diff --git a/src/ARCtrl/WebRequest/WebRequest.Node.fs b/src/ARCtrl/WebRequest/WebRequest.Node.fs
index 1a239003..6886c2eb 100644
--- a/src/ARCtrl/WebRequest/WebRequest.Node.fs
+++ b/src/ARCtrl/WebRequest/WebRequest.Node.fs
@@ -1,9 +1,9 @@
-module ARCtrl.WebRequestHelpers.NodeJs
+module ARCtrl.WebRequestHelpers.NodeJs
 
+#if FABLE_COMPILER_JAVASCRIPT
 open Fable.Core
 open Fable.SimpleHttp
 
-#if FABLE_COMPILER_JAVASCRIPT
 open Fable.Core.JsInterop
 
 open Fable.SimpleHttp 
diff --git a/src/Json/ARC.fs b/src/Json/ARC.fs
index 781bd642..a129ec8c 100644
--- a/src/Json/ARC.fs
+++ b/src/Json/ARC.fs
@@ -1,4 +1,4 @@
-namespace ARCtrl.Json
+namespace ARCtrl.Json
 
 open Thoth.Json.Core
 
@@ -17,8 +17,8 @@ module ARC =
                 Encode.tryInclude "@type" Encode.string (Some "CreativeWork")
                 Encode.tryInclude "@id" Encode.string (Some "ro-crate-metadata.json")
                 Encode.tryInclude "about" Investigation.ROCrate.encoder (Some isa)
-                "conformsTo", ROCrateContext.ROCrate.conformsTo_jsonvalue
-                "@context", ROCrateContext.ROCrate.context_jsonvalue
+                "conformsTo", ROCrateContext.ROCrate.conformsTo_jsonvalue |> Some
+                "@context", ROCrateContext.ROCrate.context_jsonvalue |> Some
                 ]
             |> Encode.choose
             |> Encode.object
diff --git a/src/Json/ARCtrl.Json.fsproj b/src/Json/ARCtrl.Json.fsproj
index aa191f3b..e7ae82e5 100644
--- a/src/Json/ARCtrl.Json.fsproj
+++ b/src/Json/ARCtrl.Json.fsproj
@@ -82,10 +82,10 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="NJsonSchema" Version="10.8.0" />
-    <PackageReference Include="Thoth.Json.Core" Version="0.2.1" />
-    <PackageReference Include="Thoth.Json.Newtonsoft" Version="0.1.0" />
-    <PackageReference Condition="'$(FABLE_COMPILER_PYTHON)' == 'true'" Include="Thoth.Json.Python" Version="0.2.0" />
-    <PackageReference Condition="'$(FABLE_COMPILER_JAVASCRIPT)' == 'true'" Include="Thoth.Json.JavaScript" Version="0.1.0" />
+    <PackageReference Include="Thoth.Json.Core" Version="0.4.0" />
+    <PackageReference Include="Thoth.Json.Newtonsoft" Version="0.2.0" />
+    <PackageReference Include="FsSpreadsheet.Js" Version="6.3.0-alpha.3" />
+    <PackageReference Include="FsSpreadsheet.Py" Version="6.3.0-alpha.3" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\Core\ARCtrl.Core.fsproj" />
diff --git a/src/Json/Assay.fs b/src/Json/Assay.fs
index 97b6d51a..65b48863 100644
--- a/src/Json/Assay.fs
+++ b/src/Json/Assay.fs
@@ -11,7 +11,7 @@ module Assay =
     
     let encoder (assay:ArcAssay) = 
         [ 
-            "Identifier", Encode.string assay.Identifier
+            "Identifier", Encode.string assay.Identifier |> Some
             Encode.tryInclude "MeasurementType" OntologyAnnotation.encoder assay.MeasurementType
             Encode.tryInclude "TechnologyType" OntologyAnnotation.encoder assay.TechnologyType
             Encode.tryInclude "TechnologyPlatform" OntologyAnnotation.encoder assay.TechnologyPlatform
@@ -43,7 +43,7 @@ module Assay =
 
     let encoderCompressed (stringTable : StringTableMap) (oaTable : OATableMap) (cellTable : CellTableMap) (assay:ArcAssay) =
         [ 
-            "Identifier", Encode.string assay.Identifier
+            "Identifier", Encode.string assay.Identifier |> Some
             Encode.tryInclude "MeasurementType" OntologyAnnotation.encoder assay.MeasurementType
             Encode.tryInclude "TechnologyType" OntologyAnnotation.encoder assay.TechnologyType
             Encode.tryInclude "TechnologyPlatform" OntologyAnnotation.encoder assay.TechnologyPlatform
@@ -84,11 +84,11 @@ module Assay =
             let dataFiles = ProcessSequence.getData processes
 
