diff --git a/js/mobile/src/features/stream-view/EditParticleSheet.tsx b/js/mobile/src/features/stream-view/EditParticleSheet.tsx
new file mode 100644
index 0000000..2f480df
--- /dev/null
+++ b/js/mobile/src/features/stream-view/EditParticleSheet.tsx
@@ -0,0 +1,90 @@
+import { useEffect, useState } from "react";
+import { Pressable, Text, TextInput, View } from "react-native";
+import { toast } from "sonner-native";
+import { cn } from "@/lib/utils";
+import { toUserMessage } from "@/lib/errors";
+import { editTextParticleContent } from "@/lib/firestore-particles";
+import { particlePath, toFirestoreDocPath } from "@/lib/particle-path";
+import { useSuspendPlayback } from "@/hooks/use-suspend-playback";
+import { BottomSheet } from "@/components/BottomSheet";
+
+interface EditParticleSheetProps {
+  open: boolean;
+  onClose: () => void;
+  networkId: string;
+  streamId: string;
+  particleId: string;
+  currentContent: string;
+}
+
+export function EditParticleSheet({
+  open,
+  onClose,
+  networkId,
+  streamId,
+  particleId,
+  currentContent,
+}: EditParticleSheetProps) {
+  useSuspendPlayback(open, "edit-particle");
+
+  const [content, setContent] = useState(currentContent);
+  const [saving, setSaving] = useState(false);
+
+  useEffect(() => {
+    if (open) {
+      setContent(currentContent);
+      setSaving(false);
+    }
+  }, [open, currentContent]);
+
+  const trimmed = content.trim();
+  const canSave = !saving && trimmed.length > 0 && trimmed !== currentContent;
+
+  const handleSave = async () => {
+    if (!canSave) return;
+    setSaving(true);
+    try {
+      const docPath = toFirestoreDocPath(
+        particlePath(networkId, [streamId, particleId]),
+      );
+      await editTextParticleContent(docPath, trimmed);
+      onClose();
+    } catch (err) {
+      toast.error(toUserMessage(err));
+      setSaving(false);
+    }
+  };
+
+  return (
+    <BottomSheet open={open} onClose={onClose} avoidKeyboard>
+      <View className="flex-row items-center justify-between px-5 pb-3">
+        <Pressable onPress={onClose} hitSlop={12}>
+          <Text className="text-white/70 text-base">Cancel</Text>
+        </Pressable>
+        <Text className="text-white text-base font-semibold">Edit</Text>
+        <Pressable onPress={handleSave} disabled={!canSave} hitSlop={12}>
+          <Text
+            className={cn(
+              "text-base font-semibold",
+              canSave ? "text-white" : "text-white/30",
+            )}
+          >
+            {saving ? "Saving..." : "Save"}
+          </Text>
+        </Pressable>
+      </View>
+      <View className="px-5 pb-6">
+        <TextInput
+          value={content}
+          onChangeText={setContent}
+          autoFocus
+          multiline
+          placeholder="Message"
+          placeholderTextColor="rgba(255,255,255,0.3)"
+          className="bg-white/10 rounded-xl px-4 py-3 text-white text-lg min-h-[120px]"
+          textAlignVertical="top"
+        />
+      </View>
+    </BottomSheet>
+  );
+}
diff --git a/js/mobile/src/features/stream-view/StreamActionsSheet.tsx b/js/mobile/src/features/stream-view/StreamActionsSheet.tsx
index ddb2a2d..948f4de 100644
--- a/js/mobile/src/features/stream-view/StreamActionsSheet.tsx
+++ b/js/mobile/src/features/stream-view/StreamActionsSheet.tsx
@@ -14,6 +14,7 @@ export type StreamActionId =
   | "toggle-status"
   | "rename"
   | "members"
+  | "edit-particle"
   | "delete-particle";
 
 interface StreamActionsSheetProps {
@@ -22,6 +23,8 @@ interface StreamActionsSheetProps {
   onSelect: (action: StreamActionId) => void;
   streamStatus: "open" | "closed";
   isCreator: boolean;
+  /** True when the *current* particle is a text particle this user authored. */
+  canEditParticle: boolean;
   /** True when the *current* particle is one this user can soft-delete. */
   canDeleteParticle: boolean;
 }
@@ -32,6 +35,7 @@ export function StreamActionsSheet({
   onSelect,
   streamStatus,
   isCreator,
+  canEditParticle,
   canDeleteParticle,
 }: StreamActionsSheetProps) {
   // Hold the picked action until the sheet's Modal has fully unmounted, then
@@ -82,6 +86,13 @@ export function StreamActionsSheet({
             onPress={() => choose("rename")}
           />
         ) : null}
+        {canEditParticle ? (
+          <ActionRow
+            icon={<Pencil color="white" size={20} />}
+            label="Edit particle"
+            onPress={() => choose("edit-particle")}
+          />
+        ) : null}
         {canDeleteParticle ? (
           <ActionRow
             icon={<Trash2 color="#ef4444" size={20} />}
diff --git a/js/mobile/src/features/stream-view/StreamView.tsx b/js/mobile/src/features/stream-view/StreamView.tsx
index 33a6da2..348f2a1 100644
--- a/js/mobile/src/features/stream-view/StreamView.tsx
+++ b/js/mobile/src/features/stream-view/StreamView.tsx
@@ -60,6 +60,7 @@ import { StreamTopActions } from "./StreamTopActions";
 import { StreamActionsSheet, type StreamActionId } from "./StreamActionsSheet";
 import { StreamMembersSheet } from "./StreamMembersSheet";
 import { RenameStreamSheet } from "./RenameStreamSheet";
+import { EditParticleSheet } from "./EditParticleSheet";
 import { ReactionStack } from "./ReactionStack";
 
