swarm UI: log an agent into claude from its card; the credentials go to bao and the agent picks them up

A new swarm service, `swarm-claude-login`, in its own container on the host
that sets `deploy.claude-login.enable` (defaulted on by `allSwarmServices`
where the host has the minter's store leaf, like the review classifier).

- swarm-ui: an agent card showing "login needed" gets a "log in" button.
  Its dialog starts the login, shows the URL claude printed, and takes the
  pasted code.
- swarm-controller: `POST/DELETE /api/agents/{name}/claude-login` and
  `POST /api/agents/{name}/claude-login/code`, behind the swarm UI's
  authelia-gated `/api/`, relay the steps to the minter as requests on
  `$SWARM.claude-login.request`.
- swarm-claude-login: runs `claude auth login` over piped stdio with HOME
  and CLAUDE_CONFIG_DIR in a per-login scratch dir, scrapes the first
  https URL, writes the code to stdin, and stores the `.credentials.json`
  at `swarm/agents/<agent>/claude-credentials` with a KV v2 write, a new
  version over any earlier one. The scratch dir goes on every exit path; a
  login waits 15 minutes for its code.
- hive-agent: while parked in `wait_for_login`, reads that leaf every 30 s
  under the agent's own cert and installs it only when its KV version is
  newer than the one recorded in `<harness>/claude-credentials-version`.
  An equal or older version is never put back, because claude rotates the
  refresh token and the stored copy is stale after the first refresh.
- swarm-secret-client: `claude_login` paths and `SecretStore::read_versioned`.
- Credentials: a `claude-login` store leaf minted by glue-bao-tls, a
  `swarm-claude-login` policy (create/update on
  `swarm/agents/+/claude-credentials`, read on its own queue client
  secret), an authelia machine client, and a `--claude-login-client`
  grant in the queue's auth-callout responder. The unit runs as a static
  system user.

The hive's own web-UI login is unchanged.

Refs #5268

nix/host-modules/default.nix

@@ -47,6 +47,7 @@
     ./glue-nats-wireguard.nix
     ./glue-queue-agent-credential.nix
     ./glue-builder-oidc-client.nix
+    ./glue-claude-login-oidc-client.nix
     ./glue-review-classifier-oidc-client.nix
     ./glue-secret-publisher-authelia.nix
     ./glue-secret-publisher-bao-identity.nix
@@ -57,6 +58,7 @@
     ./swarm-bao-service.nix
     ./swarm-bao.nix
     ./swarm-builder.nix
+    ./swarm-claude-login.nix
     ./swarm-ci-runner.nix
     ./swarm-review-classifier.nix
     ./swarm-secret-publisher.nix

nix/host-modules/deploy.nix

@@ -700,6 +700,26 @@ in
       '';
     };
 
+    claude-login.enable = lib.mkOption {
+      type = lib.types.bool;
+      default = false;
+      example = true;
+      description = ''
+        Run the claude login minter in a `swarm-claude-login` container on
+        this host. It runs `claude auth login` for the agent an operator logs
+        in from its card in the swarm UI, and writes the credentials to that
+        agent's `secret/swarm/agents/<agent>/claude-credentials`, which the
+        agent's harness installs. Run it on one host: a login in progress
+        lives in the service's memory.
+
+        On by default where
+        {option}`services.hyperhive.deploy.allSwarmServices` is set and this
+        host has the minter's store identity (the pair
+        {option}`services.hyperhive.deploy.bao.claudeLoginClientCertFile`
+        and `claudeLoginClientKeyFile`, minted on the store's host).
+      '';
+    };
+
     builder.enable = lib.mkOption {
       type = lib.types.bool;
       default = false;

nix/host-modules/glue-bao-tls.nix

@@ -117,6 +117,8 @@ in
       reviewClassifierClientKeyFile = lib.mkDefault "${pkiDir}/review-classifier-key.pem";
       builderClientCertFile = lib.mkDefault "${pkiDir}/builder.pem";
       builderClientKeyFile = lib.mkDefault "${pkiDir}/builder-key.pem";
+      claudeLoginClientCertFile = lib.mkDefault "${pkiDir}/claude-login.pem";
+      claudeLoginClientKeyFile = lib.mkDefault "${pkiDir}/claude-login-key.pem";
       forgePublisherClientCertFile = lib.mkDefault "${pkiDir}/forge-publisher.pem";
       forgePublisherClientKeyFile = lib.mkDefault "${pkiDir}/forge-publisher-key.pem";
       servicesIssuerClientCertFile = lib.mkDefault "${pkiDir}/services-issuer.pem";
@@ -303,6 +305,13 @@ in
         [ -s ${pkiDir}/builder.pem ] || ${signLeaf} ${pkiDir} builder \
           ${lib.escapeShellArg deployCfg.bao.builderCommonName} "" clientAuth
 
