From 5b869b4d740eaae4a3251d082587ed0fd40fdd9b Mon Sep 17 00:00:00 2001
From: Mac L <mjladson@pm.me>
Date: Tue, 28 Oct 2025 23:10:19 +1100
Subject: [PATCH 1/2] Add context_deserialize impl

---
 ssz/Cargo.toml                 | 14 ++++++++------
 ssz/src/context_deserialize.rs | 33 +++++++++++++++++++++++++++++++++
 ssz/src/lib.rs                 |  3 +++
 3 files changed, 44 insertions(+), 6 deletions(-)
 create mode 100644 ssz/src/context_deserialize.rs

diff --git a/ssz/Cargo.toml b/ssz/Cargo.toml
index 38a691b..ab0a338 100644
--- a/ssz/Cargo.toml
+++ b/ssz/Cargo.toml
@@ -13,10 +13,9 @@ categories = ["cryptography::cryptocurrencies"]
 [lib]
 name = "ssz"
 
-[dev-dependencies]
-alloy-primitives = { version = "1.0", features = ["getrandom"] }
-ethereum_ssz_derive = { version = "0.9.0", path = "../ssz_derive" }
-serde_json = "1.0.0"
+[features]
+arbitrary = ["dep:arbitrary", "alloy-primitives/arbitrary"]
+context_deserialize = ["dep:context_deserialize"]
 
 [dependencies]
 alloy-primitives = "1.0"
@@ -27,6 +26,9 @@ serde = "1.0.0"
 serde_derive = "1.0.0"
 typenum = "1.12.0"
 arbitrary = { version = "1.0", features = ["derive"], optional = true }
+context_deserialize = { version = "0.1", optional = true }
 
-[features]
-arbitrary = ["dep:arbitrary", "alloy-primitives/arbitrary"]
+[dev-dependencies]
+alloy-primitives = { version = "1.0", features = ["getrandom"] }
+ethereum_ssz_derive = { version = "0.9.0", path = "../ssz_derive" }
+serde_json = "1.0.0"
diff --git a/ssz/src/context_deserialize.rs b/ssz/src/context_deserialize.rs
new file mode 100644
index 0000000..0bc57f7
--- /dev/null
+++ b/ssz/src/context_deserialize.rs
@@ -0,0 +1,33 @@
+use crate::{Bitfield, Fixed, Variable};
+use context_deserialize::ContextDeserialize;
+use serde::{
+    de::{Deserializer, Error},
+    Deserialize,
+};
+use typenum::Unsigned;
+
+impl<'de, C, N> ContextDeserialize<'de, C> for Bitfield<Variable<N>>
+where
+    N: Unsigned + Clone,
+{
+    fn context_deserialize<D>(deserializer: D, _context: C) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        Bitfield::<Variable<N>>::deserialize(deserializer)
+            .map_err(|e| D::Error::custom(format!("{:?}", e)))
+    }
+}
+
+impl<'de, C, N> ContextDeserialize<'de, C> for Bitfield<Fixed<N>>
+where
+    N: Unsigned + Clone,
+{
+    fn context_deserialize<D>(deserializer: D, _context: C) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        Bitfield::<Fixed<N>>::deserialize(deserializer)
+            .map_err(|e| D::Error::custom(format!("{:?}", e)))
+    }
+}
diff --git a/ssz/src/lib.rs b/ssz/src/lib.rs
index edfed0d..a5eaa26 100644
--- a/ssz/src/lib.rs
+++ b/ssz/src/lib.rs
@@ -40,6 +40,9 @@ mod encode;
 pub mod legacy;
 mod union_selector;
 
+#[cfg(feature = "context_deserialize")]
+mod context_deserialize;
+
 pub use bitfield::bitvector_dynamic::{BitVectorDynamic, Dynamic};
 #[doc(hidden)]
 pub use bitfield::{BitList, BitVector, Bitfield, Error as BitfieldError, Fixed, Variable};

From 16e9103ef9d2e8bf786dbc9278934b62eb340ff4 Mon Sep 17 00:00:00 2001
From: Mac L <mjladson@pm.me>
Date: Fri, 7 Nov 2025 22:41:41 +1100
Subject: [PATCH 2/2] Use new `context_deserialize` version

---
 ssz/Cargo.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ssz/Cargo.toml b/ssz/Cargo.toml
index ab0a338..12ad059 100644
--- a/ssz/Cargo.toml
+++ b/ssz/Cargo.toml
@@ -26,7 +26,7 @@ serde = "1.0.0"
 serde_derive = "1.0.0"
 typenum = "1.12.0"
 arbitrary = { version = "1.0", features = ["derive"], optional = true }
-context_deserialize = { version = "0.1", optional = true }
+context_deserialize = { version = "0.2", optional = true }
 
 [dev-dependencies]
 alloy-primitives = { version = "1.0", features = ["getrandom"] }