diff --git a/src/components/Composer.tsx b/src/components/Composer.tsx
index 5ab7e23..16ea114 100644
--- a/src/components/Composer.tsx
+++ b/src/components/Composer.tsx
@@ -1,11 +1,13 @@
-import { StyleSheet, TextInput, View } from "react-native";
+import { StyleSheet, View } from "react-native";
 import { Text } from "./primitive/Text";
 import { Button } from "./primitive/Button";
-import { useContext, useEffect, useMemo, useState } from "react";
+import { useContext, useEffect, useState } from "react";
 import { AuthContext } from "../context/AuthContext";
 import { Profile, resolveProfile } from "../lib/profile";
 import { RichTextEditor } from "../lib/richtext/editor";
 import { useRouter } from "expo-router";
+import { RichTextContent } from "../lib/richtext";
+import { dev } from "../lexicons";
 
 const styles = StyleSheet.create({
   composerHeader: {
@@ -61,10 +63,14 @@ function ComposerHeader() {
   );
 }
 
-function ComposerBody() {
+function ComposerBody({
+  onChange,
+}: {
+  onChange: (content: RichTextContent) => void;
+}) {
   return (
     <View style={styles.composerBody}>
-      <RichTextEditor />
+      <RichTextEditor onChange={onChange} />
     </View>
   );
 }
@@ -72,34 +78,57 @@ function ComposerBody() {
 function ComposerFooter({
   onPublish,
   onCancel,
+  disabled,
 }: {
   onPublish: () => void;
   onCancel: () => void;
+  disabled?: boolean;
 }) {
   return (
     <View style={styles.composerFooter}>
-      <Button text={"Cancel"} onPress={onCancel} />
-      <Button primary text={"Publish"} onPress={onPublish} />
+      <Button text={"Cancel"} onPress={onCancel} disabled={disabled} />
+      <Button
+        primary
+        text={"Publish"}
+        onPress={onPublish}
+        disabled={disabled}
+      />
     </View>
   );
 }
 
 export default function Composer() {
-  const router = useRouter()
+  const router = useRouter();
+  const [publishing, setPublishing] = useState(false);
+  const [content, setContent] = useState<RichTextContent>([])
+  const authCtx = useContext(AuthContext)
 
   const dismiss = () => {
-    router.canDismiss() ? router.dismiss() : router.navigate('/')
-  }
+    router.canDismiss() ? router.dismiss() : router.navigate("/");
+  };
 
-  const publish = () => {
-    // dismiss()
-  }
+  // TODO: Disable modal dismissal (ie by clicking background) when this is true
+  const publish = async () => {
+    setPublishing(true);
+    await authCtx.client?.create(dev.maelstrom.bramblr.post, {
+      content: content,
+      thread: [],
+      createdAt: new Date().toISOString() as any, // TODO: Fix this
+    })
+    dismiss()
+  };
 
   return (
     <View>
       <ComposerHeader />
-      <ComposerBody />
-      <ComposerFooter onCancel={dismiss} onPublish={publish} />
+      <ComposerBody onChange={setContent} />
+      <ComposerFooter
+        onCancel={dismiss}
+        onPublish={publish}
+        disabled={publishing}
+      />
+      {/* TODO: Add preview */}
+      {/* <RichTextBody richText={content} /> */}
     </View>
   );
 }
diff --git a/src/components/primitive/Button.tsx b/src/components/primitive/Button.tsx
index 485c245..0ee9574 100644
--- a/src/components/primitive/Button.tsx
+++ b/src/components/primitive/Button.tsx
@@ -15,6 +15,14 @@ const styles = StyleSheet.create({
     backgroundColor: "#0084ff",
     borderColor: "#0084ff",
   },
+  buttonDisabledPrimary: {
+    backgroundColor: "#1e5b95",
+    borderColor: "#1e5b95",
+  },
+  buttonDisabled: {
+    backgroundColor: "#535353",
+    borderColor: "#535353",
+  },
   buttonText: {
     color: "#fff",
     fontSize: 15,
@@ -25,14 +33,17 @@ export function Button({
   text,
   onPress,
   primary,
+  disabled,
 }: {
   text: string;
   onPress?: () => void;
   primary?: boolean;
+  disabled?: boolean;
 }) {
   return (
     <Pressable
-      style={[styles.button, primary && styles.buttonPrimary]}
+      disabled={disabled}
+      style={[styles.button, disabled ? (primary ? styles.buttonDisabledPrimary : styles.buttonDisabled) : (primary && styles.buttonPrimary)]}
       onPress={onPress ? () => onPress() : undefined}
     >
       <Text style={styles.buttonText}>{text}</Text>
diff --git a/src/components/primitive/Select.tsx b/src/components/primitive/Select.tsx
index a76649f..fd349ba 100644
--- a/src/components/primitive/Select.tsx
+++ b/src/components/primitive/Select.tsx
@@ -1,7 +1,6 @@
 import React, {
   ReactElement,
   ReactNode,
-  useEffect,
   useMemo,
   useState,
 } from "react";
@@ -37,12 +36,9 @@ export function Select({
   const [selected, setSelected] = useState(defaultElement);
   const [open, setOpen] = useState(false);
 
