{
  pkgs,
  lib,
  config,
  # Flake inputs routed through _module.args by the agent flake.nix.
  # Default to {} so the module evaluates cleanly even when the agent
  # flake doesn't set up the routing pattern (e.g. during standalone
  # nixos-rebuild without a flake wrapper).
  flakeInputs ? { },
  ...
}:
let
  # Agent user metadata. `userName` defaults to `"agent"` when the
  # meta-flake doesn't inject the per-agent override (stand-alone
  # `nixos-rebuild` against `nixosConfigurations.agent-base` works
  # without erroring on a missing per-agent name). `homeDir` derives
  # from `userName` to keep them coupled.
  userName = config.hyperhive.user.name;
  homeDir = "/home/${userName}";
  # Single source of truth for the default matrix homeserver URL, shared
  # by the `hyperhive.matrix.url` option default and the daemon-unit guard
  # that decides whether to set a unit-level HIVE_MATRIX_URL (so the two
  # cannot drift). Matches the daemon's own built-in default
  # (`paths::DEFAULT_HOMESERVER`).
  matrixUrlDefault = "http://localhost:8008";
in
{
  # Shared scaffolding for every hyperhive harness container.
  # `agent-base.nix` and `manager.nix` both import this; all agents
  # use the same service unit regardless of which entry-point they came from.

  # Optional feature modules. Each declares its own `hyperhive.*`
  # option(s), default-off, so every agent has them available but
  # only opts in from its own `agent.nix`.
  imports = [ ./weston-vnc.nix ];

  # Per-agent unix user the harness + co-process daemons run as.
  # Defaults to `"agent"` so a standalone evaluation (e.g.
  # `nix flake check` against `nixosConfigurations.agent-base`) builds
  # cleanly; the meta-flake's per-agent module rebinds this to the
  # agent name (`"damocles"`, `"iris"`, …) so each container has a
  # uniquely-named user matching its agent label. UID auto-assigned
  # by NixOS (the auto-allocation range for normal users); no hard-
  # coded UID.
  options.hyperhive.user.name = lib.mkOption {
    type = lib.types.strMatching "^[a-z_][a-z0-9_-]{0,30}$";
    default = "agent";
    example = "iris";
    description = ''
      Unix user the harness service runs as inside the container.
      The meta-flake overrides this to the agent's own name so the
      user inside the container matches the agent label (`HIVE_LABEL`).
      Stand-alone evaluation defaults to `"agent"` so module evaluation
      without the meta-flake wrapper still builds.

      Constraints match `useradd`'s NAME_REGEX: lowercase / `_` start,
      total length ≤ 31, no special characters. UID is auto-assigned
      by NixOS; no `uid =` override surface (intentional — pinning
      across rebuilds isn't a concern when the home and state dirs
      stay bind-mounted from the host).
    '';
  };

  options.hyperhive.user.passwordlessSudo = lib.mkOption {
    type = lib.types.bool;
    default = true;
    example = false;
    description = ''
      Grant `${config.hyperhive.user.name}` passwordless sudo
      (`NOPASSWD: ALL`). True by default so claude's `Bash` tool
      keeps working for tools that expect root inside the container
      (`systemctl`, package managers in dev shells, etc.) — the
      same surface the previous root-user shape had, just elevated
      explicitly instead of implicitly.

      Flip to `false` for agents that should be strictly
      unprivileged. Anything claude shells out to that needs root
      will then fail loudly with the standard sudo error rather
      than silently succeeding — easier to spot the leak.
    '';
  };

  options.hyperhive.web.useUnixSocket = lib.mkOption {
    type = lib.types.bool;
    default = false;
    example = true;
    description = ''
      Deprecated. Unix socket mode is now always enabled for all agents.
      Setting this option to `true` has no effect and the option will be
      removed in a future version. Safe to drop from agent configs.
    '';
  };

  options.hyperhive.model = lib.mkOption {
    type = lib.types.str;
    default = "haiku";
    example = "sonnet";
    description = ''
      Claude model for this agent. Sets the `HIVE_DEFAULT_MODEL`
      environment variable; the harness applies it at boot and it takes
      priority over any persisted runtime override. The operator can still
      switch the model at runtime via the per-agent web UI — that choice
      is tracked in the state dir for the current session but is reset by
      any rebuild that changes this option.

      Valid values are the short model names that `claude --model` accepts:
      `"haiku"`, `"sonnet"`, `"opus"` (or any future identifier). Context
      window sizes are looked up at runtime from the
      `HIVE_CONTEXT_WINDOW_TOKENS_<KEY_UPPER>` env vars injected by the
      meta flake; override sizes via `services.hyperhive.c0re.contextWindowTokens`
      on the host.
    '';
  };

  options.hyperhive.availableModels = lib.mkOption {
    type = lib.types.listOf lib.types.str;
    default = [
      "haiku"
      "sonnet"
      "opus"
    ];
    example = [
      "sonnet"
      "opus"
    ];
    description = ''
      Models offered in the per-agent web UI's model quick-picker. Rendered
      into the `HIVE_AVAILABLE_MODELS` environment variable (comma-separated)
      which the harness surfaces to the agent UI, so the picker lists exactly
      these models instead of a hardcoded set.

      Configure hive-wide by setting a shared default (e.g. in your
      `agent-base.nix`) or per-agent to narrow the menu — for example a
      haiku-only agent can hide `opus` and `sonnet`. The *current* model is
      still set by `hyperhive.model` and remains switchable at runtime via the
      UI; this option only controls which choices the picker presents.

      Values are the short model names that `claude --model` accepts:
      `"haiku"`, `"sonnet"`, `"opus"` (or any future identifier).
    '';
  };

  options.hyperhive.effortLevel = lib.mkOption {
    type = lib.types.enum [
      "medium"
      "high"
      "xhigh"
    ];
    default = "medium";
    example = "high";
    description = ''
      Baseline claude effort level for this agent. Rendered into the
      `HIVE_DEFAULT_EFFORT` environment variable; the harness resolves
      effort as operator-override-file → this env → built-in `"medium"`,
      and passes the result to `claude --effort` at turn launch.