             [
-                "@id", Encode.string (a |> genID)
-                "@type", (Encode.list [ Encode.string "Assay"])
-                "additionalType", Encode.string "Assay"
-                "identifier", Encode.string a.Identifier
-                "filename", Encode.string fileName
+                "@id", Encode.string (a |> genID) |> Some
+                "@type", (Encode.list [ Encode.string "Assay"]) |> Some
+                "additionalType", Encode.string "Assay" |> Some
+                "identifier", Encode.string a.Identifier |> Some
+                "filename", Encode.string fileName |> Some
                 Encode.tryInclude "measurementType" OntologyAnnotation.ROCrate.encoderPropertyValue a.MeasurementType
                 Encode.tryInclude "technologyType" OntologyAnnotation.ROCrate.encoderDefinedTerm a.TechnologyType
                 Encode.tryInclude "technologyPlatform" OntologyAnnotation.ROCrate.encoderDefinedTerm a.TechnologyPlatform
@@ -96,7 +96,7 @@ module Assay =
                 Encode.tryIncludeList "dataFiles" Data.ROCrate.encoder dataFiles
                 Encode.tryIncludeList "processSequence" (Process.ROCrate.encoder studyName (Some a.Identifier)) processes
                 Encode.tryIncludeSeq "comments" Comment.ROCrate.encoder a.Comments
-                "@context", ROCrateContext.Assay.context_jsonvalue
+                "@context", ROCrateContext.Assay.context_jsonvalue |> Some
             ]
             |> Encode.choose
             |> Encode.object
@@ -139,7 +139,7 @@ module Assay =
                     |> Encode.tryIncludeList "dataFiles" (Data.ISAJson.encoder idMap) 
                 let units = ProcessSequence.getUnits processes
                 [
-                    "filename", Encode.string fileName
+                    "filename", Encode.string fileName |> Some
                     Encode.tryInclude "@id" Encode.string (ROCrate.genID a |> Some)
                     Encode.tryInclude "measurementType" (OntologyAnnotation.ISAJson.encoder idMap) a.MeasurementType
                     Encode.tryInclude "technologyType" (OntologyAnnotation.ISAJson.encoder idMap) a.TechnologyType
@@ -199,7 +199,7 @@ module AssayExtensions =
 
         static member fromCompressedJsonString (s: string) =
             try Decode.fromJsonString (Compression.decode Assay.decoderCompressed) s with
-            | e -> failwithf "Error. Unable to parse json string to ArcStudy: %s" e.Message
+            | e -> failwithf "Error. Unable to parse json string to ArcAssay: %s" e.Message
 
         static member toCompressedJsonString(?spaces) =
             fun (obj:ArcAssay) ->
diff --git a/src/Json/Comment.fs b/src/Json/Comment.fs
index 8ac0926b..00384d2c 100644
--- a/src/Json/Comment.fs
+++ b/src/Json/Comment.fs
@@ -32,11 +32,11 @@ module Comment =
     
         let encoder (comment : Comment) = 
             [
-                "@id", Encode.string (comment |> genID)
-                "@type", Encode.string "Comment"
+                "@id", Encode.string (comment |> genID) |> Some
+                "@type", Encode.string "Comment" |> Some
                 Encode.tryInclude "name" Encode.string (comment.Name)
                 Encode.tryInclude "value" Encode.string (comment.Value)
-                "@context", ROCrateContext.Comment.context_jsonvalue
+                "@context", ROCrateContext.Comment.context_jsonvalue |> Some
             ]
             |> Encode.choose
             |> Encode.object
diff --git a/src/Json/Data.fs b/src/Json/Data.fs
index 42986661..1f969ceb 100644
--- a/src/Json/Data.fs
+++ b/src/Json/Data.fs
@@ -76,14 +76,14 @@ module Data =
     
         let encoder (oa : Data) = 
             [
-                "@id", Encode.string (oa |> genID)           
-                "@type", (Encode.list [Encode.string "Data"])
+                "@id", Encode.string (oa |> genID) |> Some           
+                "@type", (Encode.list [Encode.string "Data"]) |> Some
                 Encode.tryInclude "name" Encode.string (oa.Name)
                 Encode.tryInclude "type" DataFile.ROCrate.encoder oa.DataType
                 Encode.tryInclude "encodingFormat" Encode.string oa.Format
                 Encode.tryInclude "usageInfo" Encode.string oa.SelectorFormat
                 Encode.tryIncludeSeq "comments" Comment.ROCrate.encoder oa.Comments
-                "@context", ROCrateContext.Data.context_jsonvalue
+                "@context", ROCrateContext.Data.context_jsonvalue |> Some
             ]
             |> Encode.choose
             |> Encode.object
diff --git a/src/Json/DataMap/DataContext.fs b/src/Json/DataMap/DataContext.fs
index ff868359..b7edbca7 100644
--- a/src/Json/DataMap/DataContext.fs
+++ b/src/Json/DataMap/DataContext.fs
@@ -11,7 +11,7 @@ module DataContext =
 
     let encoder (dc:DataContext) = 
         [ 
-            "data", Data.encoder dc
+            "data", Data.encoder dc |> Some
             Encode.tryInclude "explication" OntologyAnnotation.encoder dc.Explication 
             Encode.tryInclude "unit" OntologyAnnotation.encoder dc.Unit
             Encode.tryInclude "objectType" OntologyAnnotation.encoder dc.ObjectType
diff --git a/src/Json/Encode.fs b/src/Json/Encode.fs
index 4b480dcb..72f38233 100644
--- a/src/Json/Encode.fs
+++ b/src/Json/Encode.fs
@@ -14,7 +14,7 @@ open Fable.Core.JsInterop
 [<RequireQualifiedAccess>]
 module Encode = 
 
-    let inline toJsonString spaces (value : Json) = 
+    let inline toJsonString spaces (value : IEncodable) = 
         #if FABLE_COMPILER_PYTHON
         Thoth.Json.Python.Encode.toString spaces value
         #endif
@@ -25,44 +25,43 @@ module Encode =
         Thoth.Json.Newtonsoft.Encode.toString spaces value
         #endif
 
-    let inline choose (kvs : (string * Json) list) = 
+    let inline choose (kvs : (string * IEncodable option) list) = 
         kvs
-        |> List.choose (fun (k,v) -> 
-            if v = Encode.nil then None
-            else Some (k,v)
+        |> List.choose (fun (k,v) ->
+            v
+            |> Option.map (fun v -> k,v)
         )       
 
