diff --git a/Cargo.lock b/Cargo.lock
index e6cd6443e..2094098a2 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -71,7 +71,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "db02d390bf6643fb404d3d22d31aee1c4bc4459600aef9113833d17e786c6e44"
 dependencies = [
  "quote",
- "syn",
+ "syn 1.0.103",
 ]
 
 [[package]]
@@ -81,7 +81,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b3ba0a3cf584a8ede533a1749b86040e9018cf752265fc39a71c69fe1fafaba5"
 dependencies = [
  "quote",
- "syn",
+ "syn 1.0.103",
 ]
 
 [[package]]
@@ -93,7 +93,7 @@ dependencies = [
  "num-bigint",
  "num-traits 0.2.15",
  "quote",
- "syn",
+ "syn 1.0.103",
 ]
 
 [[package]]
@@ -106,7 +106,7 @@ dependencies = [
  "num-traits 0.2.15",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.103",
 ]
 
 [[package]]
@@ -173,7 +173,7 @@ checksum = "1e805d94e6b5001b651426cf4cd446b1ab5f319d27bab5c644f61de0a804360c"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.103",
 ]
 
 [[package]]
@@ -196,7 +196,7 @@ dependencies = [
  "proc-macro-error",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.103",
 ]
 
 [[package]]
@@ -307,7 +307,7 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-casm"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "cairo-lang-utils",
  "env_logger",
@@ -316,6 +316,7 @@ dependencies = [
  "num-bigint",
  "num-traits 0.2.15",
  "pretty_assertions",
+ "serde",
  "test-case",
  "test-log",
  "thiserror",
@@ -323,7 +324,7 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-compiler"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "anyhow",
  "cairo-lang-defs",
@@ -347,7 +348,7 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-debug"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "cairo-lang-proc-macros",
  "cairo-lang-utils",
@@ -358,7 +359,7 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-defs"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "cairo-lang-debug",
  "cairo-lang-diagnostics",
@@ -379,7 +380,7 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-diagnostics"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "cairo-lang-filesystem",
  "cairo-lang-proc-macros",
@@ -394,7 +395,7 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-eq-solver"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "cairo-lang-utils",
  "env_logger",
@@ -408,7 +409,7 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-filesystem"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "cairo-lang-debug",
  "cairo-lang-utils",
@@ -421,7 +422,7 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-formatter"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "anyhow",
  "cairo-lang-diagnostics",
@@ -444,8 +445,9 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-language-server"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
+ "anyhow",
  "cairo-lang-compiler",
  "cairo-lang-debug",
  "cairo-lang-defs",
@@ -460,10 +462,14 @@ dependencies = [
  "cairo-lang-starknet",
  "cairo-lang-syntax",
  "cairo-lang-utils",
+ "indoc",
+ "log",
  "lsp-types",
  "salsa",
+ "scarb-metadata",
  "serde",
  "serde_json",
+ "smol_str",
  "test-log",
  "tokio",
  "tower-lsp",
@@ -471,7 +477,7 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-lowering"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "cairo-lang-debug",
  "cairo-lang-defs",
@@ -486,6 +492,7 @@ dependencies = [
  "cairo-lang-utils",
  "env_logger",
  "id-arena",
+ "indexmap",
  "indoc",
  "itertools",
  "log",
@@ -499,7 +506,7 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-parser"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "cairo-lang-diagnostics",
  "cairo-lang-filesystem",
@@ -520,7 +527,7 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-plugins"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "cairo-lang-debug",
  "cairo-lang-defs",
@@ -543,16 +550,16 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-proc-macros"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "cairo-lang-debug",
  "quote",
- "syn",
+ "syn 1.0.103",
 ]
 
 [[package]]
 name = "cairo-lang-project"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "cairo-lang-filesystem",
  "indoc",
@@ -565,7 +572,7 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-runner"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "anyhow",
  "ark-ff 0.4.0-alpha.7",
@@ -593,7 +600,7 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-semantic"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "assert_matches",
  "cairo-lang-debug",
@@ -623,7 +630,7 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-sierra"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "assert_matches",
  "bimap",
@@ -651,7 +658,7 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-sierra-ap-change"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "cairo-lang-eq-solver",
  "cairo-lang-sierra",
@@ -666,7 +673,7 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-sierra-gas"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "cairo-lang-eq-solver",
  "cairo-lang-sierra",
@@ -683,7 +690,7 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-sierra-generator"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "cairo-lang-debug",
  "cairo-lang-defs",
@@ -714,8 +721,9 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-sierra-to-casm"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
+ "anyhow",
  "assert_matches",
  "cairo-felt",
  "cairo-lang-casm",
@@ -738,9 +746,10 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-starknet"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "anyhow",
+ "cairo-lang-casm",
  "cairo-lang-compiler",
  "cairo-lang-defs",
  "cairo-lang-diagnostics",
@@ -780,7 +789,7 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-syntax"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "cairo-lang-debug",
  "cairo-lang-filesystem",
@@ -794,7 +803,7 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-syntax-codegen"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "cairo-lang-utils",
  "env_logger",
@@ -806,7 +815,7 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-test-runner"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "anyhow",
  "cairo-felt",
@@ -839,7 +848,7 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-test-utils"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "cairo-lang-utils",
  "env_logger",
@@ -850,13 +859,18 @@ dependencies = [
 
 [[package]]
 name = "cairo-lang-utils"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "chrono",
  "env_logger",
  "indexmap",
  "itertools",
  "log",
+ "num-bigint",
+ "num-integer",
+ "num-traits 0.2.15",
+ "serde",
+ "serde_json",
  "test-case",
  "test-log",
 ]
@@ -890,6 +904,15 @@ dependencies = [
  "thiserror",
 ]
 
