diff --git a/flake.nix b/flake.nix
index 4eea9b2..3247c21 100644
--- a/flake.nix
+++ b/flake.nix
@@ -85,6 +85,7 @@
           modules = [
             disko.nixosModules.disko
             sops-nix.nixosModules.sops
+            inputs.hermes-agent.nixosModules.default
             ./hosts/jupiter/configuration.nix
           ];
         };
diff --git a/hosts/jupiter/configuration.nix b/hosts/jupiter/configuration.nix
index 4d0c0b8..8e9b547 100644
--- a/hosts/jupiter/configuration.nix
+++ b/hosts/jupiter/configuration.nix
@@ -6,6 +6,7 @@
     ./hardware-configuration.nix
     ./disk-config.nix          # disko: OS-disk partitions + filesystems
     ./secrets.nix              # sops-nix: samba password, tailscale key, ...
+    ./hermes-agent.nix         # Hermes Agent, isolated instance (see file for why)
     ../../common.nix              # shared base: user / ssh / nix / firewall
     ../../services/network/samba.nix
     ../../services/network/avahi.nix
diff --git a/hosts/jupiter/hermes-agent.nix b/hosts/jupiter/hermes-agent.nix
new file mode 100644
index 0000000..e04674a
--- /dev/null
+++ b/hosts/jupiter/hermes-agent.nix
@@ -0,0 +1,77 @@
+{ config, ... }:
+
+# Hermes Agent — a SEPARATE, isolated instance from terra's
+# (services/desktop/hermes-agent.nix). Locked down harder than terra given
+# jupiter's much bigger blast radius (irreplaceable immich photos on an
+# unredundant RAID0, gitea/CI tokens, the whole media stack):
+#
+#   - Own dedicated "hermes" system user (module default: user/group "hermes",
+#     createUser = true) — NOT darman. darman is in jupiter's "docker" group
+#     (services/containers.nix: rootful podman with dockerCompat), which is
+#     root-equivalent (`docker run -v /:/host --privileged ...`). Handing an
+#     LLM-driven agent that identity would mean a container escape = root on
+#     the whole NAS.
+#   - container.enable = true, backend = "podman": the ENTIRE gateway process
+#     runs inside a container (reusing jupiter's existing rootful podman
+#     instead of also standing up a second Docker daemon), not just the shell
+#     tool. Per upstream's own SECURITY.md this is "whole-process wrapping" —
+#     shell, file tools, MCP subprocesses, and the code-exec tool are all
+#     confined, unlike the lighter "terminal-backend"-only isolation.
+#   - Its own Telegram bot (own token, in secrets.nix) with an EXPLICIT
+#     TELEGRAM_ALLOWED_USERS rather than relying solely on the adapter's
+#     fail-closed default. Sharing terra's bot token would 409-conflict two
+#     long-pollers on the same token.
+#   - No container.extraVolumes into /mnt/data or the homelab repo — nothing
+#     valuable is in reach if a command goes wrong or gets injected via
+#     Telegram/tool output. stateDir/workingDirectory live on the array
+#     (below) purely because coding-task state (repo clones, npm/pip caches
+#     inside the container's writable layer) belongs off the 29G eMMC, same
+#     reasoning as postgres/containers.storage in configuration.nix — NOT
+#     because anything else on /mnt/data is exposed to the agent.
+{
+  services.hermes-agent = {
+    enable = true;
+    addToSystemPackages = true;   # `hermes` on darman's PATH for interactive
+                                   # debugging over ssh — routes through to the
+                                   # container, does not grant darman any group.
+
+    # Off the eMMC: stateDir bind-mounts into the container as /data, so this
+    # is where any future scoped repo clone (container.extraVolumes) and the
+    # container's own writable layer (npm/pip installs during coding tasks)
+    # actually land. RequiresMountsFor below (mirrors podman/sabnzbd/gitea-runner
+    # in configuration.nix) keeps the service from starting — and bind-mounting
+    # the wrong, empty eMMC path — before the nofail array is up.
+    stateDir = "/mnt/data/AppData/hermes";
+    workingDirectory = "/mnt/data/AppData/hermes/workspaces";
+
+    container = {
+      enable = true;
+      backend = "podman";   # jupiter already runs podman (services/containers.nix);
+                             # default "docker" would stand up a second daemon.
+    };
+
+    # Same OpenCode Go provider account as terra (services/desktop/hermes-agent.nix)
+    # — just an API key, not a stateful identity like the Telegram bot token, so
+    # sharing it across hosts is fine.
+    settings.model = {
+      provider = "opencode-go";
+      base_url = "https://opencode.ai/zen/go/v1";
+      default = "gpt-5.6-luna";
+      api_mode = "codex_responses";
+    };
+
+    settings.platforms.telegram = {
+      enabled = true;
+      home_channel = {
+        platform = "telegram";
+        chat_id = "15151223";
+        name = "Erik Simon";
+        user_id = "15151223";
+      };
+    };
+
+    environmentFiles = [ config.sops.templates."hermes-agent.env".path ];
+  };
+
+  systemd.services.hermes-agent.unitConfig.RequiresMountsFor = [ "/mnt/data" ];
+}
diff --git a/hosts/jupiter/secrets.nix b/hosts/jupiter/secrets.nix
index e79f12b..f98e941 100644
--- a/hosts/jupiter/secrets.nix
+++ b/hosts/jupiter/secrets.nix
@@ -64,4 +64,21 @@
   sops.secrets.sabnzbd_eweka_username.owner = "sabnzbd";
   sops.secrets.sabnzbd_eweka_password.owner = "sabnzbd";
 
+  # Hermes Agent (hosts/jupiter/hermes-agent.nix) — a separate, isolated
+  # instance from terra's, with its OWN Telegram bot token (sharing terra's
+  # would 409-conflict two long-pollers on one token). opencode_go_api_key
+  # is the same provider account as terra (hosts/terra/secrets.nix) — a
+  # stateless API key, fine to duplicate across hosts. No owner override:
+  # sops.templates renders via a root-run activation script, which the
+  # hermes module's own activation script (also root) then reads — unlike
+  # sabnzbd's preStart, this doesn't run as the service's own user.