     /// Try to encode the given object using the given encoder, or return Encode.nil if the object is null
-    let tryInclude (name : string) (encoder : 'Value -> Json) (value : 'Value option) = 
+    let tryInclude (name : string) (encoder : 'Value -> IEncodable) (value : 'Value option) = 
         name,
-        match value with
-        | Some(o) -> encoder o
-        | _ -> Encode.nil
+        value
+        |> Option.map encoder
 
     /// Try to encode the given object using the given encoder, or return Encode.nil if the object is null
-    let tryIncludeSeq name (encoder : 'Value -> Json) (value : #seq<'Value>) = 
+    let tryIncludeSeq name (encoder : 'Value -> IEncodable) (value : #seq<'Value>) = 
         name,
-        if Seq.isEmpty value then Encode.nil
-        else value |> Seq.map encoder |> Encode.seq
+        if Seq.isEmpty value then None 
+        else value |> Seq.map encoder |> Encode.seq |> Some
 
-    let tryIncludeArray name (encoder : 'Value -> Json) (value : 'Value array) = 
+    let tryIncludeArray name (encoder : 'Value -> IEncodable) (value : 'Value array) = 
         name,
-        if Array.isEmpty value then Encode.nil
-        else value |> Array.map encoder |> Encode.array
+        if Array.isEmpty value then None
+        else value |> Array.map encoder |> Encode.array |> Some
 
-    let tryIncludeList name (encoder : 'Value -> Json) (value : 'Value list) = 
+    let tryIncludeList name (encoder : 'Value -> IEncodable) (value : 'Value list) = 
         name,
-        if List.isEmpty value then Encode.nil
-        else value |> List.map encoder |> Encode.list
+        if List.isEmpty value then None
+        else value |> List.map encoder |> Encode.list |> Some
 
-    let tryIncludeListOpt name (encoder : 'Value -> Json) (value : 'Value list option) = 
+    let tryIncludeListOpt name (encoder : 'Value -> IEncodable) (value : 'Value list option) = 
         name,
         match value with
         | Some(o) -> 
-            if List.isEmpty o then Encode.nil
-            else o |> List.map encoder |> Encode.list
+            if List.isEmpty o then None
+            else o |> List.map encoder |> Encode.list |> Some
         | _ -> 
-            Encode.nil
+            None
         
     let DefaultSpaces = 0
 
diff --git a/src/Json/IDTable.fs b/src/Json/IDTable.fs
index b1fa4b11..34fcc3a5 100644
--- a/src/Json/IDTable.fs
+++ b/src/Json/IDTable.fs
@@ -1,4 +1,4 @@
-namespace ARCtrl.Json
+namespace ARCtrl.Json
 
 open System.Collections.Generic
 open Thoth.Json.Core
@@ -8,7 +8,7 @@ open ARCtrl.Helper
 
 module IDTable =
 
-    type IDTableWrite = Dictionary<URI,Json>
+    type IDTableWrite = Dictionary<URI,IEncodable>
 
     type IDTableRead = Dictionary<URI,obj>
 
@@ -16,7 +16,7 @@ module IDTable =
         ["@id",Encode.string id]
         |> Encode.object
 
-    let encode (genID: 'Value -> URI) (encoder : 'Value -> Json) (value : 'Value) (table:IDTableWrite) =
+    let encode (genID: 'Value -> URI) (encoder : 'Value -> IEncodable) (value : 'Value) (table:IDTableWrite) =
         let id = genID value
         if table.ContainsKey id then 
            encodeID id
diff --git a/src/Json/Investigation.fs b/src/Json/Investigation.fs
index a34e148a..49a54c8c 100644
--- a/src/Json/Investigation.fs
+++ b/src/Json/Investigation.fs
@@ -9,7 +9,7 @@ module Investigation =
     
     let encoder (inv : ArcInvestigation) = 
         [ 
-            "Identifier", Encode.string inv.Identifier
+            "Identifier", Encode.string inv.Identifier |> Some
             Encode.tryInclude "Title" Encode.string inv.Title
             Encode.tryInclude "Description" Encode.string inv.Description
             Encode.tryInclude "SubmissionDate" Encode.string inv.SubmissionDate
@@ -50,7 +50,7 @@ module Investigation =
 
     let encoderCompressed (stringTable : StringTableMap) (oaTable : OATableMap) (cellTable : CellTableMap) (inv : ArcInvestigation) = 
         [ 
-            "Identifier", Encode.string inv.Identifier
+            "Identifier", Encode.string inv.Identifier |> Some
             Encode.tryInclude "Title" Encode.string inv.Title
             Encode.tryInclude "Description" Encode.string inv.Description
             Encode.tryInclude "SubmissionDate" Encode.string inv.SubmissionDate
@@ -100,11 +100,11 @@ module Investigation =
 
