diff --git a/package.json b/package.json
index f49c831c97..2759a59119 100644
--- a/package.json
+++ b/package.json
@@ -108,7 +108,7 @@
     "@bsky.app/expo-scroll-edge-effect": "^0.1.9",
     "@bsky.app/expo-translate-text": "^0.2.9",
     "@bsky.app/peek-menu": "^0.3.2",
-    "@bsky.app/react-native-uitextview": "^2.5.0",
+    "@bsky.app/react-native-uitextview": "^2.6.0",
     "@bsky.app/sift": "^0.3.9",
     "@bsky.app/tapper": "^0.6.1",
     "@bsky.app/video": "0.3.6",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 7952820f4d..1ec1f5267c 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -278,8 +278,8 @@ importers:
         specifier: ^0.3.2
         version: 0.3.2(expo@54.0.35(@babel/core@7.29.0)(react-native-webview@13.15.0(react-native@0.81.5(patch_hash=91fd85363059530dea649a5ca6012b933f79c8491737fbfdc685abc727e48403)(@babel/core@7.29.0)(@react-native/metro-config@0.86.0(@babel/core@7.29.0))(@types/react@19.1.17)(react@19.1.0))(react@19.1.0))(react-native@0.81.5(patch_hash=91fd85363059530dea649a5ca6012b933f79c8491737fbfdc685abc727e48403)(@babel/core@7.29.0)(@react-native/metro-config@0.86.0(@babel/core@7.29.0))(@types/react@19.1.17)(react@19.1.0))(react@19.1.0))(react-native@0.81.5(patch_hash=91fd85363059530dea649a5ca6012b933f79c8491737fbfdc685abc727e48403)(@babel/core@7.29.0)(@react-native/metro-config@0.86.0(@babel/core@7.29.0))(@types/react@19.1.17)(react@19.1.0))(react@19.1.0)
       '@bsky.app/react-native-uitextview':
-        specifier: ^2.5.0
-        version: 2.5.0(react-native@0.81.5(patch_hash=91fd85363059530dea649a5ca6012b933f79c8491737fbfdc685abc727e48403)(@babel/core@7.29.0)(@react-native/metro-config@0.86.0(@babel/core@7.29.0))(@types/react@19.1.17)(react@19.1.0))(react@19.1.0)
+        specifier: ^2.6.0
+        version: 2.6.0(react-native@0.81.5(patch_hash=91fd85363059530dea649a5ca6012b933f79c8491737fbfdc685abc727e48403)(@babel/core@7.29.0)(@react-native/metro-config@0.86.0(@babel/core@7.29.0))(@types/react@19.1.17)(react@19.1.0))(react@19.1.0)
       '@bsky.app/sift':
         specifier: ^0.3.9
         version: 0.3.9(expo@54.0.35(@babel/core@7.29.0)(react-native-webview@13.15.0(react-native@0.81.5(patch_hash=91fd85363059530dea649a5ca6012b933f79c8491737fbfdc685abc727e48403)(@babel/core@7.29.0)(@react-native/metro-config@0.86.0(@babel/core@7.29.0))(@types/react@19.1.17)(react@19.1.0))(react@19.1.0))(react-native@0.81.5(patch_hash=91fd85363059530dea649a5ca6012b933f79c8491737fbfdc685abc727e48403)(@babel/core@7.29.0)(@react-native/metro-config@0.86.0(@babel/core@7.29.0))(@types/react@19.1.17)(react@19.1.0))(react@19.1.0))(react-native-safe-area-context@5.6.2(react-native@0.81.5(patch_hash=91fd85363059530dea649a5ca6012b933f79c8491737fbfdc685abc727e48403)(@babel/core@7.29.0)(@react-native/metro-config@0.86.0(@babel/core@7.29.0))(@types/react@19.1.17)(react@19.1.0))(react@19.1.0))(react-native@0.81.5(patch_hash=91fd85363059530dea649a5ca6012b933f79c8491737fbfdc685abc727e48403)(@babel/core@7.29.0)(@react-native/metro-config@0.86.0(@babel/core@7.29.0))(@types/react@19.1.17)(react@19.1.0))(react@19.1.0)
@@ -1676,8 +1676,8 @@ packages:
       react: '*'
       react-native: '*'
 
-  '@bsky.app/react-native-uitextview@2.5.0':
-    resolution: {integrity: sha512-8DyQAJEkr0ZPEb9QMmT3088V70B6xRsY8e/jvi2oq13hCsLEXCw5M1S48xKRnr8263bJxSH0BjK0nfhPS8Myqw==}
+  '@bsky.app/react-native-uitextview@2.6.0':
+    resolution: {integrity: sha512-d6efoPKixj7ycaQWYSDr4JDB1jzIewWie6UtP4Pylgh+K//aXCNaudbLjHN4WP6RVGBfFqNac13hSh3tRikH7A==}
     peerDependencies:
       react: '*'
       react-native: '>=0.81.5'
@@ -10420,7 +10420,7 @@ snapshots:
       react: 19.1.0
       react-native: 0.81.5(patch_hash=91fd85363059530dea649a5ca6012b933f79c8491737fbfdc685abc727e48403)(@babel/core@7.29.0)(@react-native/metro-config@0.86.0(@babel/core@7.29.0))(@types/react@19.1.17)(react@19.1.0)
 
-  '@bsky.app/react-native-uitextview@2.5.0(react-native@0.81.5(patch_hash=91fd85363059530dea649a5ca6012b933f79c8491737fbfdc685abc727e48403)(@babel/core@7.29.0)(@react-native/metro-config@0.86.0(@babel/core@7.29.0))(@types/react@19.1.17)(react@19.1.0))(react@19.1.0)':