+[[package]]
+name = "camino"
+version = "1.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c530edf18f37068ac2d977409ed5cd50d53d73bc653c7647b48eb78976ac9ae2"
+dependencies = [
+ "serde",
+]
+
 [[package]]
 name = "cc"
 version = "1.0.77"
@@ -959,7 +982,7 @@ dependencies = [
  "proc-macro-error",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.103",
 ]
 
 [[package]]
@@ -972,7 +995,7 @@ dependencies = [
  "proc-macro-error",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.103",
 ]
 
 [[package]]
@@ -1132,7 +1155,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6d2301688392eb071b0bf1a37be05c469d3cc4dbbd95df672fe28ab021e6a096"
 dependencies = [
  "quote",
- "syn",
+ "syn 1.0.103",
 ]
 
 [[package]]
@@ -1159,7 +1182,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "scratch",
- "syn",
+ "syn 1.0.103",
 ]
 
 [[package]]
@@ -1176,7 +1199,42 @@ checksum = "a08a6e2fcc370a089ad3b4aaf54db3b1b4cee38ddabce5896b33eb693275f470"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.103",
+]
+
+[[package]]
+name = "darling"
+version = "0.14.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7b750cb3417fd1b327431a470f388520309479ab0bf5e323505daf0290cd3850"
+dependencies = [
+ "darling_core",
+ "darling_macro",
+]
+
+[[package]]
+name = "darling_core"
+version = "0.14.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "109c1ca6e6b7f82cc233a97004ea8ed7ca123a9af07a8230878fcfda9b158bf0"
+dependencies = [
+ "fnv",
+ "ident_case",
+ "proc-macro2",
+ "quote",
+ "strsim",
+ "syn 1.0.103",
+]
+
+[[package]]
+name = "darling_macro"
+version = "0.14.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4aab4dbc9f7611d8b55048a3a16d2d010c2c8334e46304b40ac1cc14bf3b48e"
+dependencies = [
+ "darling_core",
+ "quote",
+ "syn 1.0.103",
 ]
 
 [[package]]
@@ -1200,7 +1258,38 @@ checksum = "fcc3dd5e9e9c0b295d6e1e4d811fb6f157d5ffd784b8d202fc62eac8035a770b"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.103",
+]
+
+[[package]]
+name = "derive_builder"
+version = "0.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8d67778784b508018359cbc8696edb3db78160bab2c2a28ba7f56ef6932997f8"
+dependencies = [
+ "derive_builder_macro",
+]
+
+[[package]]
+name = "derive_builder_core"
+version = "0.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c11bdc11a0c47bc7d37d582b5285da6849c96681023680b906673c5707af7b0f"
+dependencies = [
+ "darling",
+ "proc-macro2",
+ "quote",
+ "syn 1.0.103",
+]
+
+[[package]]
+name = "derive_builder_macro"
+version = "0.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ebcda35c7a396850a55ffeac740804b40ffec779b98fffbb1738f4033f0ee79e"
+dependencies = [
+ "derive_builder_core",
+ "syn 1.0.103",
 ]
 
 [[package]]
@@ -1315,6 +1404,7 @@ checksum = "38390104763dc37a5145a53c29c63c1290b5d316d6086ec32c293f6736051bb0"
 dependencies = [
  "futures-channel",
  "futures-core",
+ "futures-executor",
  "futures-io",
  "futures-sink",
  "futures-task",
@@ -1337,6 +1427,17 @@ version = "0.3.25"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "04909a7a7e4633ae6c4a9ab280aeb86da1236243a77b694a49eacd659a4bd3ac"
 
+[[package]]
+name = "futures-executor"
+version = "0.3.25"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7acc85df6714c176ab5edf386123fafe217be88c0840ec11f199441134a074e2"
+dependencies = [
+ "futures-core",
+ "futures-task",
+ "futures-util",
+]
+
 [[package]]
 name = "futures-io"
 version = "0.3.25"
@@ -1351,7 +1452,7 @@ checksum = "bdfb8ce053d86b91919aad980c220b1fb8401a9394410e1c289ed7e66b61835d"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.103",
 ]
 
 [[package]]
@@ -1366,6 +1467,12 @@ version = "0.3.25"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2ffb393ac5d9a6eaa9d3fdf37ae2776656b706e200c8e16b1bdb227f5198e6ea"
 
+[[package]]
+name = "futures-timer"
+version = "3.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e64b03909df88034c26dc1547e8970b91f98bdb65165d6a4e9110d94263dbb2c"
+
 [[package]]
 name = "futures-util"
 version = "0.3.25"
@@ -1403,7 +1510,7 @@ checksum = "40803f2757f84c877f088e62420931f6e05a72514f1f03630384aa30b91d667b"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.103",
 ]
 
 [[package]]
@@ -1549,6 +1656,12 @@ version = "2.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "25a2bc672d1148e28034f176e01fffebb08b35768468cc954630da77a1449005"
 
+[[package]]
+name = "ident_case"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b9e0384b61958566e926dc50660321d12159025e767c18e043daf26b70104c39"
+
 [[package]]
 name = "idna"
 version = "0.3.0"
@@ -2058,7 +2171,7 @@ checksum = "069bdb1e05adc7a8990dce9cc75370895fbe4e3d58b9b73bf1aee56359344a55"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.103",
 ]
 
 [[package]]
@@ -2106,7 +2219,7 @@ dependencies = [
  "proc-macro-error-attr",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.103",
  "version_check",
 ]
 
@@ -2123,18 +2236,18 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.47"
+version = "1.0.52"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5ea3d908b0e36316caf9e9e2c4625cdde190a7e6f440d794667ed17a1855e725"
+checksum = "1d0e1ae9e836cc3beddd63db0df682593d7e2d3d891ae8c9083d2113e1744224"
 dependencies = [
  "unicode-ident",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.21"
+version = "1.0.26"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bbe448f377a7d6961e30f5955f9b8d106c3f5e449d493ee1b125c1d43c2b5179"
+checksum = "4424af4bf778aae2051a77b60283332f386554255d722233d09fbfc7e30da2fc"
 dependencies = [
  "proc-macro2",
 ]
@@ -2176,9 +2289,9 @@ checksum = "60a357793950651c4ed0f3f52338f53b2f809f32d83a07f72909fa13e4c6c1e3"
 