      `"medium"` (the default) keeps token spend low and works well with
      the harness across families. `"high"` matches the current platform
      default; `"xhigh"` is recommended for coding / high-autonomy work on
      capable models (Opus 4.8+) at higher token cost. The operator can
      override at runtime per-agent via the web UI (applied on the next
      session); any rebuild that changes this option resets that override.
    '';
  };

  options.hyperhive.allowedBashPatterns = lib.mkOption {
    type = lib.types.listOf lib.types.str;
    default = [ ];
    description = ''
      Deprecated - has no effect. The built-in Bash tool is fully
      disabled regardless of this list; agents use mcp__bash__run
      instead. Remove this option from your agent.nix.
    '';
    visible = false;
  };

  options.hyperhive.allowedRecipients = lib.mkOption {
    type = lib.types.listOf lib.types.str;
    default = [ ];
    example = [
      "alice"
      "manager"
    ];
    description = ''
      Names this agent is allowed to `send` to via
      `mcp__hyperhive__send`. Empty list (the default) means
      unrestricted — the agent can message any peer, the
      operator, or the manager. Non-empty list constrains the
      surface: only the listed names + the manager (always
      allowed) get through; anything else returns an error
      string to claude without touching the broker. The
      operator (`operator`) needs to be in the list if the
      agent should be able to surface output on the
      dashboard.

      Useful for sandboxing untrusted sub-agents — set
      `[ "manager" ]` to scope them to manager-only chatter.
      The manager itself is always exempt; this option only
      affects sub-agent `send`.
    '';
  };

  options.hyperhive.extraMcpServers = lib.mkOption {
    type = lib.types.attrsOf (
      lib.types.submodule {
        options = {
          command = lib.mkOption {
            type = lib.types.str;
            description = "Absolute path to the MCP server binary. Use `\${pkgs.foo}/bin/foo` or `/run/current-system/sw/bin/foo`.";
          };
          args = lib.mkOption {
            type = lib.types.listOf lib.types.str;
            default = [ ];
            description = "Args passed to the MCP server binary.";
          };
          env = lib.mkOption {
            type = lib.types.attrsOf lib.types.str;
            default = { };
            description = "Environment variables for the MCP server child process.";
          };
          allowedTools = lib.mkOption {
            type = lib.types.listOf lib.types.str;
            default = [ "*" ];
            example = [
              "send_message"
              "join_room"
            ];
            description = ''
              Tool names this MCP server is auto-approved to call via
              `--allowedTools`. Single entry `"*"` (the default) means
              "every tool from this server" — convenient but trusting.
              Tighten to a specific list when you only want a subset.
              Names are bare (e.g. `send_message`); the harness prepends
              `mcp__<server-key>__` at build time.
            '';
          };
        };
      }
    );
    default = { };
    example = lib.literalExpression ''
      {
        matrix = {
          command = "/run/current-system/sw/bin/mcp-matrix";
          args = [ "--config" "/state/matrix.toml" ];
          env.MATRIX_HOMESERVER = "https://matrix.example.org";
          allowedTools = [ "send_message" "join_room" ];
        };
      }
    '';
    description = ''
      Extra MCP servers claude sees alongside the hyperhive tool surface.
      Keys are the server names (claude addresses tools as
      `mcp__<key>__<tool>`). Rendered to `/etc/hyperhive/extra-mcp.json`
      at activation time; the harness reads that file at boot and merges
      it into `--mcp-config` + `--allowedTools`. Take effect on the
      agent's next harness restart (no operator approval needed beyond
      whatever brought the new agent.nix into deployed/*).
    '';
  };

  options.hyperhive.matrix.enable = lib.mkOption {
    type = lib.types.bool;
    default = true;
    description = ''
      Enable per-agent matrix integration via `hive-matrix-mcp`.
      When true (the default), the harness:

      - runs `hive-matrix-daemon` as a systemd unit that holds a
        matrix-sdk Client + sync against the homeserver at
        `HIVE_MATRIX_URL` (default `http://localhost:8008` — the
        in-host tuwunel from `nix/modules/hive-matrix.nix`). The
        daemon auto-skips when `<state>/matrix-token` is missing,
        and a `systemd.paths` watcher restarts it the moment
        hive-c0re provisions the token (same path-trigger shape
        as `matrix-avatar-sync`).
      - exposes the matrix tool surface (send_message, send_dm,
        send_reaction, send_reply, mark_read, list_rooms,
        list_room_members, read_room) to claude via an auto-injected
        `extraMcpServers.matrix` entry. Claude spawns the stdio
        `hive-matrix-mcp` bridge per turn, which forwards each tool
        call to the daemon over `/run/hive-matrix/socket`.
      - wakes the agent on incoming room events via a short teaser
        Wake signal (`[matrix] <sender> in <room>: <first 100c>…`)
        to the hyperhive control socket; the full event stays
        unread server-side until `read_room` consumes it.

