diff --git a/app/exec/extension/_lib/interfaces.ts b/app/exec/extension/_lib/interfaces.ts
index 8357c450..168b866e 100644
--- a/app/exec/extension/_lib/interfaces.ts
+++ b/app/exec/extension/_lib/interfaces.ts
@@ -79,22 +79,22 @@ export interface AssetDeclaration {
 /**
  * Describes a screenshot in the manifest
  */
-export interface ScreenshotDeclaration extends AssetDeclaration {
-
-}
+export interface ScreenshotDeclaration extends AssetDeclaration { }
 
 /**
  * Describes a details file in the manifest
  */
-export interface DetailsDeclaration extends AssetDeclaration {
-
+export interface DetailsDeclaration extends AssetDeclaration { }
+export interface ContentDeclaration extends AssetDeclaration { }
+export interface ContentsDeclaration {
+	[key: string]: ContentDeclaration;
 }
-
 /**
  * Describes a link in the manifest
  */
 export interface LinkDeclaration {
-	url: string;
+	url?: string;
+	uri?: string;
 }
 
 /**
@@ -112,6 +112,30 @@ export interface TargetDeclaration {
 	version?: string;
 }
 
+export interface ContributionDeclaration {
+	id: string;
+}
+
+export interface ContributionTypeDeclaration {
+	id: string;
+}
+
+export interface BadgeDeclaration {
+	link?: string;
+	imgUri?: string;
+	description?: string;
+	href?: string;
+	uri?: string
+}
+
+export interface RepositoryDeclaration {
+	type: RepositoryType;
+	url?: string;
+	uri?: string;
+}
+
+export type RepositoryType = 'git';
+
 /**
  * Describes the extension's branding in the manifest.
  */
@@ -120,6 +144,48 @@ export interface BrandingDeclaration {
 	theme: string;
 }
 
+export interface VssManifest {
+	manifestVersion: string | number;
+	manifestversion: VssManifest['manifestVersion'];
+	targets: TargetDeclaration[];
+	version: string;
+	files: FileDeclaration[];
+	icons: { [key: string]: string };
+	eventcallbacks: {};
+	scopes: string[];
+	baseuri: string;
+	contributions: ContributionDeclaration[];
+	contributionTypes: ContributionTypeDeclaration[];
+	contributiontypes: VssManifest['contributionTypes'];
+	namespace: string;
+	extensionid: string;
+	id: string;
+	name: string;
+	description: string;
+	screenshots: ScreenshotDeclaration[];
+	details: DetailsDeclaration;
+	links: Links;
+	branding: BrandingDeclaration;
+	public: boolean;
+	publisher: string;
+	releasenotes: string;
+	tags: string|string[];
+	flags: {};
+	vsoflags: {};
+	galleryflags: string|string[];
+	categories: string|string[];
+	githubflavoredmarkdown: boolean;
+	showpricingcalculator: boolean;
+	content: ContentsDeclaration;
+	repository: RepositoryDeclaration;
+	badges: BadgeDeclaration[];
+}
+
+
+export interface VssManifestData extends VssManifest {
+	__origin: string;
+}
+
 /**
  * Settings for doing the merging
  */
@@ -142,7 +208,7 @@ export interface MergeSettings {
 	/**
 	 * Highest priority partial manifest
 	 */
-	overrides: any;
+	overrides: VssManifestData;
 
