diff --git a/Cargo.lock b/Cargo.lock
index 00ad6b6286..8c3955f880 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -449,7 +449,7 @@ checksum = "2b09cae092c27b6f1bde952653a22708691802e57bfef4a2973b80bea21efd3f"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -560,7 +560,7 @@ dependencies = [
  "proc-macro-error2",
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -577,7 +577,7 @@ dependencies = [
  "proc-macro-error2",
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
  "syn-solidity",
  "tiny-keccak",
 ]
@@ -595,7 +595,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "serde_json",
- "syn 2.0.77",
+ "syn 2.0.96",
  "syn-solidity",
 ]
 
@@ -1391,6 +1391,7 @@ dependencies = [
  "evm-storage-verifier",
  "rlp",
  "sha3 0.10.8",
+ "slotlib",
  "thiserror",
  "unionlabs",
 ]
@@ -1795,7 +1796,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "strum 0.26.3",
- "syn 2.0.77",
+ "syn 2.0.96",
  "thiserror",
 ]
 
@@ -1854,7 +1855,7 @@ checksum = "16e62a023e7c117e27523144c5d2459f4397fcc3cab0085af8e2224f643a0193"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -1865,7 +1866,7 @@ checksum = "a27b8a3a6e1a44fa4c8baf1f653e4172e81486d4941f2237e20dc2d0cf4ddff1"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -1930,7 +1931,7 @@ checksum = "3c87f3f15e7794432337fc718554eaa4dc8f04c9677a950ffe366f20a162ae42"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -2055,7 +2056,7 @@ dependencies = [
  "heck 0.4.1",
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -2585,7 +2586,7 @@ dependencies = [
  "proc-macro-crate 3.1.0",
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
  "syn_derive",
 ]
 
@@ -2989,7 +2990,7 @@ dependencies = [
  "heck 0.5.0",
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -3430,7 +3431,7 @@ checksum = "1b5658b1dc64e10b56ae7a449f678f96932a96f6cfad1769d608d1d1d656480a"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -3478,7 +3479,7 @@ checksum = "c8ef1b5835a65fcca3ab8b9a02b4f4dacc78e233a5c2f20b270efb9db0666d12"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -3840,7 +3841,7 @@ checksum = "f46882e17999c6cc590af592290432be3bce0428cb0d5f8b6715e4dc7b383eb3"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -4095,7 +4096,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "strsim 0.10.0",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -4106,7 +4107,7 @@ checksum = "a668eda54683121533a393014d8692171709ff57a7d61f187b6e782719f8933f"
 dependencies = [
  "darling_core",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -4191,7 +4192,7 @@ checksum = "d65d7ce8132b7c0e54497a4d9a55a1c2a0912a0d786cf894472ba818fba45762"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -4201,7 +4202,7 @@ source = "git+https://github.com/unionlabs/arbitrary#b5796f1a0066dc5707d7681a80e
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -4222,7 +4223,7 @@ dependencies = [
  "darling",
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -4232,7 +4233,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4abae7035bf79b9877b779505d8cf3749285b80c43941eda66604841889451dc"
 dependencies = [
  "derive_builder_core",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -4265,7 +4266,7 @@ checksum = "cb7330aeadfbe296029522e6c40f315320aba36fc43a5b3632f3795348f3bd22"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
  "unicode-xid",
 ]
 