      Set to `false` for agents that should NOT have matrix tools at
      all (e.g. agents on a host without `hyperhive.matrix.enable` on
      the meta side). When token file is absent the daemon and MCP
      both no-op cleanly anyway, so `false` is rarely necessary.
    '';
  };

  options.hyperhive.matrix.url = lib.mkOption {
    type = lib.types.str;
    default = matrixUrlDefault;
    example = "https://matrix.darkest.space";
    description = ''
      Matrix homeserver URL the agent's `hive-matrix-daemon` connects
      to. Default points at the in-host tuwunel (shared netns).
      Override per-agent when an agent should talk to an external
      homeserver instead (e.g. a federation-only setup or a remote
      hive's tuwunel reached via a vpn).
    '';
  };

  options.hyperhive.matrixAccounts = lib.mkOption {
    type = lib.types.attrsOf (
      lib.types.submodule {
        options = {
          tokenFile = lib.mkOption {
            type = lib.types.str;
            example = "/agents/dmatrix/state/matrix-token-ccc";
            description = ''
              Path to this account's bearer-token file. The daemon reads
              the token from here to restore the matrix session; how the
              file gets populated is the provisioner's concern (an
              operator-supplied secret for an external account). The
              daemon skips an extra account whose token file is absent.
            '';
          };
          sessionDir = lib.mkOption {
            type = lib.types.str;
            example = "/agents/dmatrix/state/matrix-sdk-state-ccc";
            description = ''
              Per-account matrix-sdk sqlite store directory (crypto keys
              + event cache). Must differ between accounts so their
              sessions do not collide.
            '';
          };
          homeserver = lib.mkOption {
            type = lib.types.nullOr lib.types.str;
            default = null;
            example = "https://matrix.example.org";
            description = ''
              Homeserver URL for this account. When null (the default),
              the account falls back to `hyperhive.matrix.url`. Set it for
              an account on a different homeserver than the agent's
              default (e.g. an external public-matrix account).
            '';
          };
        };
      }
    );
    default = { };
    example = lib.literalExpression ''
      {
        ccc = {
          tokenFile = "/agents/dmatrix/state/matrix-token-ccc";
          sessionDir = "/agents/dmatrix/state/matrix-sdk-state-ccc";
          homeserver = "https://matrix.example.org";
        };
      }
    '';
    description = ''
      Declare *additional* matrix accounts served by the single
      `hive-matrix-daemon` (one matrix-sdk Client + sync loop each),
      beyond the agent's built-in hive-internal account. This replaces
      the wasteful "one MCP server + daemon per account" pattern. The
      attribute name keys each account (unique by construction) and is
      the handle the matrix MCP tools target via their `account`
      argument.

      The **hive-internal account is always present and is the primary**:
      it is named `main`, synthesized by the daemon from
      `hyperhive.matrix.url` + `<state>/matrix-token` +
      `<state>/matrix-sdk-state`, and is the account a tool call acts as
      when it omits `account`. You never declare it here --- this option
      is only for the extras (e.g. an external public-matrix account).

      Leave empty (the default) for the common single-account case: the
      agent then has only `main`, exactly as before. When non-empty, the
      extras are serialized to the daemon's `HIVE_MATRIX_ACCOUNTS`
      environment variable and the daemon appends them after `main`.
      Requires `hyperhive.matrix.enable` (there is no `main` to extend
      otherwise).
    '';
  };

  options.hyperhive.frontend.dist = lib.mkOption {
    type = lib.types.package;
    default = pkgs.hyperhive-frontend;
    defaultText = lib.literalExpression "pkgs.hyperhive-frontend";
    description = ''
      The shipped frontend dist (built by `nix/frontend.nix`). Output
      layout: `dashboard/` (used by hive-c0re on the host) and
      `agent/` (used here, layered with `extraFiles` below at
      activation time). Override to ship a fully custom per-agent SPA;
      the JSON contract (`/api/state`, `/events/stream`, the action
      endpoints) is the source of truth for any replacement.
    '';
  };

  options.hyperhive.frontend.mergedDist = lib.mkOption {
    type = lib.types.package;
    readOnly = true;
    description = ''
      Computed: the merged static tree consumed by the harness via
      `HIVE_STATIC_DIR`. Composed at evaluation time by copying
      `hyperhive.frontend.dist`'s `agent/` subdir as the base, then
      layering each `extraFiles` entry on top. Read-only — do not set directly.
    '';
  };

  options.hyperhive.frontend.extraFiles = lib.mkOption {
    type = lib.types.attrsOf (
      lib.types.submodule (
        { name, ... }:
        {
          options = {
            source = lib.mkOption {
              type = lib.types.path;
              description = ''
                Source file or directory to layer over the default
                agent dist. A path (relative to `agent.nix` or
                absolute) — nix copies its contents into the merged
                static tree.
              '';
            };
            target = lib.mkOption {
              # First char must be alphanumeric/underscore (rules out
              # leading `/`, leading `.`, leading `-`); inner chars
              # include `.` and `/` so nested layouts like
              # `"games/bitburner"` work. This is the shape check —
              # the `..`-segment traversal check is the assertion in
              # `config.assertions` below (regex alone can't reject
              # mid-path `..` segments without lookahead, which nix
              # POSIX regex doesn't support).
              type = lib.types.strMatching "^[A-Za-z0-9_][A-Za-z0-9_./-]*$";
              default = name;
              defaultText = lib.literalMD "the attribute name";
              description = ''
                Destination path within the merged static tree, used
                as both the served URL prefix (`/<target>/...`) and
                the on-disk layout in the merged derivation. Defaults
                to the attribute name. Use forward slashes for
                nested layouts (e.g. `"games/bitburner"`).

                Constrained shape: must start with an alphanumeric or
                `_`, and only contain alphanumerics, `_`, `.`, `/`,
                `-`. `..` segments are separately rejected at config
                eval time.
              '';
            };
          };
        }
      )
    );
    default = { };
    example = lib.literalExpression ''
      {
        bitburner = {
          source = ./bitburner-dist;
          # served at GET /bitburner/...
        };
      }
    '';
    description = ''
      Per-agent additions layered on top of the default frontend
      dist. Each entry copies its `source` into the served static
      tree under `target`. Useful for shipping a self-contained
      agent-specific surface alongside the standard agent UI (e.g.
      the bitburner agent's game page at `/bitburner/`).

