diff --git a/src/Cid.cs b/src/Cid.cs
index 074640a..60c3779 100644
--- a/src/Cid.cs
+++ b/src/Cid.cs
@@ -1,7 +1,9 @@
 using Google.Protobuf;
+using Newtonsoft.Json;
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Runtime.Serialization;
 using System.Text;
 
 namespace Ipfs
@@ -22,6 +24,7 @@ namespace Ipfs
     ///   </note>
     /// </remarks>
     /// <seealso href="https://github.com/ipld/cid"/>
+    [JsonConverter(typeof(Cid.Json))]
     public class Cid : IEquatable<Cid>
     {
         /// <summary>
@@ -482,5 +485,33 @@ static public implicit operator string(Cid id)
         {
             return id.Encode();
         }
+
+        /// <summary>
+        ///   Conversion of a <see cref="Cid"/> to and from JSON.
+        /// </summary>
+        /// <remarks>
+        ///   The JSON is just a single string value.
+        /// </remarks>
+        class Json : JsonConverter
+        {
+            public override bool CanConvert(Type objectType)
+            {
+                return true;
+            }
+            public override bool CanRead => true;
+            public override bool CanWrite => true;
+            public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
+            {
+                var cid = value as Cid;
+                writer.WriteValue(cid?.Encode());
+            }
+
+            public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
+            {
+                var s = reader.Value as string;
+                return s == null ? null : Cid.Decode(s);
+            }
+        }
+
     }
 }
diff --git a/src/MultiAddress.cs b/src/MultiAddress.cs
index bce04d9..e640990 100644
--- a/src/MultiAddress.cs
+++ b/src/MultiAddress.cs
@@ -5,6 +5,7 @@
 using System.IO;
 using Common.Logging;
 using Google.Protobuf;
+using Newtonsoft.Json;
 
 namespace Ipfs
 {
@@ -25,6 +26,7 @@ namespace Ipfs
     ///   </para>
     /// </remarks>
     /// <seealso href="https://github.com/multiformats/multiaddr"/>
+    [JsonConverter(typeof(MultiAddress.Json))]
     public class MultiAddress : IEquatable<MultiAddress>
     {
         /// <summary>
@@ -379,6 +381,34 @@ public static MultiAddress TryCreate(string s)
             }
         }
 
+        /// <summary>
+        ///   Conversion of a <see cref="MultiAddress"/> to and from JSON.
+        /// </summary>
+        /// <remarks>
+        ///   The JSON is just a single string value.
+        /// </remarks>
+        class Json : JsonConverter
+        {
+            public override bool CanConvert(Type objectType)
+            {
+                return true;
+            }
+            public override bool CanRead => true;
+            public override bool CanWrite => true;
+            public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
+            {
+                var ma = value as MultiAddress;
+                writer.WriteValue(ma?.ToString());
+            }
+
+            public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
+            {
+                var s = reader.Value as string;
+                return s == null ? null : new MultiAddress(s);
+            }
+        }
+
+
     }
 
 }
\ No newline at end of file
diff --git a/src/MultiHash.cs b/src/MultiHash.cs
index 0cf726a..7cb30fc 100644
--- a/src/MultiHash.cs
+++ b/src/MultiHash.cs
@@ -7,6 +7,7 @@
 using Common.Logging;
 using Google.Protobuf;
 using Ipfs.Registry;
+using Newtonsoft.Json;
 
 namespace Ipfs
 {
@@ -18,6 +19,7 @@ namespace Ipfs
     ///   See the <see cref="HashingAlgorithm">registry</see> for supported algorithms.
     /// </remarks>
     /// <seealso href="https://github.com/jbenet/multihash"/>
+    [JsonConverter(typeof(MultiHash.Json))]
     public class MultiHash : IEquatable<MultiHash>
     {
         static readonly ILog log = LogManager.GetLogger<MultiHash>();
@@ -497,6 +499,32 @@ public static MultiHash ComputeHash(Stream data, string algorithmName = DefaultA
             return new MultiHash(algorithmName, GetHashAlgorithm(algorithmName).ComputeHash(data));
         }
 
+        /// <summary>
+        ///   Conversion of a <see cref="MultiHash"/> to and from JSON.
+        /// </summary>
+        /// <remarks>
+        ///   The JSON is just a single string value.
+        /// </remarks>
+        class Json : JsonConverter
+        {
+            public override bool CanConvert(Type objectType)
+            {
+                return true;
+            }
+            public override bool CanRead => true;
+            public override bool CanWrite => true;
+            public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
+            {
+                var mh = value as MultiHash;
+                writer.WriteValue(mh?.ToString());
+            }
+
+            public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
+            {
+                var s = reader.Value as string;
+                return s == null ? null : new MultiHash(s);
+            }
+        }
     }
 