@@ -4637,7 +4638,7 @@ checksum = "f282cfdfe92516eb26c2af8589c274c7c17681f5ecc03c18255fe741c6aa64eb"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -4649,7 +4650,7 @@ dependencies = [
  "once_cell",
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -4660,7 +4661,7 @@ checksum = "6d3e2610493c0a1fc3bf33fb420650c6ebf7990c55e3d5e71a57bee374486824"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -4829,7 +4830,7 @@ dependencies = [
  "prettier-please",
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -5131,7 +5132,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "sp-crypto-hashing",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -5144,7 +5145,7 @@ dependencies = [
  "proc-macro-crate 3.1.0",
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -5155,7 +5156,7 @@ checksum = "ed971c6435503a099bdac99fe4c5bea08981709e5b5a0a8535a1856f48561191"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -5258,7 +5259,7 @@ checksum = "87750cf4b7a4c0625b1529e4c543c2182106e4dedc60a2a6455e00d212c489ac"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -6793,7 +6794,7 @@ dependencies = [
  "proc-macro-crate 3.1.0",
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -7041,6 +7042,7 @@ dependencies = [
  "linea-types",
  "linea-zktrie",
  "rlp",
+ "slotlib",
  "thiserror",
  "unionlabs",
 ]
@@ -7117,7 +7119,7 @@ dependencies = [
  "macro_magic_core",
  "macro_magic_macros",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -7131,7 +7133,7 @@ dependencies = [
  "macro_magic_core_macros",
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -7142,7 +7144,7 @@ checksum = "b02abfe41815b5bd98dbd4260173db2c116dda171dc0fe7838cb206333b83308"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -7153,7 +7155,7 @@ checksum = "73ea28ee64b88876bf45277ed9a5817c1817df061a74f2b988971a12570e5869"
 dependencies = [
  "macro_magic_core",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -7162,7 +7164,7 @@ version = "0.0.0"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -7357,7 +7359,7 @@ dependencies = [
  "quote",
  "serde",
  "serde_json",
- "syn 2.0.77",
+ "syn 2.0.96",
  "tokio",
  "tracing",
 ]
@@ -7368,7 +7370,7 @@ version = "0.0.0"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -7975,7 +7977,7 @@ dependencies = [
  "serde_json",
  "strum 0.26.3",
  "strum_macros 0.26.4",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -8222,7 +8224,7 @@ dependencies = [
  "proc-macro-crate 3.1.0",
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -8299,7 +8301,7 @@ checksum = "a948666b637a0f465e8564c73e89d4dde00d72d4d473cc972f390fc3dcee7d9c"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -8663,7 +8665,7 @@ dependencies = [
  "pest_meta",
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -8805,7 +8807,7 @@ checksum = "2f38a4412a78282e09a2cf38d195ea5420d15ba0602cb375210efbc877243965"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -8926,7 +8928,7 @@ dependencies = [
  "proc-macro-crate 3.1.0",
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -8967,7 +8969,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "regex",
- "syn 2.0.77",
+ "syn 2.0.96",
  "thiserror",
 ]
 
