diff --git a/.gitignore b/.gitignore
index 7ae52d1..7eca8a9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,5 @@
 .vscode/
 /target
 Cargo.lock
+#winmerge
+**/*.bak
\ No newline at end of file
diff --git a/Cargo.toml b/Cargo.toml
index c89d4b8..8fe5730 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,18 +11,21 @@ readme = "README.md"
 repository = "https://github.com/stencillogic/astro-float"
 
 [dependencies]
-astro-float-num = { version = "0.3.6", default-features = false }
-astro-float-macro = "0.4.5"
+astro-float-num = {path = "astro-float-num",default-features = false } #{ version = "0.3.6", default-features = false }
+astro-float-macro = {path = "astro-float-macro" } #"0.4.5"
 
 [features]
 default = ["std", "random", "serde"]
 std = ["astro-float-num/std"]
 random = ["astro-float-num/random"]
 serde = ["astro-float-num/serde"]
+rkyv = ["astro-float-num/rkyv"]
 
 [dev-dependencies]
+astro-float-num = { path = "astro-float-num",default-features = false , features = [ "rkyv" ] }
 trybuild = "1.0"
 rusty-hook = "0.11.2"
+rkyv = "0.8" #couldn't run tests in astro-num on msvc(mpfr won't build)
 
 [workspace]
 members = [
diff --git a/astro-float-num/Cargo.toml b/astro-float-num/Cargo.toml
index d31c677..6700043 100644
--- a/astro-float-num/Cargo.toml
+++ b/astro-float-num/Cargo.toml
@@ -23,9 +23,11 @@ serde = { version = "1.0.147", optional = true }
 rand = { version = "0.8.5", optional = true }
 lazy_static = { version = "1.4.0", default-features = false, features = [] }
 itertools = { version = "0.10.3", default-features = false, features = [] }
+rkyv = { version = "0.8", features = [ "bytecheck" ] , optional = true } 
 
 [features]
 default = ["std", "random", "serde"]
 std = []
 random = ["dep:rand"]
 serde = ["dep:serde"]
+rkyv = ["dep:rkyv"]
\ No newline at end of file
diff --git a/astro-float-num/src/common/buf.rs b/astro-float-num/src/common/buf.rs
index 844d8e5..9459b8a 100644
--- a/astro-float-num/src/common/buf.rs
+++ b/astro-float-num/src/common/buf.rs
@@ -15,8 +15,12 @@ use crate::common::util::shift_slice_right;
 #[cfg(not(feature = "std"))]
 use alloc::vec::Vec;
 
+#[cfg(feature = "rkyv")]
+use rkyv::{Archive, Serialize, Deserialize};
+
 /// Buffer for holding mantissa gidits.
 #[derive(Debug, Hash)]
+#[cfg_attr(feature = "rkyv", derive(Archive, Serialize, Deserialize))]
 pub struct WordBuf {
     inner: Vec<Word>,
 }
diff --git a/astro-float-num/src/defs.rs b/astro-float-num/src/defs.rs
index 022a91f..0a69250 100644
--- a/astro-float-num/src/defs.rs
+++ b/astro-float-num/src/defs.rs
@@ -8,6 +8,9 @@ use std::collections::TryReserveError;
 #[cfg(not(feature = "std"))]
 use alloc::collections::TryReserveError;
 
+#[cfg(feature = "rkyv")]
+use rkyv::{Archive, Serialize, Deserialize};
+
 /// A word.
 #[cfg(not(target_arch = "x86"))]
 pub type Word = u64;
@@ -79,6 +82,87 @@ pub enum Sign {
     Pos = 1,
 }
 