 [[package]]
 name = "rayon"
-version = "0.9.0"
+version = "1.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ed02d09394c94ffbdfdc755ad62a132e94c3224a8354e78a1200ced34df12edf"
+checksum = "1d2df5196e37bcc87abebc0053e20787d73847bb33134a69841207dd0a47f03b"
 dependencies = [
  "either",
  "rayon-core",
@@ -2186,9 +2299,9 @@ dependencies = [
 
 [[package]]
 name = "rayon-core"
-version = "1.10.1"
+version = "1.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cac410af5d00ab6884528b4ab69d1e8e146e8d471201800fa1b4524126de6ad3"
+checksum = "4b8f95bd6966f5c87776639160a66bd8ab9895d9d4ab01ddba9fc60661aebe8d"
 dependencies = [
  "crossbeam-channel",
  "crossbeam-deque",
@@ -2250,6 +2363,32 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "rstest"
+version = "0.16.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b07f2d176c472198ec1e6551dc7da28f1c089652f66a7b722676c2238ebc0edf"
+dependencies = [
+ "futures",
+ "futures-timer",
+ "rstest_macros",
+ "rustc_version 0.4.0",
+]
+
+[[package]]
+name = "rstest_macros"
+version = "0.16.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7229b505ae0706e64f37ffc54a9c163e11022a6636d58fe1f3f52018257ff9f7"
+dependencies = [
+ "cfg-if",
+ "proc-macro2",
+ "quote",
+ "rustc_version 0.4.0",
+ "syn 1.0.103",
+ "unicode-ident",
+]
+
 [[package]]
 name = "rustc-hash"
 version = "1.1.0"
@@ -2271,7 +2410,7 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bfa0f585226d2e68097d4f95d113b15b83a82e819ab25717ec0590d9584ef366"
 dependencies = [
- "semver 1.0.16",
+ "semver 1.0.17",
 ]
 
 [[package]]
@@ -2312,7 +2451,7 @@ dependencies = [
  "heck 0.3.3",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.103",
 ]
 
 [[package]]
@@ -2324,6 +2463,20 @@ dependencies = [
  "winapi-util",
 ]
 
+[[package]]
+name = "scarb-metadata"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2480a9a896395a1414feebcfe8550b35f4dce0e6a437eeaa0c3d79ec938ddf42"
+dependencies = [
+ "camino",
+ "derive_builder",
+ "semver 1.0.17",
+ "serde",
+ "serde_json",
+ "thiserror",
+]
+
 [[package]]
 name = "scopeguard"
 version = "1.1.0"
@@ -2347,9 +2500,12 @@ dependencies = [
 
 [[package]]
 name = "semver"
-version = "1.0.16"
+version = "1.0.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "58bc9567378fc7690d6b2addae4e60ac2eeea07becb2c64b9f218b53865cba2a"
+checksum = "bebd363326d05ec3e2f532ab7660680f3b02130d780c299bca73469d521bc0ed"
+dependencies = [
+ "serde",
+]
 
 [[package]]
 name = "semver-parser"
@@ -2362,9 +2518,9 @@ dependencies = [
 
 [[package]]
 name = "serde"
-version = "1.0.147"
+version = "1.0.158"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d193d69bae983fc11a79df82342761dfbf28a99fc8d203dca4c3c1b590948965"
+checksum = "771d4d9c4163ee138805e12c710dd365e4f44be8be0503cb1bb9eb989425d9c9"
 dependencies = [
  "serde_derive",
 ]
@@ -2380,20 +2536,20 @@ dependencies = [
 
 [[package]]
 name = "serde_derive"
-version = "1.0.147"
+version = "1.0.158"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4f1d362ca8fc9c3e3a7484440752472d68a6caa98f1ab81d99b5dfe517cec852"
+checksum = "e801c1712f48475582b7696ac71e0ca34ebb30e09338425384269d9717c62cad"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.3",
 ]
 
 [[package]]
 name = "serde_json"
-version = "1.0.89"
+version = "1.0.94"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "020ff22c755c2ed3f8cf162dbb41a7268d934702f3ed3631656ea597e08fc3db"
+checksum = "1c533a59c9d8a93a09c6ab31f0fd5e5f4dd1b8fc9434804029839884765d04ea"
 dependencies = [
  "itoa",
  "ryu",
@@ -2408,7 +2564,7 @@ checksum = "1fe39d9fbb0ebf5eb2c7cb7e2a47e4f462fad1379f1166b8ae49ad9eae89a7ca"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.103",
 ]
 
 [[package]]
@@ -2534,7 +2690,7 @@ checksum = "6569d70430f0f6edc41f6820d00acf63356e6308046ca01e57eeac22ad258c47"
 dependencies = [
  "starknet-curve",
  "starknet-ff",
- "syn",
+ "syn 1.0.103",
 ]
 
 [[package]]
@@ -2598,6 +2754,17 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "syn"
+version = "2.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e8234ae35e70582bfa0f1fedffa6daa248e41dd045310b19800c4a36382c8f60"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
 [[package]]
 name = "synstructure"
 version = "0.12.6"
@@ -2606,7 +2773,7 @@ checksum = "f36bdaa60a83aca3921b5259d5400cbf5e90fc51931376a9bd4a0eb79aa7210f"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.103",
  "unicode-xid",
 ]
 
@@ -2649,7 +2816,7 @@ dependencies = [
  "proc-macro-error",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.103",
 ]
 