+        # The claude login minter's, which writes agents' claude credentials
+        # and reads its queue client secret. Minted here for the matrix-ctl
+        # leaf's reason: the minter is a swarm service, so on a minter host
+        # without the store this is the file an operator copies.
+        [ -s ${pkiDir}/claude-login.pem ] || ${signLeaf} ${pkiDir} claude-login \
+          ${lib.escapeShellArg deployCfg.bao.claudeLoginCommonName} "" clientAuth
+
         # The forge's token publisher. Minted here for the matrix-ctl leaf's
         # reason: the forge is a swarm singleton, so on a forge host without the
         # store this is the file an operator copies.

nix/host-modules/glue-claude-login-oidc-client.nix

@@ -0,0 +1,35 @@
+# Glue: register the claude login minter as an OIDC client wherever authelia
+# runs.
+#
+# ONE PAIRING PER FILE — swarm-claude-login ← authelia, and nothing else.
+# Deleting this leaves a minter whose token requests authelia answers with a
+# 401, and no minted secret for swarm-secret-publish to put in the store.
+#
+# ⚠️ Gated on authelia being HERE, and NOT on this host running the minter,
+# for ./glue-controller-oidc-client.nix's reason: a client is a row in THIS
+# host's provider config. Registered whether or not any host enables the
+# minter: nothing in `swarm.*` records that, so a swarm without one carries
+# one unused client and one unused minted secret.
+{
+  lib,
+  config,
+  ...
+}:
+let
+  hyperhiveCfg = config.services.hyperhive;
+  deployCfg = hyperhiveCfg.deploy;
+  clientId = hyperhiveCfg.swarm.claude-login.clientId;
+in
+{
+  config = lib.mkIf deployCfg.authelia.enable {
+    services.hyperhive.swarm.authelia.oidc.clients = [
+      {
+        id = clientId;
+        description = "HyperHive claude login minter";
+        # `client_credentials`: a daemon authenticating as itself.
+        kind = "machine";
+        audience = [ clientId ];
+      }
+    ];
+  };
+}

nix/host-modules/swarm-bao.nix

@@ -1054,6 +1054,22 @@ let
     }
   ];
 
+  # The claude login minter: every agent's `claude-credentials` leaf,
+  # create and update so a relogin replaces the last, and nothing else under
+  # an agent; and its own queue client secret, read at start.
+  claudeLoginWriters = [
+    {
+      name = "swarm-claude-login";
+      cn = baoDeploy.claudeLoginCommonName;
+      policyText = ''
+        path "${credentialMountPath}/data/swarm/agents/+/claude-credentials" {
+          capabilities = ["create", "update"]
+        }
+      ''
+      + readStanza "${credentialMountPath}/data/swarm/services/${hyperhiveCfg.swarm.claude-login.clientId}/oidc/client";
+    }
+  ];
+
   # The forge host's one store identity. `swarm-bao-forge-publisher` writes
   # the controller's forge token under it, the one writer of that path and
   # write-only: it copies a file in and never reads one back.
@@ -1932,6 +1948,19 @@ in
       '';
     };
 
+    claudeLoginCommonName = lib.mkOption {
+      type = lib.types.str;
+      default = "swarm-claude-login";
+      description = ''
+        Subject the store's `swarm-claude-login` cert-auth role accepts: the
+        identity the claude login minter presents from inside its container.
+        Its grant is create and update on `swarm/agents/+/claude-credentials`
+        and read on its own queue client secret.
+
+        ⚠️ Reserved as a hive name by ./swarm.nix, like its siblings.
+      '';
+    };
+
     forgePublisherCommonName = lib.mkOption {
       type = lib.types.str;
       default = "swarm-forge-publisher";
@@ -2232,6 +2261,31 @@ in
       '';
     };
 
