feat: Use X-Swarm-Source-Domain header to identify the sender's node domain in chat messages.

src/app/api/chat/receive/route.ts

@@ -38,6 +38,11 @@ export async function POST(request: NextRequest) {
             if (handle.includes('@')) {
                 const parts = handle.split('@');
                 senderNodeDomain = parts[parts.length - 1];
+            } else {
+                // Try to get from header first
+                const sourceDomainHeader = request.headers.get('X-Swarm-Source-Domain');
+                if (sourceDomainHeader) {
+                    senderNodeDomain = sourceDomainHeader;
                 } else {
                     // Try handle registry (though we likely don't have it if we don't have the user)
                     const registryEntry = await db.query.handleRegistry.findFirst({
@@ -45,6 +50,7 @@ export async function POST(request: NextRequest) {
                     });
                     if (registryEntry) senderNodeDomain = registryEntry.nodeDomain;
                 }
+            }
 
             if (senderNodeDomain) {
                 try {

src/app/api/chat/send/route.ts

@@ -165,7 +165,10 @@ export async function POST(request: NextRequest) {
                 const protocol = targetDomain.includes('localhost') ? 'http' : 'https';
                 const res = await fetch(`${protocol}://${targetDomain}/api/chat/receive`, {
                     method: 'POST',
-                    headers: { 'Content-Type': 'application/json' },
+                    headers: {
+                        'Content-Type': 'application/json',
+                        'X-Swarm-Source-Domain': process.env.NEXT_PUBLIC_NODE_DOMAIN || ''
+                    },
                     body: JSON.stringify(signedAction) // Forward the user's signed intent
                 });