         let encoder (oa : ArcInvestigation) = 
             [
-                "@id", Encode.string (oa |> genID)
-                "@type", Encode.string "Investigation"
-                "additionalType", Encode.string "Investigation"
-                "identifier", Encode.string oa.Identifier
-                "filename", Encode.string ArcInvestigation.FileName
+                "@id", Encode.string (oa |> genID) |> Some
+                "@type", Encode.string "Investigation" |> Some
+                "additionalType", Encode.string "Investigation" |> Some
+                "identifier", Encode.string oa.Identifier |> Some
+                "filename", Encode.string ArcInvestigation.FileName |> Some
                 Encode.tryInclude "title" Encode.string oa.Title
                 Encode.tryInclude "description" Encode.string oa.Description
                 Encode.tryInclude "submissionDate" Encode.string oa.SubmissionDate
@@ -114,7 +114,7 @@ module Investigation =
                 Encode.tryIncludeSeq "people" Person.ROCrate.encoder oa.Contacts
                 Encode.tryIncludeSeq "studies" (Study.ROCrate.encoder None) oa.Studies
                 Encode.tryIncludeSeq "comments" Comment.ROCrate.encoder oa.Comments
-                "@context", ROCrateContext.Investigation.context_jsonvalue
+                "@context", ROCrateContext.Investigation.context_jsonvalue |> Some
             ]
             |> Encode.choose
             |> Encode.object
@@ -155,8 +155,8 @@ module Investigation =
                 Encode.tryInclude "@type" Encode.string (Some "CreativeWork")
                 Encode.tryInclude "@id" Encode.string (Some "ro-crate-metadata.json")
                 Encode.tryInclude "about" encoder (Some oa)
-                "conformsTo", ROCrateContext.ROCrate.conformsTo_jsonvalue
-                "@context", ROCrateContext.ROCrate.context_jsonvalue
+                "conformsTo", ROCrateContext.ROCrate.conformsTo_jsonvalue |> Some
+                "@context", ROCrateContext.ROCrate.context_jsonvalue |> Some
                 ]
             |> Encode.choose
             |> Encode.object
@@ -167,9 +167,9 @@ module Investigation =
 
         let encoder idMap (inv: ArcInvestigation) = 
             [
-                "@id", Encode.string (inv |> ROCrate.genID)
-                "filename", Encode.string ArcInvestigation.FileName
-                "identifier", Encode.string (inv.Identifier)
+                "@id", Encode.string (inv |> ROCrate.genID) |> Some
+                "filename", Encode.string ArcInvestigation.FileName |> Some
+                "identifier", Encode.string (inv.Identifier) |> Some
                 Encode.tryInclude "title" Encode.string (inv.Title)
                 Encode.tryInclude "description" Encode.string (inv.Description)
                 Encode.tryInclude "submissionDate" Encode.string (inv.SubmissionDate)
diff --git a/src/Json/OntologyAnnotation.fs b/src/Json/OntologyAnnotation.fs
index 2ea0dbf1..bb2a2cd0 100644
--- a/src/Json/OntologyAnnotation.fs
+++ b/src/Json/OntologyAnnotation.fs
@@ -79,13 +79,13 @@ module OntologyAnnotation =
 
         let encoderDefinedTerm (oa : OntologyAnnotation) = 
             [
-                "@id", Encode.string (oa |> genID)
-                "@type", Encode.string "OntologyAnnotation"
+                "@id", Encode.string (oa |> genID) |> Some
+                "@type", Encode.string "OntologyAnnotation" |> Some
                 Encode.tryInclude "annotationValue" Encode.string (oa.Name)
                 Encode.tryInclude "termSource" Encode.string (oa.TermSourceREF)
                 Encode.tryInclude "termAccession" Encode.string (oa.TermAccessionNumber)
                 Encode.tryIncludeSeq "comments" Comment.ROCrate.encoderDisambiguatingDescription (oa.Comments)
-                "@context", ROCrateContext.OntologyAnnotation.context_jsonvalue
+                "@context", ROCrateContext.OntologyAnnotation.context_jsonvalue |> Some
             ]
             |> Encode.choose
             |> Encode.object
@@ -102,13 +102,13 @@ module OntologyAnnotation =
 
         let encoderPropertyValue (oa : OntologyAnnotation) = 
             [
-                "@id", Encode.string (oa |> genID)
-                "@type", Encode.string "PropertyValue"
+                "@id", Encode.string (oa |> genID) |> Some
+                "@type", Encode.string "PropertyValue" |> Some
 
                 Encode.tryInclude "category" Encode.string oa.Name
                 Encode.tryInclude "categoryCode" Encode.string oa.TermAccessionNumber
                 Encode.tryIncludeSeq "comments" Comment.ROCrate.encoderDisambiguatingDescription (oa.Comments)
-                "@context", ROCrateContext.PropertyValue.context_jsonvalue
+                "@context", ROCrateContext.PropertyValue.context_jsonvalue |> Some
             ]
             |> Encode.choose
             |> Encode.object
diff --git a/src/Json/OntologySourceReference.fs b/src/Json/OntologySourceReference.fs
index 4bb17177..90d34a01 100644
--- a/src/Json/OntologySourceReference.fs
+++ b/src/Json/OntologySourceReference.fs
@@ -1,4 +1,4 @@
-namespace ARCtrl.Json
+namespace ARCtrl.Json
 
 open Thoth.Json.Core
 open ARCtrl
@@ -42,14 +42,14 @@ module OntologySourceReference =
 
         let encoder (osr : OntologySourceReference) = 
             [
-                "@id", Encode.string (osr |> genID)
-                "@type", Encode.string "OntologySourceReference"
+                "@id", Encode.string (osr |> genID) |> Some
+                "@type", Encode.string "OntologySourceReference" |> Some
                 Encode.tryInclude "description" Encode.string (osr.Description)
                 Encode.tryInclude "file" Encode.string (osr.File)
                 Encode.tryInclude "name" Encode.string (osr.Name)
                 Encode.tryInclude "version" Encode.string (osr.Version)
                 Encode.tryIncludeSeq "comments" Comment.encoder (osr.Comments)
-                "@context", ROCrateContext.OntologySourceReference.context_jsonvalue
+                "@context", ROCrateContext.OntologySourceReference.context_jsonvalue |> Some
             ]
             |> Encode.choose
             |> Encode.object
diff --git a/src/Json/Person.fs b/src/Json/Person.fs
index a6fd6d3a..11838e5b 100644
--- a/src/Json/Person.fs
+++ b/src/Json/Person.fs
@@ -81,8 +81,8 @@ module Person =
 
