diff --git a/server/commands/device.ts b/server/commands/device.ts
new file mode 100644
index 0000000..c114a74
--- /dev/null
+++ b/server/commands/device.ts
@@ -0,0 +1,161 @@
+import { flags } from "@oclif/command";
+import { ux } from "cli-ux";
+import { capitalize } from "lodash";
+import { FindConditions } from "typeorm";
+
+import ManageCommand from "../ManageCommand";
+
+import { Input } from "@oclif/parser/lib/flags";
+import { SprinklersDevice, User } from "@server/entities";
+
+type DeviceFlags = (typeof DeviceCommand)["flags"] extends Input<infer F>
+  ? F
+  : never;
+
+type Action = "show" | "delete" | "add-user" | "remove-user";
+
+const VALID_ACTIONS: Action[] = [ "show", "delete", "add-user", "remove-user" ];
+
+// tslint:disable:no-shadowed-variable
+
+export default class DeviceCommand extends ManageCommand {
+  static description = "Manage devices";
+
+  static flags = {
+    show: flags.boolean({
+      char: "s",
+      exclusive: ["add-user", "delete"],
+      description: "Show devices(s)",
+    }),
+    "add-user": flags.boolean({
+      char: "a",
+      exclusive: ["show", "delete"],
+      description: "Add a user as owning this device (specify --username)"
+    }),
+    "remove-user": flags.boolean({
+      char: "r",
+      exclusive: ["add-user", "show", "delete"],
+      description: "Remove a user as owning this device (specify --username)"
+    }),
+    delete: flags.boolean({
+      char: "d",
+      exclusive: ["show", "add-user"],
+      description: "Delete a user (by --id or --username)"
+    }),
+    id: flags.integer({
+      description: "The id of the device to update or delete",
+    }),
+    name: flags.string({
+      description: "The name of the device, when creating or updating"
+    }),
+    deviceId: flags.string({
+      description: "The deviceId of the device, when creating or updating"
+    }),
+    username: flags.string({
+      description: "Specify a username for --show or --add-user"
+    }),
+  };
+
+  getAction(flags: DeviceFlags): Action {
+    for (const action of VALID_ACTIONS) {
+      if (flags[action]) {
+        return action;
+      }
+    }
+    const actionFlags = VALID_ACTIONS.map(action => `--${action}`);
+    this.error(`Must specify an action (${actionFlags.join(', ')})`, {
+      exit: false,
+    });
+    return this._help();
+  }
+
+  getFindConditions(flags: DeviceFlags, action: Action): FindConditions<SprinklersDevice> {
+    let whereClause: FindConditions<SprinklersDevice> = {};
+    if (flags.id) {
+      whereClause.id = flags.id;
+    }
+    if (flags.name) {
+      whereClause.name = flags.name;
+    }
+    if (flags.deviceId) {
+      whereClause.deviceId = flags.deviceId;
+    }
+    if (false) {
+      this.error(`Must specify --id to ${action}`, {
+        exit: false
+      });
+      return this._help();
+    }
+    return whereClause;
+  }
+
+  async getOrDeleteDevice(flags: DeviceFlags, action: Action): Promise<SprinklersDevice | never> {
+    const findConditions = this.getFindConditions(flags, action);
+    if (action === "delete") {
+      const result = await this.database.sprinklersDevices.delete(findConditions);
+      if (result.raw[1] > 0) {
+        this.log(`Deleted device`);
+      } else {
+        this.error("Did not find device to delete");
+      }
+      return this.exit();
+    } else {
+      const device = await this.database.sprinklersDevices.findOne(findConditions);
+      if (!device) {
+        return this.error(`The specified device does not exist`);
+      }
+      return device;
+    }
+  }
+
+  async run() {
+    const parseResult = this.parse(DeviceCommand);
+
+    const flags = parseResult.flags;
+    const action = this.getAction(flags);
+
+    await this.connect();
+
+    if (flags.show) {
+      const findConditions = this.getFindConditions(flags, action);
+      let query = this.database.sprinklersDevices.createQueryBuilder("device")
+        .leftJoinAndSelect("device.users", "user")
+        .where(findConditions);
+      if (flags.username) {
+        query = query.where("user.username = :username", { username: flags.username });
+      }
+      const devices = await query.getMany();
+      if (devices.length == 0) {
+        this.log("No sprinklers devices found");
+        return 1;
+      }
+      this.log("Devices: ")
+      for (const device of devices) {
+        this.log(JSON.stringify(device, null, "  "));
+      }
+      return;
+    }
+
+    const device = await this.getOrDeleteDevice(flags, action);
+
+    if (flags["add-user"] || flags["remove-user"]) {
+      if (!flags.username) {
+        return this.error("Must specify --username for --add-user")
+      }
+      const user = await this.database.users.findByUsername(flags.username);
+      if (!user) {
+        return this.error(`Could not find user with username '${flags.username}'`);
+      }
+      let query = this.database.sprinklersDevices.createQueryBuilder()
+        .relation("users")
+        .of(device);
+      if (flags["add-user"]) {
+        await query.add(user);
+        this.log(`Added user '${user.username}' to device '${device.name}`);
+      } else {
+        await query.remove(user);
+        this.log(`Removed user '${user.username}' from device '${device.name}`);
+      }
+    }
+  }
+}
diff --git a/server/commands/user.ts b/server/commands/user.ts
index 224e90f..d53c494 100644
--- a/server/commands/user.ts
+++ b/server/commands/user.ts
@@ -89,7 +89,6 @@ export default class UserCommand extends ManageCommand {
     } else {
       const findConditions = this.getFindConditions(flags, action);
       if (action === "delete") {
-        this.log("findConditions: ", findConditions)
         const result = await this.database.users.delete(findConditions);
         this.log(`Deleted user: `, result);
         return this.exit();
@@ -121,12 +120,11 @@ export default class UserCommand extends ManageCommand {
       }
       const users = await this.database.users.find({ where: whereClause });
       if (users.length == 0) {
-        console.log("No users found");
-        return 1;
+        this.error("No users found");
       }
-      console.log("Users: ")
+      this.log("Users: ")
       for (const user of users) {
-        console.log(JSON.stringify(user.toJSON()));
+        this.log(JSON.stringify(user.toJSON()));
       }
       return;
     }