@@ -9040,7 +9042,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "22020dfcf177fcc7bf5deaf7440af371400c67c0de14c399938d8ed4fb4645d3"
 dependencies = [
  "proc-macro2",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -9050,7 +9052,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "479cf940fbbb3426c32c5d5176f62ad57549a0bb84773423ba8be9d089f5faba"
 dependencies = [
  "proc-macro2",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -9158,7 +9160,7 @@ dependencies = [
  "proc-macro-error-attr2",
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -9181,14 +9183,14 @@ checksum = "834da187cfe638ae8abb0203f0b33e5ccdb02a28e7199f2f47b3e2754f50edca"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.86"
+version = "1.0.93"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5e719e8df665df0d1c8fbfd238015744736151d4445ec0836b8e628aae103b77"
+checksum = "60946a68e5f9d28b0dc1c21bb8a97ee7d018a8b322fa57838ba31cc878e22d99"
 dependencies = [
  "unicode-ident",
 ]
@@ -9290,7 +9292,7 @@ dependencies = [
  "prost 0.12.6",
  "prost-types",
  "regex",
- "syn 2.0.77",
+ "syn 2.0.96",
  "tempfile",
  "which",
 ]
@@ -9305,7 +9307,7 @@ dependencies = [
  "itertools 0.12.1",
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -9318,7 +9320,7 @@ dependencies = [
  "itertools 0.13.0",
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -9704,7 +9706,7 @@ checksum = "bcc303e793d3734489387d205e9b186fac9c6cfacedd98cbb2e8a5943595f3e6"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -10276,7 +10278,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "serde_derive_internals",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -10351,6 +10353,7 @@ dependencies = [
  "rlp",
  "scroll-codec",
  "scroll-light-client-types",
+ "slotlib",
  "thiserror",
  "unionlabs",
  "zktrie",
@@ -10576,7 +10579,7 @@ checksum = "500cbc0ebeb6f46627f50f3f5811ccf6bf00643be300b4c3eabc0ef55dc5b5ba"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -10587,7 +10590,7 @@ checksum = "18d26a20a969b9e3fdf2fc2d9f21eda6c40e2de84c9408bb5d3b05d499aae711"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -10642,7 +10645,7 @@ checksum = "0b2e6b945e9d3df726b65d6ee24060aff8e3533d431f677a9695db04eff9dfdb"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -10693,7 +10696,7 @@ dependencies = [
  "darling",
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -10902,6 +10905,29 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "slot-calculator"
+version = "0.1.0"
+dependencies = [
+ "clap 4.5.4",
+ "hex-literal",
+ "proc-macro2",
+ "slotlib",
+ "syn-solidity",
+ "typed-arena",
+ "unionlabs",
+]
+
+[[package]]
+name = "slotlib"
+version = "0.1.0"
+dependencies = [
+ "hex-literal",
+ "sha2 0.10.8",
+ "sha3 0.10.8",
+ "unionlabs-primitives",
+]
+
 [[package]]
 name = "smallbitvec"
 version = "2.5.3"
@@ -11259,7 +11285,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d904e7009df136af5297832a3ace3370cd14ff1546a232f4f185036c2736fcac"
 dependencies = [
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -11467,7 +11493,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "rustversion",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -11480,7 +11506,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "rustversion",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -11500,7 +11526,7 @@ dependencies = [
  "quote",
  "serde",
  "serde_json",
- "syn 2.0.77",
+ "syn 2.0.96",
  "trybuild",
 ]
 
@@ -11557,9 +11583,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "2.0.77"
+version = "2.0.96"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9f35bcdf61fd8e7be6caf75f429fdca8beb3ed76584befb503b1569faee373ed"
+checksum = "d5d0adab1ae378d7f53bdebc67a39f1f151407ef230f0ce2883572f5d8985c80"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -11568,14 +11594,14 @@ dependencies = [
 
 [[package]]
 name = "syn-solidity"
-version = "0.8.12"
+version = "0.8.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f76fe0a3e1476bdaa0775b9aec5b869ed9520c2b2fedfe9c6df3618f8ea6290b"
+checksum = "b84e4d83a0a6704561302b917a932484e1cae2d8c6354c64be8b7bac1c1fe057"
 dependencies = [
  "paste",
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -11587,7 +11613,7 @@ dependencies = [
  "proc-macro-error",
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -11860,7 +11886,7 @@ checksum = "46c3384250002a6d5af4d114f2845d37b57521033f30d5c3f46c4d70e1197533"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -12046,7 +12072,7 @@ checksum = "693d596312e88961bc67d7f1f97af8a70227d9f90c31bba5806eec004978d752"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -12325,7 +12351,7 @@ checksum = "34704c8d6ebcbc939824180af020566b01a7c01f80641264eba0999f6c2b6be7"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -12587,7 +12613,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a615d6c2764852a2e88a4f16e9ce1ea49bb776b5872956309e170d63a042a34f"
 dependencies = [
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -12758,6 +12784,7 @@ dependencies = [
  "serde_json",
  "sha2 0.10.8",
  "sha3 0.10.8",
+ "slotlib",
  "ssz",
  "static_assertions 1.1.0 (git+https://github.com/nvzqz/static-assertions)",
  "subtle-encoding",
@@ -13993,7 +14020,7 @@ dependencies = [
  "once_cell",
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
  "wasm-bindgen-shared",
 ]
 