         let encoder (oa : Person) = 
             [
-                "@id", Encode.string (oa |> genID)
-                "@type", Encode.string "Person"
+                "@id", Encode.string (oa |> genID) |> Some
+                "@type", Encode.string "Person" |> Some
                 Encode.tryInclude "orcid" Encode.string oa.ORCID 
                 Encode.tryInclude "firstName" Encode.string oa.FirstName
                 Encode.tryInclude "lastName" Encode.string oa.LastName
@@ -94,7 +94,7 @@ module Person =
                 Encode.tryInclude "affiliation" Affiliation.encoder oa.Affiliation
                 Encode.tryIncludeSeq "roles" OntologyAnnotation.ROCrate.encoderDefinedTerm oa.Roles
                 Encode.tryIncludeSeq "comments" Comment.ROCrate.encoderDisambiguatingDescription oa.Comments
-                "@context", ROCrateContext.Person.context_jsonvalue
+                "@context", ROCrateContext.Person.context_jsonvalue |> Some
             ]
             |> Encode.choose
             |> Encode.object
@@ -133,9 +133,9 @@ module Person =
             let names = authorList.Split([|separator|], System.StringSplitOptions.None) |> Array.map (fun s -> s.Trim())
             let encodeSingle (name:string) =
                 [
-                    "@type", Encode.string "Person"
+                    "@type", Encode.string "Person" |> Some
                     Encode.tryInclude "name" Encode.string (Some name)
-                    "@context", ROCrateContext.Person.contextMinimal_jsonValue
+                    "@context", ROCrateContext.Person.contextMinimal_jsonValue  |> Some
                 ]
                 |> Encode.choose
                 |> Encode.object
diff --git a/src/Json/Process/Component.fs b/src/Json/Process/Component.fs
index 003def93..13c95a57 100644
--- a/src/Json/Process/Component.fs
+++ b/src/Json/Process/Component.fs
@@ -10,7 +10,7 @@ module Component =
 
     module ROCrate =
 
-        let encoder : Component -> Json= 
+        let encoder : Component -> IEncodable = 
             PropertyValue.ROCrate.encoder
 
         let decoder : Decoder<Component> =
diff --git a/src/Json/Process/FactorValue.fs b/src/Json/Process/FactorValue.fs
index 59408c32..640b9f4f 100644
--- a/src/Json/Process/FactorValue.fs
+++ b/src/Json/Process/FactorValue.fs
@@ -12,7 +12,7 @@ module FactorValue =
     
     module ROCrate =
 
-        let encoder : FactorValue -> Json= 
+        let encoder : FactorValue -> IEncodable = 
             PropertyValue.ROCrate.encoder
 
         let decoder : Decoder<FactorValue> =
diff --git a/src/Json/Process/Material.fs b/src/Json/Process/Material.fs
index d724b746..9173c25e 100644
--- a/src/Json/Process/Material.fs
+++ b/src/Json/Process/Material.fs
@@ -18,13 +18,13 @@ module Material =
     
         let rec encoder (oa : Material) = 
             [
-                "@id", Encode.string (oa |> genID)
-                "@type", (Encode.list [Encode.string "Material"])
+                "@id", Encode.string (oa |> genID) |> Some
+                "@type", (Encode.list [Encode.string "Material"]) |> Some
                 Encode.tryInclude "name" Encode.string oa.Name
                 Encode.tryInclude "type" MaterialType.ROCrate.encoder oa.MaterialType
                 Encode.tryIncludeListOpt "characteristics" MaterialAttributeValue.ROCrate.encoder oa.Characteristics
                 Encode.tryIncludeListOpt "derivesFrom" encoder oa.DerivesFrom
-                "@context", ROCrateContext.Material.context_jsonvalue
+                "@context", ROCrateContext.Material.context_jsonvalue |> Some
             ]
             |> Encode.choose
             |> Encode.object
diff --git a/src/Json/Process/MaterialAttributeValue.fs b/src/Json/Process/MaterialAttributeValue.fs
index 71e79a7d..afd1b047 100644
--- a/src/Json/Process/MaterialAttributeValue.fs
+++ b/src/Json/Process/MaterialAttributeValue.fs
@@ -10,7 +10,7 @@ module MaterialAttributeValue =
 
     module ROCrate =
 
-        let encoder : MaterialAttributeValue -> Json= 
+        let encoder : MaterialAttributeValue -> IEncodable = 
             PropertyValue.ROCrate.encoder
 
         let decoder : Decoder<MaterialAttributeValue> =
diff --git a/src/Json/Process/Process.fs b/src/Json/Process/Process.fs
index d00eaa23..f1a1b46e 100644
--- a/src/Json/Process/Process.fs
+++ b/src/Json/Process/Process.fs
@@ -18,8 +18,8 @@ module Process =
 
