diff --git a/Forge.TreeWalker.UnitTests/Forge.TreeWalker.UnitTests.csproj b/Forge.TreeWalker.UnitTests/Forge.TreeWalker.UnitTests.csproj
index 5dd596f..1cba3da 100644
--- a/Forge.TreeWalker.UnitTests/Forge.TreeWalker.UnitTests.csproj
+++ b/Forge.TreeWalker.UnitTests/Forge.TreeWalker.UnitTests.csproj
@@ -64,10 +64,6 @@
     <None Include="packages.config" />
   </ItemGroup>
   <ItemGroup>
-    <ProjectReference Include="..\Forge.DataContracts\Forge.DataContracts.csproj">
-      <Project>{c49a8494-13e5-4214-8434-708ba280c5b1}</Project>
-      <Name>Forge.DataContracts</Name>
-    </ProjectReference>
     <ProjectReference Include="..\Forge.TreeWalker\Forge.TreeWalker.csproj">
       <Project>{00fc1c22-6ae9-4f60-8a3e-05885ba34c9c}</Project>
       <Name>Forge.TreeWalker</Name>
diff --git a/Forge.TreeWalker/Forge.TreeWalker.csproj b/Forge.TreeWalker/Forge.TreeWalker.csproj
index 0158631..1c111c5 100644
--- a/Forge.TreeWalker/Forge.TreeWalker.csproj
+++ b/Forge.TreeWalker/Forge.TreeWalker.csproj
@@ -46,6 +46,7 @@
     <Reference Include="System.Threading.Tasks" />
     <Reference Include="System.Core" />
     <Reference Include="System.Runtime" />
+    <Reference Include="System.Runtime.Serialization" />
     <Reference Include="System.Data" />
     <Reference Include="System.Net.Http" />
     <Reference Include="Microsoft.CSharp" />
@@ -66,6 +67,7 @@
     </Reference>
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="contracts\ForgeTree.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="src\ActionContext.cs" />
     <Compile Include="src\ActionDefinition.cs" />
@@ -83,14 +85,9 @@
   </ItemGroup>
   <ItemGroup>
     <None Include="app.config" />
+    <None Include="contracts\ForgeSchemaValidationRules.json" />
     <None Include="packages.config" />
   </ItemGroup>
-  <ItemGroup>
-    <ProjectReference Include="..\Forge.DataContracts\Forge.DataContracts.csproj">
-      <Project>{c49a8494-13e5-4214-8434-708ba280c5b1}</Project>
-      <Name>Forge.DataContracts</Name>
-    </ProjectReference>
-  </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
     <PropertyGroup>
diff --git a/Forge.TreeWalker/Properties/AssemblyInfo.cs b/Forge.TreeWalker/Properties/AssemblyInfo.cs
index 4cea6eb..d591c5e 100644
--- a/Forge.TreeWalker/Properties/AssemblyInfo.cs
+++ b/Forge.TreeWalker/Properties/AssemblyInfo.cs
@@ -2,16 +2,14 @@
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
-[assembly: InternalsVisibleTo("Forge.TreeWalker.UnitTests")]
-
 // General Information about an assembly is controlled through the following
 // set of attributes. Change these attribute values to modify the information
 // associated with an assembly.