      The default agent UI remains served at `/`; entries here only
      add new routes and never replace the default. Overwrite
      semantics are **hard-fail**: if `target` collides with an
      existing file or directory in the default dist (or with a
      prior entry's target), the `mergedDist` build aborts with
      `refusing to overwrite existing path '<target>' in the
      default dist`. To override a default file, fork the dist via
      `hyperhive.frontend.dist` instead — `extraFiles` is for
      pure additions.

      `target` must be a relative path inside the static dir. An
      assertion rejects leading `/` and `..` segments at config
      eval time (string-concat-into-paths safety, even though
      agent.nix goes through operator review before deploy).
    '';
  };

  options.hyperhive.forge.url = lib.mkOption {
    type = lib.types.str;
    default = "http://localhost:3000";
    example = "http://forge.internal:3000";
    description = ''
      Base URL of the hyperhive-managed Forgejo. Used at container
      boot by a oneshot systemd unit that calls
      `tea login add --url <this> --token "$(cat $HYPERHIVE_STATE_DIR/forge-token)"`
      (= `/agents/<name>/state/forge-token`) so the agent's claude can
      shell out to `tea` without an extra auth dance. No-op when the
      forge-token file is missing (i.e. hive-forge isn't running on
      the host).
    '';
  };

  options.hyperhive.forge.keepSubscriptions = lib.mkOption {
    type = lib.types.bool;
    default = true;
    description = ''
      When true (the default), the forge notification poller will NOT
      auto-unsubscribe from repo watches after delivering a
      "subscribed"-reason notification. Sub-agents keep their broad
      subscriptions so they stay informed about repos they contribute to.
      Set to false for agents (e.g. the manager) that use reason-based
      filtering and do not need firehose-level repo visibility — they will
      auto-unsubscribe after receiving a watched-repo notification.
    '';
  };

  options.hyperhive.forge.skipNotifyReasons = lib.mkOption {
    type = lib.types.listOf lib.types.str;
    default = [ ];
    example = [
      "subscribed"
      "participating"
    ];
    description = ''
      Forgejo notification `reason` values to suppress in the forge
      notification poller. Notifications with these reasons are marked
      read and silently dropped; all others — including notifications
      with a null or unrecognised reason — are delivered.

      Drop-list is safer than an allow-list: directed signals
      (`review_requested`, `assigned`, `mention`) are never silently
      missed even if Forgejo returns an unexpected reason string.

      Empty list (the default) delivers all notifications. Set to
      `[ "subscribed" "participating" ]` for agents like the manager
      that want only direct mentions and reviews, not the full repo
      firehose. Rendered to the `HIVE_FORGE_NOTIFY_SKIP_REASONS`
      environment variable consumed by the harness poller at runtime.
    '';
  };

  options.hyperhive.dashboardLinks = lib.mkOption {
    type = lib.types.listOf (
      lib.types.submodule {
        options = {
          label = lib.mkOption {
            type = lib.types.str;
            description = "Display label for the link.";
          };
          icon = lib.mkOption {
            type = lib.types.str;
            default = "";
            description = "Optional icon emoji or short glyph.";
          };
          url = lib.mkOption {
            type = lib.types.str;
            description = "Full URL (may include a different port, e.g. http://localhost:9001/stats).";
          };
        };
      }
    );
    default = [ ];
    example = lib.literalExpression ''
      [
        { label = "Stats"; icon = "📊"; url = "http://localhost:9001/stats"; }
      ]
    '';
    description = ''
      Extra navigation links surfaced on the hive-c0re dashboard card for
      this agent. Declare any additional web UI pages the agent exposes —
      stats pages, custom UIs, etc. hive-c0re reads the JSON file this
      option produces at each container-view snapshot and attaches the
      links to the agent card without any code changes.
    '';
  };

  options.hyperhive.claudeMarketplaces = lib.mkOption {
    type = lib.types.listOf lib.types.str;
    default = [ "anthropics/claude-plugins-official" ];
    example = [
      "anthropics/claude-plugins-official"
      "anthropics/claude-plugins-community"
    ];
    description = ''
      Claude Code plugin marketplaces to add at harness boot. Each
      entry is passed to `claude plugin marketplace add <source>`
      (`owner/repo`, full git URL, or local path). Idempotent —
      re-adding an existing marketplace is treated as success.
      Required before `hyperhive.claudePlugins` entries that
      reference a marketplace (e.g. `foo@claude-plugins-official`).
      Rendered to `/etc/hyperhive/claude-marketplaces.json`.

      Defaults to Anthropic's official marketplace; agents get it
      out of the box without any per-agent.nix wiring.
    '';
  };

  options.hyperhive.claudePlugins = lib.mkOption {
    type = lib.types.listOf lib.types.str;
    default = [ ];
    example = [
      "formatter@my-marketplace"
      "thinking-tools@anthropics"
    ];
    description = ''
      Claude Code plugins to install at harness boot. Each entry is
      passed verbatim to `claude plugin install <spec>` once per
      container start, before the turn loop opens. `claude plugin
      install` is expected to be idempotent, so reinstalling on every
      boot is cheap. Failures log a warning but do not abort boot — a
      missing plugin is preferable to a non-serving agent. Rendered to
      `/etc/hyperhive/claude-plugins.json`; the harness reads it via
      `plugins::install_configured`.
    '';
  };

  options.hyperhive.claudePluginsAutoUpdate = lib.mkOption {
    type = lib.types.bool;
    default = false;
    description = ''
      When true, the harness runs `claude plugin marketplace update`
      before installing plugins at boot, pulling the latest index from
      all configured marketplaces. Disabled by default — most agents
      want pinned plugin versions and the network round-trip adds to
      boot time. Enable for agents that should always install the latest
      available version of their plugins.
    '';
  };

  options.hyperhive.icon = lib.mkOption {
    type = lib.types.nullOr lib.types.path;
    default = null;
    example = lib.literalExpression "./icon.svg";
    description = ''
      Path to an SVG file used as this agent's icon — shown on the
      dashboard and the per-agent web UI (header + favicon). Commit
      the SVG into the agent's config repo next to `agent.nix` and
      reference it as a relative path (`./icon.svg`).