     /// <summary>
@@ -510,4 +538,5 @@ public class UnknownHashingAlgorithmEventArgs : EventArgs
         /// </summary>
         public HashingAlgorithm Algorithm { get; set; }
     }
+
 }
\ No newline at end of file
diff --git a/test/CidTest.cs b/test/CidTest.cs
index f571bce..eac8c41 100644
--- a/test/CidTest.cs
+++ b/test/CidTest.cs
@@ -5,6 +5,7 @@
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using System.IO;
 using Google.Protobuf;
+using Newtonsoft.Json;
 
 namespace Ipfs
 {
@@ -359,5 +360,38 @@ public void Immutable()
             ExceptionAssert.Throws<NotSupportedException>(() => cid.Hash = "QmaozNR7DZHQK1ZcU9p7QdrshMvXqWK6gpu5rmrkPdT3L5");
             ExceptionAssert.Throws<NotSupportedException>(() => cid.Version = 0);
         }
+
+        class CidAndX
+        {
+            public Cid Cid;
+            public int X;
+        }
+
+        [TestMethod]
+        public void JsonSerialization()
+        {
+            Cid a = "QmaozNR7DZHQK1ZcU9p7QdrshMvXqWK6gpu5rmrkPdT3L4";
+            string json = JsonConvert.SerializeObject(a);
+            Assert.AreEqual($"\"{a.Encode()}\"", json);
+            var b = JsonConvert.DeserializeObject<Cid>(json);
+            Assert.AreEqual(a, b);
+
+            a = null;
+            json = JsonConvert.SerializeObject(a);
+            b = JsonConvert.DeserializeObject<Cid>(json);
+            Assert.IsNull(b);
+
+            var x = new CidAndX { Cid = "QmaozNR7DZHQK1ZcU9p7QdrshMvXqWK6gpu5rmrkPdT3L4", X = 42 };
+            json = JsonConvert.SerializeObject(x);
+            var y = JsonConvert.DeserializeObject<CidAndX>(json);
+            Assert.AreEqual(x.Cid, y.Cid);
+            Assert.AreEqual(x.X, y.X);
+
+            x.Cid = null;
+            json = JsonConvert.SerializeObject(x);
+            y = JsonConvert.DeserializeObject<CidAndX>(json);
+            Assert.AreEqual(x.Cid, y.Cid);
+            Assert.AreEqual(x.X, y.X);
+        }
     }
 }
diff --git a/test/MultiAddressTest.cs b/test/MultiAddressTest.cs
index 218dea0..d249681 100644
--- a/test/MultiAddressTest.cs
+++ b/test/MultiAddressTest.cs
@@ -4,6 +4,7 @@
 using System.Linq;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using System.IO;
+using Newtonsoft.Json;
 
 namespace Ipfs
 {
@@ -307,6 +308,22 @@ public void TryCreate()
             Assert.IsNull(MultiAddress.TryCreate("/tcp/alpha")); // bad port
             Assert.IsNull(MultiAddress.TryCreate("/foobar")); // bad protocol
         }
+
+        [TestMethod]
+        public void JsonSerialization()
+        {
+            var a = new MultiAddress("/ip6/fe80::7573:b0a8:46b0:0bad/tcp/4009");
+            string json = JsonConvert.SerializeObject(a);
+            Assert.AreEqual($"\"{a.ToString()}\"", json);
+            var b = JsonConvert.DeserializeObject<MultiAddress>(json);
+            Assert.AreEqual(a.ToString(), b.ToString());
+
+            a = null;
+            json = JsonConvert.SerializeObject(a);
+            b = JsonConvert.DeserializeObject<MultiAddress>(json);
+            Assert.IsNull(b);
+        }
+
     }
 }
 
diff --git a/test/MultiHashTest.cs b/test/MultiHashTest.cs
index 0d90f0f..320dcb8 100644
--- a/test/MultiHashTest.cs
+++ b/test/MultiHashTest.cs
@@ -6,6 +6,7 @@
 using System.Text;
 using System.IO;
 using Google.Protobuf;
+using Newtonsoft.Json;
 
 namespace Ipfs
 {
@@ -469,5 +470,20 @@ public void Binary()
             CollectionAssert.AreEqual(mh.Digest, mh1.Digest);
         }
 
+        [TestMethod]
+        public void JsonSerialization()
+        {
+            var a = new MultiHash("QmPZ9gcCEpqKTo6aq61g2nXGUhM4iCL3ewB6LDXZCtioEB");
+            string json = JsonConvert.SerializeObject(a);
+            Assert.AreEqual($"\"{a.ToString()}\"", json);
+            var b = JsonConvert.DeserializeObject<MultiHash>(json);
+            Assert.AreEqual(a, b);
+
+            a = null;
+            json = JsonConvert.SerializeObject(a);
+            b = JsonConvert.DeserializeObject<MultiHash>(json);
+            Assert.IsNull(b);
+        }
+
     }
 }