diff --git a/core/archipelago/src/api/rpc/mesh/typed_messages.rs b/core/archipelago/src/api/rpc/mesh/typed_messages.rs
index f0709726..da0b0326 100644
--- a/core/archipelago/src/api/rpc/mesh/typed_messages.rs
+++ b/core/archipelago/src/api/rpc/mesh/typed_messages.rs
@@ -220,6 +220,12 @@ impl RpcHandler {
             .ok_or_else(|| anyhow::anyhow!("Missing cid"))?
             .to_string();
         let caption = params["caption"].as_str().map(|s| s.to_string());
+        // Optional override: frontend can resolve the peer's federation onion
+        // itself (by matching mesh peer name against federation.list-nodes)
+        // and pass it in directly. Bypasses the mesh-peer→DID→federation
+        // lookup, which currently fails because meshcore adverts don't carry
+        // the archipelago master DID.
+        let explicit_peer_onion = params["peer_onion"].as_str().map(|s| s.to_string());
 
         // Pull the shared blob store (set by ApiHandler at startup).
         let blob_store = {
@@ -237,16 +243,21 @@ impl RpcHandler {
             .as_ref()
             .ok_or_else(|| anyhow::anyhow!("Mesh service not running"))?;
 
-        // Resolve peer Ed25519 pubkey from contact_id so we can scope the cap.
+        // Resolve peer Ed25519 pubkey + DID from contact_id. The pubkey scopes
+        // the capability token; the DID is the stable cross-transport identity
+        // used to match the peer against our federation node list (mesh and
+        // federation use different ed25519 keys but the same master DID).
         let state = svc.shared_state();
-        let peer_pubkey_hex = {
+        let (peer_pubkey_hex, peer_did) = {
             let peers = state.peers.read().await;
             let peer = peers
                 .get(&contact_id)
                 .ok_or_else(|| anyhow::anyhow!("Unknown mesh contact_id {}", contact_id))?;
-            peer.pubkey_hex
+            let pk = peer
+                .pubkey_hex
                 .clone()
-                .ok_or_else(|| anyhow::anyhow!("Peer has no pubkey yet"))?
+                .ok_or_else(|| anyhow::anyhow!("Peer has no pubkey yet"))?;
+            (pk, peer.did.clone())
         };
 
         // Our onion (stripped of scheme/trailing slash) for the URL the receiver will hit.
@@ -291,14 +302,21 @@ impl RpcHandler {
         // budget (cid alone is 64 hex chars, plus onion + cap). Route via
         // federation when the peer has a known onion; fall back to LoRa
         // only for tiny envelopes that could theoretically fit.
-        let federation_onion = {
+        // Match mesh peer → federation node by master DID, NOT by pubkey.
+        // Mesh adverts carry a LoRa-local ed25519 key that differs from the
+        // archipelago node's identity key in federation/nodes.json; the DID
+        // is the only stable identifier the two transports share.
+        let federation_onion = if let Some(onion) = explicit_peer_onion {
+            Some(onion)
+        } else {
             let nodes = crate::federation::load_nodes(&self.config.data_dir)
                 .await
                 .unwrap_or_default();
-            nodes
-                .into_iter()
-                .find(|n| n.pubkey == peer_pubkey_hex)
-                .map(|n| n.onion)
+            if let Some(did) = peer_did.as_ref() {
+                nodes.into_iter().find(|n| &n.did == did).map(|n| n.onion)
+            } else {
+                None
+            }
         };
         let msg = if let Some(onion) = federation_onion {
             svc.send_typed_wire_via_federation(
diff --git a/core/archipelago/src/mesh/mod.rs b/core/archipelago/src/mesh/mod.rs
index 5f4f0aaf..3c5a4bd4 100644
--- a/core/archipelago/src/mesh/mod.rs
+++ b/core/archipelago/src/mesh/mod.rs
@@ -601,17 +601,31 @@ impl MeshService {
         wire: Vec<u8>,
     ) -> Result<()> {
         let envelope = crate::mesh::message_types::TypedEnvelope::from_wire(&wire)?;
-        // Find the contact_id by pubkey match; fall back to synthetic.
+        // The sender's `from_pubkey_hex` is their archipelago identity key,
+        // which differs from the mesh peer's LoRa advert pubkey. Resolve
+        // identity → DID → mesh contact_id via federation/nodes.json (the
+        // DID is the only stable cross-transport key).
+        let federation_did = {
+            let nodes = crate::federation::load_nodes(&self.data_dir)
+                .await
+                .unwrap_or_default();
+            nodes
+                .into_iter()
+                .find(|n| n.pubkey == from_pubkey_hex)
+                .map(|n| n.did)
+        };
         let contact_id = {
             let peers = self.state.peers.read().await;
             peers
                 .iter()
                 .find_map(|(cid, p)| {
-                    if p.pubkey_hex.as_deref() == Some(from_pubkey_hex) {
-                        Some(*cid)
-                    } else {
-                        None
-                    }
+                    let did_match = federation_did
+                        .as_ref()
+                        .zip(p.did.as_ref())
+                        .map(|(a, b)| a == b)
+                        .unwrap_or(false);
+                    let pk_match = p.pubkey_hex.as_deref() == Some(from_pubkey_hex);
+                    if did_match || pk_match { Some(*cid) } else { None }
                 })
                 .unwrap_or_else(|| {
                     let bytes = hex::decode(from_pubkey_hex).unwrap_or_default();
diff --git a/neode-ui/src/stores/mesh.ts b/neode-ui/src/stores/mesh.ts
index 84506409..5a4f0dd5 100644
--- a/neode-ui/src/stores/mesh.ts
+++ b/neode-ui/src/stores/mesh.ts
@@ -382,13 +382,13 @@ export const useMeshStore = defineStore('mesh', () => {
     }
   }
 
