diff --git a/app/Services/Social/BlueskyPublisher.php b/app/Services/Social/BlueskyPublisher.php
index 38094fc6..b3a7943e 100644
--- a/app/Services/Social/BlueskyPublisher.php
+++ b/app/Services/Social/BlueskyPublisher.php
@@ -60,7 +60,7 @@ public function publish(PostPlatform $postPlatform): array
 
         // Parse facets (links, mentions, hashtags) from text
         $text = $content ?? '';
-        $facets = $this->parseFacets($text);
+        $facets = $this->parseFacets($text, $service, $account);
 
         // Create post record
         $record = [
@@ -166,7 +166,7 @@ private function uploadBlob(SocialAccount $account, string $service, string $url
         }
     }
 
-    private function parseFacets(string $text): array
+    private function parseFacets(string $text, ?string $service = null, ?SocialAccount $account = null): array
     {
         $facets = [];
 
@@ -205,9 +205,22 @@ private function parseFacets(string $text): array
             PREG_OFFSET_CAPTURE
         );
 
+        $didCache = [];
         foreach ($mentionMatches[0] as $match) {
             $mention = $match[0];
             $handle = substr($mention, 1); // Remove @
+
+            // A mention facet requires the target's DID, not the handle. Bluesky
+            // does NOT resolve a handle placed in the `did` field — sending one
+            // makes the whole record invalid (InvalidRequest / "Invalid post
+            // data"), so every post containing a mention fails to publish.
+            // Resolve the handle to a DID here; if it can't be resolved, skip the
+            // facet so the post still publishes with the @handle as plain text.
+            $did = $didCache[$handle] ?? ($didCache[$handle] = $this->resolveHandleToDid($handle, $service, $account));
+            if ($did === null) {
+                continue;
+            }
+
             $start = $this->getUtf8ByteOffset($text, $match[1]);
             $end = $start + strlen($mention);
 
@@ -219,7 +232,7 @@ private function parseFacets(string $text): array
                 'features' => [
                     [
                         '$type' => 'app.bsky.richtext.facet#mention',
-                        'did' => $handle, // Will be resolved by Bluesky
+                        'did' => $did,
                     ],
                 ],
             ];
@@ -256,6 +269,66 @@ private function parseFacets(string $text): array
         return $facets;
     }
 
+    /**
+     * Resolve a Bluesky handle to its DID via com.atproto.identity.resolveHandle.
+     *
+     * Tries the account's own PDS first (authenticated), then falls back to the
+     * public AppView and the bsky.social entryway. Returns null on failure so the
+     * caller can skip the mention facet instead of sending an invalid record.
+     */
+    private function resolveHandleToDid(string $handle, ?string $service = null, ?SocialAccount $account = null): ?string
+    {
+        // Normalize so a trailing slash neither produces a double-slash URL nor
+        // breaks the `=== $service` check below (which decides authentication).
+        $service = $service !== null ? rtrim($service, '/') : null;
+
+        $endpoints = array_values(array_unique(array_filter([
+            $service,
+            'https://public.api.bsky.app',
+            'https://bsky.social',
+        ])));
+
+        $lastError = null;
+        $lastEndpoint = null;
+        foreach ($endpoints as $endpoint) {
+            try {
+                $request = $this->socialHttp();
+                if ($account && $endpoint === $service) {
+                    $request = $request->withToken($account->access_token);
+                }
+
+                $response = $request->get(
+                    "{$endpoint}/xrpc/com.atproto.identity.resolveHandle",
+                    ['handle' => $handle],
+                );
+
+                $did = $response->successful() ? data_get($response->json(), 'did') : null;
+                if (is_string($did) && str_starts_with($did, 'did:')) {
+                    return $did;
+                }
+            } catch (\Throwable $e) {
+                // Per-endpoint failures are expected during transient outages;
+                // keep them at debug to avoid noisy logs and surface a single
+                // warning below only when every endpoint has been exhausted.
+                $lastError = $e->getMessage();
+                $lastEndpoint = $endpoint;
+                Log::debug('Bluesky handle resolution attempt failed', [
+                    'handle' => $handle,
+                    'endpoint' => $endpoint,
+                    'error' => $e->getMessage(),
+                ]);
+            }
+        }
+
+        Log::warning('Bluesky handle resolution failed; mention will be sent as plain text', [
+            'handle' => $handle,
+            'endpoint' => $lastEndpoint,
+            'error' => $lastError,
+        ]);
+
+        return null;
+    }
+
     private function getUtf8ByteOffset(string $text, int $charOffset): int
     {
         return strlen(substr($text, 0, $charOffset));
diff --git a/tests/Feature/Services/Social/BlueskyPublisherTest.php b/tests/Feature/Services/Social/BlueskyPublisherTest.php
index 0d017b88..6ce6df4a 100644
--- a/tests/Feature/Services/Social/BlueskyPublisherTest.php
+++ b/tests/Feature/Services/Social/BlueskyPublisherTest.php
@@ -101,6 +101,74 @@
     });
 });
 
