diff --git a/QGL/qasm/create_ast.py b/QGL/qasm/create_ast.py
new file mode 100644
index 00000000..46740f75
--- /dev/null
+++ b/QGL/qasm/create_ast.py
@@ -0,0 +1,159 @@
+"""
+Original Author: Guilhem Ribeill
+
+Copyright 2020 Raytheon BBN Technologies
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+"""
+import os, sys
+from lark import Lark, tree, ast_utils, Transformer, v_args
+from lark.tree import Meta
+import ast
+
+py="""
+pots = 1000
+pans = 2000
+pens = 2001
+fens = pens + 1
+fens += 1
+q1 = qubit()
+"""
+print("---- Python AST -----")
+# print("Python AST:", tree)
+print(ast.dump(ast.parse(py)))
+
+
+
+
+this_module = sys.modules[__name__]
+
+from dataclasses import dataclass
+
+# Define AST passthroughs
+
+class _Ast(ast_utils.Ast):
+    pass
+
+class _Decl(_Ast):
+    pass
+
+class _Expr(_Ast):
+    pass
+
+class _Assignment(_Ast):
+    pass
+# Define useful AST classes
+
+@dataclass
+class ConstDecl(_Decl):
+    name: str
+    value: _Expr
+
+@dataclass
+class Version(_Ast):
+    number: int
+
+@dataclass
+class Assign(_Ast):
+    value: object
+
+@dataclass
+class AugAssign(_Ast):
+    operand: str
+    value: object
+
+class ClassicalAssignment(_Ast):
+    def __init__(self, name, expr):
+        self.name = name
+        self.expr = expr
+        print(name, expr)
+        # return None
+    def __str__(self):
+        return(f"ClassicalAssignment(name={self.name}, expr={self.expr})")
+
+
+try:
+    import pydot
+    _has_pydot = True
+except ImportError:
+    _has_pydot = False
+
+grammar_path = os.path.join(os.path.dirname(
+                            os.path.abspath(__file__)),
+                             "grammar.lark")
+with open(grammar_path, "r") as f:
+    _QASM_GRAMMAR = f.read()
+
+class QASM3Parser(Lark):
+
+    def __init__(self, **kwargs):
+        super().__init__(_QASM_GRAMMAR, **kwargs)
+        self.cst = None
+
+    def build_tree(self, input):
+        self.cst = self.parse(input)
+
+    def __str__(self):
+        return self.cst.pretty()
+
+    def cst_graph(self, filename):
+        if _has_pydot:
+            tree.pydot__tree_to_png(self.cst, filename)
+        else:
+            raise ModuleNotFoundError("Please install pydot to generate tree graphs.")
+
+    def run(self):
+        transformer = ast_utils.create_transformer(sys.modules[__name__], QASM3Transformer())
+        self.ast = transformer.transform(self.cst)
+        return self.ast 
+        # return QASM3Transformer().transform(self.cst)
+
+    def ast_graph(self, filename):
+        if _has_pydot:
+            tree.pydot__tree_to_png(self.ast, filename)
+        else:
+            raise ModuleNotFoundError("Please install pydot to generate tree graphs.")
+
+
+class QASM3Transformer(Transformer):
+    def start(self, x):
+        return x
+    def expr(self, x):
+        return x
+    def NUMBER(self, tok):
+        "Convert the value of `tok` from string to int, while maintaining line number & column."
+        return float(tok) #tok.update(value=float(tok))
+    def id(self, tok):
+        return str(tok[0].value)
+
+
+if __name__ == '__main__':
+    q = QASM3Parser()
+    with open(sys.argv[1]) as f:
+        src = f.read()
+        q.build_tree(src)
+    q.cst_graph("qasm_tree.png")
+    print("---- SRC -----")
+    print(src)
+    print("---- CST -----")
+    print(q.cst)
+    print("\n---- AST -----")
+    # def prpr(x, n=1):
+    #     if isinstance(x, list):
+
+    for l in q.run():
+        # if isinstance(l, list):
+        print(l)
+    # print(q.run())
+    # q.ast_graph("qasm_tree_ast.png")
+    
diff --git a/QGL/qasm/grammar.lark b/QGL/qasm/grammar.lark
new file mode 100644
index 00000000..c40f95c4
--- /dev/null
+++ b/QGL/qasm/grammar.lark
@@ -0,0 +1,284 @@
+//////////////////////////////////////////////////////////////////////////////
+//Original Author: Guilhem Ribeill
+//
+//Copyright 2020 Raytheon BBN Technologies
+//
+//Licensed under the Apache License, Version 2.0 (the "License");
+//you may not use this file except in compliance with the License.