-[assembly: AssemblyTitle("Forge")]
+[assembly: AssemblyTitle("Forge.TreeWalker")]
 [assembly: AssemblyDescription("")]
 [assembly: AssemblyConfiguration("")]
 [assembly: AssemblyCompany("Microsoft")]
-[assembly: AssemblyProduct("Forge")]
+[assembly: AssemblyProduct("Forge.TreeWalker")]
 [assembly: AssemblyCopyright("Copyright ©  2019")]
 [assembly: AssemblyTrademark("")]
 [assembly: AssemblyCulture("")]
diff --git a/Forge.TreeWalker/contracts/ForgeSchemaValidationRules.json b/Forge.TreeWalker/contracts/ForgeSchemaValidationRules.json
new file mode 100644
index 0000000..8c763a4
--- /dev/null
+++ b/Forge.TreeWalker/contracts/ForgeSchemaValidationRules.json
@@ -0,0 +1,193 @@
+{
+  "type": "object",
+  "definitions": {
+    "TreeDefinition": {
+      "type": "object",
+      "patternProperties": {
+        ".*?": {
+          "$ref": "#/definitions/TreeNodeDefinition"
+        }
+      }
+    },
+    "TreeNodeDefinition": {
+      "oneOf": [
+        {
+          "$ref": "#/definitions/SelectionTypeNodeDefinition"
+        },
+        {
+          "$ref": "#/definitions/ActionTypeNodeDefinition"
+        },
+        {
+          "$ref": "#/definitions/LeafTypeNodeDefinition"
+        }
+      ]
+    },
+    "SelectionTypeNodeDefinition": {
+      "type": "object",
+      "properties": {
+        "Type": {
+          "type": "string",
+          "enum": [ "Selection" ]
+        },
+        "ChildSelector": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/ChildSelectorDefinition"
+          },
+          "minItems": 1
+        },
+        "Properties": {
+          "type": "object"
+        }
+      },
+      "additionalProperties": false,
+      "required": [ "Type" ]
+    },
+    "ActionTypeNodeDefinition": {
+      "type": "object",
+      "properties": {
+        "Type": {
+          "type": "string",
+          "enum": [ "Action" ]
+        },
+        "Timeout": {
+          "type": [ "number", "string" ]
+        },
+        "Actions": {
+          "patternProperties": {
+            ".*?": {
+              "$ref": "#/definitions/ActionDefinition"
+            }
+          },
+          "minProperties": 1
+        },
+        "ChildSelector": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/ChildSelectorDefinition"
+          },
+          "minItems": 1
+        },
+        "Properties": {
+          "type": "object"
+        }
+      },
+      "additionalProperties": false,
+      "required": [ "Type", "Actions" ]
+    },
+    "LeafTypeNodeDefinition": {
+      "type": "object",
+      "properties": {
+        "Type": {
+          "type": "string",
+          "enum": [ "Leaf" ]
+        },
+        "Actions": {
+          "patternProperties": {
+            ".*?": {
+              "$ref": "#/definitions/LeafNodeSummaryActionDefinition"
+            }
+          },
+          "minProperties": 1,
+          "maxProperties": 1
+        },
+        "Properties": {
+          "type": "object"
+        }
+      },
+      "additionalProperties": false,
+      "required": [ "Type" ]
+    },
+    "ChildSelectorDefinition": {
+      "type": "object",
+      "properties": {
+        "Label": {
+          "type": "string"
+        },
+        "ShouldSelect": {
+          "type": "string"
+        },
+        "Child": {
+          "type": "string"
+        }
+      },
+      "additionalProperties": false,
+      "required": [ "Label", "Child" ]
+    },
+    "RetryPolicy": {
+      "type": "object",
+      "properties": {
+        "Type": {
+          "type": "string",
+          "enum": [ "None", "FixedInterval", "ExponentialBackoff" ]
+        },
+        "MinBackoffMs": {
+          "type": "number"
+        },
+        "MaxBackoffMs": {
+          "type": "number"
+        }
+      },
+      "required": [ "Type" ]
+    },
+    "ActionDefinition": {
+      "type": "object",
+      "properties": {
+        "Action": {
+          "type": "string"
+        },
+        "Input": {
+          "type": "object"
+        },
+        "Properties": {
+          "type": "object"
+        },
+        "Timeout": {
+          "type": [ "number", "string" ]
+        },
+        "ContinuationOnTimeout": {
+          "type": "boolean"
+        },
+        "RetryPolicy": {
+          "$ref": "#/definitions/RetryPolicy"
+        },
+        "ContinuationOnRetryExhaustion": {
+          "type": "boolean"
+        }
+      },
+      "additionalProperties": false,
+      "required": [ "Action" ]
+    },
+    "LeafNodeSummaryActionDefinition": {
+      "type": "object",
+      "properties": {
+        "Action": {
+          "enum": [ "LeafNodeSummaryAction" ]
+        },
+        "Input": {
+          "type": [ "object", "string" ],
+          "properties": {
+            "Status": {
+              "type": "string"
+            },
+            "StatusCode": {
+              "type": [ "number", "string" ]
+            },
+            "Output": {
+              "type": [ "object", "string" ]
+            }
+          },
+          "additionalProperties": false
+        }
+      },
+      "additionalProperties": false,
+      "required": [ "Action", "Input" ]
+    }
+  },
+  "properties": {
+    "Tree": {
+      "$ref": "#/definitions/TreeDefinition"
+    }
+  },
+  "additionalProperties": false
+}
\ No newline at end of file
diff --git a/Forge.TreeWalker/contracts/ForgeTree.cs b/Forge.TreeWalker/contracts/ForgeTree.cs
new file mode 100644
index 0000000..155e897
--- /dev/null
+++ b/Forge.TreeWalker/contracts/ForgeTree.cs
@@ -0,0 +1,252 @@
+//-----------------------------------------------------------------------
+// <copyright file="ForgeTree.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+// <summary>
+//     The Forge schema data contracts.