+  '@bsky.app/react-native-uitextview@2.6.0(react-native@0.81.5(patch_hash=91fd85363059530dea649a5ca6012b933f79c8491737fbfdc685abc727e48403)(@babel/core@7.29.0)(@react-native/metro-config@0.86.0(@babel/core@7.29.0))(@types/react@19.1.17)(react@19.1.0))(react@19.1.0)':
     dependencies:
       react: 19.1.0
       react-native: 0.81.5(patch_hash=91fd85363059530dea649a5ca6012b933f79c8491737fbfdc685abc727e48403)(@babel/core@7.29.0)(@react-native/metro-config@0.86.0(@babel/core@7.29.0))(@types/react@19.1.17)(react@19.1.0)
diff --git a/src/analytics/features/types.ts b/src/analytics/features/types.ts
index 62fe079b7b..4e8d183c8d 100644
--- a/src/analytics/features/types.ts
+++ b/src/analytics/features/types.ts
@@ -24,6 +24,7 @@ export enum Features {
   SearchStarterPacksV2Enable = 'search_starter_packs_v2:enable',
   FollowSortEnable = 'follow_sort:enable',
   OnboardingInterestsRequiredEnable = 'onboarding:interests:required:enable',
+  CanonicalPostNumberingEnable = 'canonical_post_numbering:enable',
 
   // values
   TrendingDiscoverValues = 'trending_discover:values',
diff --git a/src/components/RichText.tsx b/src/components/RichText.tsx
index 25af851723..4be7aebbc6 100644
--- a/src/components/RichText.tsx
+++ b/src/components/RichText.tsx
@@ -27,6 +27,7 @@ export type RichTextProps = TextStyleProp &
     interactiveStyle?: StyleProp<TextStyle>
     emojiMultiplier?: number
     shouldProxyLinks?: boolean
+    suffix?: React.ReactNode
     /**
      * DANGEROUS: Disable facet lexicon validation
      *
@@ -54,6 +55,7 @@ export function RichText({
   onLayout,
   onTextLayout,
   shouldProxyLinks,
+  suffix,
   disableMentionFacetValidation,
 }: RichTextProps) {
   const richText = useMemo(() => {
@@ -87,6 +89,8 @@ export function RichText({
           // @ts-ignore web only -prf
           dataSet={WORD_WRAP}>
           {text}
+          {suffix ? ' ' : null}
+          {suffix}
         </Text>
       )
     }
@@ -102,6 +106,8 @@ export function RichText({
         // @ts-ignore web only -prf
         dataSet={WORD_WRAP}>
         {text}
+        {suffix ? ' ' : null}
+        {suffix}
       </Text>
     )
   }
@@ -188,6 +194,8 @@ export function RichText({
       // @ts-ignore web only -prf
       dataSet={WORD_WRAP}>
       {els}
+      {suffix ? ' ' : null}
+      {suffix}
     </Text>
   )
 }
diff --git a/src/screens/PostThread/components/ThreadItemAnchor.tsx b/src/screens/PostThread/components/ThreadItemAnchor.tsx
index 7973bc1a8a..0c560caa84 100644
--- a/src/screens/PostThread/components/ThreadItemAnchor.tsx
+++ b/src/screens/PostThread/components/ThreadItemAnchor.tsx
@@ -30,6 +30,10 @@ import {type PostSource} from '#/state/unstable-post-source'
 import {PreviewableUserAvatar} from '#/view/com/util/UserAvatar'
 import {KnownLikers, LikesStat} from '#/screens/PostThread/components/LikesStat'
 import {ThreadItemAnchorFollowButton} from '#/screens/PostThread/components/ThreadItemAnchorFollowButton'
+import {
+  hasThreadItemPostNumber,
+  ThreadItemPostNumber,
+} from '#/screens/PostThread/components/ThreadItemPostNumber'
 import {
   LINEAR_AVI_WIDTH,
   OUTER_SPACE,
@@ -184,6 +188,7 @@ const ThreadItemAnchorInner = memo(function ThreadItemAnchorInner({
 
   const post = postShadow
   const record = item.value.post.record
+  const postNumbering = item.value
   const moderation = item.moderation
   const authorShadow = useProfileShadow(post.author)
   const {isActive: live} = useActorStatus(post.author)
@@ -400,8 +405,15 @@ const ThreadItemAnchorInner = memo(function ThreadItemAnchorInner({
                   style={[a.flex_1, a.text_lg]}
                   authorHandle={post.author.handle}
                   shouldProxyLinks={true}
+                  suffix={
+                    hasThreadItemPostNumber(postNumbering) ? (
+                      <ThreadItemPostNumber value={postNumbering} />
+                    ) : undefined