      When null (the default) the agent falls back to the shared
      hyperhive logo. The harness serves the icon (configured or
      default) at `GET /icon` on the per-agent web port.
    '';
  };

  # Internal accumulator for shell snippets that should land in
  # `/etc/hyperhive/bash-env.sh`. Per-feature hooks set this via
  # `lib.mkIf` gated on their own option; the lines type merges
  # all contributions across modules into one file. Loaded via
  # `$BASH_ENV` for non-interactive shells (claude's `Bash` tool
  # runs `bash -c`) and via `programs.bash.interactiveShellInit`
  # for interactive shells. Generic by design so future hooks
  # don't need to rename this file or invent a parallel dispatcher.
  options.hyperhive._bashEnvFragments = lib.mkOption {
    type = lib.types.lines;
    default = "";
    internal = true;
    description = ''
      Shell snippets concatenated into `/etc/hyperhive/bash-env.sh`.
      Feature hooks contribute via `lib.mkIf` gated on their own
      option. When empty, the file isn't created, `BASH_ENV` stays
      unset, and the interactive bashrc hook is omitted — zero cost
      when no feature is on. Internal — set indirectly via the
      per-feature options that own the gate (e.g.
      `hyperhive.cargo.shortMessages`).
    '';
  };

  options.hyperhive.cargo.shortMessages = lib.mkOption {
    type = lib.types.bool;
    default = true;
    example = false;
    description = ''
      Auto-inject `--message-format short` on cargo compile
      subcommands (`build`, `check`, `clippy`, `test`, `run`,
      `doc`, `bench`, `install`, `rustc`, `fix`) when claude (or
      anything else) invokes `cargo` inside this container.
      Saves tokens + context — the verbose default output floods
      the response window with per-crate progress lines that
      carry no signal beyond the warning/error summary.

      Implementation: contributes a `cargo` shell function to
      `/etc/hyperhive/bash-env.sh` (see `hyperhive._bashEnvFragments`).
      Loaded via `BASH_ENV` for non-interactive shells (`bash -c` —
      what the claude `Bash` tool runs) and sourced from
      `programs.bash.interactiveShellInit` for interactive shells.
      The function:

      - handles the `+toolchain` selector prefix (`cargo +nightly
        build` works);
      - passes through cleanly when the caller already specified
        `--message-format` (any form);
      - leaves non-compile subcommands (`new`, `add`, `search`,
        third-party `cargo-*` subcommands) untouched so they
        don't error on the unknown flag.

      Set to `false` for agents that need full cargo output (e.g.
      tooling that parses `--message-format json` programmatically
      and doesn't pass the flag explicitly).
    '';
  };

  options.hyperhive.autoCompact = lib.mkOption {
    type = lib.types.bool;
    default = true;
    description = ''
      Enable proactive watermark-based compaction. When `true` (the
      default) the harness automatically runs a notes-checkpoint turn
      followed by `/compact` once the context window crosses 75% of
      the model's limit, keeping later turns from hitting the hard
      overflow path. Set to `false` to disable proactive compaction
      entirely (`HIVE_COMPACT_WATERMARK_TOKENS=0`); the reactive path
      (compact-on-overflow when the session is already past the limit)
      still applies.

      Disable for agents that run large-context models (sonnet/opus)
      where the heuristic fires too early and discards useful history
      before the session is actually close to the limit.
    '';
  };

  config = {
    warnings = lib.optional (config.hyperhive.allowedBashPatterns != [ ]) ''
      hyperhive.allowedBashPatterns is deprecated and has no effect.
      The built-in Bash tool is fully disabled; agents use mcp__bash__run instead.
      Remove allowedBashPatterns from your agent.nix.
    '';