-  useEffect(() => {
-    onSelected && onSelected((selected.props as any).name);
-  }, [selected]);
-
   const select = (e: ReactElement<typeof SelectItem>) => {
     setSelected(e)
+    onSelected && onSelected((e.props as any).name);
     setOpen(false)
   }
 
diff --git a/src/lib/richtext/convert.ts b/src/lib/richtext/convert.ts
new file mode 100644
index 0000000..4643a51
--- /dev/null
+++ b/src/lib/richtext/convert.ts
@@ -0,0 +1,63 @@
+import { $Typed } from "@atproto/lex";
+import { RichTextContent, RichTextEmphasis } from ".";
+import { RichTextFacet } from "./richtext";
+
+function facetsFromChildren(children: any[]): [string, RichTextFacet[]] {
+  let text = "";
+  const facets: RichTextFacet[] = [];
+
+  for (const child of children) {
+    const start = new Blob([text]).size;
+    const end = start + new Blob([child.text]).size;
+    text += child.text;
+
+    const features: RichTextFacet["features"] = []
+
+    // Add emphasis facet
+    if (child.bold || child.italic || child.strike || child.small) {
+      const emphasisFacet: $Typed<RichTextEmphasis> = {
+        "$type": "dev.maelstrom.bramblr.richtext.facet#emphasis",
+        bold: child.bold,
+        italic: child.italic,
+        strike: child.strike,
+        small: child.small,
+      };
+
+      features.push(emphasisFacet)
+    }
+
+    // Add a facet if any features exist
+    if (features.length > 0) {
+      facets.push({
+        $type: "dev.maelstrom.bramblr.richtext.facet",
+        index: {
+          byteStart: start,
+          byteEnd: end,
+        },
+        features: features,
+      });
+    }
+  }
+
+  return [text, facets];
+}
+
+export function slateToLex(value: any[]): RichTextContent {
+  return value.map((block) => {
+    switch (block.type) {
+      case "paragraph":
+        const [text, facets] = facetsFromChildren(block.children);
+        return {
+          $type: "dev.maelstrom.bramblr.richtext.block#text",
+          format: block.format ?? "regular",
+          text: text,
+          facets: facets,
+        };
+      default:
+        throw "Unknown block type";
+    }
+  });
+}
+
+// [{"type":"paragraph","children":[{"text":"A line o"},
+// {"text":"f text in ","bold":true},{"text":"a paragraph."}],"format":"regular"}]
diff --git a/src/lib/richtext/editor-dom.tsx b/src/lib/richtext/editor-dom.tsx
index 52f0078..00b876d 100644
--- a/src/lib/richtext/editor-dom.tsx
+++ b/src/lib/richtext/editor-dom.tsx
@@ -1,12 +1,10 @@
 "use dom";
 
 import { Ref, useCallback, useState } from "react";
-import { StyleSheet } from "react-native";
 import { createEditor, Editor, Path, Selection, Transforms } from "slate";
 import { withHistory } from "slate-history";
 import {
   Editable,
-  ReactEditor,
   RenderElementProps,
   RenderLeafProps,
   Slate,
@@ -18,6 +16,8 @@ import {
   useDOMImperativeHandle,
 } from "expo/dom";
 import { JSONValue } from "expo/build/dom/dom.types";
+import { slateToLex } from "./convert";
+import { RichTextContent } from ".";
 
 const formatStyles = {
   default: {
@@ -73,9 +73,11 @@ export interface DOMEditorRef extends DOMImperativeFactory {
 
 export function DOMEditor({
   onMoveToolbar,
+  onChange,
   ref,
 }: {
   onMoveToolbar: (pos?: DOMRect) => void;
+  onChange: (content: RichTextContent) => void,
   ref?: Ref<DOMEditorRef>;
   dom?: DOMProps;
 }) {
@@ -136,11 +138,16 @@ export function DOMEditor({
     }
   };
 
+  const onChangeInner = (value: any) => {
+    onChange(slateToLex(value))
+  }
+
   return (
     <Slate
       editor={editor}
       initialValue={initialValue}
       onSelectionChange={selectionChange}
+      onChange={onChangeInner}
     >
       <Editable
         renderElement={renderElement}
diff --git a/src/lib/richtext/editor.tsx b/src/lib/richtext/editor.tsx
index ea95d37..9031c92 100644
--- a/src/lib/richtext/editor.tsx
+++ b/src/lib/richtext/editor.tsx
@@ -3,6 +3,7 @@ import { DOMEditor, DOMEditorRef } from "./editor-dom";
 import { useRef, useState } from "react";
 import FontAwesome from "@expo/vector-icons/FontAwesome";
 import { Select, SelectItem } from "@/src/components/primitive/Select";
+import { RichTextContent } from ".";
 
 const styles = StyleSheet.create({
   toolbar: {
@@ -67,8 +68,9 @@ function Toolbar({
 export function RichTextEditor({
   style,
   minHeight,
+  onChange,
   ...props
-}: ViewProps & { minHeight?: number }) {
+}: ViewProps & { minHeight?: number, onChange: (content: RichTextContent) => void }) {
   const editor = useRef<DOMEditorRef>(null);
   const [pos, setPos] = useState<[number, number] | undefined>(undefined);
 
@@ -86,7 +88,7 @@ export function RichTextEditor({
 
   return (
     <View style={style}>
-      <DOMEditor onMoveToolbar={onMoveToolbar} ref={editor} />
+      <DOMEditor onMoveToolbar={onMoveToolbar} ref={editor} onChange={onChange} />
       {pos && <Toolbar pos={pos} toggleStyle={toggleStyle} setFormat={setFormat} />}
     </View>
   );
diff --git a/src/lib/richtext/index.ts b/src/lib/richtext/index.ts
new file mode 100644
index 0000000..c7c0e8e
--- /dev/null
+++ b/src/lib/richtext/index.ts
@@ -0,0 +1,2 @@
+export { Content as RichTextContent } from "@/src/lexicons/dev/maelstrom/bramblr/richtext/block.defs";
+export { Emphasis as RichTextEmphasis } from "@/src/lexicons/dev/maelstrom/bramblr/richtext/facet.defs";