@@ -14027,7 +14054,7 @@ checksum = "e94f17b526d0a461a191c78ea52bbce64071ed5c04c9ffe424dcb38f74171bb7"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
  "wasm-bindgen-backend",
  "wasm-bindgen-shared",
 ]
@@ -14439,7 +14466,7 @@ checksum = "9ce1b18ccd8e73a9321186f97e46f9f04b778851177567b1975109d26a08d2a6"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
@@ -14459,7 +14486,7 @@ checksum = "ce36e65b0d2999d2aafac989fb249189a141aee1f53c612c1f37d72631959f69"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.77",
+ "syn 2.0.96",
 ]
 
 [[package]]
diff --git a/Cargo.toml b/Cargo.toml
index 0ac663b9a5..1848d89147 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -96,6 +96,7 @@ members = [
 
   "tools/devnet-utils",
   "tools/parse-wasm-client-type",
+  "tools/slot-calculator",
   "tools/tidy",
   "tools/move-bindgen",
   "lib/move-bindgen-derive",
@@ -176,6 +177,7 @@ members = [
   "lib/state-lens-light-client-types",
   "lib/create3",
   "lib/linea-types",
+  "lib/slotlib",
 ]
 
 [workspace.package]
@@ -264,6 +266,7 @@ movement-light-client-types = { path = "lib/movement-light-client-types", defaul
 cosmos-sdk-event = { path = "lib/cosmos-sdk-event", default-features = false }
 
 serde-utils      = { path = "lib/serde-utils", default-features = false }
+slotlib          = { path = "lib/slotlib", default-features = false }
 ssz              = { path = "lib/ssz", default-features = false }
 ssz-derive       = { path = "lib/ssz-derive", default-features = false }
 subset-of        = { path = "lib/subset-of", default-features = false }
diff --git a/lib/arbitrum-verifier/Cargo.toml b/lib/arbitrum-verifier/Cargo.toml
index ce8486cc70..4c8b3089d0 100644
--- a/lib/arbitrum-verifier/Cargo.toml
+++ b/lib/arbitrum-verifier/Cargo.toml
@@ -19,6 +19,7 @@ arbitrum-light-client-types = { workspace = true }
 evm-storage-verifier        = { workspace = true }
 rlp                         = { workspace = true }
 sha3                        = { workspace = true }
+slotlib                     = { workspace = true }
 thiserror                   = { workspace = true }
 unionlabs                   = { workspace = true }
 
diff --git a/lib/arbitrum-verifier/src/lib.rs b/lib/arbitrum-verifier/src/lib.rs
index d8ef983978..b01a3aa2b3 100644
--- a/lib/arbitrum-verifier/src/lib.rs
+++ b/lib/arbitrum-verifier/src/lib.rs
@@ -3,10 +3,8 @@ use core::fmt::Debug;
 use arbitrum_light_client_types::{ClientState, Header};
 use evm_storage_verifier::{verify_account_storage_root, verify_storage_proof};
 use sha3::{Digest, Keccak256};
-use unionlabs::{
-    ethereum::slot::{MappingKey, Slot},
-    primitives::{H256, U256},
-};
+use slotlib::{MappingKey, Slot};
+use unionlabs::primitives::{H256, U256};
 