 [[package]]
@@ -2660,12 +2827,12 @@ checksum = "38f0c854faeb68a048f0f2dc410c5ddae3bf83854ef0e4977d58306a5edef50e"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.103",
 ]
 
 [[package]]
 name = "tests"
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 dependencies = [
  "assert_matches",
  "cairo-felt",
@@ -2674,6 +2841,7 @@ dependencies = [
  "cairo-lang-defs",
  "cairo-lang-diagnostics",
  "cairo-lang-filesystem",
+ "cairo-lang-lowering",
  "cairo-lang-parser",
  "cairo-lang-plugins",
  "cairo-lang-runner",
@@ -2690,6 +2858,7 @@ dependencies = [
  "log",
  "num-bigint",
  "pretty_assertions",
+ "rstest",
  "salsa",
  "test-case",
  "test-log",
@@ -2703,22 +2872,22 @@ checksum = "222a222a5bfe1bba4a77b45ec488a741b3cb8872e5e499451fd7d0129c9c7c3d"
 
 [[package]]
 name = "thiserror"
-version = "1.0.37"
+version = "1.0.40"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "10deb33631e3c9018b9baf9dcbbc4f737320d2b576bac10f6aefa048fa407e3e"
+checksum = "978c9a314bd8dc99be594bc3c175faaa9794be04a5a5e153caba6915336cebac"
 dependencies = [
  "thiserror-impl",
 ]
 
 [[package]]
 name = "thiserror-impl"
-version = "1.0.37"
+version = "1.0.40"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "982d17546b47146b28f7c22e3d08465f6b8903d0ea13c1660d9d84a6e7adcdbb"
+checksum = "f9456a42c5b0d803c8cd86e73dd7cc9edd429499f37a3550d286d5e86720569f"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.3",
 ]
 
 [[package]]
@@ -2793,7 +2962,7 @@ checksum = "9724f9a975fb987ef7a3cd9be0350edcbe130698af5b8f7a631e23d42d052484"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.103",
 ]
 
 [[package]]
@@ -2870,7 +3039,7 @@ checksum = "7ebd99eec668d0a450c177acbc4d05e0d0d13b1f8d3db13cd706c52cbec4ac04"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.103",
 ]
 
 [[package]]
@@ -3027,7 +3196,7 @@ dependencies = [
  "once_cell",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.103",
  "wasm-bindgen-shared",
 ]
 
@@ -3049,7 +3218,7 @@ checksum = "07bc0c051dc5f23e307b13285f9d75df86bfdf816c5721e573dec1f9b8aa193c"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.103",
  "wasm-bindgen-backend",
  "wasm-bindgen-shared",
 ]
@@ -3186,6 +3355,6 @@ checksum = "3f8f187641dad4f680d25c4bfc4225b418165984179f26ca76ec4fb6441d3a17"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.103",
  "synstructure",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 4294fd6aa..107fb5d91 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -31,7 +31,7 @@ members = [
 ]
 
