diff --git a/src/component.ts b/src/component.ts
index 95468fe..bb82b9a 100644
--- a/src/component.ts
+++ b/src/component.ts
@@ -46,6 +46,7 @@ export class Component extends ValueNode {
      * @since 1.0.0
      * @param text
      * @param index
+     * @see {@link SubComponent}
      * @protected
      */
     protected createChild(text: string, index: number): Node {
diff --git a/src/field.ts b/src/field.ts
index 312b52b..1d4f18b 100644
--- a/src/field.ts
+++ b/src/field.ts
@@ -1,47 +1,70 @@
-import Node from './node';
-import Delimiters from "./delimiters";
-import ValueNode from "./valueNode";
-import FieldRepetition from "./fieldRepetition";
-import NodeBase from './nodeBase';
+import {Delimiters} from "./decorators/enum/delimiters.js";
+import { Node } from "./decorators/interfaces/node.js"
+import {FieldRepetition} from "./fieldRepetition.js";
+import {NodeBase} from "./nodeBase.js";
+import {ValueNode} from "./valueNode.js";
 
-export default class Field extends ValueNode {
+/**
+ * Field Area of the HL7 Segment
+ * @since 1.0.0
+ * @extends ValueNode
+ */
+export class Field extends ValueNode {
 
+    /**
+     * @since 1.0.0
+     * @param parent
+     * @param key
+     * @param text
+     */
     constructor(parent: NodeBase, key: string, text: string) {
         super(parent, key, text, Delimiters.Repetition);
     }
 
+    /**
+     * Read a Field Path
+     * @since 1.0.0
+     * @param path
+     */
     read(path: string[]): Node {
-
-        if(this.children.length > 0) {
+        if (this.children.length > 0) {
             return this.children[0].read(path);
         }
-
-        return null;
+        throw new Error("We have a problem.")
     }
 
+    /**
+     * Write a Field
+     * @since 1.0.0
+     * @param path
+     * @param value
+     * @protected
+     */
     protected writeCore(path: string[], value: string): Node {
-
         return this._ensureChild().write(path, value);
     }
 
-    protected createChild(text: string, index: number): Node {
-
+    /**
+     * Create a field repetition field of FieldRepetition
+     * @since 1.0.0
+     * @see {@link FieldRepetition}
+     * @param text
+     * @param _index
+     * @protected
+     */
+    protected createChild(text: string, _index: number): Node {
         return new FieldRepetition(this, this.key, text);
     }
 
+    /** @internal */
     private _ensureChild(): Node {
-
-        var child: Node;
-
-        // create a repetition if we do not have one already
-        if(this.children.length == 0) {
+        let child: Node;
+        if (this.children.length == 0) {
             child = this.createChild("", 0);
             this.setChild(child, 0);
-        }
-        else {
+        } else {
             child = this.children[0];
         }
-
         return child;
     }
 }
\ No newline at end of file
diff --git a/src/fieldRepetition.ts b/src/fieldRepetition.ts
index 75b5ec2..f36b069 100644
--- a/src/fieldRepetition.ts
+++ b/src/fieldRepetition.ts
@@ -1,33 +1,69 @@
-import Node from './node';
-import Delimiters from "./delimiters";
-import ValueNode from "./valueNode";
-import Component from "./component";
-import NodeBase from './nodeBase';
+import {Component} from "./component";
+import {Delimiters} from "./decorators/enum/delimiters";
+import {Node} from  "./decorators/interfaces/node"
+import {HL7FatalError} from "./exception";
+import {NodeBase} from "./nodeBase";
+import {ValueNode} from "./valueNode";
 
-export default class FieldRepetition extends ValueNode {
+/**
+ * Create a Field Repetition in an HL7 message segment
+ * @since 1.0.0
+ * @extends ValueNode
+ */
+export class FieldRepetition extends ValueNode {
 
+    /**
+     * @since 1.0.0
+     * @param parent
+     * @param key
+     * @param text
+     */
     constructor(parent: NodeBase, key: string, text: string) {
         super(parent, key, text, Delimiters.Component);
     }
 
+    /**
+     * Read Path
+     * @since 1.0.0
+     * @param path
+     */
     read(path: string[]): Node {
-
-        var component = this.children[parseInt(path.shift())-1];
+        let component = this.children[parseInt(<string>path.shift())-1];
         return component && path.length > 0 ? component.read(path) : component;
     }
 
+    /**
+     * Write Core
+     * @since 1.0.0
+     * @param path
+     * @param value
+     * @protected
+     */
     protected writeCore(path: string[], value: string): Node {
-
-        return this.writeAtIndex(path, value, parseInt(path.shift())-1);
+        return this.writeAtIndex(path, value, parseInt(<string>path.shift())-1);
     }
 
+    /**
+     * Get Path Core
+     * @since 1.0.0
+     * @protected
+     */
     protected pathCore(): string[] {
-
+        if (this.parent == null) {
+            throw new HL7FatalError(500, "this.parent must not be null.")
+        }
         return this.parent.path;
     }
 
+    /**
+     * Create child of a field repetition
+     * @since 1.0.0
+     * @param text
+     * @param index
+     * @see {@link Component}
+     * @protected
+     */
     protected createChild(text: string, index: number): Node {
-
         return new Component(this, (index + 1).toString(), text);
     }
 }
\ No newline at end of file
diff --git a/src/index.ts b/src/index.ts
index 9d54c73..188f6a2 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,13 +1,27 @@
 import { Client } from './client.js'
+import { Component } from './component.js'
+import { Delimiters } from './decorators/enum/delimiters.js'
+import { Node } from './decorators/interfaces/node.js'
+import { EmptyNode } from './emptyNode.js'
+import { Field } from './field.js'
+import { FieldRepetition } from './fieldRepetition.js'
 import { Listener } from './listener.js'
 import { Message } from './message.js'
+import { NodeBase } from './nodeBase.js'
 import { Parser, ParserPlan } from './parser.js'
+import { Segment } from './segment.js'
+import { HL7_2_7 } from './specification/2.7.js'
+import { HL7_SPEC, HL7_SPEC_BASE } from './specification/specification.js'
+import { SubComponent } from './subComponent.js'
 
 export default Client
-export { Client, Listener, Parser, ParserPlan, Message }
+export { Client, Listener, Parser, ParserPlan, Message, Delimiters, Segment, Component, SubComponent, Field, FieldRepetition, EmptyNode, NodeBase, Node }
 
 /** HL7 Specs **/
-export type { HL7_2_7_MSH, HL7_2_7 } from './specification/2.7.js'
+export type { MSH } from './specification/specification.js'
+export type { HL7_MSH_MESSAGE_TYPE } from './specification/generic.js'
+export type { HL7_2_7_MSH } from './specification/2.7.js'
+export { HL7_SPEC, HL7_SPEC_BASE, HL7_2_7 }
 
 export type { ClientOptions, ClientListenerOptions, ClientBuilderOptions, ClientBuilderBatchOptions, ClientBuilderFileOptions, ParserProcessRawData} from './normalize.js'
 export type { HL7Error, HL7FatalError, HL7ParserError } from './exception.js'