         let encoder (studyName:string Option) (assayName:string Option) (oa : Process) =            
             [
-                "@id", Encode.string (oa |> genID)
-                "@type", (Encode.list [Encode.string "Process"])
+                "@id", Encode.string (oa |> genID) |> Some
+                "@type", (Encode.list [Encode.string "Process"]) |> Some 
                 Encode.tryInclude "name" Encode.string (oa.Name)
                 Encode.tryInclude "executesProtocol" (Protocol.ROCrate.encoder studyName assayName oa.Name) (oa.ExecutesProtocol)
                 Encode.tryIncludeListOpt "parameterValues" ProcessParameterValue.ROCrate.encoder (oa.ParameterValues)
@@ -28,7 +28,7 @@ module Process =
                 Encode.tryIncludeListOpt "inputs" ProcessInput.ROCrate.encoder (oa.Inputs)
                 Encode.tryIncludeListOpt "outputs" ProcessOutput.ROCrate.encoder (oa.Outputs)
                 Encode.tryIncludeListOpt "comments" Comment.ROCrate.encoder (oa.Comments)
-                "@context", ROCrateContext.Process.context_jsonvalue
+                "@context", ROCrateContext.Process.context_jsonvalue |> Some
             ]
             |> Encode.choose
             |> Encode.object
diff --git a/src/Json/Process/ProcessParameterValue.fs b/src/Json/Process/ProcessParameterValue.fs
index 19ad84c1..1768fdec 100644
--- a/src/Json/Process/ProcessParameterValue.fs
+++ b/src/Json/Process/ProcessParameterValue.fs
@@ -9,7 +9,7 @@ module ProcessParameterValue =
     
     module ROCrate =
 
-        let encoder : ProcessParameterValue -> Json= 
+        let encoder : ProcessParameterValue -> IEncodable = 
             PropertyValue.ROCrate.encoder
 
         let decoder : Decoder<ProcessParameterValue> =
diff --git a/src/Json/Process/Protocol.fs b/src/Json/Process/Protocol.fs
index 5460c6d3..0586e1c2 100644
--- a/src/Json/Process/Protocol.fs
+++ b/src/Json/Process/Protocol.fs
@@ -27,8 +27,8 @@ module Protocol =
 
         let encoder (studyName:string Option) (assayName:string Option) (processName:string Option) (oa : Protocol) = 
             [
-                "@id", Encode.string (genID studyName assayName processName oa)
-                "@type", (Encode.list [Encode.string "Protocol"])
+                "@id", Encode.string (genID studyName assayName processName oa) |> Some
+                "@type", (Encode.list [Encode.string "Protocol"]) |> Some
                 Encode.tryInclude "name" Encode.string (oa.Name)
                 Encode.tryInclude "protocolType" OntologyAnnotation.ROCrate.encoderDefinedTerm (oa.ProtocolType)
                 Encode.tryInclude "description" Encode.string (oa.Description)
@@ -36,7 +36,7 @@ module Protocol =
                 Encode.tryInclude "version" Encode.string (oa.Version)
                 Encode.tryIncludeListOpt "components" Component.ROCrate.encoder oa.Components
                 Encode.tryIncludeListOpt "comments" Comment.ROCrate.encoder oa.Comments
-                "@context", ROCrateContext.Protocol.context_jsonvalue
+                "@context", ROCrateContext.Protocol.context_jsonvalue |> Some
             ]
             |> Encode.choose
             |> Encode.object
diff --git a/src/Json/Process/Sample.fs b/src/Json/Process/Sample.fs
index a4743d0f..eeeed337 100644
--- a/src/Json/Process/Sample.fs
+++ b/src/Json/Process/Sample.fs
@@ -1,4 +1,4 @@
-namespace ARCtrl.Json
+namespace ARCtrl.Json
 
 open Thoth.Json.Core
 
@@ -22,11 +22,11 @@ module Sample =
                 oa.Characteristics |> Option.defaultValue [] |> List.map MaterialAttributeValue.ROCrate.encoder
                 |> List.append (oa.FactorValues |> Option.defaultValue [] |> List.map FactorValue.ROCrate.encoder)
             [
-                "@id", Encode.string (oa |> genID)
-                "@type", (Encode.list [ Encode.string "Sample"])
+                "@id", Encode.string (oa |> genID) |> Some
+                "@type", (Encode.list [ Encode.string "Sample"]) |> Some
                 Encode.tryInclude "name" Encode.string (oa.Name)
                 Encode.tryIncludeList "additionalProperties" id additionalProperties
-                "@context", ROCrateContext.Sample.context_jsonvalue
+                "@context", ROCrateContext.Sample.context_jsonvalue |> Some
             ]
             |> Encode.choose
             |> Encode.object
diff --git a/src/Json/Process/Source.fs b/src/Json/Process/Source.fs
index 6a4af31b..fdf39e50 100644
--- a/src/Json/Process/Source.fs
+++ b/src/Json/Process/Source.fs
@@ -1,4 +1,4 @@
-namespace ARCtrl.Json
+namespace ARCtrl.Json
 