+// </summary>
+//-----------------------------------------------------------------------
+
+namespace Forge.DataContracts
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Runtime.Serialization;
+
+    /// <summary>
+    /// The Forge tree.
+    /// This outermost data structure holds the Forge schema.
+    /// </summary>
+    [DataContract]
+    public class ForgeTree
+    {
+        /// <summary>
+        /// Dictionary mapping unique TreeNodeKeys to TreeNodes.
+        /// </summary>
+        [DataMember]
+        public Dictionary<string, TreeNode> Tree { get; set; }
+    }
+
+    /// <summary>
+    /// The tree node.
+    /// Holds information to navigate the tree and perform actions.
+    /// </summary>
+    [DataContract]
+    public class TreeNode
+    {
+        /// <summary>
+        /// The tree node type.
+        /// </summary>
+        [DataMember(IsRequired = true)]
+        public TreeNodeType Type { get; private set; }
+
+        /// <summary>
+        /// Additional properties passed to wrapper class.
+        /// String properties starting with <see cref="TreeWalkerSession.RoslynLeadingText"/> represent a code-snippet that will be evaluated.
+        /// </summary>
+        [DataMember]
+        public dynamic Properties { get; set; }
+
+        /// <summary>
+        /// The child selectors.
+        /// </summary>
+        [DataMember]
+        public ChildSelector[] ChildSelector { get; private set; }
+
+        #region Properties used only by TreeNodeType.Action nodes
+
+        /// <summary>
+        /// The actions to execute when the TreeNodeType is Action.
+        /// Dictionary mapping unique TreeActionKeys to TreeActions.
+        /// </summary>
+        [DataMember]
+        public Dictionary<string, TreeAction> Actions { get; set; }
+
+        /// <summary>
+        /// Timeout in milliseconds for executing the TreeActions. Default to -1 (infinite) if not specified.
+        /// String properties starting with <see cref="TreeWalkerSession.RoslynLeadingText"/> represent a code-snippet that will be evaluated.
+        /// </summary>
+        [DataMember]
+        public dynamic Timeout { get; set; }
+
+        #endregion
+    }
+
+    /// <summary>
+    /// The child selector for the TreeNode.
+    /// Used to navigate the tree by referencing child TreeNodes.
+    /// </summary>
+    [DataContract]
+    public class ChildSelector
+    {
+        /// <summary>
+        /// String code-snippet that can be parsed and evaluated to a boolean value.
+        /// If the expression is true, visit the attached child TreeNode.
+        /// If the expression is empty, evaluate to true by default.
+        /// </summary>
+        [DataMember]
+        public string ShouldSelect { get; set; }
+
+        /// <summary>
+        /// Reader-friendly label that describes the intention of the ShouldSelect expression.
+        /// Used in ForgeEditor for display purposes.
+        /// </summary>
+        [DataMember]
+        public string Label { get; set; }
+
+        /// <summary>
+        /// String key pointer to a child TreeNode.
+        /// Visit this child if the attached ShouldSelect expression evaluates to true.
+        /// </summary>
+        [DataMember(IsRequired = true)]
+        public string Child { get; private set; }
+    }
+
+    /// <summary>
+    /// The tree action for the TreeNode.
+    /// Holds instructions and policies for executing an action.
+    /// </summary>
+    [DataContract]
+    public class TreeAction
+    {
+        /// <summary>
+        /// String name of the action that maps to an action-task.