 	/**
 	 * True to bypass validation during packaging.
diff --git a/app/exec/extension/_lib/vsix-manifest-builder.ts b/app/exec/extension/_lib/vsix-manifest-builder.ts
index 7a1470b1..59db6400 100644
--- a/app/exec/extension/_lib/vsix-manifest-builder.ts
+++ b/app/exec/extension/_lib/vsix-manifest-builder.ts
@@ -332,6 +332,7 @@ export class VsixManifestBuilder extends ManifestBuilder {
 					throw "Value for gitHubFlavoredMarkdown is invalid. Only boolean values are allowed.";
 				}
 				this.addProperty("Microsoft.VisualStudio.Services.GitHubFlavoredMarkdown", value.toString());
+				break;
 			case "public":
 				if (typeof value === "boolean") {
 					let flags = _.get(this.data, "PackageManifest.Metadata[0].GalleryFlags[0]", "").split(" ");
diff --git a/manifest.schema.json b/manifest.schema.json
new file mode 100644
index 00000000..0ae167ce
--- /dev/null
+++ b/manifest.schema.json
@@ -0,0 +1,369 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "definitions": {
+        "BadgeDeclaration": {
+            "properties": {
+                "description": {
+                    "type": "string"
+                },
+                "href": {
+                    "type": "string"
+                },
+                "imgUri": {
+                    "type": "string"
+                },
+                "link": {
+                    "type": "string"
+                },
+                "uri": {
+                    "type": "string"
+                }
+            },
+            "type": "object"
+        },
+        "BrandingDeclaration": {
+            "description": "Describes the extension's branding in the manifest.",
+            "properties": {
+                "color": {
+                    "type": "string"
+                },
+                "theme": {
+                    "type": "string"
+                }
+            },
+            "type": "object"
+        },
+        "ContentDeclaration": {
+            "properties": {
+                "contentType": {
+                    "type": "string"
+                },
+                "path": {
+                    "type": "string"
+                }
+            },
+            "type": "object"
+        },
+        "ContentsDeclaration": {
+            "additionalProperties": {
+                "$ref": "#/definitions/ContentDeclaration"
+            },
+            "type": "object"
+        },
+        "ContributionDeclaration": {
+            "properties": {
+                "id": {
+                    "type": "string"
+                }
+            },
+            "type": "object"
+        },
+        "ContributionTypeDeclaration": {
+            "properties": {
+                "id": {
+                    "type": "string"
+                }
+            },
+            "type": "object"
+        },
+        "DetailsDeclaration": {
+            "description": "Describes a details file in the manifest",
+            "properties": {
+                "contentType": {
+                    "type": "string"
+                },
+                "path": {
+                    "type": "string"
+                }
+            },
+            "type": "object"
+        },
+        "FileDeclaration": {
+            "description": "Describes a file in a manifest",
+            "properties": {
+                "addressable": {
+                    "description": "If true, this asset will be addressable via a public gallery endpoint",
+                    "type": "boolean"
+                },
+                "assetType": {
+                    "anyOf": [
+                        {
+                            "items": {
+                                "type": "string"
+                            },
+                            "type": "array"
+                        },
+                        {
+                            "type": "string"
+                        }
+                    ],
+                    "description": "The type of this asset (Type attribute in the vsixmanifest's <Asset> entry)\nAlso used as the addressable name of this asset (if addressable = true)\nIf a string[] is provided, multiple <Asset> entries will be added."
+                },
+                "auto": {
+                    "description": "True means that this file was added indirectly, e.g. from a directory. Files that have\nauto = true will be overridden by files with the same path that do not.",
+                    "type": "boolean"
+                },
+                "content": {
+                    "description": "If content is not empty, this string will be used as the packaged contents\nrather than the contents of <path> on the file system.",
+                    "type": "string"
+                },
+                "contentType": {
+                    "description": "Manually specified content-type/mime-type. Otherwise, try to automatically determine.",
+                    "type": "string"
+                },
+                "lang": {
+                    "description": "Language of this asset, if any",
+                    "type": "string"
+                },
+                "packagePath": {
+                    "description": "Alias to partName",
+                    "type": "string"
+                },
+                "partName": {
+                    "description": "Path/file name to the file in the archive",
+                    "type": "string"
+                },
+                "path": {
+                    "description": "Path to the file on disk",
+                    "type": "string"
+                }
+            },
+            "type": "object"
+        },
+        "LinkDeclaration": {
+            "description": "Describes a link in the manifest",
+            "properties": {
+                "uri": {
+                    "type": "string"
+                },
+                "url": {
+                    "type": "string"
+                }
+            },
+            "type": "object"
+        },
+        "Links": {
+            "additionalProperties": {
+                "$ref": "#/definitions/LinkDeclaration"
+            },
+            "description": "Describes a set of links keyed off the link type in the manifest.",