 [workspace.package]
-version = "1.0.0-alpha.3"
+version = "1.0.0-alpha.6"
 edition = "2021"
 repository = "https://github.com/starkware-libs/cairo/"
 license = "Apache-2.0"
@@ -71,8 +71,10 @@ path-clean = "0.1.0"
 pretty_assertions = "1.2.1"
 proc-macro2 = "1.0"
 quote = "1.0.21"
-rayon = "0.9.0"
+rayon = "1.7.0"
+rstest = "0.16.0"
 salsa = "0.16.1"
+scarb-metadata = "1.0.1"
 serde = { version = "1.0.130", features = ["derive"] }
 serde_json = "1.0"
 sha3 = "0.10.6"
diff --git a/cairo b/cairo
index 903337885..9c190561c 160000
--- a/cairo
+++ b/cairo
@@ -1 +1 @@
-Subproject commit 903337885fa19e28f59988a4952d670f72b44b34
+Subproject commit 9c190561ce1e8323665857f1a77082925c817b4c
diff --git a/src/openzeppelin/lib.cairo b/src/openzeppelin/lib.cairo
index 14f00389d..daffe3c5e 100644
--- a/src/openzeppelin/lib.cairo
+++ b/src/openzeppelin/lib.cairo
@@ -1 +1,2 @@
+mod token;
 mod tests;
diff --git a/src/openzeppelin/tests.cairo b/src/openzeppelin/tests.cairo
index ba51ab5d3..0117a1281 100644
--- a/src/openzeppelin/tests.cairo
+++ b/src/openzeppelin/tests.cairo
@@ -1 +1 @@
-mod test_mytest;
+mod test_erc20;
diff --git a/src/openzeppelin/tests/test_erc20.cairo b/src/openzeppelin/tests/test_erc20.cairo
new file mode 100644
index 000000000..0b4f7f230
--- /dev/null
+++ b/src/openzeppelin/tests/test_erc20.cairo
@@ -0,0 +1,455 @@
+use openzeppelin::token::erc20::ERC20;
+use starknet::contract_address_const;
+use starknet::ContractAddress;
+use starknet::testing::set_caller_address;
+use integer::u256;
+use integer::u256_from_felt252;
+
+//
+// Constants
+//
+
+const NAME: felt252 = 111;
+const SYMBOL: felt252 = 222;
+
+fn MAX_U256() -> u256 {
+    u256 {
+        low: 0xffffffffffffffffffffffffffffffff_u128, high: 0xffffffffffffffffffffffffffffffff_u128
+    }
+}
+
+//
+// Helper functions
+//
+
+fn setup() -> (ContractAddress, u256) {
+    let initial_supply: u256 = u256_from_felt252(2000);
+    let account: ContractAddress = contract_address_const::<1>();
+    // Set account as default caller
+    set_caller_address(account);
+
+    ERC20::constructor(NAME, SYMBOL, initial_supply, account);
+    (account, initial_supply)
+}
+
+fn set_caller_as_zero() {
+    set_caller_address(contract_address_const::<0>());
+}
+
+//
+// Tests
+//
+
+#[test]
+#[available_gas(2000000)]
+fn test_initializer() {
+    ERC20::initializer(NAME, SYMBOL);
+
+    assert(ERC20::name() == NAME, 'Name should be NAME');
+    assert(ERC20::symbol() == SYMBOL, 'Symbol should be SYMBOL');
+    assert(ERC20::decimals() == 18_u8, 'Decimals should be 18');
+    assert(ERC20::total_supply() == u256_from_felt252(0), 'Supply should eq 0');
+}
+
+
+#[test]
+#[available_gas(2000000)]
+fn test_constructor() {
+    let initial_supply: u256 = u256_from_felt252(2000);
+    let account: ContractAddress = contract_address_const::<1>();
+    let decimals: u8 = 18_u8;
+
+    ERC20::constructor(NAME, SYMBOL, initial_supply, account);
+
+    let owner_balance: u256 = ERC20::balance_of(account);
+    assert(owner_balance == initial_supply, 'Should eq inital_supply');
+
+    assert(ERC20::total_supply() == initial_supply, 'Should eq inital_supply');
+    assert(ERC20::name() == NAME, 'Name should be NAME');
+    assert(ERC20::symbol() == SYMBOL, 'Symbol should be SYMBOL');
+    assert(ERC20::decimals() == decimals, 'Decimals should be 18');
+}
+
+#[test]
+#[available_gas(2000000)]
+fn test_approve() {
+    let (owner, supply) = setup();
+    let spender: ContractAddress = contract_address_const::<2>();
+    let amount: u256 = u256_from_felt252(100);
+
+    let success: bool = ERC20::approve(spender, amount);
+    assert(success, 'Should return true');
+    assert(ERC20::allowance(owner, spender) == amount, 'Spender not approved correctly');
+}
+
+#[test]
+#[available_gas(2000000)]
+#[should_panic(expected = ('ERC20: approve from 0', ))]
+fn test_approve_from_zero() {
+    let (owner, supply) = setup();
+    let spender: ContractAddress = contract_address_const::<2>();
+    let amount: u256 = u256_from_felt252(100);
+
+    set_caller_as_zero();
+
+    ERC20::approve(spender, amount);
+}
+
+#[test]
+#[available_gas(2000000)]
+#[should_panic(expected = ('ERC20: approve to 0', ))]
+fn test_approve_to_zero() {
+    let (owner, supply) = setup();
+    let spender: ContractAddress = contract_address_const::<0>();
+    let amount: u256 = u256_from_felt252(100);
+
+    ERC20::approve(spender, amount);
+}
+
+#[test]
+#[available_gas(2000000)]
+fn test__approve() {
+    let (owner, supply) = setup();
+
+    let spender: ContractAddress = contract_address_const::<2>();
+    let amount: u256 = u256_from_felt252(100);
+
+    ERC20::_approve(owner, spender, amount);
+    assert(ERC20::allowance(owner, spender) == amount, 'Spender not approved correctly');
+}
+
+#[test]
+#[available_gas(2000000)]
+#[should_panic(expected = ('ERC20: approve from 0', ))]
+fn test__approve_from_zero() {
+    let owner: ContractAddress = contract_address_const::<0>();
+    let spender: ContractAddress = contract_address_const::<1>();
+    let amount: u256 = u256_from_felt252(100);
+    ERC20::_approve(owner, spender, amount);
+}
+
+#[test]
+#[available_gas(2000000)]
+#[should_panic(expected = ('ERC20: approve to 0', ))]
+fn test__approve_to_zero() {
+    let (owner, supply) = setup();
+
+    let spender: ContractAddress = contract_address_const::<0>();
+    let amount: u256 = u256_from_felt252(100);
+    ERC20::_approve(owner, spender, amount);
+}
+
+#[test]
+#[available_gas(2000000)]
+fn test_transfer() {
+    let (sender, supply) = setup();
+
+    let recipient: ContractAddress = contract_address_const::<2>();
+    let amount: u256 = u256_from_felt252(100);
+    let success: bool = ERC20::transfer(recipient, amount);
+