 #[derive(thiserror::Error, Debug, PartialEq, Clone)]
 pub enum Error {
diff --git a/lib/linea-verifier/Cargo.toml b/lib/linea-verifier/Cargo.toml
index 73b757f586..a829b1fb3f 100644
--- a/lib/linea-verifier/Cargo.toml
+++ b/lib/linea-verifier/Cargo.toml
@@ -21,5 +21,6 @@ linea-light-client-types = { workspace = true }
 linea-types              = { workspace = true }
 linea-zktrie             = { workspace = true }
 rlp                      = { workspace = true }
+slotlib                  = { workspace = true }
 thiserror                = { workspace = true }
 unionlabs                = { workspace = true }
diff --git a/lib/linea-verifier/src/lib.rs b/lib/linea-verifier/src/lib.rs
index 333fd703f2..0ec30bece6 100644
--- a/lib/linea-verifier/src/lib.rs
+++ b/lib/linea-verifier/src/lib.rs
@@ -4,10 +4,8 @@ use evm_storage_verifier::{verify_account_storage_root, verify_storage_proof};
 use gnark_mimc::new_mimc_constants_bls12_377;
 use linea_light_client_types::{ClientState, Header};
 use linea_types::account::ZkAccount;
-use unionlabs::{
-    ethereum::slot::{MappingKey, Slot},
-    primitives::{H256, U256},
-};
+use slotlib::{MappingKey, Slot};
+use unionlabs::primitives::{H256, U256};
 
