diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..53344cf
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,4 @@
+/target
+.vscode/
+.DS_Store
+node_modules
diff --git a/Cargo.lock b/Cargo.lock
new file mode 100644
index 0000000..6b2b812
--- /dev/null
+++ b/Cargo.lock
@@ -0,0 +1,118 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "anyhow"
+version = "1.0.97"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dcfed56ad506cb2c684a14971b8861fdc3baaaae314b9e5f9bb532cbe3ba7a4f"
+
+[[package]]
+name = "itoa"
+version = "1.0.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4a5f13b858c8d314ee3e8f639011f7ccefe71f97f96e50151fb991f267928e2c"
+
+[[package]]
+name = "memchr"
+version = "2.7.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "78ca9ab1a0babb1e7d5695e3530886289c18cf2f87ec19a575a0abdce112e3a3"
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.94"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a31971752e70b8b2686d7e46ec17fb38dad4051d94024c88df49b667caea9c84"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.40"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1885c039570dc00dcb4ff087a89e185fd56bae234ddc7f056a945bf36467248d"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "revive-differential-testing-format"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "semver",
+ "serde",
+ "serde_json",
+]
+
+[[package]]
+name = "revive-differential-testing-retester"
+version = "0.1.0"
+dependencies = [
+ "revive-differential-testing-format",
+ "serde_json",
+]
+
+[[package]]
+name = "ryu"
+version = "1.0.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "28d3b2b1366ec20994f1fd18c3c594f05c5dd4bc44d8bb0c1c632c8d6829481f"
+
+[[package]]
+name = "semver"
+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 = "serde_json"
+version = "1.0.140"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "20068b6e96dc6c9bd23e01df8827e6c7e1f2fddd43c21810382803c136b99373"
+dependencies = [
+ "itoa",
+ "memchr",
+ "ryu",
+ "serde",
+]
+
+[[package]]
+name = "syn"
+version = "2.0.100"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b09a44accad81e1ba1cd74a32461ba89dee89095ba17b32f5d03683b1b1fc2a0"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5a5f39404a5da50712a4c1eecf25e90dd62b613502b7e925fd4e4d19b5c96512"
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..74827e4
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,35 @@
+[workspace]
+resolver = "2"
+members = ["crates/*"]
+
+[workspace.package]
+version = "0.1.0"
+authors = [
+    "Parity Technologies <admin@parity.io>",
+]
+license = "MIT/Apache-2.0"
+edition = "2024"
+repository = "https://github.com/paritytech/revive-differential-testing.git"
+rust-version = "1.85.0"
+
+[workspace.dependencies]
+revive-differential-testing-format = { version = "0.1.0", path = "crates/format" }
+
+anyhow = "1.0"
+semver = "1.0"
+serde = { version = "1.0", features = ["derive"] }
+serde_json = { version = "1.0", features = ["arbitrary_precision"] }
+
+# revive compiler
+revive-llvm-context = { git = "https://github.com/paritytech/revive", rev = "2bbc5d713d1bf8b38c43f6ce9382812561ca3ce1" }
+
+
+# polkadot-sdk and friends
+codec = { version = "3.6.12", default-features = false, package = "parity-scale-codec" }
+scale-info = { version = "2.11.6", default-features = false }
+polkadot-sdk = { git = "https://github.com/paritytech/polkadot-sdk", rev = "c29e72a8628835e34deb6aa7db9a78a2e4eabcee" }
+
+[profile.bench]
+inherits = "release"
+lto = true
+codegen-units = 1
diff --git a/crates/format/Cargo.toml b/crates/format/Cargo.toml
new file mode 100644
index 0000000..4f61f2c
--- /dev/null
+++ b/crates/format/Cargo.toml
@@ -0,0 +1,14 @@
+[package]
+name = "revive-differential-testing-format"
+version.workspace = true
+authors.workspace = true
+license.workspace = true
+edition.workspace = true
+repository.workspace = true
+rust-version.workspace = true
+
+[dependencies]
+anyhow = { workspace = true }
+semver = { workspace = true }
+serde = { workspace = true, features = [ "derive" ] }
+serde_json = { workspace = true }
\ No newline at end of file
diff --git a/crates/format/src/case.rs b/crates/format/src/case.rs
new file mode 100644
index 0000000..3d62704
--- /dev/null
+++ b/crates/format/src/case.rs
@@ -0,0 +1,9 @@
+use serde::Deserialize;
+
+use crate::modes::Mode;
+
+#[derive(Debug, Deserialize)]
+pub struct Case {
+    #[serde(rename(deserialize = "modes"))]
+    pub modes: Vec<Mode>,
+}
diff --git a/crates/format/src/lib.rs b/crates/format/src/lib.rs
new file mode 100644
index 0000000..8161da7
--- /dev/null
+++ b/crates/format/src/lib.rs
@@ -0,0 +1,4 @@
+//! The revive differential tests case format.