+#[cfg(feature = "rkyv")]
+mod rkyv_impl {
+  use super::Sign;
+  use rkyv::{
+    bytecheck::{CheckBytes, InvalidEnumDiscriminantError, Verify},
+    primitive::ArchivedI16,
+    rancor::{fail, Fallible, Source},
+    traits::NoUndef,
+    Archive, Deserialize, Place, Portable, Serialize,
+  };
+  // Hand-written archived enum
+  #[derive(CheckBytes, Portable)]
+  #[bytecheck(crate = rkyv::bytecheck, verify)]
+  #[repr(C)]
+  pub struct ArchivedSign(ArchivedI16);
+
+  // Implementation detail: `ArchivedMyEnum` has no undef bytes
+  unsafe impl NoUndef for ArchivedSign {}
+
+  impl ArchivedSign {
+      // Internal fallible conversion back to the original enum
+      fn try_to_native(&self) -> Option<Sign> {
+          Some(match self.0.to_native() {
+              -1 => Sign::Neg,
+              1 => Sign::Pos,
+              _ => return None,
+          })
+      }
+
+      // Public infallible conversion back to the original enum
+      pub fn to_native(&self) -> Sign {
+          unsafe { self.try_to_native().unwrap_unchecked() }
+      }
+  }
+
+  unsafe impl<C: Fallible + ?Sized> Verify<C> for ArchivedSign
+  where
+      C::Error: Source,
+  {
+      // verify runs after all of the fields have been checked
+      fn verify(&self, _: &mut C) -> Result<(), C::Error> {
+          // Use the internal conversion to try to convert back
+          if self.try_to_native().is_none() {
+              // Return an error if it fails (i.e. the discriminant did not match
+              // any valid discriminants)
+              fail!(InvalidEnumDiscriminantError {
+                  enum_name: "ArchivedSign",
+                  invalid_discriminant: self.0.to_native(),
+              })
+          }
+          Ok(())
+      }
+  }
+
+  impl Archive for Sign {
+      type Archived = ArchivedSign;
+      type Resolver = ();
+
+      fn resolve(&self, _: Self::Resolver, out: Place<Self::Archived>) {
+          // Convert Sign -> i16 -> ArchivedI16 and write to `out`
+          out.write(ArchivedSign((*self as i16).into()));
+      }
+  }
+
+  // Serialization is a no-op because there's no out-of-line data
+  impl<S: Fallible + ?Sized> Serialize<S> for Sign {
+      fn serialize(&self, _: &mut S) -> Result<Self::Resolver, <S as Fallible>::Error> {
+          Ok(())
+      }
+  }
+
+  // Deserialization just calls the public conversion and returns the result
+  impl<D: Fallible + ?Sized> Deserialize<Sign, D> for ArchivedSign {
+      fn deserialize(&self, _: &mut D) -> Result<Sign, <D as Fallible>::Error> {
+          Ok(self.to_native())
+      }
+  }
+}
+#[cfg(feature = "rkyv")]
+pub use rkyv_impl::*;
+
 impl Sign {
     /// Changes the sign to the opposite.
     pub fn invert(&self) -> Self {
@@ -106,6 +190,7 @@ impl Sign {
 
 /// Possible errors.
 #[derive(Debug, Clone, Copy)]
+#[cfg_attr(feature = "rkyv", derive(Archive, Serialize, Deserialize))]
 pub enum Error {
     /// The exponent value becomes greater than the upper limit of the range of exponent values.
     ExponentOverflow(Sign),
diff --git a/astro-float-num/src/ext.rs b/astro-float-num/src/ext.rs
index 60822c9..2b367c1 100644
--- a/astro-float-num/src/ext.rs
+++ b/astro-float-num/src/ext.rs
@@ -13,6 +13,9 @@ use crate::Word;
 use core::num::FpCategory;
 use lazy_static::lazy_static;
 
+#[cfg(feature = "rkyv")]
+use rkyv::{Archive, Serialize, Deserialize};
+
 #[cfg(feature = "std")]
 use core::fmt::Write;
 
@@ -45,11 +48,13 @@ lazy_static! {
 
 /// A floating point number of arbitrary precision.
 #[derive(Debug)]
+#[cfg_attr(feature = "rkyv", derive(Archive, Serialize, Deserialize))]
 pub struct BigFloat {
     inner: Flavor,
 }
 