+                  }
                 />
-              ) : undefined}
+              ) : (
+                <ThreadItemPostNumber inline={false} value={postNumbering} />
+              )}
               <TranslatedPost post={post} postTextStyle={[a.text_lg]} />
               {post.embed && (
                 <View style={[richText?.text ? a.py_xs : []]}>
diff --git a/src/screens/PostThread/components/ThreadItemPost.tsx b/src/screens/PostThread/components/ThreadItemPost.tsx
index de0b266526..d254d4be28 100644
--- a/src/screens/PostThread/components/ThreadItemPost.tsx
+++ b/src/screens/PostThread/components/ThreadItemPost.tsx
@@ -23,6 +23,10 @@ import {type OnPostSuccessData} from '#/state/shell/composer'
 import {useMergedThreadgateHiddenReplies} from '#/state/threadgate-hidden-replies'
 import {PostMeta} from '#/view/com/util/PostMeta'
 import {PreviewableUserAvatar} from '#/view/com/util/UserAvatar'
+import {
+  hasThreadItemPostNumber,
+  ThreadItemPostNumber,
+} from '#/screens/PostThread/components/ThreadItemPostNumber'
 import {
   LINEAR_AVI_WIDTH,
   OUTER_SPACE,
@@ -196,6 +200,7 @@ const ThreadItemPostInner = memo(function ThreadItemPostInner({
 
   const post = item.value.post
   const record = item.value.post.record
+  const postNumbering = item.value
   const moderation = item.moderation
   const richText = useMemo(
     () =>
@@ -324,15 +329,28 @@ const ThreadItemPostInner = memo(function ThreadItemPostInner({
                     numberOfLines={limitLines ? MAX_POST_LINES : undefined}
                     authorHandle={post.author.handle}
                     shouldProxyLinks={true}
+                    suffix={
+                      !limitLines && hasThreadItemPostNumber(postNumbering) ? (
+                        <ThreadItemPostNumber value={postNumbering} />
+                      ) : undefined
+                    }
                   />
                   {limitLines && (
-                    <ShowMoreTextButton
-                      style={[a.text_md]}
-                      onPress={onPressShowMore}
-                    />
+                    <View style={[a.flex_row, a.align_center, a.gap_xs]}>
+                      <ShowMoreTextButton
+                        style={[a.text_md]}
+                        onPress={onPressShowMore}
+                      />
+                      <ThreadItemPostNumber
+                        inline={false}
+                        value={postNumbering}
+                      />
+                    </View>
                   )}
                 </View>
-              ) : undefined}
+              ) : (
+                <ThreadItemPostNumber inline={false} value={postNumbering} />
+              )}
               <TranslatedPost hideTranslateLink post={post} />
               {post.embed && (
                 <View
diff --git a/src/screens/PostThread/components/ThreadItemPostNumber.tsx b/src/screens/PostThread/components/ThreadItemPostNumber.tsx
new file mode 100644
index 0000000000..55f071fd66
--- /dev/null
+++ b/src/screens/PostThread/components/ThreadItemPostNumber.tsx
@@ -0,0 +1,86 @@
+import {Text, View} from 'react-native'
+import {type AppBskyUnspeccedDefs} from '@atproto/api'
+import {Trans, useLingui} from '@lingui/react/macro'
+
+import {atoms as a, native, platform, useTheme} from '#/alf'
+import {useAnalytics} from '#/analytics'
+
+export function hasThreadItemPostNumber(
+  value: AppBskyUnspeccedDefs.ThreadItemPost,
+) {
+  const index = value.opThreadPostIndex
+  const count = value.opThreadPostCount
+
+  return (
+    index !== undefined &&
+    count !== undefined &&
+    index >= 1 &&
+    count >= 1 &&
+    index <= count
+  )
+}
+
+export function ThreadItemPostNumber({
+  value,
+  inline = true,
+}: {
+  value: AppBskyUnspeccedDefs.ThreadItemPost
+  inline?: boolean
+}) {
+  const ax = useAnalytics()
+  const t = useTheme()
+  const {t: l} = useLingui()
+  const index = value.opThreadPostIndex
+  const count = value.opThreadPostCount
+
+  const isEnabled = ax.features.enabled(