+//You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+//Unless required by applicable law or agreed to in writing, software
+//distributed under the License is distributed on an "AS IS" BASIS,
+//WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//See the License for the specific language governing permissions and
+//limitations under the License.
+//////////////////////////////////////////////////////////////////////////////
+
+// OpenQASM 3.0 Grammar in EBNF syntax for use with the Lark parser engine
+
+// Comments and whitespace
+%import common.WS
+%import common.CPP_COMMENT
+%import common.C_COMMENT 
+%ignore WS 
+%ignore CPP_COMMENT
+%ignore C_COMMENT
+
+_ENDL: ";"
+
+/////////////////////////////////////////////////////////
+// Terminals 
+
+//Constant terminals
+%import common.ESCAPED_STRING
+%import common.SIGNED_NUMBER
+%import common.INT
+
+STR: ESCAPED_STRING
+
+TEXT: /[\S\t ]+/
+
+BIN_NUMBER: /0b[01]+/ 
+HEX_NUMBER: /0x[0-9a-fA-F]+/
+CONSTANT : "pi" | "tau" | "e"
+NUMBER: HEX_NUMBER | BIN_NUMBER | SIGNED_NUMBER | CONSTANT
+BOOL: "true" | "false"
+
+TIME: "ns" | "us" | "ms" | "s" | "dt"
+
+//Variable types
+ID: /\$*[a-zA-Z_%][a-zA-Z0-9_]*/ //TODO: Support unicode
+
+//Quantum types
+QTYPE      : "qubit" | "qreg"
+
+//Classical types
+RTYPE      : "bit"   | "creg"
+NUMTYPE    : "int" | "uint" | "float" | "fixed" | "angle"
+BTYPE      : "bool"
+CTYPE      : RTYPE | NUMTYPE | BTYPE  
+
+//Math 
+MATH_FUNCS : "sqrt" | "exp" | "log" | "abs" 
+           | "sin" | "cos" | "tan" 
+           | "popcount" | "lengthof"
+
+//Operators 
+UNARY_OP   : "~" | "!" | "-"
+
+INCR_OP    : "++" | "--"
+
+ARITH_OP  : "+" | "-" | "*" | "/" 
+BITS_OP   : "&" | "|" | "^" | "<<" | ">>" | "rotl" | "rotr"
+BOOL_OP   : ">" | "<" | ">=" | "<=" | "==" | "!="  | "&&" | "||" | "in"
+BINARY_OP : ARITH_OP | BITS_OP | BOOL_OP
+
+ASSIGN_OP : "+=" | "-=" | "*=" | "/="
+
+BUILTIN_GATE : "U" | "CX" | "reset"
+
+/////////////////////////////////////////////////////////
+//Rules
+
+//Basic structure
+?start  : version include* statement+
+
+version  : "OPENQASM" NUMBER _ENDL 
+
+include  : "include" STR _ENDL
+
+pragma   : "#PRAGMA" TEXT 
+
+block : "{" block* statement* "}"
+
+?statement : pragma
+           | decl 
+           | gatedecl
+           | branch 
+           | loop 
+           | control
+           | subroutine 
+           | kernel
+           | extern
+           | qblock
+           | qstatement 
+           | cstatement 
+           | defcal
+
+
+/////////////////////////////////////////////////////////
+//Variable delcaration
+?decl : qdecl _ENDL 
+     | cdecl _ENDL 
+     | const_decl _ENDL
+     | tdecl _ENDL
+
+qdecl   : qtype ID
+
+cdecl   : ctype ID assignment?
+
+tdecl   : ttype ID assignment?
+
+const_decl : "const" ID "=" expr
+
+?assignment : "=" expr -> assign
+           | ASSIGN_OP expr -> aug_assign
+
+modifier: index 
+        | slice
+
+/////////////////////////////////////////////////////////
+// Register aliasing, concatenation, slicing and indexing
+
+alias  : "let" ID "=" concat
+       | "let" ID "=" ID slice
+       | "let" ID "=" ID index
+
+concat : ID "||" ID ("||" ID)* 
+
+slice  : "[" range "]"
+
+range  : expr ":" expr (":" expr)?