 #[derive(Debug)]
+#[cfg_attr(feature = "rkyv", derive(Archive, Serialize, Deserialize))]
 enum Flavor {
     Value(BigFloatNumber),
     NaN(Option<Error>),
diff --git a/astro-float-num/src/mantissa/mantissa.rs b/astro-float-num/src/mantissa/mantissa.rs
index 352ea0d..158d693 100644
--- a/astro-float-num/src/mantissa/mantissa.rs
+++ b/astro-float-num/src/mantissa/mantissa.rs
@@ -22,8 +22,12 @@ use crate::mantissa::util::RightShiftedSlice;
 use core::mem::size_of;
 use itertools::izip;
 
+#[cfg(feature = "rkyv")]
+use rkyv::{Archive, Serialize, Deserialize};
+
 /// Mantissa representation.
 #[derive(Debug, Hash)]
+#[cfg_attr(feature = "rkyv", derive(Archive, Serialize, Deserialize))]
 pub struct Mantissa {
     m: WordBuf,
     n: usize, // number of bits, 0 is for number 0
diff --git a/astro-float-num/src/num.rs b/astro-float-num/src/num.rs
index f477fb9..5a1d8f0 100644
--- a/astro-float-num/src/num.rs
+++ b/astro-float-num/src/num.rs
@@ -15,8 +15,12 @@ use crate::defs::WORD_BIT_SIZE;
 use crate::defs::WORD_SIGNIFICANT_BIT;
 use crate::mantissa::Mantissa;
 
+#[cfg(feature = "rkyv")]
+use rkyv::{Archive, Serialize, Deserialize};
+
 /// A finite floating point number with mantissa of an arbitrary size, an exponent, and the sign.
 #[derive(Debug, Hash)]
+#[cfg_attr(feature = "rkyv", derive(Archive, Serialize, Deserialize))]
 pub(crate) struct BigFloatNumber {
     e: Exponent,
     s: Sign,
diff --git a/tests/mod.rs b/tests/mod.rs
index a5df2b2..5e15ca7 100644
--- a/tests/mod.rs
+++ b/tests/mod.rs
@@ -1,5 +1,9 @@
 // Additional tests of the library.
 
+#[cfg(feature = "rkyv")]
+#[cfg(test)]
+mod rkyv;
+
 use astro_float_macro::expr;
 use astro_float_num::{
     ctx::Context, BigFloat, Consts, Radix, RoundingMode, Sign, EXPONENT_MAX, EXPONENT_MIN,
diff --git a/tests/rkyv.rs b/tests/rkyv.rs
new file mode 100644
index 0000000..8ad4636
--- /dev/null
+++ b/tests/rkyv.rs
@@ -0,0 +1,33 @@
+
+#[cfg(test)]
+mod tests {
+    use rkyv::{
+      to_bytes,
+      deserialize,
+      rancor::Error,
+      access_unchecked,
+      Archive,
+    };
+
+    use astro_float_num::{
+      BigFloat,
+      //ArchivedBigFloat
+    };
+
+    #[test]
+    fn to_from_rkyv() {
+        let zero = &BigFloat::new(0);
+        let bytes = to_bytes::<Error>(zero).unwrap();
+        let archived =
+          unsafe { access_unchecked::<<BigFloat as Archive>::Archived>(&bytes) };
+        let bf : BigFloat = deserialize::<BigFloat, Error>(archived).unwrap();
+        assert_eq!(bf,zero);
+        
+        let bf = BigFloat::from_f32(0.3, 64 + 1);
+        let bytes = to_bytes::<Error>(&bf).unwrap();
+        let archived =
+          unsafe { access_unchecked::<<BigFloat as Archive>::Archived>(&bytes) };
+        let bf2 : BigFloat = deserialize::<BigFloat, Error>(archived).unwrap();
+        assert_eq!(bf,bf2);
+    }
+}