+    ax.features.CanonicalPostNumberingEnable,
+  )
+
+  if (!isEnabled || !hasThreadItemPostNumber(value)) {
+    return null
+  }
+
+  return (
+    <View
+      style={[
+        a.flex_shrink_0,
+        a.rounded_full,
+        t.atoms.bg_contrast_50,
+        native(a.py_2xs),
+        {
+          paddingLeft: 5,
+          paddingRight: 5,
+        },
+        inline
+          ? platform({
+              native: {transform: [{translateY: 6}]},
+              web: {top: -2},
+            })
+          : {top: -2},
+      ]}>
+      <Text
+        accessibilityLabel={l({
+          message: `Post ${index} of ${count}`,
+          context: 'post-number-in-thread',
+          comment:
+            "Screen reader label indicating post count in a thread, e.g., the 3rd post of 5 total is 'Post 3 of 5'",
+        })}
+        accessibilityHint=""
+        style={[
+          a.text_xs,
+          a.font_medium,
+          t.atoms.text_contrast_high,
+          {
+            fontVariant: ['tabular-nums'],
+          },
+        ]}>
+        <Trans
+          context="post-number-in-thread"
+          comment="Badge indicating post count in a thread, e.g., the 3rd post of 5 total is '3/5'">
+          {index}/{count}
+        </Trans>
+      </Text>
+    </View>
+  )
+}
diff --git a/src/screens/PostThread/components/ThreadItemTreePost.tsx b/src/screens/PostThread/components/ThreadItemTreePost.tsx
index 83b77b4882..d3dca1960d 100644
--- a/src/screens/PostThread/components/ThreadItemTreePost.tsx
+++ b/src/screens/PostThread/components/ThreadItemTreePost.tsx
@@ -22,6 +22,10 @@ import {useSession} from '#/state/session'
 import {type OnPostSuccessData} from '#/state/shell/composer'
 import {useMergedThreadgateHiddenReplies} from '#/state/threadgate-hidden-replies'
 import {PostMeta} from '#/view/com/util/PostMeta'
+import {
+  hasThreadItemPostNumber,
+  ThreadItemPostNumber,
+} from '#/screens/PostThread/components/ThreadItemPostNumber'
 import {
   OUTER_SPACE,
   REPLY_LINE_WIDTH,
@@ -258,6 +262,7 @@ const ThreadItemTreePostInner = memo(function ThreadItemTreePostInner({
 
   const post = item.value.post
   const record = item.value.post.record
+  const postNumbering = item.value
   const moderation = item.moderation
   const richText = useMemo(
     () =>
@@ -354,15 +359,32 @@ const ThreadItemTreePostInner = memo(function ThreadItemTreePostInner({
                         numberOfLines={limitLines ? MAX_POST_LINES : undefined}
                         authorHandle={post.author.handle}
                         shouldProxyLinks={true}
+                        suffix={
+                          !limitLines &&
+                          hasThreadItemPostNumber(postNumbering) ? (
+                            <ThreadItemPostNumber value={postNumbering} />
+                          ) : undefined
+                        }
                       />
                       {limitLines && (
-                        <ShowMoreTextButton
-                          style={[a.text_md]}
-                          onPress={onPressShowMore}
-                        />
+                        <View style={[a.flex_row, a.align_center, a.gap_xs]}>
+                          <ShowMoreTextButton
+                            style={[a.text_md]}
+                            onPress={onPressShowMore}
+                          />
+                          <ThreadItemPostNumber
+                            inline={false}
+                            value={postNumbering}
+                          />
+                        </View>
                       )}
                     </View>
-                  ) : null}
+                  ) : (
+                    <ThreadItemPostNumber
+                      inline={false}
+                      value={postNumbering}
+                    />
+                  )}
                   <TranslatedPost hideTranslateLink post={post} />
                   {post.embed && (
                     <View style={[a.pb_xs]}>