 const SCREEN_HEIGHT = Dimensions.get("window").height;
@@ -125,6 +126,7 @@ function StreamViewInner({ streamParticle, path, onExit }: StreamViewProps) {
   const [actionsOpen, setActionsOpen] = useState(false);
   const [membersOpen, setMembersOpen] = useState(false);
   const [renameOpen, setRenameOpen] = useState(false);
+  const [editOpen, setEditOpen] = useState(false);
   const [videoFit, setVideoFit] = useState<"cover" | "contain">("cover");
 
   const isCreator = !!userId && userId === streamParticle.created_by_human_id;
@@ -135,6 +137,16 @@ function StreamViewInner({ streamParticle, path, onExit }: StreamViewProps) {
     currentParticle.type !== "stream" &&
     currentParticle.type !== "folder" &&
     !isParticleDeleted(currentParticle);
+  const canEditCurrentParticle =
+    !!currentParticle &&
+    !!userId &&
+    currentParticle.created_by_human_id === userId &&
+    currentParticle.type === "text" &&
+    !isParticleDeleted(currentParticle);
+  const editableTextParticle =
+    canEditCurrentParticle && currentParticle && currentParticle.type === "text"
+      ? currentParticle
+      : null;
 
   const showFitToggle =
     !!currentParticle &&
@@ -165,6 +177,10 @@ function StreamViewInner({ streamParticle, path, onExit }: StreamViewProps) {
         case "members":
           setMembersOpen(true);
           return;
+        case "edit-particle":
+          if (!canEditCurrentParticle) return;
+          setEditOpen(true);
+          return;
         case "delete-particle": {
           if (!currentParticle || !userId) return;
           if (!canDeleteCurrentParticle) return;
@@ -203,6 +219,7 @@ function StreamViewInner({ streamParticle, path, onExit }: StreamViewProps) {
       currentParticle,
       userId,
       canDeleteCurrentParticle,
+      canEditCurrentParticle,
     ],
   );
 
@@ -634,6 +651,7 @@ function StreamViewInner({ streamParticle, path, onExit }: StreamViewProps) {
           onSelect={(action) => void handleStreamAction(action)}
           streamStatus={streamParticle.status ?? "open"}
           isCreator={isCreator}
+          canEditParticle={canEditCurrentParticle}
           canDeleteParticle={canDeleteCurrentParticle}
         />
 
@@ -652,6 +670,17 @@ function StreamViewInner({ streamParticle, path, onExit }: StreamViewProps) {
           streamId={streamParticle.id}
           currentName={streamParticle.properties.name}
         />
+
+        {editableTextParticle ? (
+          <EditParticleSheet
+            open={editOpen}
+            onClose={() => setEditOpen(false)}
+            networkId={networkId}
+            streamId={streamParticle.id}
+            particleId={editableTextParticle.id}
+            currentContent={editableTextParticle.properties.content}
+          />
+        ) : null}
       </Animated.View>
     </Animated.View>
   );
diff --git a/js/mobile/src/features/stream-view/TextParticleView.tsx b/js/mobile/src/features/stream-view/TextParticleView.tsx
index f4aead1..d15182f 100644
--- a/js/mobile/src/features/stream-view/TextParticleView.tsx
+++ b/js/mobile/src/features/stream-view/TextParticleView.tsx
@@ -2,6 +2,7 @@ import { useEffect, useRef } from "react";
 import { ScrollView, Text, View } from "react-native";
 import type { Particle } from "@/api/types";
 import { cn } from "@/lib/utils";
+import { RelativeTimestamp } from "@/components/RelativeTimestamp";
 import { useStreamSafeArea } from "./stream-safe-area";
 
 type TextParticle = Extract<Particle, { type: "text" }>;
@@ -43,10 +44,19 @@ export function TextParticleView({
   onProgress,
 }: TextParticleViewProps) {
   const content = particle.properties.content;
+  const editedAt = particle.properties.edited_at;
   const durationS = computeReadDuration(content);
   const elapsedRef = useRef(0);
   const safe = useStreamSafeArea();
 
+  const editedLabel = editedAt ? (
+    <View className="mt-3 items-center">
+      <Text className="text-white/40 text-xs">
+        edited <RelativeTimestamp date={editedAt} />
+      </Text>
+    </View>
+  ) : null;
+
   // Reset when the particle changes.
   useEffect(() => {
     elapsedRef.current = 0;
@@ -85,6 +95,7 @@ export function TextParticleView({
         >
           {content}
         </Text>
+        {editedLabel}
       </View>
     );
   }
@@ -108,6 +119,7 @@ export function TextParticleView({
         indicatorStyle="white"
       >
         <Text className="text-white text-lg leading-relaxed">{content}</Text>
+        {editedLabel}
       </ScrollView>
     </View>
   );