2026-07-25

configuration.nix

@@ -9,18 +9,18 @@
   ...
 }:
 {
+  nix.settings.experimental-features = [
+    "nix-command"
+    "flakes"
+  ];
+  nixpkgs.hostPlatform = lib.mkDefault "x86_64-linux";
+
   sops.defaultSopsFile = ./secrets/home.yaml;
   sops.age.keyFile = "/.persist/root/.config/sops/age/keys.txt";
   sops.secrets."root/ssh/desktop" = {
     path = "/root/.ssh/desktop";
     mode = "0600";
   };
-  nix.settings.experimental-features = [
-    "nix-command"
-    "flakes"
-  ];
-
-  nixpkgs.hostPlatform = lib.mkDefault "x86_64-linux";
 
   boot.initrd.systemd.enable = true;
   boot.loader.systemd-boot.enable = true;

executables/claude-code.sh

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+SSH_TARGET="sandbox@vsock%3"
+
+if [[ "$PWD" == /home/user* ]] || [[ "$PWD" == /etc/nixos* ]]; then
+    project="${PWD/\/home\/user/\/home\/sandbox}"
+else
+    project="$(ssh "$SSH_TARGET" 'mktemp -d -p /tmp claude-XXXXXX')"
+fi
+
+exec ssh -t "$SSH_TARGET" claude-code "$project" "$@"

executables/opencode.sh

@@ -3,7 +3,7 @@ set -euo pipefail
 
 SSH_TARGET="sandbox@vsock%3"
 
-if [[ "$PWD" == /home/user* ]]; then
+if [[ "$PWD" == /home/user* ]] || [[ "$PWD" == /etc/nixos* ]]; then
     project="${PWD/\/home\/user/\/home\/sandbox}"
 else
     project="$(ssh "$SSH_TARGET" 'mktemp -d -p /tmp opencode-XXXXXX')"

firejail.nix

@@ -4,59 +4,10 @@
   pkgs,
   ...
 }:
-let
-  agentProfile = pkgs.writeText "agent.profile" ''
-    whitelist /nix/store
-    whitelist /nix/var
-    read-only /nix/store
-    whitelist ''${HOME}/.cache/nix
-    whitelist ''${HOME}/.local/state/nix
-    whitelist /etc/nix
-    whitelist /etc/nixos
-    whitelist /nix/var/nix/daemon-socket
-    whitelist ''${HOME}/dev
-    whitelist ''${HOME}/work
-    whitelist ''${HOME}/.config
-
-    blacklist ''${HOME}
-    blacklist /etc/nixos/secrets
-    blacklist /etc/shadow
-    blacklist /etc/sudoers
-    blacklist /etc/sudoers.d
-    blacklist /root
-
-    caps.drop all
-    nonewprivs
-    noroot
-    seccomp
-
-    no3d
-    nodvd
-    notv
-    nou2f
-    novideo
-
-
-    ignore net none
-
-    machine-id
-    disable-mnt
-    private-dev
-    private-tmp
-    private-cache
-  '';
-in
 {
   programs.firejail = {
     enable = true;
     wrappedBinaries = {
-      claude = {
-        executable = "${pkgs.claude-code}/bin/claude";
-        profile = agentProfile;
-        extraArgs = [
-          "--private=~/.local/state/claude-home"
-        ];
-      };
       chromium-sandbox = {
         executable = "${pkgs.chromium}/bin/chromium";
         profile = "${pkgs.firejail}/etc/firejail/chromium-browser.profile";

home/user.nix

@@ -58,25 +58,38 @@
       #   "Xft.antialias" = 1;
       #   "Xft.rgba" = "rgb";
       # };
-
+      systemd.user.services.screenshot-latest = {
-      systemd.user.services.waypipe-socket = {
         Unit = {
-          Description = "start waypipe client";
+          Description = "Update latest.png symlink";
-          After = [ "niri.service" ];
-          Requires = [ "niri.service" ];
-        };
-        Install = {
-          WantedBy = [ "graphical-session.target" ];
         };
         Service = {
-          ExecStart = "${pkgs.waypipe}/bin/waypipe --socket /tmp/waypipe.sock client";
+          Type = "oneshot";
-          ExecStartPost = "${pkgs.acl}/bin/setfacl -m g:sandbox:rw /tmp/waypipe.sock";
+          ExecStart =
-          ExecStopPost = "${pkgs.coreutils}/bin/rm /tmp/waypipe.sock";
+            let
-          RuntimeDirectory = "waypipe";
+              screenshotDir = "${config.home.homeDirectory}/pictures/screenshots";
-          Type = "simple";
+              script = pkgs.writeShellScript "screenshot-latest-update" ''
-          Restart = "on-failure";
+                latest=$(${pkgs.coreutils}/bin/ls -t "${screenshotDir}"/*.png 2>/dev/null | head -1)
+                if [ -n "$latest" ]; then
+                  ${pkgs.coreutils}/bin/ln -sf "$latest" "${screenshotDir}/latest.png"
+                fi
+              '';
+            in
+            "${script}";
         };
       };
+
+      systemd.user.paths.screenshot-latest = {
+        Unit = {
+          Description = "Watch screenshot directory for new files";
+        };
+        Install = {
+          WantedBy = [ "default.target" ];
+        };
+        Path = {
+          PathChanged = "${config.home.homeDirectory}/pictures/screenshots";
+        };
+      };
+
       sops.secrets."user/gpg/legacy_fnzr" = { };
       home.activation.importGpgKey = config.lib.dag.entryAfter [ "writeBoundary" ] ''
         if [[ -f "${config.sops.secrets."user/gpg/legacy_fnzr".path}" ]]; then
@@ -258,7 +271,7 @@
       };
 