    assertions = [
      # Guard the inputs-routed-as-output pattern: the agent flake.nix is
      # expected to set `_module.args.flakeInputs = builtins.removeAttrs inputs ["self"]`.
      # If `self` leaks into flakeInputs the agent gets a spurious attrset
      # entry that can shadow real inputs and is almost certainly a bug.
      # Guard with `or {}` so standalone evaluation stays clean when
      # flakeInputs is absent from _module.args.
      {
        assertion = !(builtins.hasAttr "self" (config._module.args.flakeInputs or { }));
        message = ''
          hyperhive: `flakeInputs` must not contain "self".
          In your agent flake.nix, use:
            _module.args.flakeInputs = builtins.removeAttrs inputs [ "self" ];
        '';
      }
      # hyperhive.model must be a non-empty string — an empty value causes
      # the harness to pass an invalid model flag to claude.
      {
        assertion = config.hyperhive.model != "";
        message = "hyperhive.model must not be empty (set it to e.g. \"haiku\" or \"sonnet\")";
      }
      # The current model must appear in the quick-picker menu, otherwise the
      # UI would offer no way back to the model the agent is actually running.
      {
        assertion =
          config.hyperhive.availableModels == [ ]
          || builtins.elem config.hyperhive.model config.hyperhive.availableModels;
        message =
          "hyperhive.model (\"${config.hyperhive.model}\") must be one of "
          + "hyperhive.availableModels ([ ${lib.concatStringsSep " " config.hyperhive.availableModels} ]) "
          + "— add it to the list or change the model.";
      }
      # hyperhive.forge.url must look like an HTTP URL when non-default.
      {
        assertion =
          config.hyperhive.forge.url == ""
          || lib.hasPrefix "http://" config.hyperhive.forge.url
          || lib.hasPrefix "https://" config.hyperhive.forge.url;
        message = "hyperhive.forge.url must be an http:// or https:// URL (got: \"${config.hyperhive.forge.url}\")";
      }
      # hyperhive.icon must reference an SVG file when set.
      {
        assertion = config.hyperhive.icon == null || lib.hasSuffix ".svg" (toString config.hyperhive.icon);
        message = "hyperhive.icon must point to an .svg file";
      }
      # Extra matrix accounts only make sense alongside the hive-internal
      # `main` account they extend, which exists only when matrix is
      # enabled.
      {
        assertion = config.hyperhive.matrixAccounts == { } || config.hyperhive.matrix.enable;
        message =
          "hyperhive.matrixAccounts requires hyperhive.matrix.enable = true "
          + "(the extras extend the hive-internal `main` account, which only "
          + "exists when matrix is enabled).";
      }
      # `main` is reserved for the synthesized hive-internal account; a
      # declared extra by that name would silently collide with it.
      {
        assertion = !builtins.hasAttr "main" config.hyperhive.matrixAccounts;
        message =
          "hyperhive.matrixAccounts cannot contain a key named \"main\" "
          + "--- that name is reserved for the hive-internal account.";
      }
      # Token files must land at the `matrix-token*` name the daemon
      # path-watcher globs (`/agents/*/state/matrix-token*`), or the account
      # never gets picked up live (it loads only on a full daemon restart).
      # Enforce the basename prefix so a deviating name (e.g. the historical
      # `matrix-catgirl-token`) is caught at build time, not silently.
      {
        assertion = lib.all (a: lib.hasPrefix "matrix-token" (baseNameOf a.tokenFile)) (
          lib.attrValues config.hyperhive.matrixAccounts
        );
        message =
          "every hyperhive.matrixAccounts.<name>.tokenFile basename must start with "
          + "\"matrix-token\" so the daemon path-watcher glob "
          + "(/agents/*/state/matrix-token*) picks it up live. Offending: "
          + lib.concatStringsSep ", " (
            lib.mapAttrsToList (n: a: "${n}=${baseNameOf a.tokenFile}") (
              lib.filterAttrs (
                _n: a: !lib.hasPrefix "matrix-token" (baseNameOf a.tokenFile)
              ) config.hyperhive.matrixAccounts
            )
          )
          + ".";
      }
      # hyperhive.frontend.extraFiles[*].target is concatenated into
      # $out during the mergedDist build. The option's strMatching
      # type already rejects leading `/`, leading `.`, and the
      # weirder characters; this assertion catches mid-path `..`
      # segments (e.g. `foo/../etc/passwd`) that the type's regex
      # can't easily express without lookahead. agent.nix is
      # operator-reviewed, so this is belt-and-braces — but it's the
      # kind of mistake that's easy to make and hard to spot.
      {
        assertion = lib.all (entry: !(builtins.any (seg: seg == "..") (lib.splitString "/" entry.target))) (
          lib.attrValues config.hyperhive.frontend.extraFiles
        );
        message = ''
          hyperhive.frontend.extraFiles: `target` must not contain
          `..` path segments.
        '';
      }
    ];

    # Per-agent unix user. Runs the hive harness +
    # co-process daemons under a non-root principal. UID auto-assigned by
    # NixOS. The container activation script (hive-agent-user-migrate)
    # chowns the bind-mounted state dir — including credential files
    # written by hive-c0re before the container was built — to this user
    # on every boot, so agent processes can always read their own tokens.
    users.users.${userName} = {
      isNormalUser = true;
      home = homeDir;
      createHome = true;
      group = userName;
      extraGroups = lib.optional config.hyperhive.user.passwordlessSudo "wheel";
      # Matches /bin/bash on NixOS — the harness's claude shell-outs
      # expect a POSIX shell at $SHELL; bashInteractive is already
      # the system default for the root user too (see SHELL env
      # var declaration below).
      shell = pkgs.bashInteractive;
    };
    users.groups.${userName} = { };

    # `NOPASSWD: ALL` for the agent user. Lets claude's Bash tool
    # keep working with anything that expected root (systemctl,
    # nix-env, etc.) without prompting — same surface as the
    # previous root-by-default shape, just elevated explicitly.
    # Flip `hyperhive.user.passwordlessSudo = false` to drop both
    # the wheel-group membership and this sudoers entry; anything
    # that needs root then fails loudly instead of silently
    # succeeding.
    security.sudo.extraRules = lib.mkIf config.hyperhive.user.passwordlessSudo [
      {
        users = [ userName ];
        commands = [
          {
            command = "ALL";
            options = [ "NOPASSWD" ];
          }
        ];
      }
    ];

