
 
+[[package]]
+name = "foldhash"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d9c4f5dac5e15c24eb999c26181a6ca40b39fe946cbe4c263c7209467bc83af2"
+
+[[package]]
+name = "hashbrown"
+version = "0.15.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5971ac85611da7067dbfcabef3c70ebb5606018acd9e2a3903a0da507521e0d5"
+dependencies = [
+ "allocator-api2",
+ "equivalent",
+ "foldhash",
+]
+
 [[package]]
 name = "lang"
 version = "0.1.0"
 dependencies = [
+ "chumsky",
  "logos",
 ]
 
@@ -27,6 +95,12 @@ version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
 
+[[package]]
+name = "libc"
+version = "0.2.174"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1171693293099992e19cddea4e8b849964e9846f4acee11b3948bcc337be8776"
+
 [[package]]
 name = "logos"
 version = "0.15.0"
@@ -47,7 +121,7 @@ dependencies = [
  "lazy_static",
  "proc-macro2",
  "quote",
- "regex-syntax",
+ "regex-syntax 0.8.5",
  "rustc_version",
  "syn",
 ]
@@ -61,6 +135,12 @@ dependencies = [
  "logos-codegen",
 ]
 
+[[package]]
+name = "memchr"
+version = "2.7.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "32a282da65faaf38286cf3be983213fcf1d2e2a58700e808f83f4ea9a4804bc0"
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.95"
@@ -70,6 +150,15 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "psm"
+version = "0.1.26"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e944464ec8536cd1beb0bbfd96987eb5e3b72f2ecdafdc5c769a37f1fa2ae1f"
+dependencies = [
+ "cc",
+]
+
 [[package]]
 name = "quote"
 version = "1.0.40"
@@ -79,6 +168,23 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "regex-automata"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "59b23e92ee4318893fa3fe3e6fb365258efbfe6ac6ab30f090cdcbb7aa37efa9"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax 0.7.5",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.7.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dbb5fb1acd8a1a18b3dd5be62d25485eb770e05afb408a9627d14d451bae12da"
+
 [[package]]
 name = "regex-syntax"
 version = "0.8.5"
@@ -100,6 +206,45 @@ version = "1.0.26"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "56e6fa9c48d24d85fb3de5ad847117517440f6beceb7798af16b4a87d616b8d0"
 
+[[package]]
+name = "serde"
+version = "1.0.219"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5f0e2c6ed6606019b4e29e69dbaba95b11854410e5347d525002456dbbb786b6"
+dependencies = [
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_derive"
+version = "1.0.219"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5b0276cf7f2c73365f7157c8123c21cd9a50fbbd844757af28ca1f5925fc2a00"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "shlex"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
+
+[[package]]
+name = "stacker"
+version = "0.1.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cddb07e32ddb770749da91081d8d0ac3a16f1a569a18b20348cd371f5dead06b"
+dependencies = [
+ "cc",
+ "cfg-if",
+ "libc",
+ "psm",
+ "windows-sys",
+]
+
 [[package]]
 name = "syn"
 version = "2.0.104"
@@ -116,3 +261,82 @@ name = "unicode-ident"
 version = "1.0.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5a5f39404a5da50712a4c1eecf25e90dd62b613502b7e925fd4e4d19b5c96512"
+
+[[package]]
+name = "unicode-segmentation"
+version = "1.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f6ccf251212114b54433ec949fd6a7841275f9ada20dddd2f29e9ceea4501493"
+
+[[package]]
+name = "windows-sys"
+version = "0.59.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e38bc4d79ed67fd075bcc251a1c39b32a1776bbe92e5bef1f0bf1f8c531853b"
+dependencies = [
+ "windows-targets",
+]
+
+[[package]]
+name = "windows-targets"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9b724f72796e036ab90c1021d4780d4d3d648aca59e491e6b98e725b84e99973"
+dependencies = [
+ "windows_aarch64_gnullvm",
+ "windows_aarch64_msvc",
+ "windows_i686_gnu",
+ "windows_i686_gnullvm",
+ "windows_i686_msvc",
+ "windows_x86_64_gnu",
+ "windows_x86_64_gnullvm",
+ "windows_x86_64_msvc",
+]
+
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "32a4622180e7a0ec044bb555404c800bc9fd9ec262ec147edd5989ccd0c02cd3"
+
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "09ec2a7bb152e2252b53fa7803150007879548bc709c039df7627cabbd05d469"
+
+[[package]]
+name = "windows_i686_gnu"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e9b5ad5ab802e97eb8e295ac6720e509ee4c243f69d781394014ebfe8bbfa0b"
+
+[[package]]
+name = "windows_i686_gnullvm"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0eee52d38c090b3caa76c563b86c3a4bd71ef1a819287c19d586d7334ae8ed66"
+
+[[package]]
+name = "windows_i686_msvc"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "240948bc05c5e7c6dabba28bf89d89ffce3e303022809e73deaefe4f6ec56c66"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "147a5c80aabfbf0c7d901cb5895d1de30ef2907eb21fbbab29ca94c5b08b1a78"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "24d5b23dc417412679681396f2b49f3de8c1473deb516bd34410872eff51ed0d"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"
diff --git a/Cargo.toml b/Cargo.toml
index 090227e..f6c6272 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,3 +5,4 @@ edition = "2024"
 