+        /// These actions may be predefined Forge actions or action-tasks passed by a Wrapper class.
+        /// </summary>
+        [DataMember(IsRequired = true)]
+        public string Action { get; set; }
+
+        /// <summary>
+        /// Dynamic input parameters passed to the action-task.
+        /// Wrapper class is responsible for making sure the action-task input matches the input defined in the schema.
+        /// String properties starting with <see cref="TreeWalkerSession.RoslynLeadingText"/> represent a code-snippet that will be evaluated.
+        /// </summary>
+        [DataMember]
+        public dynamic Input { get; private set; }
+
+        /// <summary>
+        /// Additional properties passed to wrapper class.
+        /// String properties starting with <see cref="TreeWalkerSession.RoslynLeadingText"/> represent a code-snippet that will be evaluated.
+        /// </summary>
+        [DataMember]
+        public dynamic Properties { get; set; }
+
+        /// <summary>
+        /// Timeout in milliseconds for executing the action. Default to -1 (infinite) if not specified.
+        /// String properties starting with <see cref="TreeWalkerSession.RoslynLeadingText"/> represent a code-snippet that will be evaluated.
+        /// </summary>
+        [DataMember]
+        public dynamic Timeout { get; set; }
+
+        /// <summary>
+        /// A flag that represents how to handle the exit of the action due to timeout. If false (default), then the session will end on the
+        /// timeout. If true and a timeout is hit, the action will continue on as if it were successful after committing a "TimeoutOnAction" response.
+        /// </summary>
+        [DataMember]
+        public bool ContinuationOnTimeout { get; set; }
+
+        /// <summary>
+        /// Retry policy of the action.
+        /// </summary>
+        [DataMember]
+        public RetryPolicy RetryPolicy { get; private set; }
+
+        /// <summary>
+        /// A flag that represents how to handle the exit of the action due to retry exhaustion. If false (default), then the session will end once
+        /// retries are exhausted or no retries are specified. If true and retries are exhausted, the action will continue on as if it were successful 
+        /// after committing a "RetryExhaustedOnAction" response.
+        /// </summary>
+        [DataMember]
+        public bool ContinuationOnRetryExhaustion { get; set; }
+    }
+
+    /// <summary>
+    /// The retry policy for the TreeAction.
+    /// </summary>
+    [DataContract]
+    public class RetryPolicy
+    {
+        /// <summary>
+        /// The retry policy type.
+        /// </summary>
+        [DataMember(IsRequired = true)]
+        public RetryPolicyType Type { get; private set; }
+
+        /// <summary>
+        /// Minimum backoff time in milliseconds.
+        /// When retrying an action, wait at least this long before your next attempt.
+        /// This is useful to ensure actions are not retried too quickly.
+        /// </summary>
+        [DataMember]
+        public long MinBackoffMs { get; private set; }
+
+        /// <summary>
+        /// Maximum backoff time in milliseconds.
+        /// When retrying an action, wait at most this long before your next attempt.
+        /// This is useful to ensure exponential backoff doesn't wait too long.
+        /// </summary>
+        [DataMember]
+        public long MaxBackoffMs { get; private set; }
+    }
+
+    /// <summary>
+    /// The retry policy types.
+    /// </summary>
+    [DataContract]
+    public enum RetryPolicyType
+    {
+        /// <summary>
+        /// Do not retry.
+        /// </summary>
+        [EnumMember]
+        None = 0,
+
+        /// <summary>
+        /// Retry at a fixed interval every MinBackoffMs.
+        /// </summary>
+        [EnumMember]
+        FixedInterval = 1,
+
+        /// <summary>
+        /// Retry with an exponential backoff.
+        /// Start with MinBackoffMs, then wait Math.Min(MinBackoffMs * 2^(retryCount), MaxBackoffMs).
+        /// </summary>
+        [EnumMember]
+        ExponentialBackoff = 2
+
+        // TODO: Add a FixedCount type that will give the full timeout duration for the set number of retries.
+    }
+
+    /// <summary>
+    /// The tree node types.
+    /// </summary>
+    [DataContract]
+    public enum TreeNodeType
+    {
+        /// <summary>
+        /// Undefined.
+        /// </summary>
+        [EnumMember]
+        Unknown = 0,
+
+        /// <summary>
+        /// Selection type node.