    # First-boot migration to the per-agent unix user — creates the
    # home dir, chowns the bind-mounted state + `~/.claude/`, and
    # (marker-guarded) moves any leftover `/root/.claude` content
    # from the previous root-run shape. See
    # `docs/persistence.md::First-boot agent-user migration` for the
    # step-by-step rationale; this script implements it.
    system.activationScripts.hive-agent-user-migrate = lib.stringAfter [ "users" "specialfs" ] ''
      homeDir=${lib.escapeShellArg homeDir}
      userName=${lib.escapeShellArg userName}
      mkdir -p "$homeDir"
      chown "$userName:$userName" "$homeDir"
      marker=/var/lib/hive-agent-user-migrated
      if [ ! -e "$marker" ] && [ -d /root/.claude ] && [ "$(ls -A /root/.claude 2>/dev/null)" ]; then
        mkdir -p "$homeDir/.claude"
        if cp -an /root/.claude/. "$homeDir/.claude/" 2>/dev/null; then
          rm -rf /root/.claude
          echo "hive-agent-user-migrate: moved /root/.claude → $homeDir/.claude"
        fi
      fi
      mkdir -p "$(dirname "$marker")"
      : > "$marker"
      # Scope state + harness chowns to THIS container's own dirs only.
      # The glob `/agents/*/state` also matches child-agent state dirs that
      # are bind-mounted into parent containers, which would clobber the
      # ownership those dirs' own activation scripts set — producing
      # intermittent EACCES for the child agent's harness between a parent
      # rebuild and the child's next activation. Config dirs are kept broad
      # because the parent legitimately owns child proposed-config repos.
      if [ -d "/agents/$userName/state" ]; then
        chown -hR "$userName:$userName" "/agents/$userName/state" 2>/dev/null || true
      fi
      if [ -d "/agents/$userName/harness" ]; then
        chown -hR "$userName:$userName" "/agents/$userName/harness" 2>/dev/null || true
      fi
      # The proposed-config repo is RW-mounted into the editing (parent/
      # manager) agent and owned by it; hive-c0re only pulls from it. Heal
      # it to this user too — same as state/harness. In an agent's own
      # container its config is RO-mounted, so the chown there just fails
      # harmlessly (|| true).
      for configDir in /agents/*/config; do
        [ -d "$configDir" ] || continue
        chown -hR "$userName:$userName" "$configDir" 2>/dev/null || true
      done
      if [ -d "$homeDir/.claude" ]; then
        chown -hR "$userName:$userName" "$homeDir/.claude" 2>/dev/null || true
        # 0755 so hive-core (a different unix user) can list the dir and
        # detect a valid claude session. Credential files inside are 0600
        # so secrets stay private regardless of the directory mode.
        # ensure_claude_dir sets 0755 on creation but cannot re-chmod after
        # hive-agent-user-migrate chowns the dir to the agent user; this
        # activation script runs as root and handles the correction.
        chmod 755 "$homeDir/.claude" 2>/dev/null || true
      fi
    '';

    # Auto-inject built-in MCP servers. bash is always present; matrix is
    # conditional on hyperhive.matrix.enable. Both use lib.mkDefault so
    # the operator's own agent.nix can override individual entries.
    hyperhive.extraMcpServers = lib.mkMerge [
      {
        bash = lib.mkDefault {
          command = "${pkgs.hyperhive}/bin/hive-bash-mcp";
          args = [ ];
          env.HIVE_BASH_SOCKET = "/run/hive-bash/socket";
          allowedTools = [ "*" ];
        };
      }
      (lib.mkIf config.hyperhive.matrix.enable {
        matrix = lib.mkDefault {
          command = "${pkgs.hyperhive}/bin/hive-matrix-mcp";
          args = [ ];
          # Same socket path the hive-matrix-daemon service binds
          # via its `RuntimeDirectory = "hive-matrix"`. Keeps the
          # bridge + daemon in sync without baking the path into
          # the Rust default — the env override wins for both.
          env.HIVE_MATRIX_SOCKET = "/run/hive-matrix/socket";
          allowedTools = [ "*" ];
        };
      })
    ];

    environment.etc."hyperhive/extra-mcp.json".text = builtins.toJSON config.hyperhive.extraMcpServers;

    # Operator-set per-agent icon (hyperhive.icon). When configured, the
    # SVG lands at /etc/hyperhive/icon.svg; the harness serves it at
    # GET /icon, falling back to the bundled hyperhive logo when absent.
    environment.etc."hyperhive/icon.svg" = lib.mkIf (config.hyperhive.icon != null) {
      source = config.hyperhive.icon;
    };

    # Cargo `--message-format short` injector. Contributes a `cargo`
    # shell function to `hyperhive._bashEnvFragments`; the bash-env
    # infrastructure below packages that into a single file sourced
    # by both non-interactive and interactive shells.
    # `command cargo …` falls back to the un-wrapped binary in PATH
    # (the rust toolchain's cargo — either from `environment.systemPackages`
    # or from whatever `nix develop` shell the agent's working in).
    hyperhive._bashEnvFragments = lib.mkIf config.hyperhive.cargo.shortMessages ''
      # Auto-injects --message-format short on cargo compile
      # subcommands so per-crate progress lines don't flood
      # claude's context. Bypassed when the caller already passes
      # --message-format (any form).
      cargo() {
        # Strip leading +toolchain selectors (cargo +nightly …).
        local pre=()
        while [ "''${1:0:1}" = "+" ] && [ -n "''${1:-}" ]; do
          pre+=("$1")
          shift
        done
        case "''${1:-}" in
          build|check|clippy|test|run|doc|bench|install|rustc|fix)
            local sub="$1"
            shift
            local arg
            for arg in "$@"; do
              case "$arg" in
                --message-format|--message-format=*)
                  command cargo "''${pre[@]}" "$sub" "$@"
                  return $?
                  ;;
              esac
            done
            command cargo "''${pre[@]}" "$sub" --message-format short "$@"
            ;;
          *)
            command cargo "''${pre[@]}" "$@"
            ;;
        esac
      }
    '';

    # Single bash-env file with all configured shell fragments.
    # Wiring is gated on at least one fragment being active so a
    # fully feature-disabled agent has neither the file nor the
    # `BASH_ENV` / interactive sourcing — zero cost in that case.
    environment.etc."hyperhive/bash-env.sh" = lib.mkIf (config.hyperhive._bashEnvFragments != "") {
      text = config.hyperhive._bashEnvFragments;
    };

    environment.etc."hyperhive/send-allow.json".text =
      builtins.toJSON config.hyperhive.allowedRecipients;

    environment.etc."hyperhive/claude-plugins.json".text =
      builtins.toJSON config.hyperhive.claudePlugins;

    environment.etc."hyperhive/claude-marketplaces.json".text =
      builtins.toJSON config.hyperhive.claudeMarketplaces;

    environment.etc."hyperhive/claude-plugins-auto-update.json".text =
      builtins.toJSON config.hyperhive.claudePluginsAutoUpdate;