 [dependencies]
 logos = "0.15.0"
+chumsky = "0.10.1"
diff --git a/src/ast/evaluator.rs b/src/ast/evaluator.rs
new file mode 100644
index 0000000..69a52da
--- /dev/null
+++ b/src/ast/evaluator.rs
@@ -0,0 +1,18 @@
+use crate::ast::Expression;
+
+
+impl Expression {
+    pub fn eval(&self) -> isize {
+        match self {
+            Expression::Integer(n) => *n,
+
+            
+            Expression::Negate(rhs) => -rhs.eval(),
+
+            Expression::Add(lhs, rhs) => lhs.eval() + rhs.eval(),
+            Expression::Substract(lhs, rhs) => lhs.eval() - rhs.eval(),
+            Expression::Multiply(lhs, rhs) => lhs.eval() * rhs.eval(),
+            Expression::Divide(lhs, rhs) => lhs.eval() / rhs.eval(),
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/ast/mod.rs b/src/ast/mod.rs
new file mode 100644
index 0000000..24d7150
--- /dev/null
+++ b/src/ast/mod.rs
@@ -0,0 +1,12 @@
+pub mod evaluator;
+
+#[derive(Debug)]
+pub enum Expression {
+    Integer(isize),
+    Negate(Box<Expression>),
+    // Binary operators,
+    Add(Box<Expression>, Box<Expression>),
+    Substract(Box<Expression>, Box<Expression>),
+    Multiply(Box<Expression>, Box<Expression>),
+    Divide(Box<Expression>, Box<Expression>),
+}
diff --git a/src/lib.rs b/src/lib.rs
deleted file mode 100644
index 1c185d8..0000000
--- a/src/lib.rs
+++ /dev/null
@@ -1,16 +0,0 @@
-mod lexer;
-
-pub fn add(left: u64, right: u64) -> u64 {
-    left + right
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn it_works() {
-        let result = add(2, 2);
-        assert_eq!(result, 4);
-    }
-}
diff --git a/src/main.rs b/src/main.rs
new file mode 100644
index 0000000..96a31ae
--- /dev/null
+++ b/src/main.rs
@@ -0,0 +1,36 @@
+use chumsky::Parser;
+use logos::Logos;
+
+use crate::{parser::parser, tokens::Token};
+
+mod tokens;
+mod ast;
+mod parser;
+
+fn main() {
+    let lexer = Token::lexer("(1 + 1) * 3");
+
+    let mut tokens = vec![];
+    for (token, span) in lexer.spanned() {
+        match token {
+            Ok(token) => tokens.push(token),
+            Err(e) => {
+                println!("lexer error at {:?}: {:?}", span, e);
+                return;
+            }
+        }
+    }
+
+    let ast = match parser().parse(&tokens).into_result() {
+        Ok(expr) => {
+            println!("[AST]\n{:#?}", expr);
+            expr
+        }
+        Err(e) => {
+            println!("parse error: {:#?}", e);
+            return;
+        }
+    };
+
+    println!("\n[result]\n{}", ast.eval());
+}
diff --git a/src/parser.rs b/src/parser.rs
new file mode 100644
index 0000000..e7114ef
--- /dev/null
+++ b/src/parser.rs
@@ -0,0 +1,56 @@
+use chumsky::{prelude::{just, recursive}, recursive, select, IterParser, Parser};
+
+use crate::{ast::Expression, tokens::Token};
+
+
+#[allow(clippy::let_and_return)]
+/* ANCHOR: parser */
+pub fn parser<'src>(
+) -> impl Parser<'src, &'src [Token<'src>], Expression, chumsky::extra::Err<chumsky::error::Simple<'src, Token<'src>>>>
+{
+    recursive(
+        |p| 
+        {
+            let atom = {
+            let parenthesized = p
+                .clone()
+                .delimited_by(just(Token::ParenBegin), just(Token::ParenEnd));
+
+            let integer = select! {
+                Token::Integer(n) => Expression::Integer(n),
+            };
+
+            parenthesized.or(integer)
+        };
+
+        let unary = just(Token::Substract)
+            .repeated()
+            .foldr(atom, |_op, rhs| Expression::Negate(Box::new(rhs)));
+
+        let binary_1 = unary.clone().foldl(
+            just(Token::Multiply)
+                .or(just(Token::Divide))
+                .then(unary)
+                .repeated(),
+            |lhs, (op, rhs)| match op {
+                Token::Multiply => Expression::Multiply(Box::new(lhs), Box::new(rhs)),
+                Token::Divide => Expression::Divide(Box::new(lhs), Box::new(rhs)),
+                _ => unreachable!(),
+            },
+        );
+
+        let binary_2 = binary_1.clone().foldl(
+            just(Token::Add)
+                .or(just(Token::Substract))
+                .then(binary_1)
+                .repeated(),
+            |lhs, (op, rhs)| match op {
+                Token::Add => Expression::Add(Box::new(lhs), Box::new(rhs)),
+                Token::Substract => Expression::Substract(Box::new(lhs), Box::new(rhs)),
+                _ => unreachable!(),
+            },
+        );
+
+        binary_2
+    })
+}
\ No newline at end of file
diff --git a/src/lexer.rs b/src/tokens.rs
similarity index 54%
rename from src/lexer.rs
rename to src/tokens.rs
index 610b4dc..30a5b41 100644
--- a/src/lexer.rs
+++ b/src/tokens.rs
@@ -2,7 +2,7 @@ use logos::{Lexer, Logos};
 