 open Thoth.Json.Core
 
@@ -18,11 +18,11 @@ module Source =
     
         let rec encoder (oa : Source) = 
             [
-                "@id", Encode.string (oa |> genID)
-                "@type", (Encode.list [ Encode.string "Source"])
+                "@id", Encode.string (oa |> genID) |> Some
+                "@type", (Encode.list [ Encode.string "Source"]) |> Some
                 Encode.tryInclude "name" Encode.string (oa.Name)
                 Encode.tryIncludeListOpt "characteristics" MaterialAttributeValue.ROCrate.encoder (oa.Characteristics)      
-                "@context", ROCrateContext.Source.context_jsonvalue
+                "@context", ROCrateContext.Source.context_jsonvalue |> Some
                 ]
             |> Encode.choose
             |> Encode.object
diff --git a/src/Json/PropertyValue.fs b/src/Json/PropertyValue.fs
index ed96feeb..2f1bfbe0 100644
--- a/src/Json/PropertyValue.fs
+++ b/src/Json/PropertyValue.fs
@@ -38,9 +38,9 @@ module PropertyValue =
                     oa.Name, oa.TermAccessionNumber
                 | None -> None, None
             [
-                "@id", Encode.string (pv |> genID)
-                "@type", Encode.string "PropertyValue"
-                "additionalType", Encode.string (pv.GetAdditionalType())
+                "@id", Encode.string (pv |> genID) |> Some
+                "@type", Encode.string "PropertyValue" |> Some
+                "additionalType", Encode.string (pv.GetAdditionalType()) |> Some
                 Encode.tryInclude "alternateName" Encode.string (pv.AlternateName())
                 Encode.tryInclude "measurementMethod" Encode.string (pv.MeasurementMethod())
                 Encode.tryInclude "description" Encode.string (pv.Description())
@@ -50,7 +50,7 @@ module PropertyValue =
                 Encode.tryInclude "valueCode" id valueCode
                 Encode.tryInclude "unit" Encode.string unit
                 Encode.tryInclude "unitCode" Encode.string unitCode
-                "@context", ROCrateContext.PropertyValue.context_jsonvalue
+                "@context", ROCrateContext.PropertyValue.context_jsonvalue |> Some
             ]
             |> Encode.choose
             |> Encode.object
diff --git a/src/Json/Publication.fs b/src/Json/Publication.fs
index c841e00c..5a12b226 100644
--- a/src/Json/Publication.fs
+++ b/src/Json/Publication.fs
@@ -46,15 +46,15 @@ module Publication =
 
         let encoder (oa : Publication) = 
             [
-                "@id", Encode.string (oa |> genID)
-                "@type", Encode.string "Publication"
+                "@id", Encode.string (oa |> genID) |> Some
+                "@type", Encode.string "Publication" |> Some
                 Encode.tryInclude "pubMedID" Encode.string oa.PubMedID
                 Encode.tryInclude "doi" Encode.string (oa.DOI)
                 Encode.tryInclude "authorList" Person.ROCrate.encodeAuthorListString oa.Authors
                 Encode.tryInclude "title" Encode.string (oa.Title)
                 Encode.tryInclude "status" OntologyAnnotation.ROCrate.encoderDefinedTerm oa.Status
                 Encode.tryIncludeSeq "comments" Comment.ROCrate.encoderDisambiguatingDescription oa.Comments
-                "@context", ROCrateContext.Publication.context_jsonvalue
+                "@context", ROCrateContext.Publication.context_jsonvalue |> Some
             ]
             |> Encode.choose
             |> Encode.object
diff --git a/src/Json/Study.fs b/src/Json/Study.fs
index 020ac31c..0bb5489a 100644
--- a/src/Json/Study.fs
+++ b/src/Json/Study.fs
@@ -28,7 +28,7 @@ module Study =
 
     let encoder (study:ArcStudy) = 
         [ 
-            "Identifier", Encode.string study.Identifier
+            "Identifier", Encode.string study.Identifier  |> Some
             Encode.tryInclude "Title" Encode.string study.Title
             Encode.tryInclude "Description" Encode.string study.Description
             Encode.tryInclude "SubmissionDate" Encode.string study.SubmissionDate
@@ -68,7 +68,7 @@ module Study =
 
     let encoderCompressed (stringTable : StringTableMap) (oaTable : OATableMap) (cellTable : CellTableMap) (study:ArcStudy) =
         [ 
-            "Identifier", Encode.string study.Identifier
+            "Identifier", Encode.string study.Identifier  |> Some
             Encode.tryInclude "Title" Encode.string study.Title
             Encode.tryInclude "Description" Encode.string study.Description
             Encode.tryInclude "SubmissionDate" Encode.string study.SubmissionDate
@@ -116,10 +116,10 @@ module Study =
             let processes = s.GetProcesses()
             let assays = Helper.getAssayInformation assays s
             [
-                "@id", Encode.string (s |> genID)               
-                "@type", (Encode.list [Encode.string "Study"])
-                "additionalType", Encode.string "Study"
-                "identifier", Encode.string (s.Identifier)
+                "@id", Encode.string (s |> genID) |> Some
+                "@type", (Encode.list [Encode.string "Study"])  |> Some
+                "additionalType", Encode.string "Study" |> Some
+                "identifier", Encode.string (s.Identifier) |> Some
                 Encode.tryInclude "filename" Encode.string fileName
                 Encode.tryInclude "title" Encode.string (s.Title)
                 Encode.tryInclude "description" Encode.string (s.Description)
@@ -131,7 +131,7 @@ module Study =
                 Encode.tryIncludeList "processSequence" (Process.ROCrate.encoder (Some s.Identifier) None) processes
                 Encode.tryIncludeSeq "assays" (Assay.ROCrate.encoder (Some s.Identifier)) assays           
                 Encode.tryIncludeSeq "comments" Comment.ROCrate.encoder s.Comments
-                "@context", ROCrateContext.Study.context_jsonvalue
+                "@context", ROCrateContext.Study.context_jsonvalue |> Some
             ]
             |> Encode.choose
             |> Encode.object
@@ -205,9 +205,9 @@ module Study =
                     ProcessSequence.getProtocols processes
                     |> Encode.tryIncludeList "protocols" (Protocol.ISAJson.encoder (Some s.Identifier) None None idMap)
                 [
-                    "@id", Encode.string (study |> ROCrate.genID)
-                    "filename", Encode.string fileName
-                    "identifier", Encode.string study.Identifier
+                    "@id", Encode.string (study |> ROCrate.genID) |> Some
+                    "filename", Encode.string fileName |> Some
+                    "identifier", Encode.string study.Identifier |> Some
                     Encode.tryInclude "title" Encode.string study.Title
                     Encode.tryInclude "description" Encode.string study.Description
                     Encode.tryInclude "submissionDate" Encode.string study.SubmissionDate
diff --git a/src/Json/Table/Compression.fs b/src/Json/Table/Compression.fs
index 2a56fa63..a6376fc9 100644
--- a/src/Json/Table/Compression.fs
+++ b/src/Json/Table/Compression.fs
@@ -1,4 +1,4 @@
-namespace ARCtrl.Json
+namespace ARCtrl.Json
 
 
 open Thoth.Json.Core
@@ -9,16 +9,21 @@ open System.Collections.Generic
 /// This module is used to generalize json compression helpers
 module Compression =
 