+test('bluesky publisher resolves mentions to DIDs as facets', function () {
+    $this->post->update(['content' => 'Shout out to @friend.bsky.social']);
+
+    Http::fake([
+        // Wildcard so the fake matches whichever endpoint resolveHandleToDid()
+        // tries first (the account PDS, public AppView, or bsky.social) and the
+        // test stays isolated from the configured service URL.
+        '*/xrpc/com.atproto.identity.resolveHandle*' => Http::response([
+            'did' => 'did:plc:friend456',
+        ], 200),
+        'https://bsky.social/xrpc/com.atproto.repo.createRecord' => Http::response([
+            'uri' => 'at://did:plc:testuser123/app.bsky.feed.post/3abc123xyz',
+            'cid' => 'bafyreiabc123',
+        ], 200),
+    ]);
+
+    $this->publisher->publish($this->postPlatform);
+
+    Http::assertSent(function ($request) {
+        $record = $request->data()['record'] ?? null;
+
+        if (! $record || ! isset($record['facets'])) {
+            return false;
+        }
+
+        foreach ($record['facets'] as $facet) {
+            $feature = $facet['features'][0];
+            if ($feature['$type'] === 'app.bsky.richtext.facet#mention') {
+                // The facet must carry the resolved DID, not the raw handle.
+                return $feature['did'] === 'did:plc:friend456';
+            }
+        }
+
+        return false;
+    });
+});
+
+test('bluesky publisher skips mention facet when handle cannot be resolved', function () {
+    $this->post->update(['content' => 'Shout out to @ghost.bsky.social']);
+
+    Http::fake([
+        '*/xrpc/com.atproto.identity.resolveHandle*' => Http::response(['error' => 'InvalidRequest'], 400),
+        'https://bsky.social/xrpc/com.atproto.repo.createRecord' => Http::response([
+            'uri' => 'at://did:plc:testuser123/app.bsky.feed.post/3abc123xyz',
+            'cid' => 'bafyreiabc123',
+        ], 200),
+    ]);
+
+    // Post still publishes; the unresolved @handle stays as plain text.
+    $result = $this->publisher->publish($this->postPlatform);
+
+    expect($result['id'])->toBe('3abc123xyz');
+
+    Http::assertSent(function ($request) {
+        $record = $request->data()['record'] ?? null;
+
+        if (! $record) {
+            return false;
+        }
+
+        $hasMentionFacet = collect($record['facets'] ?? [])->contains(
+            fn ($facet) => $facet['features'][0]['$type'] === 'app.bsky.richtext.facet#mention'
+        );
+
+        return str_contains($record['text'], '@ghost.bsky.social') && ! $hasMentionFacet;
+    });
+});
+
 test('bluesky publisher uploads images', function () {
     // Create a media item through the PostPlatform's media() relation
     $this->post->update([