+    claudeLoginClientCertFile = lib.mkOption {
+      type = lib.types.nullOr lib.types.str;
+      default = null;
+      example = "/var/lib/swarm-bao-pki/claude-login.pem";
+      description = ''
+        Certificate the claude login minter presents to the store. Its subject
+        must be {option}`services.hyperhive.deploy.bao.claudeLoginCommonName`.
+
+        ./glue-bao-tls.nix points it at the leaf it mints on the store's host.
+        On a minter host without the store, it is a file the operator copies
+        from the store's host. A path, never a value.
+      '';
+    };
+
+    claudeLoginClientKeyFile = lib.mkOption {
+      type = lib.types.nullOr lib.types.str;
+      default = null;
+      example = "/var/lib/swarm-bao-pki/claude-login-key.pem";
+      description = ''
+        Private key for
+        {option}`services.hyperhive.deploy.bao.claudeLoginClientCertFile`.
+        A path, never a value.
+      '';
+    };
+
     forgePublisherClientCertFile = lib.mkOption {
       type = lib.types.nullOr lib.types.str;
       default = null;
@@ -3318,6 +3372,8 @@ in
 
       systemd.services.swarm-bao-builder-policy = readerPolicyUnit "write the swarm builder's forge-token-reader bao policy and cert-auth role" builderReaders;
 
+      systemd.services.swarm-bao-claude-login-policy = readerPolicyUnit "write the claude login minter's credentials-writer bao policy and cert-auth role" claudeLoginWriters;
+
       systemd.services.swarm-bao-forge-publisher-policy = readerPolicyUnit "write the forge's controller-token-publisher bao policy and cert-auth role" forgePublisherWriters;
 