+    assert(success, 'Should return true');
+    assert(ERC20::balance_of(recipient) == amount, 'Balance should eq amount');
+    assert(ERC20::balance_of(sender) == supply - amount, 'Should eq supply - amount');
+    assert(ERC20::total_supply() == supply, 'Total supply should not change');
+}
+
+#[test]
+#[available_gas(2000000)]
+fn test__transfer() {
+    let (sender, supply) = setup();
+
+    let recipient: ContractAddress = contract_address_const::<2>();
+    let amount: u256 = u256_from_felt252(100);
+    ERC20::_transfer(sender, recipient, amount);
+
+    assert(ERC20::balance_of(recipient) == amount, 'Balance should eq amount');
+    assert(ERC20::balance_of(sender) == supply - amount, 'Should eq supply - amount');
+    assert(ERC20::total_supply() == supply, 'Total supply should not change');
+}
+
+#[test]
+#[available_gas(2000000)]
+#[should_panic(expected = ('u256_sub Overflow', ))]
+fn test__transfer_not_enough_balance() {
+    let (sender, supply) = setup();
+
+    let recipient: ContractAddress = contract_address_const::<2>();
+    let amount: u256 = supply + u256_from_felt252(1);
+    ERC20::_transfer(sender, recipient, amount);
+}
+
+#[test]
+#[available_gas(2000000)]
+#[should_panic(expected = ('ERC20: transfer from 0', ))]
+fn test__transfer_from_zero() {
+    let sender: ContractAddress = contract_address_const::<0>();
+    let recipient: ContractAddress = contract_address_const::<1>();
+    let amount: u256 = u256_from_felt252(100);
+    ERC20::_transfer(sender, recipient, amount);
+}
+
+#[test]
+#[available_gas(2000000)]
+#[should_panic(expected = ('ERC20: transfer to 0', ))]
+fn test__transfer_to_zero() {
+    let (sender, supply) = setup();
+
+    let recipient: ContractAddress = contract_address_const::<0>();
+    let amount: u256 = u256_from_felt252(100);
+    ERC20::_transfer(sender, recipient, amount);
+}
+
+#[test]
+#[available_gas(2000000)]
+fn test_transfer_from() {
+    let (owner, supply) = setup();
+
+    let recipient: ContractAddress = contract_address_const::<2>();
+    let spender: ContractAddress = contract_address_const::<3>();
+    let amount: u256 = u256_from_felt252(100);
+
+    ERC20::approve(spender, amount);
+
+    set_caller_address(spender);
+
+    let success: bool = ERC20::transfer_from(owner, recipient, amount);
+    assert(success, 'Should return true');
+
+    // Will dangle without setting as a var
+    let spender_allowance: u256 = ERC20::allowance(owner, spender);
+
+    assert(ERC20::balance_of(recipient) == amount, 'Should eq amount');
+    assert(ERC20::balance_of(owner) == supply - amount, 'Should eq suppy - amount');
+    assert(spender_allowance == u256_from_felt252(0), 'Should eq 0');
+    assert(ERC20::total_supply() == supply, 'Total supply should not change');
+}
+
+#[test]
+#[available_gas(2000000)]
+fn test_transfer_from_doesnt_consume_infinite_allowance() {
+    let (owner, supply) = setup();
+
+    let recipient: ContractAddress = contract_address_const::<2>();
+    let spender: ContractAddress = contract_address_const::<3>();
+    let amount: u256 = u256_from_felt252(100);
+
+    ERC20::approve(spender, MAX_U256());
+
+    set_caller_address(spender);
+    ERC20::transfer_from(owner, recipient, amount);
+
+    let spender_allowance: u256 = ERC20::allowance(owner, spender);
+    assert(spender_allowance == MAX_U256(), 'Allowance should not change');
+}
+
+#[test]
+#[available_gas(2000000)]
+#[should_panic(expected = ('u256_sub Overflow', ))]
+fn test_transfer_from_greater_than_allowance() {
+    let (owner, supply) = setup();
+
+    let recipient: ContractAddress = contract_address_const::<2>();
+    let spender: ContractAddress = contract_address_const::<3>();
+    let amount: u256 = u256_from_felt252(100);
+    let amount_plus_one: u256 = amount + u256_from_felt252(1);
+
+    ERC20::approve(spender, amount);
+
+    set_caller_address(spender);
+
+    ERC20::transfer_from(owner, recipient, amount_plus_one);
+}
+
+#[test]
+#[available_gas(2000000)]
+#[should_panic(expected = ('ERC20: transfer to 0', ))]
+fn test_transfer_from_to_zero_address() {
+    let (owner, supply) = setup();
+
+    let recipient: ContractAddress = contract_address_const::<0>();
+    let spender: ContractAddress = contract_address_const::<3>();
+    let amount: u256 = u256_from_felt252(100);
+
+    ERC20::approve(spender, amount);
+
+    set_caller_address(spender);
+
+    ERC20::transfer_from(owner, recipient, amount);
+}
+
+#[test]
+#[available_gas(2000000)]
+#[should_panic(expected = ('u256_sub Overflow', ))]
+fn test_transfer_from_from_zero_address() {
+    let (owner, supply) = setup();
+
+    let zero_address: ContractAddress = contract_address_const::<0>();
+    let recipient: ContractAddress = contract_address_const::<2>();
+    let spender: ContractAddress = contract_address_const::<3>();
+    let amount: u256 = u256_from_felt252(100);
+
+    set_caller_address(zero_address);
+
+    ERC20::transfer_from(owner, recipient, amount);
+}
+
+#[test]
+#[available_gas(2000000)]
+fn test_increase_allowance() {
+    let (owner, supply) = setup();
+
+    let spender: ContractAddress = contract_address_const::<2>();
+    let amount: u256 = u256_from_felt252(100);
+
+    ERC20::approve(spender, amount);
+    let success: bool = ERC20::increase_allowance(spender, amount);
+    assert(success, 'Should return true');
+
+    let spender_allowance: u256 = ERC20::allowance(owner, spender);
+    assert(spender_allowance == amount + amount, 'Should be amount * 2');
+}
+
+#[test]
+#[available_gas(2000000)]
+#[should_panic(expected = ('ERC20: approve to 0', ))]
+fn test_increase_allowance_to_zero_address() {
+    let (owner, supply) = setup();
+
+    let spender: ContractAddress = contract_address_const::<0>();