+
+pub mod case;
+pub mod modes;
diff --git a/crates/format/src/modes.rs b/crates/format/src/modes.rs
new file mode 100644
index 0000000..27616a7
--- /dev/null
+++ b/crates/format/src/modes.rs
@@ -0,0 +1,70 @@
+use serde::Deserialize;
+use serde::de::Deserializer;
+
+/// Specifies the compilation mode of the test artifact.
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub enum Mode {
+    Solidity(SolcMode),
+    Unknown(String),
+}
+
+/// Specify Solidity specific compiler options.
+#[derive(Debug, Default, Clone, Eq, PartialEq)]
+pub struct SolcMode {
+    pub solc_version: Option<semver::VersionReq>,
+    pub solc_optimize: Option<bool>,
+    pub llvm_optimizer_settings: Vec<String>,
+}
+
+impl SolcMode {
+    /// Try to parse a mode string into a solc mode.
+    /// Returns `None` if the string wasn't a solc YUL mode string.
+    ///
+    /// The mode string is expected to start with the `Y` ID (YUL ID),
+    /// optionally followed by `+` or `-` for the solc optimizer settings.
+    ///
+    /// Options can be separated by a whitespace contain the following
+    /// - A solc `SemVer version requirement` string
+    /// - One or more `-OX` where X is a supposed to be an LLVM opt mode
+    pub fn parse_from_mode_string(mode_string: &str) -> Option<Self> {
+        let mut result = Self::default();
+
+        let mut parts = mode_string.trim().split(" ");
+
+        match parts.next()? {
+            "Y" => {}
+            "Y+" => result.solc_optimize = Some(true),
+            "Y-" => result.solc_optimize = Some(false),
+            _ => return None,
+        }
+
+        while let Some(part) = parts.next() {
+            if let Ok(solc_version) = semver::VersionReq::parse(part) {
+                result.solc_version = Some(solc_version);
+                continue;
+            }
+            if part.starts_with("-O") {
+                result.llvm_optimizer_settings.push(part[2..].to_string());
+                continue;
+            }
+            panic!("the YUL mode string {mode_string} failed to parse, invalid part: {part}")
+        }
+
+        Some(result)
+    }
+}
+
+impl<'de> Deserialize<'de> for Mode {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let mode_string = String::deserialize(deserializer)?;
+
+        if let Some(solc_mode) = SolcMode::parse_from_mode_string(&mode_string) {
+            return Ok(Self::Solidity(solc_mode));
+        }
+
+        Ok(Self::Unknown(mode_string))
+    }
+}
diff --git a/crates/retester/Cargo.toml b/crates/retester/Cargo.toml
new file mode 100644
index 0000000..1b41551
--- /dev/null
+++ b/crates/retester/Cargo.toml
@@ -0,0 +1,16 @@
+[package]
+name = "revive-differential-testing-retester"
+version.workspace = true
+authors.workspace = true
+license.workspace = true
+edition.workspace = true
+repository.workspace = true
+rust-version.workspace = true
+
+[[bin]]
+name = "retester"
+path = "src/main.rs"
+
+[dependencies]
+revive-differential-testing-format = { workspace = true }
+serde_json = { workspace = true }
diff --git a/crates/retester/src/main.rs b/crates/retester/src/main.rs
new file mode 100644
index 0000000..ae3eb69
--- /dev/null
+++ b/crates/retester/src/main.rs
@@ -0,0 +1,9 @@
+use revive_differential_testing_format::case::Case;
+
+fn main() {
+    let example_def = include_str!("../../../test.json");
+
+    let case: Case = serde_json::from_str(example_def).unwrap();
+
+    println!("{case:?}");
+}