       # A FOURTH sibling, same shape and same reasons as the two above. This

nix/host-modules/swarm-claude-login.nix

@@ -0,0 +1,203 @@
+# The claude login minter, in a `swarm-claude-login` container on the host
+# that sets `deploy.claude-login.enable`, which `deploy.allSwarmServices`
+# defaults on where the host has the minter's store identity. An operator logs
+# an agent in from its card in the swarm UI: swarm-controller relays the start
+# and the pasted code over the queue, and the daemon runs `claude auth login`
+# and writes the credentials to that agent's store leaf.
+# docs/swarm/claude-login.md has the design.
+#
+# Its own network namespace on the bridge, as ./swarm-review-classifier.nix
+# has: it reaches the swarm services by name and nothing on the host's
+# loopback.
+#
+# The container holds one credential, its own store leaf, which nspawn hands in
+# as a system credential with no copy on disk. The daemon reads its queue
+# client secret with it and writes agents' credentials under it.
+{
+  pkgs,
+  lib,
+  config,
+  ...
+}:
+let
+  hyperhiveCfg = config.services.hyperhive;
+  cfg = hyperhiveCfg.deploy.claude-login;
+  baoCfg = hyperhiveCfg.swarm.bao;
+  baoDeploy = hyperhiveCfg.deploy.bao;
+  natsCfg = hyperhiveCfg.swarm.nats;
+  autheliaCfg = hyperhiveCfg.swarm.authelia;
+  gatewayCfg = hyperhiveCfg.gateway;
+  networkCfg = hyperhiveCfg.network;
+  tlsCfg = hyperhiveCfg.deploy.hive-controller.tls;
+
+  machine = "swarm-claude-login";
+  unit = "swarm-claude-login";
+  clientId = hyperhiveCfg.swarm.claude-login.clientId;
+
+  # The daemon reaches authelia, the store and the queue by name over TLS, and
+  # in self-signed mode their leaves chain to the hive CA.
+  caTrust = import ./lib/hive-ca-trust.nix { inherit lib tlsCfg gatewayCfg; };
+  caBundleModule = caTrust.trustBundle {
+    inherit pkgs;
+    name = machine;
+    consumers = [ unit ];
+  };
+
+  haveClientIdentity =
+    baoDeploy.claudeLoginClientCertFile != null && baoDeploy.claudeLoginClientKeyFile != null;
+
+  # Credential id → host source, as ./swarm-review-classifier.nix hands its
+  # leaf in.
+  storeFiles = lib.filterAttrs (_: source: source != null) {
+    claude-login-bao-cert = baoDeploy.claudeLoginClientCertFile;
+    claude-login-bao-key = baoDeploy.claudeLoginClientKeyFile;
+    claude-login-bao-server-ca = baoDeploy.serverCaFile;
+  };
+  # nixos-container expands `extraFlags` unquoted, so a source path must be
+  # one word.
+  oneWord = path: builtins.match ".*[[:space:]].*" path == null;
+  credential = id: "/run/credentials/${unit}.service/${id}";
+
+  privateNetwork = true;
+in
+{
+  options.services.hyperhive.swarm.claude-login.clientId = lib.mkOption {
+    type = lib.types.str;
+    readOnly = true;
+    default = "swarm-claude-login";
+    description = ''
+      The OAuth2 client id the claude login minter presents to the swarm
+      queue. Read-only: the host running authelia registers it, the queue's
+      auth-callout responder grants it the login subject, and the secret
+      publisher carries its secret to the store, all from this one value.
+    '';
+  };
+
+  options.services.hyperhive.deploy.claude-login.package = lib.mkOption {
+    type = lib.types.package;
+    defaultText = lib.literalExpression "hyperhive.packages.\${system}.swarm-claude-login";
+    description = "The claude login minter daemon package.";
+  };
+
+  config = lib.mkIf cfg.enable {
+    assertions = [
+      {
+        assertion = haveClientIdentity;
+        message = ''
+          services.hyperhive.deploy.claude-login.enable requires the minter's
+          swarm-secret-store client identity: set both
+
+            services.hyperhive.deploy.bao.claudeLoginClientCertFile
+            services.hyperhive.deploy.bao.claudeLoginClientKeyFile
+
+          The minter reads its queue client secret and writes agents' claude
+          credentials with it.
+
+          Both default to the pair glue-bao-tls.nix mints when
+          services.hyperhive.deploy.bao.enable is true (the host that runs the
+          store). Otherwise copy claude-login.pem and claude-login-key.pem from
+          the store host's /var/lib/swarm-bao-pki/ and name them in those two
+          options.
+        '';
+      }
+      {
+        assertion = lib.all oneWord (lib.attrValues storeFiles);
+        message = ''
+          The claude login minter's store identity paths must not contain
+          whitespace: nspawn's --load-credential receives them through
+          nixos-container's unquoted extra flags.
+        '';
+      }
+    ];
+
+    # The container hangs off the bridge, takes its address from the gateway's
+    # DHCP and resolves through its dnsmasq.
+    services.hyperhive.network.enable = lib.mkDefault true;
+    services.hyperhive.gateway.enable = lib.mkDefault true;
+    services.hyperhive.gateway.dns.enable = lib.mkDefault true;
+
+    # nspawn fails to start the container when a credential source is
+    # missing, so where this host mints the leaf the container waits for it.
+    systemd.services."container@${machine}" = lib.mkMerge [
+      caTrust.containerOrdering
+      { after = [ "swarm-bao-pki.service" ]; }
+    ];
+
+    containers.${machine} = {
+      autoStart = true;
+      # The daemon keeps no state; each login's scratch directory is under
+      # PrivateTmp.
+      ephemeral = false;
+      # Journal files on the host, not inside the container: nixpkgs hardcodes
+      # --link-journal=try-guest, and EXTRA_NSPAWN_FLAGS expands after it.
+      extraFlags = [
+        "--link-journal=host"
+      ]
+      ++ lib.mapAttrsToList (id: source: "--load-credential=${id}:${source}") storeFiles;
+      inherit privateNetwork;
+      hostBridge = networkCfg.bridgeName;
+      bindMounts = caTrust.bindMount;
+
+      config =
+        { pkgs, lib, ... }:
+        {
+          imports = [
+            ../container-modules/swarm-container.nix
+            caBundleModule
+          ];
+
+          services.hyperhive.swarmContainer = {
+            inherit privateNetwork;
+            writesOwnResolvConf = false;
+          };
+          networking.nameservers = [ networkCfg.bridgeIp ];
+          networking.interfaces.eth0.useDHCP = true;
+
+          # `claude-code` is unfree, and this container evaluates its own
+          # nixpkgs, so the host's allowance does not reach here.
+          nixpkgs.config.allowUnfreePredicate = pkg: builtins.elem (lib.getName pkg) [ "claude-code" ];
+
+          users.users.${unit} = {
+            isSystemUser = true;
+            group = unit;
+          };
+          users.groups.${unit} = { };
+
+          systemd.services.${unit} = {
+            description = "log agents in to claude for the swarm UI";
+            wantedBy = [ "multi-user.target" ];
+            wants = [ "network-online.target" ];
+            after = [ "network-online.target" ];
+            environment = {
+              BAO_ADDR = "https://${baoCfg.domain}:${toString baoCfg.port}";
+              BAO_CLIENT_CERT = credential "claude-login-bao-cert";
+              BAO_CLIENT_KEY = credential "claude-login-bao-key";
+              SWARM_CLAUDE_LOGIN_NATS_URL = "tls://${natsCfg.domain}:${toString natsCfg.port}";
+              SWARM_CLAUDE_LOGIN_OIDC_TOKEN_ENDPOINT = "${autheliaCfg.url}/api/oidc/token";
+              SWARM_CLAUDE_LOGIN_OIDC_CLIENT_ID = clientId;
+              SWARM_CLAUDE_LOGIN_CLAUDE = "${pkgs.claude-code}/bin/claude";
+            }
+            // lib.optionalAttrs (storeFiles ? claude-login-bao-server-ca) {
+              BAO_CACERT = credential "claude-login-bao-server-ca";
+            }
+            // lib.optionalAttrs caTrust.useSelfSigned {
+              SWARM_CLAUDE_LOGIN_OIDC_CA_FILE = caTrust.bundlePathFor machine;
+            };
+            serviceConfig = {
+              ExecStart = "${cfg.package}/bin/swarm-claude-login";
+              User = unit;
+              Group = unit;
+              # Each login's scratch directory, gone with the unit.
+              PrivateTmp = true;
+              UMask = "0077";
+              # Bare ids: the system credentials nspawn handed in.
+              LoadCredential = lib.attrNames storeFiles;
+              Restart = "on-failure";
+              RestartSec = "10s";
+              SyslogIdentifier = unit;
+            };
+          };
+        };
+    };
+  };
+}