+
+index  : "[" expr ("," expr)? "]"
+
+/////////////////////////////////////////////////////////
+//Quantum operatiors and gates
+
+qblock : "{" qblock* qstatement* "}"
+
+qstatement : gatecall _ENDL
+           | meas_decl _ENDL
+           | measure _ENDL
+
+gatedecl :"gate" gatedef qblock
+
+gatedef : ID ("(" carg_list? ")")? id_list 
+
+gatecall : gatemod? gate ("(" expr_list? ")")? duration? id_list
+
+gate    : BUILTIN_GATE
+        | ID
+        | gatemod gate
+
+gatemod : "inv" "@"                       -> gate_inv
+        | "pow" "(" SIGNED_NUMBER ")" "@" -> gate_pow
+        | "ctrl" "@"                      -> gate_ctrl 
+
+measure : "measure" id_list
+
+meas_decl : measure "->" id_list 
+          | id_list "=" measure
+
+defcal : "defcal" gatedef qblock* cblock*
+       | "defcalgrammar" "\"" ID "\"" _ENDL
+
+
+/////////////////////////////////////////////////////////
+//Classical operations
+
+cblock : "{" cblock* cstatement* "}"
+
+?cstatement : expr _ENDL
+            | "return" cstatement -> return
+
+expr   : ID assignment -> classical_assignment
+       | unary_op expr 
+       | expr incr_op
+       | call "(" expr_list? ")"
+       | member
+       | measure
+       | expr binary_op expr -> bin_op
+       | value 
+       | tvalue
+       | ID
+
+call : MATH_FUNCS 
+     | cast 
+     | ID
+
+cast : ctype
+
+member : ID "in" "{" expr_list "}"
+       | ID "in" slice
+
+expr_list : (expr ",")* expr
+
+binary_op : BINARY_OP 
+unary_op  : UNARY_OP 
+incr_op   : INCR_OP
+
+/////////////////////////////////////////////////////////
+//Control flow
+branch_block : statement
+             | block 
+
+branch : "if" "(" expr ")" branch_block ("else" branch_block)?
+
+loop : for_loop branch_block 
+     | while_loop branch_block
+
+for_loop : "for" member
+
+while_loop: "while" "(" expr ")"
+
+control : "break" _ENDL    -> break 
+        | "continue" _ENDL -> continue 
+        | "end" _ENDL      -> end
+
+/////////////////////////////////////////////////////////
+//Timing instructions
+
+barrier : "barrier" id_list
+
+delay : "delay" index id_list
+
+box : "boxas" ID qblock 
+    | "boxto" tvalue qblock
+
+ttype : "length"       -> length 
+          | "stretch" INT? -> stretch
+          | "duration" -> duration_decl
+
+duration : "[" tvalue "]"
+         | "[" expr "]"
+         | "[" "stretchinf" "]"
+
+/////////////////////////////////////////////////////////
+//Subroutines
+
+subroutine : "def" ID ("(" carg_list? qarg_list? ")")? return_sig? block
+
+kernel : "kernel" ID ("(" carg_list? ")")? return_sig?
+
+extern : "extern" ID ("(" id_list? ")")? (return_sig ID)? _ENDL 
+
+return_sig : "->" carg
+
+
+/////////////////////////////////////////////////////////
+// Helpers
+id_index : ID index?
+?id_list  : (id_index ",")* id_index
+
+carg     : ctype association
+qarg     : qtype association
+
+?carg_list : (carg ",")* carg 
+?qarg_list : (qarg ",")* qarg
+
+association: ":" ID
+
+//Type declaration with width
+?qtype : QTYPE ("[" SIGNED_NUMBER "]")?
+?ctype : CTYPE ("[" SIGNED_NUMBER ("," SIGNED_NUMBER)* "]")?
+
+?tvalue : NUMBER TIME
+
+?value : NUMBER
+       | STR 
+       | BOOL
+
+
diff --git a/QGL/qasm/parse.py b/QGL/qasm/parse.py
new file mode 100644
index 00000000..c8629e6e
--- /dev/null
+++ b/QGL/qasm/parse.py
@@ -0,0 +1,59 @@
+"""
+Original Author: Guilhem Ribeill
+
+Copyright 2020 Raytheon BBN Technologies
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+"""
+import os, sys
+import logging 
+from lark import Lark, tree, logger 
+
+#logger.setLevel(logging.DEBUG)
+
+try:
+    import pydot
+    _has_pydot = True
+except ImportError:
+    _has_pydot = False
+
+grammar_path = os.path.join(os.path.dirname(
+                            os.path.abspath(__file__)),
+                             "grammar.lark")
+with open(grammar_path, "r") as f:
+    _QASM_GRAMMAR = f.read()
+
+class QASM3Parser(Lark):
+
+    def __init__(self, **kwargs):
+        super().__init__(_QASM_GRAMMAR, **kwargs)
+        self.cst = None
+
+    def build_tree(self, input):
+        self.cst = self.parse(input)
+
+    def __str__(self):
+        return self.cst.pretty()
+
+    def cst_graph(self, filename):
+        if _has_pydot:
+            tree.pydot__tree_to_png(self.cst, filename)
+        else:
+            raise ModuleNotFoundError("Please install pydot to generate tree graphs.")