       programs = {
-        opencode.enable = true;
+        # opencode.enable = true;
         dank-material-shell.enable = true;
         ssh = {
           enable = true;
@@ -364,11 +377,13 @@
 
       home.packages = with pkgs; [
         xrdb
-        # (writeShellScriptBin "agent" ''
-        #   machinectl shell agent@ ${waypipe}/bin/waypipe --socket /run/waypipe.sock server fish
-        # '')
         (writeShellApplication {
-          name = "opencode-sandbox";
+          name = "claude-code";
+          runtimeInputs = [ openssh ];
+          text = builtins.readFile ../executables/claude-code.sh;
+        })
+        (writeShellApplication {
+          name = "opencode";
           runtimeInputs = [ openssh ];
           text = builtins.readFile ../executables/opencode.sh;
         })

kernel/default.nix

@@ -56,6 +56,7 @@ in
         keepEnv = true;
         persist = true;
         setEnv = [
+          "HOME=/root"
           "EDITOR"
           "TERM"
         ];

microvm/sandbox.nix

@@ -26,6 +26,13 @@ in
           homeManagerModule
         ];
 
+        nix.settings.experimental-features = [
+          "nix-command"
+          "flakes"
+        ];
+        nix.nixPath = [ "nixpkgs=${pkgs.path}" ];
+        nixpkgs.hostPlatform = lib.mkDefault "x86_64-linux";
+
         sops.defaultSopsFile = ./secrets/sandbox.yaml;
         sops.age.keyFile = "/.persist/secrets/age-keys.txt";
         sops.secrets."root-password-hash" = {
@@ -92,6 +99,7 @@ in
           fd
           ripgrep
           podman-compose
+          claude-code
         ];
 
         environment.persistence."/.persist" = {
@@ -186,17 +194,17 @@ in
             {
               mountPoint = "/var";
               image = "var.img";
-              size = 256;
+              size = 2 * 1024;
             }
             {
               mountPoint = "/nix/.rw-store";
               image = "nix-store-overlay.img";
-              size = 512;
+              size = 2 * 1024;
             }
             {
               mountPoint = "/.persist";
               image = "persist.img";
-              size = 1;
+              size = 2 * 1024;
             }
           ];
           shares = [
@@ -212,6 +220,12 @@ in
               source = "/home/user/work";
               mountPoint = "/home/sandbox/work";
             }
+            {
+              proto = "virtiofs";
+              tag = "nixos";
+              source = "/etc/nixos";
+              mountPoint = "/etc/nixos";
+            }
             {
               proto = "virtiofs";
               tag = "screenshots";

networking.nix

@@ -5,7 +5,10 @@
   ...
 }:
 {
-  imports = [ ./wireguard.nix ];
+  imports = [
+    ./wireguard.nix
+    ./tailscale.nix
+  ];
   sops.secrets = {
     "wg0/conf".sopsFile = ./secrets/vpn.yaml;
     "wg-br0/conf".sopsFile = ./secrets/vpn.yaml;
@@ -13,6 +16,13 @@
     "wg-uk0/conf".sopsFile = ./secrets/vpn.yaml;
   };
 
+  services.tailscale-netns = {
+    enable = true;
+    instances.work = {
+      extraDaemonFlags = [ "--accept-routes=false" ];
+    };
+  };
+
   networking = {
     hostName = hostname;
     networkmanager.enable = false;

tailscale.nix

@@ -10,137 +10,24 @@ with lib;
 let
   cfg = config.services.tailscale-netns;
 