-    let encode (encoder: Dictionary<string, int> -> Dictionary<OntologyAnnotation, int> -> Dictionary<CompositeCell, int> -> 'A -> Json) (obj: 'A) = 
-        let stringTable = Dictionary()
-        let oaTable = Dictionary()
-        let cellTable = Dictionary()
-        let arcStudy = encoder stringTable oaTable cellTable obj 
+    let encode (encoder: Dictionary<string, int> -> Dictionary<OntologyAnnotation, int> -> Dictionary<CompositeCell, int> -> 'A -> IEncodable) (obj: 'A) = 
+        let stringTable = Dictionary<string, int>()
+        let oaTable = Dictionary<OntologyAnnotation, int>()
+        let cellTable = Dictionary<CompositeCell, int>()
+        let object = encoder stringTable oaTable cellTable obj
+        object |> Encode.toJsonString 0 |> ignore
+        let encodedCellTable = CellTable.arrayFromMap cellTable |> CellTable.encoder stringTable oaTable
+        let encodedOATable = OATable.arrayFromMap oaTable |> OATable.encoder stringTable
+        let encodedStringTable = StringTable.arrayFromMap stringTable |> StringTable.encoder
+
         Encode.object [
-            "cellTable", CellTable.arrayFromMap cellTable |> CellTable.encoder stringTable oaTable
-            "oaTable", OATable.arrayFromMap oaTable |> OATable.encoder stringTable
-            "stringTable", StringTable.arrayFromMap stringTable |> StringTable.encoder
-            "object", arcStudy
+            "cellTable", encodedCellTable
+            "oaTable", encodedOATable
+            "stringTable", encodedStringTable
+            "object", object
         ] 
 
     let decode (decoder) =
diff --git a/src/Json/Table/Templates.fs b/src/Json/Table/Templates.fs
index 56577960..fafea678 100644
--- a/src/Json/Table/Templates.fs
+++ b/src/Json/Table/Templates.fs
@@ -1,4 +1,4 @@
-namespace ARCtrl.Json
+namespace ARCtrl.Json
 
 open Thoth.Json.Core
 
@@ -28,9 +28,9 @@ module Template =
             "description", Encode.string template.Description
             "organisation", Organisation.encoder template.Organisation
             "version", Encode.string template.Version
-            Encode.tryIncludeSeq "authors" Person.encoder template.Authors 
-            Encode.tryIncludeSeq "endpoint_repositories" OntologyAnnotation.encoder template.EndpointRepositories 
-            Encode.tryIncludeSeq "tags" OntologyAnnotation.encoder template.Tags 
+            "authors", (template.Authors |> Seq.map Person.encoder |> Encode.seq)
+            "endpoint_repositories", (template.EndpointRepositories |> Seq.map OntologyAnnotation.encoder |> Encode.seq)
+            "tags", (template.Tags |> Seq.map OntologyAnnotation.encoder |> Encode.seq)
             "last_updated", Encode.dateTime template.LastUpdated
         ]
 
@@ -52,15 +52,15 @@ module Template =
 
     let encoderCompressed stringTable oaTable cellTable (template: Template) =
         Encode.object [
-            "id", Encode.guid template.Id
+            "id", Encode.guid template.Id 
             "table", ArcTable.encoderCompressed stringTable oaTable cellTable template.Table
             "name", Encode.string template.Name
             "description", Encode.string template.Description
             "organisation", Organisation.encoder template.Organisation
             "version", Encode.string template.Version
-            Encode.tryIncludeSeq "authors" Person.encoder template.Authors 
-            Encode.tryIncludeSeq "endpoint_repositories" OntologyAnnotation.encoder template.EndpointRepositories 
-            Encode.tryIncludeSeq "tags" OntologyAnnotation.encoder template.Tags 
+            "authors", (template.Authors |> Seq.map Person.encoder |> Encode.seq)
+            "endpoint_repositories", (template.EndpointRepositories |> Seq.map OntologyAnnotation.encoder |> Encode.seq)
+            "tags", (template.Tags |> Seq.map OntologyAnnotation.encoder |> Encode.seq)
             "last_updated", Encode.datetime template.LastUpdated
         ]
 
diff --git a/src/Spreadsheet/ARCtrl.Spreadsheet.fsproj b/src/Spreadsheet/ARCtrl.Spreadsheet.fsproj
index f1f6cada..a98bcabb 100644
--- a/src/Spreadsheet/ARCtrl.Spreadsheet.fsproj
+++ b/src/Spreadsheet/ARCtrl.Spreadsheet.fsproj
@@ -33,7 +33,7 @@
     <Compile Include="Template.fs" />
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="FsSpreadsheet" Version="6.2.0" />
+    <PackageReference Include="FsSpreadsheet" Version="6.3.0-alpha.3" />
   </ItemGroup>
   <ItemGroup>
     <Content Include="*.fsproj; **\*.fs; **\*.fsi" PackagePath="fable\" />