diff --git a/hive-ag3nt/src/web_ui.rs b/hive-ag3nt/src/web_ui.rs
index d4f22ea9..1997265e 100644
--- a/hive-ag3nt/src/web_ui.rs
+++ b/hive-ag3nt/src/web_ui.rs
@@ -104,11 +104,27 @@ async fn index(State(state): State<AppState>) -> Html<String> {
 fn render_online(label: &str) -> String {
     format!(
         "<p class=\"status-online\">▓█▓▒░ harness alive — turn loop running ▓█▓▒░</p>\n\
-         <form method=\"POST\" action=\"/send\" class=\"sendform\">\n  \
-           <input name=\"body\" placeholder=\"message {label} as operator…\" required autocomplete=\"off\">\n  \
+         <form id=\"sendform\" class=\"sendform\">\n  \
+           <input id=\"sendbody\" name=\"body\" placeholder=\"message {label} as operator…\" required autocomplete=\"off\">\n  \
            <button type=\"submit\" class=\"btn btn-send\">◆ S3ND</button>\n\
          </form>\n\
          <p class=\"meta\">enqueued with <code>from: operator</code> on this agent's inbox; the next turn picks it up.</p>\n\
+         <script>\n\
+         document.getElementById('sendform').addEventListener('submit', async function(e) {{\n  \
+           e.preventDefault();\n  \
+           const input = document.getElementById('sendbody');\n  \
+           const body = input.value.trim();\n  \
+           if (!body) return;\n  \
+           const fd = new FormData();\n  \
+           fd.set('body', body);\n  \
+           const resp = await fetch('/send', {{ method: 'POST', body: fd, redirect: 'manual' }});\n  \
+           if (resp.type === 'opaqueredirect' || (resp.ok && resp.status < 400)) {{\n    \
+             input.value = '';\n  \
+           }} else {{\n    \
+             alert('send failed: ' + resp.status);\n  \
+           }}\n\
+         }});\n\
+         </script>\n\
          {LIVE_PANEL}",
     )
 }
diff --git a/nix/templates/agent-base.nix b/nix/templates/agent-base.nix
index 17262a7c..4683023a 100644
--- a/nix/templates/agent-base.nix
+++ b/nix/templates/agent-base.nix
@@ -7,9 +7,12 @@
   environment.systemPackages = with pkgs; [
     hyperhive
     claude-code
+    bashInteractive
     git
     coreutils-full
   ];
+  # claude's Bash tool refuses to run without a POSIX shell + $SHELL set.
+  environment.variables.SHELL = "${pkgs.bashInteractive}/bin/bash";
 
   systemd.services.hive-ag3nt = {
     description = "hive-ag3nt harness";
@@ -18,7 +21,12 @@
     # The harness shells out to `claude` (turn loop + login flow). systemd
     # units get a minimal PATH by default, so we have to put claude-code on
     # it explicitly even though it's in environment.systemPackages above.
-    path = [ pkgs.claude-code ];
+    # bash is on PATH so claude's Bash tool can spawn `$SHELL`.
+    path = [
+      pkgs.claude-code
+      pkgs.bashInteractive
+    ];
+    environment.SHELL = "${pkgs.bashInteractive}/bin/bash";
     serviceConfig = {
       ExecStart = "${pkgs.hyperhive}/bin/hive-ag3nt serve";
       Restart = "on-failure";
diff --git a/nix/templates/manager.nix b/nix/templates/manager.nix
index 13ad1919..0859e0b1 100644
--- a/nix/templates/manager.nix
+++ b/nix/templates/manager.nix
@@ -7,9 +7,12 @@
   environment.systemPackages = with pkgs; [
     hyperhive
     claude-code
+    bashInteractive
     git
     coreutils-full
   ];
+  # claude's Bash tool refuses to run without a POSIX shell + $SHELL set.
+  environment.variables.SHELL = "${pkgs.bashInteractive}/bin/bash";
 
   environment.etc."gitconfig".text = ''
     [user]
@@ -27,9 +30,13 @@
       HIVE_PORT = "8000";
       HIVE_LABEL = "hm1nd";
     };
-    # See note in agent-base.nix — `claude` has to be on the service PATH
-    # explicitly for the harness to shell out to it.
-    path = [ pkgs.claude-code ];
+    # See note in agent-base.nix — `claude` and a POSIX shell have to be on
+    # the service PATH explicitly for the harness + claude's Bash tool.
+    path = [
+      pkgs.claude-code
+      pkgs.bashInteractive
+    ];
+    environment.SHELL = "${pkgs.bashInteractive}/bin/bash";
     serviceConfig = {
       ExecStart = "${pkgs.hyperhive}/bin/hive-m1nd serve";
       Restart = "on-failure";