-  instanceOptions =
+  instanceOptions = {
-    { name, ... }:
+    options.extraDaemonFlags = mkOption {
-    {
+      type = types.listOf types.str;
-      options = {
+      default = [ ];
-        authKeyFile = mkOption {
+      description = "Extra flags passed to `tailscaled`.";
-          type = types.nullOr types.path;
-          default = null;
-          description = "Path to file containing a Tailscale auth key.";
-        };
-
-        hostname = mkOption {
-          type = types.nullOr types.str;
-          default = null;
-          description = ''
-            Tailscale hostname for this instance.
-            Defaults to "<system-hostname>-<instance-name>".
-          '';
-        };
-
-        advertiseRoutes = mkOption {
-          type = types.listOf types.str;
-          default = [ ];
-          description = "Subnet routes to advertise (e.g. [ \"10.0.0.0/24\" ]).";
-        };
-
-        dns = mkOption {
-          type = types.nullOr types.str;
-          default = null;
-          description = ''
-            Bootstrap DNS server for the namespace before Tailscale is connected.
-            Defaults to `1.1.1.1`. Only used for the initial coordination server
-            connection; once Tailscale is up it manages DNS inside the namespace.
-          '';
-        };
-
-        advertiseExitNode = mkOption {
-          type = types.bool;
-          default = false;
-          description = "Whether to advertise this node as an exit node.";
-        };
-
-        acceptRoutes = mkOption {
-          type = types.bool;
-          default = false;
-          description = "Whether to accept routes advertised by other nodes.";
-        };
-
-        exitNode = mkOption {
-          type = types.nullOr types.str;
-          default = null;
-          description = "Tailscale IP or hostname of exit node to use.";
-        };
-
-        extraUpFlags = mkOption {
-          type = types.listOf types.str;
-          default = [ ];
-          description = "Extra flags passed to `tailscale up`.";
-        };
-
-        extraDaemonFlags = mkOption {
-          type = types.listOf types.str;
-          default = [ ];
-          description = "Extra flags passed to `tailscaled`.";
-        };
-      };
     };
-
+  };
-  mkUpFlags =
-    instanceCfg:
-    let
-      hostFlag = optional (
-        instanceCfg.hostname != null
-      ) "--hostname=${escapeShellArg instanceCfg.hostname}";
-      routeFlags = map (r: "--advertise-routes=${escapeShellArg r}") instanceCfg.advertiseRoutes;
-      exitFlag = optional instanceCfg.advertiseExitNode "--advertise-exit-node";
-      acceptFlag = optional instanceCfg.acceptRoutes "--accept-routes";
-      exitNodeFlag = optional (
-        instanceCfg.exitNode != null
-      ) "--exit-node=${escapeShellArg instanceCfg.exitNode}";
-    in
-    hostFlag ++ routeFlags ++ exitFlag ++ acceptFlag ++ exitNodeFlag ++ instanceCfg.extraUpFlags;
-
-  mkAutoconnectScript =
-    name: instanceCfg:
-    pkgs.writers.writeBash "tailscale-autoconnect-${name}" ''
-      set -euo pipefail
-
-      TS="${pkgs.tailscale}/bin/tailscale"
-      SOCKET="/run/tailscale-${name}/tailscaled.sock"
-      TS_ARGS="--socket $SOCKET"
-
-      get_state() {
-        $TS $TS_ARGS status --json --peers=false 2>/dev/null | ${pkgs.jq}/bin/jq -r '.BackendState // "NoState"'
-      }
-
-      last_state=""
-      while state="$(get_state)"; do
-        if [[ "$state" != "$last_state" ]]; then
-          case "$state" in
-            NeedsLogin|NeedsMachineAuth|Stopped)
-              echo "[tailscale-netns:${name}] server needs authentication, sending auth key"
-              $TS $TS_ARGS up \
-                --auth-key "$(cat ${instanceCfg.authKeyFile})" \
-                ${escapeShellArgs (mkUpFlags instanceCfg)}
-              ;;
-            Running)
-              echo "[tailscale-netns:${name}] tailscale is running"
-              ${pkgs.systemd}/bin/systemd-notify --ready
-              exit 0
-              ;;
-            NoState)
-              echo "[tailscale-netns:${name}] tailscaled not ready yet"
-              ;;
-            *)
-              echo "[tailscale-netns:${name}] waiting for Running (state=$state)"
-              ;;
-          esac
-        fi
-        last_state="$state"
-        sleep 1
-      done
-    '';
 
   mkNetnsSetup =
     index: name: instanceCfg:
     let
       ns = "ts-${name}ns";
-      hostIP = "10.201.${toString index}.1/24";
+      hostAddr = "10.201.${toString index}.1";
+      hostIP = "${hostAddr}/24";
       nsIP = "10.201.${toString index}.2/24";
       vethHost = "veth-ts-${name}";
       vethNS = "veth-ts-${name}-ns";
+      fallbackLines = concatMapStrings (n: "  echo nameserver ${n}\n") config.networking.nameservers;
     in
     {
       "netns@ts-${name}" = {
@@ -153,12 +40,42 @@ let
             set -euo pipefail
             ${pkgs.coreutils}/bin/mkdir -p /etc/netns/${ns}
 