+        /// </summary>
+        [EnumMember]
+        Selection = 1,
+
+        /// <summary>
+        /// Action type node.
+        /// This node includes TreeAction(s).
+        /// </summary>
+        [EnumMember]
+        Action = 2,
+
+        /// <summary>
+        /// Leaf type node.
+        /// This represents an end state in tree.
+        /// </summary>
+        [EnumMember]
+        Leaf = 3
+    }
+}
\ No newline at end of file
diff --git a/Forge.TreeWalker/packages.config b/Forge.TreeWalker/packages.config
index 53b4e31..5179306 100644
--- a/Forge.TreeWalker/packages.config
+++ b/Forge.TreeWalker/packages.config
@@ -7,6 +7,7 @@
   <package id="Microsoft.CodeAnalysis.CSharp.Scripting" version="1.3.2" targetFramework="net462" />
   <package id="Microsoft.CodeAnalysis.Scripting" version="1.3.2" targetFramework="net462" />
   <package id="Microsoft.CodeAnalysis.Scripting.Common" version="1.3.2" targetFramework="net462" />
+  <package id="Microsoft.CSharp" version="4.5.0" targetFramework="net462" />
   <package id="Newtonsoft.Json" version="12.0.2" targetFramework="net462" />
   <package id="System.Collections.Immutable" version="1.1.37" targetFramework="net462" />
   <package id="System.Reflection.Metadata" version="1.2.0" targetFramework="net462" />
diff --git a/Forge.TreeWalker/src/TreeWalkerSession.cs b/Forge.TreeWalker/src/TreeWalkerSession.cs
index a0a01fb..47cb780 100644
--- a/Forge.TreeWalker/src/TreeWalkerSession.cs
+++ b/Forge.TreeWalker/src/TreeWalkerSession.cs
@@ -371,7 +371,7 @@ namespace Forge.TreeWalker
         /// <exception cref="OperationCanceledException">If the cancellation token was triggered.</exception>
         /// <exception cref="Exception">If an unexpected exception was thrown.</exception>
         /// <returns>The key of the next child to visit, or <c>null</c> if no match was found.</returns>
-        internal async Task<string> VisitNode(string treeNodeKey)
+        public async Task<string> VisitNode(string treeNodeKey)
         {
             TreeNode treeNode = this.Schema.Tree[treeNodeKey];
 
diff --git a/Forge.sln b/Forge.sln
index 59a24ba..49973d6 100644
--- a/Forge.sln
+++ b/Forge.sln
@@ -5,8 +5,6 @@ VisualStudioVersion = 16.0.29215.179
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Forge.TreeWalker", "Forge.TreeWalker\Forge.TreeWalker.csproj", "{00FC1C22-6AE9-4F60-8A3E-05885BA34C9C}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Forge.DataContracts", "Forge.DataContracts\Forge.DataContracts.csproj", "{C49A8494-13E5-4214-8434-708BA280C5B1}"
-EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Forge.TreeWalker.UnitTests", "Forge.TreeWalker.UnitTests\Forge.TreeWalker.UnitTests.csproj", "{A33AF1FF-1291-4CB1-A733-3243E1FE967E}"
 EndProject
 Global
@@ -19,10 +17,6 @@ Global
 		{00FC1C22-6AE9-4F60-8A3E-05885BA34C9C}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{00FC1C22-6AE9-4F60-8A3E-05885BA34C9C}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{00FC1C22-6AE9-4F60-8A3E-05885BA34C9C}.Release|Any CPU.Build.0 = Release|Any CPU
-		{C49A8494-13E5-4214-8434-708BA280C5B1}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{C49A8494-13E5-4214-8434-708BA280C5B1}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{C49A8494-13E5-4214-8434-708BA280C5B1}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{C49A8494-13E5-4214-8434-708BA280C5B1}.Release|Any CPU.Build.0 = Release|Any CPU
 		{A33AF1FF-1291-4CB1-A733-3243E1FE967E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{A33AF1FF-1291-4CB1-A733-3243E1FE967E}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{A33AF1FF-1291-4CB1-A733-3243E1FE967E}.Release|Any CPU.ActiveCfg = Release|Any CPU