+  sops.secrets.opencode_go_api_key = { };
+  sops.secrets.telegram_bot_token = { };
+  sops.templates."hermes-agent.env".content = ''
+    OPENCODE_GO_API_KEY=${config.sops.placeholder.opencode_go_api_key}
+    TELEGRAM_BOT_TOKEN=${config.sops.placeholder.telegram_bot_token}
+    TELEGRAM_HOME_CHANNEL=15151223
+    TELEGRAM_ALLOWED_USERS=15151223
+  '';
+
 }
diff --git a/secrets/jupiter.yaml b/secrets/jupiter.yaml
index 636899f..ad6299e 100644
--- a/secrets/jupiter.yaml
+++ b/secrets/jupiter.yaml
@@ -14,6 +14,8 @@ sabnzbd_web_password: ENC[AES256_GCM,data:9Lo=,iv:H0Kz8A534RxX+7/Aue8Q87gCzSY5e/
 sabnzbd_nzb_key: ENC[AES256_GCM,data:DNVenqhJ7wf5Ng0XRA1gJN95e+90e6D9NImOSHJv/Us=,iv:eqFn0stB5pqh0ls4/impD8gc/lOkORwEJzRP6m7u1XU=,tag:Zs8ogLBZEZLyMvFBqhfpIA==,type:str]
 sabnzbd_eweka_username: ENC[AES256_GCM,data:eLsTZoM8T8fAlGaXWlDaoQ==,iv:eawyGhN7+d6UfBIbI3y1qgq+MYBGrXP6VfAkSOK6llA=,tag:ELOfQGHU5NOxZFhKOKf8LA==,type:str]
 sabnzbd_eweka_password: ENC[AES256_GCM,data:Mt3ZHAe2wzacCQq3x9Uy8WxjrVNad1SmU6sl8ZgrkMLymfq2eP4JzO/uPdD33A==,iv:PnFT95Zxqz4QBpPF5PRloKpoa15AU7Ef/Owwy+iDotw=,tag:/uRX00RzHLJN3gws5Qz8SA==,type:str]
+opencode_go_api_key: ENC[AES256_GCM,data:7kgWiye0wHCxzKFsrzX2WQNDkSVpuvJN6w5Zw9tuyYj5ysDRnWDjCvQtWEJlBalq+Fz7HfT28uFLFtrjFornGEPPdQ==,iv:9Ue/nMpJozVy7oHvhvHwKNuMlsb3tXjwnpC3jok5IWs=,tag:K2UqXBnMH3lpnATa2A/Agg==,type:str]
+telegram_bot_token: ENC[AES256_GCM,data:wU3CgKqbO1twJMIAlVi6rzVP5IUu34l1JOBVnlvTzhGL+Teq/sodQ9nlZOkzfg==,iv:8WxWDkGitljLa8aiwiT8td/3WeEnZAvz38oVPF5TQ4I=,tag:x9ldeAJOsTUJqAE4YZMPNg==,type:str]
 sops:
     age:
         - enc: |
@@ -34,7 +36,7 @@ sops:
             CzjSDQZTcseEXZNwuzZcfB5Mvq0BQvjOj7lGuxzuE4qwWkdJWGfVLQ==
             -----END AGE ENCRYPTED FILE-----
           recipient: age1zak7glavmg4026p2389fyqe769vqm4jrryknuqckgqq4merz5f7q44rkkt
-    lastmodified: "2026-08-19T18:39:11Z"
-    mac: ENC[AES256_GCM,data:nyfcDjWrmAHPb4wKPIUGOfQGQtX79Kz4KnOQJClMAicvLZThYP32WJqmNeZiS8QfqDGJMrTmEfxraYsDiMgKA6xDPCJDIB8WajEbXMqN0oSa7s8lxYmwZvHEA3n5G/GOezjr1nqYV4U35wLQrIk1ja4I1Pii5pOe2dgE9/7ugVY=,iv:qTV5813A0PBzukPM6CwCare0c6qo1fckqgM5wUGTbPc=,tag:AgtZ2p9Vi+u8LBplScBUTA==,type:str]
+    lastmodified: "2026-08-19T19:44:22Z"
+    mac: ENC[AES256_GCM,data:ZgHrvBYUeUDo7ZydN3K5CbIUXDvbvj1whnSWuzc+x5TlejqQH89zXRMKBuDD2DgzS+ET6PFHgN+0KoQchOI9SVGmdzz0b3mKpAMZc1BXYWOy5OcxF2xToA2Gub+QV3KQ1VsLSuR6bHcPKR6h4vAs1iwRKYAguQqo7LJMKAduuWs=,iv:EhUYS1iZOT9AbTk2A0EfLFjqIjLU7KYd1xHWwbwzUpU=,tag:Lh2yKA2AELEZk8axXdJJiA==,type:str]
     unencrypted_suffix: _unencrypted
     version: 3.13.3