 #[derive(Logos, Debug, Clone, PartialEq)]
 #[logos(skip r"[ \t\r\n\f]+")] // Skips whitespace
-enum Token<'source> {
+pub enum Token<'source> {
     #[token("false", |_| false)]
     #[token("true", |_| true)]
     Bool(bool),
@@ -18,16 +18,40 @@ enum Token<'source> {
 
     #[token("/")]
     Divide,
+
+    #[token("=")]
+    Equals,
+
+    #[token(":")]
+    Colon,
+
+    #[token("(")]
+    ParenBegin,
+
+    #[token(")")]
+    ParenEnd,
+
+    #[token("{")]
+    BraceBegin,
+
+    #[token("}")]
+    BraceEnd,
+
+    #[regex("[0-9]+", |lex| lex.slice().parse::<isize>().unwrap())]
+    Integer(isize),
     
     #[regex(r"[_a-zA-Z][_0-9a-zA-Z]*")]
     Ident(&'source str),
 
     #[regex(r#""([^"\\\x00-\x1F]|\\(["\\bnfrt/]|u[a-fA-F0-9]{4}))*""#, |lex| lex.slice().to_owned())]
     String(String),
-}
 
-fn float<'a>(lex: &mut Lexer<'a, Token<'a>>) -> Result<f64, ()> {
-    lex.slice().parse().map_err(|_| ())
+    #[token("class")]
+    #[token("fun")]
+    #[token("var")]
+    #[token("if")]
+    #[token("else")]
+    Keyword(&'source str),
 }
 
 
diff --git a/syntax.akai b/syntax.akai
index fa07ff9..b4293f4 100644
--- a/syntax.akai
+++ b/syntax.akai
@@ -1,3 +1,20 @@
+class Position:
+    // Properties
+    var int: x
+    var int: y
+
+    // Constructor
+    Position(_x, _y) {
+        x = _x
+        y = _y
+    }
+
+// Inheritance
+class Cat derive Animal:
+    /*
+        code goes here
+    */
+
 fun helloWorld() {
     // Variables either dynamically or statically typed
     var String: test = "I'm a string"
@@ -6,4 +23,24 @@ fun helloWorld() {
     var bar = foo + 10
 
     print("Hello World " + bar)
-}
\ No newline at end of file
+}
+
+/*
+Keywords/ Tokens:
+    - class
+    - fun 
+    - var
+    - bool
+    - if
+    - else
+    - (
+    - )
+    - {
+    - }
+    - :
+    - +
+    - -
+    - /
+    - *
+    - =
+*/