-  async function sendContent(contactId: number, cid: string, caption?: string) {
+  async function sendContent(contactId: number, cid: string, caption?: string, peerOnion?: string) {
     try {
       sending.value = true
       error.value = null
       const res = await rpcClient.call<{ sent: boolean; message_id: number; cid: string; size: number }>({
         method: 'mesh.send-content',
-        params: { contact_id: contactId, cid, caption },
+        params: { contact_id: contactId, cid, caption, peer_onion: peerOnion },
       })
       if (res.sent) await fetchMessages()
       return res
diff --git a/neode-ui/src/views/Mesh.vue b/neode-ui/src/views/Mesh.vue
index 0b42c7ac..591b725e 100644
--- a/neode-ui/src/views/Mesh.vue
+++ b/neode-ui/src/views/Mesh.vue
@@ -639,7 +639,31 @@ async function handleAttachFile(ev: Event) {
       return
     }
     const { cid } = (await up.json()) as { cid: string }
-    await mesh.sendContent(activeChatPeer.value.contact_id, cid, messageText.value.trim() || undefined)
+    // Resolve the federation onion for this mesh peer. Meshcore adverts
+    // don't carry an archipelago DID so the backend can't link them on its
+    // own — we match on name (both sides use the node's display name).
+    // Falls back to undefined; the backend will try its own DID lookup or
+    // error out if no federation path exists.
+    let peerOnion: string | undefined
+    try {
+      const fed = await rpcClient.federationListNodes()
+      const peerName = activeChatPeer.value.advert_name
+      const hit = fed.nodes.find(
+        (n: { name?: string; onion?: string }) =>
+          (n.name ?? '').toLowerCase() === peerName.toLowerCase() ||
+          (n.name ?? '').toLowerCase().includes(peerName.toLowerCase()) ||
+          peerName.toLowerCase().includes((n.name ?? '').toLowerCase()),
+      )
+      peerOnion = hit?.onion ?? undefined
+    } catch {
+      /* non-fatal — backend will try its own lookup */
+    }
+    await mesh.sendContent(
+      activeChatPeer.value.contact_id,
+      cid,
+      messageText.value.trim() || undefined,
+      peerOnion,
+    )
     messageText.value = ''
     nextTick(() => scrollChatToBottom())
   } catch (e) {