+    let amount: u256 = u256_from_felt252(100);
+
+    ERC20::increase_allowance(spender, amount);
+}
+
+#[test]
+#[available_gas(2000000)]
+#[should_panic(expected = ('ERC20: approve from 0', ))]
+fn test_increase_allowance_from_zero_address() {
+    let (owner, supply) = setup();
+
+    let zero_address: ContractAddress = contract_address_const::<0>();
+    let spender: ContractAddress = contract_address_const::<2>();
+    let amount: u256 = u256_from_felt252(100);
+
+    set_caller_address(zero_address);
+
+    ERC20::increase_allowance(spender, amount);
+}
+
+#[test]
+#[available_gas(2000000)]
+fn test_decrease_allowance() {
+    let (owner, supply) = setup();
+
+    let spender: ContractAddress = contract_address_const::<2>();
+    let amount: u256 = u256_from_felt252(100);
+
+    ERC20::approve(spender, amount);
+    let success: bool = ERC20::decrease_allowance(spender, amount);
+    assert(success, 'Should return true');
+
+    let spender_allowance: u256 = ERC20::allowance(owner, spender);
+    assert(spender_allowance == amount - amount, 'Should be 0');
+}
+
+#[test]
+#[available_gas(2000000)]
+#[should_panic(expected = ('u256_sub Overflow', ))]
+fn test_decrease_allowance_to_zero_address() {
+    let (owner, supply) = setup();
+
+    let spender: ContractAddress = contract_address_const::<0>();
+    let amount: u256 = u256_from_felt252(100);
+
+    ERC20::decrease_allowance(spender, amount);
+}
+
+#[test]
+#[available_gas(2000000)]
+#[should_panic(expected = ('u256_sub Overflow', ))]
+fn test_decrease_allowance_from_zero_address() {
+    let (owner, supply) = setup();
+
+    let zero_address: ContractAddress = contract_address_const::<0>();
+    let spender: ContractAddress = contract_address_const::<2>();
+    let amount: u256 = u256_from_felt252(100);
+
+    set_caller_address(zero_address);
+
+    ERC20::decrease_allowance(spender, amount);
+}
+
+#[test]
+#[available_gas(2000000)]
+fn test__spend_allowance_not_unlimited() {
+    let (owner, supply) = setup();
+
+    let spender: ContractAddress = contract_address_const::<2>();
+    let amount: u256 = u256_from_felt252(100);
+
+    ERC20::_approve(owner, spender, supply);
+    ERC20::_spend_allowance(owner, spender, amount);
+    assert(ERC20::allowance(owner, spender) == supply - amount, 'Should eq supply - amount');
+}
+
+#[test]
+#[available_gas(2000000)]
+fn test__spend_allowance_unlimited() {
+    let (owner, supply) = setup();
+
+    let spender: ContractAddress = contract_address_const::<2>();
+    let max_minus_one: u256 = MAX_U256() - u256_from_felt252(1);
+
+    ERC20::_approve(owner, spender, MAX_U256());
+    ERC20::_spend_allowance(owner, spender, max_minus_one);
+
+    assert(ERC20::allowance(owner, spender) == MAX_U256(), 'Allowance should not change');
+}
+
+#[test]
+#[available_gas(2000000)]
+fn test__mint() {
+    let minter: ContractAddress = contract_address_const::<2>();
+    let amount: u256 = u256_from_felt252(100);
+
+    ERC20::_mint(minter, amount);
+
+    let minter_balance: u256 = ERC20::balance_of(minter);
+    assert(minter_balance == amount, 'Should eq amount');
+
+    assert(ERC20::total_supply() == amount, 'Should eq total supply');
+}
+
+#[test]
+#[available_gas(2000000)]
+#[should_panic(expected = ('ERC20: mint to 0', ))]
+fn test__mint_to_zero() {
+    let minter: ContractAddress = contract_address_const::<0>();
+    let amount: u256 = u256_from_felt252(100);
+
+    ERC20::_mint(minter, amount);
+}
+
+#[test]
+#[available_gas(2000000)]
+fn test__burn() {
+    let (owner, supply) = setup();
+
+    let amount: u256 = u256_from_felt252(100);
+    ERC20::_burn(owner, amount);
+
+    assert(ERC20::total_supply() == supply - amount, 'Should eq supply - amount');
+    assert(ERC20::balance_of(owner) == supply - amount, 'Should eq supply - amount');
+}
+
+#[test]
+#[available_gas(2000000)]
+#[should_panic(expected = ('ERC20: burn from 0', ))]
+fn test__burn_from_zero() {
+    setup();
+    let zero_address: ContractAddress = contract_address_const::<0>();
+    let amount: u256 = u256_from_felt252(100);
+
+    ERC20::_burn(zero_address, amount);
+}
diff --git a/src/openzeppelin/tests/test_mytest.cairo b/src/openzeppelin/tests/test_mytest.cairo
deleted file mode 100644
index 1f5f2ca0e..000000000
--- a/src/openzeppelin/tests/test_mytest.cairo
+++ /dev/null
@@ -1,5 +0,0 @@
-#[test]
-#[available_gas(2000000)]
-fn test_pass() {
-    assert(true, 'Should pass');
-}
diff --git a/src/openzeppelin/token.cairo b/src/openzeppelin/token.cairo
new file mode 100644
index 000000000..bfe4665e0
--- /dev/null
+++ b/src/openzeppelin/token.cairo
@@ -0,0 +1 @@
+mod erc20;
diff --git a/src/openzeppelin/token/erc20.cairo b/src/openzeppelin/token/erc20.cairo
new file mode 100644
index 000000000..ad231f2d2
--- /dev/null
+++ b/src/openzeppelin/token/erc20.cairo
@@ -0,0 +1,207 @@
+use starknet::ContractAddress;
+
+trait IERC20 {
+    fn name() -> felt252;
+    fn symbol() -> felt252;
+    fn decimals() -> u8;
+    fn total_supply() -> u256;
+    fn balance_of(account: ContractAddress) -> u256;
+    fn allowance(owner: ContractAddress, spender: ContractAddress) -> u256;
+    fn transfer(recipient: ContractAddress, amount: u256) -> bool;
+    fn transfer_from(sender: ContractAddress, recipient: ContractAddress, amount: u256) -> bool;
+    fn approve(spender: ContractAddress, amount: u256) -> bool;
+}
+
+#[contract]
+mod ERC20 {
+    use openzeppelin::token::erc20::IERC20;
+    use starknet::get_caller_address;
+    use starknet::ContractAddress;
+    use starknet::contract_address_const;
+    use starknet::ContractAddressZeroable;
+    use zeroable::Zeroable;
+
+    struct Storage {
+        _name: felt252,
+        _symbol: felt252,