 #[derive(Debug, Clone, PartialEq, thiserror::Error)]
 pub enum Error {
diff --git a/lib/scroll-verifier/Cargo.toml b/lib/scroll-verifier/Cargo.toml
index 79362f017c..3944dc48f4 100644
--- a/lib/scroll-verifier/Cargo.toml
+++ b/lib/scroll-verifier/Cargo.toml
@@ -19,6 +19,7 @@ evm-storage-verifier      = { workspace = true }
 rlp                       = { workspace = true }
 scroll-codec              = { workspace = true }
 scroll-light-client-types = { workspace = true }
+slotlib                   = { workspace = true }
 thiserror                 = { workspace = true }
 unionlabs                 = { workspace = true }
 zktrie                    = { workspace = true }
diff --git a/lib/scroll-verifier/src/lib.rs b/lib/scroll-verifier/src/lib.rs
index 3b31ac07e6..47f37659df 100644
--- a/lib/scroll-verifier/src/lib.rs
+++ b/lib/scroll-verifier/src/lib.rs
@@ -3,8 +3,8 @@ use core::fmt::Debug;
 use evm_storage_verifier::{verify_account_storage_root, verify_storage_proof};
 use scroll_codec::{hash_batch, HashBatchError};
 use scroll_light_client_types::{ClientState, Header};
+use slotlib::{MappingKey, Slot};
 use unionlabs::{
-    ethereum::slot::{MappingKey, Slot},
     primitives::{H160, H256, U256},
     scroll::account::Account,
 };
diff --git a/lib/slotlib/Cargo.toml b/lib/slotlib/Cargo.toml
new file mode 100644
index 0000000000..e77a1adee7
--- /dev/null
+++ b/lib/slotlib/Cargo.toml
@@ -0,0 +1,15 @@
+[package]
+edition.workspace      = true
+license-file.workspace = true
+name                   = "slotlib"
+repository.workspace   = true
+version                = "0.1.0"
+
+[dependencies]
+hex-literal          = { workspace = true }
+sha2                 = { workspace = true }
+sha3                 = { workspace = true }
+unionlabs-primitives = { workspace = true }
+
+[lints]
+workspace = true
diff --git a/lib/slotlib/src/lib.rs b/lib/slotlib/src/lib.rs
new file mode 100644
index 0000000000..137f5f5dd8
--- /dev/null
+++ b/lib/slotlib/src/lib.rs
@@ -0,0 +1,3 @@
+pub mod slot;
+
+pub use crate::slot::{MappingKey, Slot};
diff --git a/lib/slotlib/src/slot.rs b/lib/slotlib/src/slot.rs
new file mode 100644
index 0000000000..1e4a4abb12
--- /dev/null
+++ b/lib/slotlib/src/slot.rs
@@ -0,0 +1,85 @@
+use sha2::Digest;
+use sha3::Keccak256;
+use unionlabs_primitives::{H256, U256};
+
+// Duplication of keccak256 function defined in /lib/unionlabs/ethereum.rs, otherwise it creates a dependency cycle.
+#[inline]
+#[must_use]
+pub fn keccak256(bytes: impl AsRef<[u8]>) -> H256 {
+    Keccak256::new().chain_update(bytes).finalize().into()
+}
+
+/// Solidity storage slot calculations. Note that this currently does not handle dynamic arrays with packed values; the index passed to [`Slot::Array`] will need to be calculated manually in this case.
+pub enum Slot<'a> {
+    /// (base slot, index)
+    Array(&'a Slot<'a>, U256),
+    /// (base slot, mapping key)
+    Mapping(&'a Slot<'a>, MappingKey<'a>),
+    Offset(U256),
+}
+
+impl Slot<'_> {
+    // https://docs.soliditylang.org/en/latest/internals/layout_in_storage.html#mappings-and-dynamic-arrays
+    #[inline]
+    #[must_use = "calculating the slot has no effect"]
+    // REVIEW: Make const? <https://crates.io/crates/keccak-const/0.2.0>
+    pub fn slot(&self) -> U256 {
+        match self {
+            // keccak256(p)
+            Slot::Array(p, idx) => {
+                U256::from_be_bytes(*keccak256(p.slot().to_be_bytes()).get()) + *idx
+            }
+            // keccak256(h(k) . p)
+            Slot::Mapping(p, k) => {
+                let mut hasher = Keccak256::new();
+                match &k {
+                    MappingKey::String(string) => hasher.update(string.as_bytes()),
+                    MappingKey::Uint256(k) => hasher.update(k.to_be_bytes()),
+                    MappingKey::Uint64(k) => hasher.update(U256::from(*k).to_be_bytes()),
+                    MappingKey::Bytes32(k) => hasher.update(k.get()),
+                };
+
+                U256::from_be_bytes(
+                    hasher
+                        .chain_update(p.slot().to_be_bytes())
+                        .finalize()
+                        .into(),
+                )
+            }
+            Slot::Offset(p) => *p,
+        }
+    }
+}
+
+#[derive(Debug)]
+pub enum MappingKey<'a> {
+    String(&'a str),
+    Uint256(U256),
+    Uint64(u64),
+    Bytes32(H256),
+}
+
+#[test]
+fn test() {
+    // Test contract uploaded here: https://sepolia.etherscan.io/address/0x6845dbaa9513d3d07737ea9f6e350011dcfeb9bd
+
+    // mapping(uint256 => mapping(uint256 => uint256)[])
+    let slot = Slot::Mapping(
+        &Slot::Array(
+            &Slot::Mapping(
+                &Slot::Offset(0u32.into()),
+                MappingKey::Uint256(123u32.into()),
+            ),
+            1u32.into(),
+        ),
+        MappingKey::Uint256(100u32.into()),
+    )
+    .slot();
+
+    assert_eq!(
+        <H256>::new(slot.to_be_bytes()),
+        <H256>::new(hex_literal::hex!(
+            "00a9b48fe93e5d10ebc2d9021d1477088c6292bf047876944343f57fdf3f0467"
+        ))
+    );
+}
diff --git a/lib/unionlabs/Cargo.toml b/lib/unionlabs/Cargo.toml
index 06e1007fe5..0d6c520825 100644
--- a/lib/unionlabs/Cargo.toml
+++ b/lib/unionlabs/Cargo.toml
@@ -53,6 +53,7 @@ near-primitives-core = { version = "0.21", optional = true }
 near-sdk             = { workspace = true, optional = true }
 schemars             = { workspace = true, features = ["derive"], optional = true }
 serde_bytes          = "0.11.6"
+slotlib              = { workspace = true }
 unionlabs-primitives = { workspace = true, features = ["generic-array-compat", "serde", "base64"] }
 