+            "type": "object"
+        },
+        "RepositoryDeclaration": {
+            "properties": {
+                "type": {
+                    "enum": [
+                        "git"
+                    ],
+                    "type": "string"
+                },
+                "uri": {
+                    "type": "string"
+                },
+                "url": {
+                    "type": "string"
+                }
+            },
+            "type": "object"
+        },
+        "ScreenshotDeclaration": {
+            "description": "Describes a screenshot in the manifest",
+            "properties": {
+                "contentType": {
+                    "type": "string"
+                },
+                "path": {
+                    "type": "string"
+                }
+            },
+            "type": "object"
+        },
+        "TargetDeclaration": {
+            "description": "Describes a target in the manifest",
+            "properties": {
+                "id": {
+                    "type": "string"
+                },
+                "version": {
+                    "type": "string"
+                }
+            },
+            "type": "object"
+        }
+    },
+    "properties": {
+        "badges": {
+            "items": {
+                "$ref": "#/definitions/BadgeDeclaration"
+            },
+            "type": "array"
+        },
+        "baseuri": {
+            "type": "string"
+        },
+        "branding": {
+            "$ref": "#/definitions/BrandingDeclaration"
+        },
+        "categories": {
+            "anyOf": [
+                {
+                    "items": {
+                        "type": "string"
+                    },
+                    "type": "array"
+                },
+                {
+                    "type": "string"
+                }
+            ]
+        },
+        "content": {
+            "$ref": "#/definitions/ContentsDeclaration"
+        },
+        "contributionTypes": {
+            "items": {
+                "$ref": "#/definitions/ContributionTypeDeclaration"
+            },
+            "type": "array"
+        },
+        "contributions": {
+            "items": {
+                "$ref": "#/definitions/ContributionDeclaration"
+            },
+            "type": "array"
+        },
+        "contributiontypes": {
+            "items": {
+                "$ref": "#/definitions/ContributionTypeDeclaration"
+            },
+            "type": "array"
+        },
+        "description": {
+            "type": "string"
+        },
+        "details": {
+            "$ref": "#/definitions/DetailsDeclaration"
+        },
+        "eventcallbacks": {
+            "properties": {
+            },
+            "type": "object"
+        },
+        "extensionid": {
+            "type": "string"
+        },
+        "files": {
+            "items": {
+                "$ref": "#/definitions/FileDeclaration"
+            },
+            "type": "array"
+        },
+        "flags": {
+            "properties": {
+            },
+            "type": "object"
+        },
+        "galleryflags": {
+            "anyOf": [
+                {
+                    "items": {
+                        "type": "string"
+                    },
+                    "type": "array"
+                },
+                {
+                    "type": "string"
+                }
+            ]
+        },
+        "githubflavoredmarkdown": {
+            "type": "boolean"
+        },
+        "icons": {
+            "additionalProperties": {
+                "type": "string"
+            },
+            "type": "object"
+        },
+        "id": {
+            "type": "string"
+        },
+        "links": {
+            "$ref": "#/definitions/Links"
+        },
+        "manifestVersion": {
+            "type": [
+                "string",
+                "number"
+            ]
+        },
+        "manifestversion": {
+            "type": [
+                "string",
+                "number"
+            ]
+        },
+        "name": {
+            "type": "string"
+        },
+        "namespace": {
+            "type": "string"
+        },
+        "public": {
+            "type": "boolean"
+        },
+        "publisher": {
+            "type": "string"
+        },
+        "releasenotes": {
+            "type": "string"
+        },
+        "repository": {
+            "$ref": "#/definitions/RepositoryDeclaration"
+        },
+        "scopes": {
+            "items": {
+                "type": "string"
+            },
+            "type": "array"
+        },
+        "screenshots": {
+            "items": {
+                "$ref": "#/definitions/ScreenshotDeclaration"
+            },
+            "type": "array"
+        },
+        "showpricingcalculator": {
+            "type": "boolean"
+        },
+        "tags": {
+            "anyOf": [
+                {
+                    "items": {
+                        "type": "string"
+                    },
+                    "type": "array"
+                },
+                {
+                    "type": "string"
+                }
+            ]
+        },
+        "targets": {
+            "items": {
+                "$ref": "#/definitions/TargetDeclaration"
+            },
+            "type": "array"
+        },
+        "version": {
+            "type": "string"
+        },
+        "vsoflags": {
+            "properties": {
+            },
+            "type": "object"
+        }
+    },
+    "type": "object"
+}
+
diff --git a/package.json b/package.json
index 7599b787..7afeb1e7 100644
--- a/package.json
+++ b/package.json
@@ -15,7 +15,8 @@
     "clean": "rimraf _build",
     "build": "tsc -p .",
     "postbuild": "ncp app/tfx-cli.js _build/tfx-cli.js && ncp package.json _build/package.json && ncp app/exec/build/tasks/_resources _build/exec/build/tasks/_resources",
-    "prepublish": "npm run build"
+    "prepublish": "npm run build",
+    "buildschema": "typescript-json-schema ./tsconfig.json VssManifest > manifest.schema.json"
   },
   "dependencies": {
     "@types/colors": "^0.6.31",