-            # Build resolv.conf for the netns. Skip loopback addresses
-            # (systemd-resolved stub at 127.0.0.53 is not reachable from the netns).
-            NS_DNS="${if instanceCfg.dns != null then instanceCfg.dns else "1.1.1.1"}"
             {
-              ${pkgs.gawk}/bin/awk '$1 == "nameserver" && $2 !~ /^127\./ && $2 != "::1" {print}' /etc/resolv.conf
+              dns_found=0
-              echo "nameserver $NS_DNS"
+              if ${pkgs.systemd}/bin/resolvectl dns 2>/dev/null; then
+                saved_ifs="$IFS"
+                IFS=$'\n'
+                for line in $(${pkgs.systemd}/bin/resolvectl dns 2>/dev/null); do
+                  case "$line" in
+                    *:*)
+                      server=$(echo "$line" | ${pkgs.gnused}/bin/sed 's/^[^:]*: //')
+                      case "$server" in
+                        127.*|::1|"") ;;
+                        *) echo "nameserver $server"; dns_found=1 ;;
+                      esac
+                      ;;
+                  esac
+                done
+                IFS="$saved_ifs"
+              fi
+
+              if [ "$dns_found" -eq 0 ]; then
+                while IFS= read -r rline; do
+                  case "$rline" in
+                    nameserver*)
+                      ip=$(echo "$rline" | ${pkgs.gnused}/bin/sed 's/^nameserver //')
+                      case "$ip" in
+                        127.*|::1) ;;
+                        *) echo "$rline"; dns_found=1 ;;
+                      esac
+                      ;;
+                  esac
+                done < /etc/resolv.conf
+              fi
+              ${optionalString (fallbackLines != "") ''
+                if [ "$dns_found" -eq 0 ]; then
+              ${fallbackLines}    fi
+              ''}
             } > /etc/netns/${ns}/resolv.conf
 
             ${pkgs.iproute2}/bin/ip netns add ${ns}
@@ -171,6 +88,7 @@ let
             ${pkgs.iproute2}/bin/ip -n ${ns} addr add ${nsIP} dev ${vethNS}
             ${pkgs.iproute2}/bin/ip -n ${ns} link set ${vethNS} up
             ${pkgs.iproute2}/bin/ip -n ${ns} link set lo up
+            ${pkgs.iproute2}/bin/ip -n ${ns} route add default via ${hostAddr}
 
             ${pkgs.iptables}/bin/iptables -t nat -C POSTROUTING -s ${nsIP} -j MASQUERADE 2>/dev/null \
               || ${pkgs.iptables}/bin/iptables -t nat -A POSTROUTING -s ${nsIP} -j MASQUERADE
@@ -231,10 +149,7 @@ in
       description = "Tailscale instances configured in separate network namespaces.";
       example = literalExpression ''
         {
-          work = {
+          work = {};
-            authKeyFile = "/run/secrets/ts-work/authkey";
-            acceptRoutes = true;
-          };
         }
       '';
     };
@@ -247,25 +162,12 @@ in
           index: elem:
           let
             name = elem.name;
-            instanceCfg = elem.value;
+            units = mkNetnsSetup index name elem.value;
-            units = mkNetnsSetup index name instanceCfg;
           in
           [
-            units."netns@ts-${name}"
+            { name = "netns@ts-${name}"; value = units."netns@ts-${name}"; }
-            units."tailscaled-${name}"
+            { name = "tailscaled-${name}"; value = units."tailscaled-${name}"; }
           ]
-          ++ optional (instanceCfg.authKeyFile != null) {
-            "tailscaled-autoconnect-${name}" = {
-              description = "Tailscale autoconnect for instance ${name}";
-              after = [ "tailscaled-${name}.service" ];
-              requires = [ "tailscaled-${name}.service" ];
-              wantedBy = [ "multi-user.target" ];
-              serviceConfig = {
-                Type = "notify";
-              };
-              script = "${mkAutoconnectScript name instanceCfg}";
-            };
-          }
         ) (attrsToList cfg.instances)
       )
     );