 [dev-dependencies]
diff --git a/lib/unionlabs/src/ethereum.rs b/lib/unionlabs/src/ethereum.rs
index 4928cc2f46..037d6ed7b0 100644
--- a/lib/unionlabs/src/ethereum.rs
+++ b/lib/unionlabs/src/ethereum.rs
@@ -1,10 +1,8 @@
 use sha2::Digest;
 use sha3::Keccak256;
+use slotlib::{MappingKey, Slot};
 
-use crate::{
-    ethereum::slot::{MappingKey, Slot},
-    primitives::{H256, U256},
-};
+use crate::primitives::{H256, U256};
 
 pub mod slot;
 
diff --git a/tools/slot-calculator/Cargo.toml b/tools/slot-calculator/Cargo.toml
new file mode 100644
index 0000000000..9b47f2fe58
--- /dev/null
+++ b/tools/slot-calculator/Cargo.toml
@@ -0,0 +1,19 @@
+[package]
+edition      = { workspace = true }
+license-file = { workspace = true }
+name         = "slot-calculator"
+publish      = false
+repository   = { workspace = true }
+version      = "0.1.0"
+
+[lints]
+workspace = true
+
+[dependencies]
+clap         = { workspace = true, features = ["derive", "help"] }
+hex-literal  = { workspace = true }
+proc-macro2  = "1.0.93"
+slotlib      = { workspace = true }
+syn-solidity = "0.8.19"
+typed-arena  = "2.0"
+unionlabs    = { workspace = true, features = ["rlp"] }
diff --git a/tools/slot-calculator/src/main.rs b/tools/slot-calculator/src/main.rs
new file mode 100644
index 0000000000..debf2c42d1
--- /dev/null
+++ b/tools/slot-calculator/src/main.rs
@@ -0,0 +1,152 @@
+use clap::{Arg, Command};
+use proc_macro2::TokenStream;
+use slotlib::{MappingKey, Slot};
+use std::{collections::VecDeque, str::FromStr};
+use syn_solidity::{parse2, Item, Type};
+use typed_arena::Arena;
+use unionlabs::primitives::{H256, U256};
+
+// Examples:
+// mapping(uint256 => uint256)
+// uint256[] => ["uint256[]"]
+// mapping(uint256 => uint256[])
+// mapping(uint256 => mapping(uint256 => uint256))
+// mapping(uint256 => mapping(uint256 => mapping(uint256 => uint256)[])[])
+// mapping(uint256 => mapping(uint256 => mapping(uint256 => mapping(uint256 => uint256)[]))[])
+// mapping(uint256 => mapping(uint256 => uint256)[])
+fn parse_layout(layout: &mut String) -> Result<Type, String> {
+    // Check if the layout already includes a visibility modifier and a variable name
+    if !layout.contains("public") && !layout.contains("internal") && !layout.contains("private") {
+        layout.push_str(" public dummyName;");
+    }
+
+    let parsed_layout = layout
+        .parse::<TokenStream>()
+        .map_err(|_| "Failed to parse layout".to_string())?;
+    let parsed_layout = parse2(parsed_layout).map_err(|e| e.to_string())?;
+
+    match &parsed_layout.items[0] {
+        Item::Variable(var) => match &var.ty {
+            Type::Mapping(map) => Ok(Type::Mapping(map.clone())),
+            Type::Array(arr) => Ok(Type::Array(arr.clone())),
+            _ => return Err("Unsupported type".to_string()),
+        },
+        _ => return Err("Unsupported item".to_string()),
+    }
+}
+
+fn parse_mapping_key<'a>(key_type: &'a Type, key: &'a str) -> MappingKey<'a> {
+    match key_type {
+        Type::Uint(_, size) => {
+            let size = size.and_then(|s| Some(s.get())).unwrap_or(256);
+            match size {
+                256 => MappingKey::Uint256(U256::from(
+                    key.parse::<u64>().expect("Invalid uint256 key"),
+                )),
+                64 => MappingKey::Uint64(key.parse::<u64>().expect("Invalid uint64 key")),
+                _ => panic!("Unsupported uint size: {}", size),