+        _total_supply: u256,
+        _balances: LegacyMap<ContractAddress, u256>,
+        _allowances: LegacyMap<(ContractAddress, ContractAddress), u256>,
+    }
+
+    #[event]
+    fn Transfer(from: ContractAddress, to: ContractAddress, value: u256) {}
+
+    #[event]
+    fn Approval(owner: ContractAddress, spender: ContractAddress, value: u256) {}
+
+    impl ERC20 of IERC20 {
+        fn name() -> felt252 {
+            _name::read()
+        }
+
+        fn symbol() -> felt252 {
+            _symbol::read()
+        }
+
+        fn decimals() -> u8 {
+            18_u8
+        }
+
+        fn total_supply() -> u256 {
+            _total_supply::read()
+        }
+
+        fn balance_of(account: ContractAddress) -> u256 {
+            _balances::read(account)
+        }
+
+        fn allowance(owner: ContractAddress, spender: ContractAddress) -> u256 {
+            _allowances::read((owner, spender))
+        }
+
+        fn transfer(recipient: ContractAddress, amount: u256) -> bool {
+            let sender = get_caller_address();
+            _transfer(sender, recipient, amount);
+            true
+        }
+
+        fn transfer_from(
+            sender: ContractAddress, recipient: ContractAddress, amount: u256
+        ) -> bool {
+            let caller = get_caller_address();
+            _spend_allowance(sender, caller, amount);
+            _transfer(sender, recipient, amount);
+            true
+        }
+
+        fn approve(spender: ContractAddress, amount: u256) -> bool {
+            let caller = get_caller_address();
+            _approve(caller, spender, amount);
+            true
+        }
+    }
+
+    #[constructor]
+    fn constructor(
+        name: felt252, symbol: felt252, initial_supply: u256, recipient: ContractAddress
+    ) {
+        initializer(name, symbol);
+        _mint(recipient, initial_supply);
+    }
+
+    #[view]
+    fn name() -> felt252 {
+        ERC20::name()
+    }
+
+    #[view]
+    fn symbol() -> felt252 {
+        ERC20::symbol()
+    }
+
+    #[view]
+    fn decimals() -> u8 {
+        ERC20::decimals()
+    }
+
+    #[view]
+    fn total_supply() -> u256 {
+        ERC20::total_supply()
+    }
+
+    #[view]
+    fn balance_of(account: ContractAddress) -> u256 {
+        ERC20::balance_of(account)
+    }
+
+    #[view]
+    fn allowance(owner: ContractAddress, spender: ContractAddress) -> u256 {
+        ERC20::allowance(owner, spender)
+    }
+
+    #[external]
+    fn transfer(recipient: ContractAddress, amount: u256) -> bool {
+        ERC20::transfer(recipient, amount)
+    }
+
+    #[external]
+    fn transfer_from(sender: ContractAddress, recipient: ContractAddress, amount: u256) -> bool {
+        ERC20::transfer_from(sender, recipient, amount)
+    }
+
+    #[external]
+    fn approve(spender: ContractAddress, amount: u256) -> bool {
+        ERC20::approve(spender, amount)
+    }
+
+    #[external]
+    fn increase_allowance(spender: ContractAddress, added_value: u256) -> bool {
+        _increase_allowance(spender, added_value)
+    }
+
+    #[external]
+    fn decrease_allowance(spender: ContractAddress, subtracted_value: u256) -> bool {
+        _decrease_allowance(spender, subtracted_value)
+    }
+
+    ///
+    /// Internals
+    ///
+
+    fn initializer(name_: felt252, symbol_: felt252) {
+        _name::write(name_);
+        _symbol::write(symbol_);
+    }
+
+    fn _increase_allowance(spender: ContractAddress, added_value: u256) -> bool {
+        let caller = get_caller_address();
+        _approve(caller, spender, _allowances::read((caller, spender)) + added_value);
+        true
+    }
+
+    fn _decrease_allowance(spender: ContractAddress, subtracted_value: u256) -> bool {
+        let caller = get_caller_address();
+        _approve(caller, spender, _allowances::read((caller, spender)) - subtracted_value);
+        true
+    }
+
+    fn _mint(recipient: ContractAddress, amount: u256) {
+        assert(!recipient.is_zero(), 'ERC20: mint to 0');
+        _total_supply::write(_total_supply::read() + amount);
+        _balances::write(recipient, _balances::read(recipient) + amount);
+        Transfer(contract_address_const::<0>(), recipient, amount);
+    }
+
+    fn _burn(account: ContractAddress, amount: u256) {
+        assert(!account.is_zero(), 'ERC20: burn from 0');
+        _total_supply::write(_total_supply::read() - amount);
+        _balances::write(account, _balances::read(account) - amount);
+        Transfer(account, contract_address_const::<0>(), amount);
+    }
+
+    fn _approve(owner: ContractAddress, spender: ContractAddress, amount: u256) {
+        assert(!owner.is_zero(), 'ERC20: approve from 0');
+        assert(!spender.is_zero(), 'ERC20: approve to 0');
+        _allowances::write((owner, spender), amount);
+        Approval(owner, spender, amount);
+    }
+
+    fn _transfer(sender: ContractAddress, recipient: ContractAddress, amount: u256) {
+        assert(!sender.is_zero(), 'ERC20: transfer from 0');
+        assert(!recipient.is_zero(), 'ERC20: transfer to 0');
+        _balances::write(sender, _balances::read(sender) - amount);
+        _balances::write(recipient, _balances::read(recipient) + amount);
+        Transfer(sender, recipient, amount);
+    }
+
+    fn _spend_allowance(owner: ContractAddress, spender: ContractAddress, amount: u256) {
+        let current_allowance = _allowances::read((owner, spender));
+        let ONES_MASK = 0xffffffffffffffffffffffffffffffff_u128;
+        let is_unlimited_allowance =
+            current_allowance.low == ONES_MASK & current_allowance.high == ONES_MASK;
+        if !is_unlimited_allowance {
+            _approve(owner, spender, current_allowance - amount);
+        }
+    }
+}