diff --git a/Cargo.toml b/Cargo.toml
index 2e26b8e..83870b9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "sourmash"
-version = "0.1.1"
+version = "0.2.1"
 authors = ["Luiz Irber <luiz.irber@gmail.com>"]
 description = "MinHash sketches for genomic data"
 repository = "https://github.com/luizirber/sourmash-rust"
@@ -23,6 +23,7 @@ cbindgen = "0.6.1"
 
 [dependencies]
 backtrace = "0.3.4"
+cfg-if = "0.1"
 error-chain = "0.12"
 finch = { version = "0.1.6", optional = true }
 lazy_static = "1.0.0"
@@ -32,4 +33,10 @@ needletail = { version = "~0.2.1", optional = true }
 ordslice = "0.3.0"
 serde = "1.0"
 serde_derive = "1.0"
-serde_json = "1.0.2"
+serde_json = "1.0"
+
+#TODO: wasm-pack can't check optionals or this kind of config yet...
+# [target. 'cfg(target_arch = "wasm32")'.dependencies]
+[dependencies.wasm-bindgen]
+version = "^0.2"
+features = ["serde-serialize"]
diff --git a/Makefile b/Makefile
index 30e3c8c..f9a7448 100644
--- a/Makefile
+++ b/Makefile
@@ -6,4 +6,8 @@ test:
 target/sourmash.h: src/lib.rs src/ffi.rs src/errors.rs
 	RUST_BACKTRACE=1 cbindgen --clean -c cbindgen.toml -o $@
 
+wasm:
+#	wasm-pack init --mode no-installs
+	wasm-pack init
+
 .phony: test
diff --git a/src/lib.rs b/src/lib.rs
index 1b828c5..413c480 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,4 +1,7 @@
 extern crate backtrace;
+#[macro_use]
+extern crate cfg_if;
+
 extern crate md5;
 extern crate murmurhash3;
 extern crate ordslice;
@@ -29,9 +32,6 @@ pub mod ffi;
 #[cfg(feature = "from-finch")]
 pub mod from;
 
-use serde::de::{Deserialize, Deserializer};
-use serde::ser::{Serialize, SerializeStruct, Serializer};
-
 use std::collections::HashMap;
 use std::collections::HashSet;
 use std::hash::{BuildHasherDefault, Hasher};
@@ -40,6 +40,8 @@ use std::str;
 
 use murmurhash3::murmurhash3_x64_128;
 use ordslice::Ext;
+use serde::de::{Deserialize, Deserializer};
+use serde::ser::{Serialize, SerializeStruct, Serializer};
 
 use errors::{ErrorKind, Result};
 
@@ -72,15 +74,37 @@ impl Hasher for NoHashHasher {
     }
 }
 
-#[derive(Debug, Clone, PartialEq)]
-pub struct KmerMinHash {
-    pub num: u32,
-    pub ksize: u32,
-    pub is_protein: bool,
-    pub seed: u64,
-    pub max_hash: u64,
-    pub mins: Vec<u64>,
-    pub abunds: Option<Vec<u64>>,
+cfg_if! {
+    if #[cfg(target_arch = "wasm32")] {
+        extern crate wasm_bindgen;
+
+        use wasm_bindgen::prelude::*;
+
+        pub mod wasm;
+
+        #[wasm_bindgen]
+        #[derive(Debug, Clone, PartialEq)]
+        pub struct KmerMinHash {
+            num: u32,
+            ksize: u32,
+            is_protein: bool,
+            seed: u64,
+            max_hash: u64,
+            mins: Vec<u64>,
+            abunds: Option<Vec<u64>>,
+        }
+    } else {
+        #[derive(Debug, Clone, PartialEq)]
+        pub struct KmerMinHash {
+            pub num: u32,
+            pub ksize: u32,
+            pub is_protein: bool,
+            pub seed: u64,
+            pub max_hash: u64,
+            pub mins: Vec<u64>,
+            pub abunds: Option<Vec<u64>>,
+        }
+    }
 }
 
 impl Default for KmerMinHash {
@@ -531,6 +555,10 @@ impl KmerMinHash {
             return Ok(0.0);
         }
     }
+
+    pub fn to_vec(&self) -> Vec<u64> {
+        self.mins.clone()
+    }
 }
 
 #[derive(Serialize, Deserialize, Debug)]
diff --git a/src/wasm.rs b/src/wasm.rs
new file mode 100644
index 0000000..72bd4e5
--- /dev/null
+++ b/src/wasm.rs
@@ -0,0 +1,45 @@
+use wasm_bindgen::prelude::*;
+
+use serde_json;
+
+use KmerMinHash;
+
+#[wasm_bindgen]
+impl KmerMinHash {
+    #[wasm_bindgen(constructor)]
+    pub fn new_with_scaled(
+        num: u32,
+        ksize: u32,
+        is_protein: bool,
+        seed: u32,
+        scaled: u32,
+        track_abundance: bool,
+    ) -> KmerMinHash {
+        let max_hash = if num != 0 {
+            0
+        } else if scaled == 0 {
+            u64::max_value()
+        } else {
+            u64::max_value() / scaled as u64
+        };
+
+        KmerMinHash::new(
+            num,
+            ksize,
+            is_protein,
+            seed as u64,
+            max_hash,
+            track_abundance,
+        )
+    }
+
+    #[wasm_bindgen]
+    pub fn add_sequence_js(&mut self, buf: &str) {
+        self.add_sequence(buf.as_bytes(), true);
+    }
+
+    #[wasm_bindgen]
+    pub fn to_json(&mut self) -> String {
+        serde_json::to_string(self).unwrap()
+    }
+}