+            }
+        }
+        Type::FixedBytes(_, size) => {
+            let size = size.get();
+            match size {
+                32 => MappingKey::Bytes32(H256::from_str(key).expect("Invalid bytes32 key")),
+                _ => panic!("Unsupported bytes size: {}", size),
+            }
+        }
+        Type::String(_) => MappingKey::String(key),
+        _ => panic!("Unsupported mapping key type"),
+    }
+}
+
+fn build_slot<'a>(
+    parsed_layout: &'a Type,
+    keys: &mut VecDeque<&'a str>,
+    arena: &'a Arena<Slot<'a>>,
+) -> &'a Slot<'a> {
+    let key: &str = match keys.pop_front() {
+        Some(k) => k,
+        None => return arena.alloc(Slot::Offset(U256::from(0u32))),
+    };
+    match parsed_layout {
+        Type::Mapping(mapping) => arena.alloc(Slot::Mapping(
+            build_slot(mapping.value.as_ref(), keys, arena),
+            parse_mapping_key(mapping.key.as_ref(), key),
+        )),
+        Type::Array(arr) => arena.alloc(Slot::Array(
+            build_slot(arr.ty.as_ref(), keys, arena),
+            U256::from(key.parse::<u64>().expect("Invalid array index")),
+        )),
+        _ => panic!("Unsupported layout type or wrong key count."),
+    }
+}
+
+fn calculate_slot(layout: &str, keys: &str) -> U256 {
+    let parsed_layout = parse_layout(&mut layout.to_string()).unwrap();
+    let mut split_keys: VecDeque<&str> = keys.split(" ").collect();
+
+    let arena = Arena::new();
+    let slot = build_slot(&parsed_layout, &mut split_keys, &arena);
+    if split_keys.len() != 0 {
+        eprintln!(
+            "Warning: Unused keys: {:?}. The calculated slot might be wrong. Please check the layout and keys you provided.",
+            split_keys
+        );
+    }
+    slot.slot()
+}
+
+fn main() {
+    let matches = Command::new("Slot Calculator (post-order)")
+        .version("1.0")
+        .about("Calculates Solidity storage slots for various layouts in a post-order manner")
+        .arg(
+            Arg::new("layout")
+                .long("layout")
+                .value_name("LAYOUT")
+                .required(true)
+                .help("e.g. 'mapping(uint256 => mapping(uint256 => uint256)[])'"),
+        )
+        .arg(
+            Arg::new("keys")
+                .long("keys")
+                .value_name("KEYS")
+                .required(true)
+                .num_args(1..) // Accept one or more
+                .help("The keys in the order that matches your snippet, e.g. 123 1 100"),
+        )
+        .get_matches();
+
+    let layout = matches
+        .get_one::<String>("layout")
+        .expect("Missing --layout");
+    let keys_collected: Vec<String> = matches
+        .get_many::<String>("keys")
+        .expect("Missing --keys")
+        .map(|s| s.to_string())
+        .collect();
+
+    let keys_str = keys_collected.join(" ");
+
+    let slot_hex = calculate_slot(layout, &keys_str);
+
+    println!(
+        "Calculated storage slot: {}",
+        <H256>::new(slot_hex.to_be_bytes())
+    );
+}
+
+#[test]
+fn test_calculate_slot() {
+    let layout = "mapping(uint256 => mapping(uint256 => uint256)[]) public test;";
+    let keys = "100 1 123";
+
+    let slot = calculate_slot(layout, keys);
+
+    assert_eq!(
+        <H256>::new(slot.to_be_bytes()),
+        <H256>::new(hex_literal::hex!(
+            "00a9b48fe93e5d10ebc2d9021d1477088c6292bf047876944343f57fdf3f0467"
+        ))
+    );
+}