diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 0000000..e55370c
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,73 @@
+export type Operator =
+    | "eq"
+    | "and"
+    | "or"
+    | "gt"
+    | "ge"
+    | "lt"
+    | "le"
+    | "like"
+    | "is null"
+    | "ne";
+
+export namespace Operators {
+    const EQUALS = "eq";
+    const AND = "and";
+    const OR = "or";
+    const GREATER_THAN = "gt";
+    const GREATER_THAN_EQUAL = "ge";
+    const LESS_THAN = "lt";
+    const LESS_THAN_EQUAL = "le";
+    const LIKE = "like";
+    const IS_NULL = "is null";
+    const NOT_EQUAL = "ne";
+
+    /**
+     * Whether a defined operation is unary or binary.  Will return true
+     * if the operation only supports a subject with no value.
+     *
+     * @param op the operation to check.
+     * @return whether the operation is an unary operation.
+     */
+    export function isUnary(op: Operator): boolean;
+
+    /**
+     * Whether a defined operation is a logical operators or not.
+     *
+     * @param op the operation to check.
+     * @return whether the operation is a logical operation.
+     */
+    export function isLogical(op: Operator): boolean;
+}
+
+export interface PredicateConfig {
+    subject: string | Predicate;
+    value?: string | number | Predicate;
+    operator: Operator;
+}
+
+/**
+ * Predicate is the basic model construct of the odata expression
+ */
+export class Predicate {
+    subject: string | Predicate;
+    value?: string | number | Predicate;
+    operator: Operator;
+
+    static concat(operator: Operator, p: Predicate): Predicate;
+
+    constructor(config?: PredicateConfig);
+
+    flatten(result?: Predicate[]): Predicate[];
+
+    /**
+     * Will serialie the predicate to an ODATA compliant serialized string.
+     *
+     * @return The compliant ODATA query string
+     */
+    serialize(): string;
+}
+
+export namespace Parser {
+    export function parse(filterStr?: string): null | Predicate;
+}
diff --git a/package.json b/package.json
index 25e0753..1b9f767 100644
--- a/package.json
+++ b/package.json
@@ -3,6 +3,7 @@
   "version": "0.5.4",
   "description": "Library for parsing and building OData filter strings",
   "main": "index.js",
+  "types": "index.d.ts",
   "scripts": {
     "test": "gulp test"
   },
@@ -45,4 +46,4 @@
     "jest-createspyobj": "^2.0.0",
     "jest-junit": "^15.0.0"
   }
-}
+}
\ No newline at end of file