+
+if __name__ == "__main__":
+    with open(sys.argv[1]) as f:
+        parser = QASM3Parser(debug=True)
+        parser.build_tree(f.read())
+        print(parser)
+        parser.cst_graph("test_qasm.png")
diff --git a/QGL/qasm/test_all.py b/QGL/qasm/test_all.py
new file mode 100644
index 00000000..48d2c647
--- /dev/null
+++ b/QGL/qasm/test_all.py
@@ -0,0 +1,25 @@
+import os, sys, glob
+from parse import *
+
+qasm_path = "/home/gribeill/GitHub/openqasm/examples/*.qasm"
+
+fails = []
+
+files = glob.glob(qasm_path)
+
+print(files)
+
+for fn in files:
+	p = QASM3Parser()
+	with open(fn) as f: 
+		try:
+			p.build_tree(f.read())
+		except:
+			fails.append(fn)
+
+Nt = len(files)
+Nf = len(fails)
+
+print(f"Failed on {Nf} out of {Nt} files!")
+for f in fails:
+	print(f)
diff --git a/requirements.txt b/requirements.txt
index d0054aad..723b4d45 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,4 +3,5 @@ numpy >= 1.11.1
 scipy >= 0.17.1
 networkx >= 1.11
 bqplot >= 0.12.2
-sqlalchemy >= 1.2.15
\ No newline at end of file
+sqlalchemy >= 1.2.15
+lark-parser >= 0.11.3
diff --git a/setup.py b/setup.py
index c3b08ab6..13bdc5ae 100644
--- a/setup.py
+++ b/setup.py
@@ -1,5 +1,9 @@
 from setuptools import setup, find_packages
 
+extras = {
+  'with_qasm': ['lark-parser >= 0.11']
+}
+
 setup(name='QGL',
       version='2020.1',
       packages=find_packages(exclude=["tests"]),
@@ -12,13 +16,15 @@
         "scipy >= 0.17.1",
         "networkx >= 1.11",
         "bqplot >= 0.12.2",
-        "sqlalchemy >= 1.2.15"
+        "sqlalchemy >= 1.2.15",
+        "lark-parser >= 0.11.03"
       ],
       description="Quantum Gate Language (QGL) is a domain specific language embedded in python for specifying pulse sequences.",
       long_description_content_type='text/markdown',
       long_description=open('README.md').read(),
       python_requires='>=3.6',
-      keywords="quantum qubit experiment configuration gate language"
+      keywords="quantum qubit experiment configuration gate language",
+      extras_requier=extras
 )
 
 # python setup.py sdist
diff --git a/tests/test_QASM.py b/tests/test_QASM.py
new file mode 100644
index 00000000..7109893d
--- /dev/null
+++ b/tests/test_QASM.py
@@ -0,0 +1,25 @@
+# Test QASM parsing and (eventually) compilation
+import os
+import unittest
+
+from QGL.qasm.parse import QASM3Parser
+
+def get_qasm_test_file(filename):
+    path = os.path.dirname(os.path.abspath(__file__))
+    file = os.path.join(path, "test_data", "qasm", filename)
+    with open(file, "r") as f:
+    	qasm = f.read()
+    return qasm 
+
+class ParseTestCase(unittest.TestCase):
+
+	def setUp(self):
+		pass
+
+	def test_parse_simple(self):
+		qasm = get_qasm_test_file("basic.qasm")
+		parser = QASM3Parser()
+		parser.build_tree(qasm)
+
+if __name__ == "__main__":
+	unittest.main()
\ No newline at end of file
diff --git a/tests/test_data/qasm/basic.qasm b/tests/test_data/qasm/basic.qasm
new file mode 100644
index 00000000..c5cba60a
--- /dev/null
+++ b/tests/test_data/qasm/basic.qasm
@@ -0,0 +1,21 @@
+OPENQASM 3.0;
+#PRAGMA I <3 QGL
+
+qubit q1;
+length t;
+
+//A very special gate
+gate X(angle[32]: phi) q {
+	U(phi, -pi/2, -pi/2) q;
+}
+
+/* Let's do a ramsey experiment!
+   Fun! */
+
+for t in 4ns:10us:20ns {
+	reset    q1;
+	X(pi/2)  q1;
+	delay[t] q1;
+	X(pi/2)  q1;
+	measure  q1;
+}
\ No newline at end of file