nix/host-modules/swarm-nats.nix

@@ -795,6 +795,8 @@ in
                 "--review-classifier-client ${lib.escapeShellArg config.services.hyperhive.swarm.review-classifier.clientId}"
                 # Hears builds and answers each by reply, and nothing else.
                 "--builder-client ${lib.escapeShellArg config.services.hyperhive.swarm.builder.clientId}"
+                # Hears login steps and answers each by reply, and nothing else.
+                "--claude-login-client ${lib.escapeShellArg config.services.hyperhive.swarm.claude-login.clientId}"
                 # What an agent may publish to, keyed on its own name: its
                 # terminal rows and its turn-state header
                 # (`hive-agent::swarm_agent_state`), two subject families so a

nix/host-modules/swarm-required-services.nix

@@ -126,4 +126,12 @@ in
     && deployCfg.bao.builderClientCertFile != null
     && deployCfg.bao.builderClientKeyFile != null
   );
+
+  # The claude login minter, defaulted on the same terms as the review
+  # classifier.
+  config.services.hyperhive.deploy.claude-login.enable = lib.mkDefault (
+    deployCfg.allSwarmServices
+    && deployCfg.bao.claudeLoginClientCertFile != null
+    && deployCfg.bao.claudeLoginClientKeyFile != null
+  );
 }

nix/host-modules/swarm-secret-publisher.nix

@@ -96,6 +96,8 @@ let
     hyperhiveCfg.swarm.review-classifier.clientId
     # The swarm builder, which reads it itself inside its container.
     hyperhiveCfg.swarm.builder.clientId
+    # The claude login minter, which reads it itself inside its container.
+    hyperhiveCfg.swarm.claude-login.clientId
   ];
 
   # The swarm controller's OIDC client, which it reads back from the store

nix/host-modules/swarm.nix

@@ -59,6 +59,7 @@ let
     deployCfg.bao.metricsAuthCommonName
     deployCfg.bao.reviewClassifierCommonName
     deployCfg.bao.builderCommonName
+    deployCfg.bao.claudeLoginCommonName
     deployCfg.bao.forgePublisherCommonName
   ]
   # The per-hive subjects, spelled out per hive rather than as the prefix.