    # Merged frontend static tree. Base = `${frontend.dist}/agent/`,
    # then each `extraFiles` entry is laid on top at its `target`
    # path. The runCommand derivation aborts on overwrite so a
    # filename collision with the default dist surfaces as a build
    # failure rather than a silent override (operator gets a clear
    # nix error rather than a confusing 404 / silent dist swap).
    hyperhive.frontend.mergedDist = pkgs.runCommand "hyperhive-agent-frontend-merged" { } (
      ''
        mkdir -p $out
        cp -r ${config.hyperhive.frontend.dist}/agent/. $out/
        chmod -R u+w $out
      ''
      + lib.concatMapStrings (entry: ''
        mkdir -p $(dirname $out/${entry.target})
        if [ -e $out/${entry.target} ]; then
          echo "hyperhive.frontend.extraFiles: refusing to overwrite existing path '${entry.target}' in the default dist" >&2
          exit 1
        fi
        cp -r ${entry.source} $out/${entry.target}
      '') (lib.attrValues config.hyperhive.frontend.extraFiles)
    );

    # HIVE_DEFAULT_MODEL seeds the initial model selection when no persisted
    # model choice exists in the state dir. SHELL must be set so claude's
    # Bash tool finds a POSIX shell.
    # HIVE_ASSETS_DIR points at the project's static runtime assets
    # (branding + claude prompts; see `nix/assets.nix`). Set here so
    # both the harness binary and any user-shell `cargo run` inside the
    # container resolve them from the same path.
    # HIVE_CONTEXT_WINDOW_TOKENS_* are injected by the meta flake from the
    # host-level `services.hyperhive.c0re.contextWindowTokens` option — not set here.
    environment.variables = {
      HIVE_DEFAULT_MODEL = config.hyperhive.model;
      # HIVE_AVAILABLE_MODELS is the comma-separated menu for the per-agent
      # UI model quick-picker (see hyperhive.availableModels). The harness
      # surfaces it to the frontend; an empty value falls back to the
      # built-in default list.
      HIVE_AVAILABLE_MODELS = lib.concatStringsSep "," config.hyperhive.availableModels;
      # HIVE_DEFAULT_EFFORT is the per-agent baseline effort (see
      # hyperhive.effortLevel). The harness resolves operator-override-file
      # → this env → "medium" and passes it to claude --effort at turn launch.
      HIVE_DEFAULT_EFFORT = config.hyperhive.effortLevel;
      HIVE_ASSETS_DIR = "${pkgs.hyperhive-assets}/share/hyperhive";
      SHELL = "${pkgs.bashInteractive}/bin/bash";
    }
    // lib.optionalAttrs (!config.hyperhive.autoCompact) {
      # Zero watermark disables proactive compaction; the reactive path
      # (compact-on-overflow) still fires when the session is truly full.
      HIVE_COMPACT_WATERMARK_TOKENS = "0";
    }
    // lib.optionalAttrs config.hyperhive.forge.keepSubscriptions {
      HIVE_FORGE_KEEP_SUBSCRIPTIONS = "1";
    }
    // lib.optionalAttrs (config.hyperhive.forge.skipNotifyReasons != [ ]) {
      HIVE_FORGE_NOTIFY_SKIP_REASONS = lib.concatStringsSep "," config.hyperhive.forge.skipNotifyReasons;
    }
    // lib.optionalAttrs (config.hyperhive._bashEnvFragments != "") {
      # Non-interactive bash invocations (claude's `Bash` tool runs
      # `bash -c`) source $BASH_ENV at startup — drops every active
      # feature hook's snippet into scope without touching
      # `/etc/profile` (login-only). Interactive shells source the
      # same file via the `interactiveShellInit` hook below so
      # behaviour matches across both modes.
      BASH_ENV = "/etc/hyperhive/bash-env.sh";
    };

    # Interactive shells don't honour BASH_ENV — wire the same file
    # in via the bashrc hook so operator SSH sessions get the same
    # hook surface as claude's non-interactive calls. Gated on at
    # least one fragment being active so we don't write a no-op
    # source line into `/etc/bashrc` on fully-feature-disabled agents.
    programs.bash.interactiveShellInit = lib.mkIf (config.hyperhive._bashEnvFragments != "") ''
      if [ -r /etc/hyperhive/bash-env.sh ]; then
        . /etc/hyperhive/bash-env.sh
      fi
    '';

    boot.isNspawnContainer = true;

    # Every agent gets flakes + the modern `nix` CLI out of the box.
    # Equivalent to passing `--extra-experimental-features 'nix-command
    # flakes'` on every invocation. Agents shell out to `nix build` /
    # `nix flake` constantly (devshells, ad-hoc evals, fetching their
    # own MCP-server flakes); without this they hit the "experimental
    # feature not enabled" wall on the first try.
    nix.settings.experimental-features = [
      "nix-command"
      "flakes"
    ];

    # `lib.mkForce` overrides nixpkgs's normal-priority `false` so
    # in-container `nix build` invocations fall back to unsandboxed
    # local builds rather than failing on the missing user-namespace.
    # See `docs/gotchas.md::Containerized nix-daemon needs
    # sandbox-fallback = true` + `docs/security.md` for the rationale.
    nix.settings.sandbox-fallback = lib.mkForce true;

    # `claude-code` is unfree. Each per-agent container's nixosConfiguration
    # evaluates its own `nixpkgs` instance, so the operator's host-level
    # `nixpkgs.config.allowUnfreePredicate` does not propagate into here —
    # we have to allow it inside the container's config as well.
    nixpkgs.config.allowUnfreePredicate = pkg: builtins.elem (pkgs.lib.getName pkg) [ "claude-code" ];

    environment.systemPackages = with pkgs; [
      hyperhive
      claude-code
      bashInteractive
      coreutils-full
      # procps for pkill — used by the web UI's /api/cancel to SIGINT the
      # in-flight claude turn.
      procps
      # tea: gitea/forgejo CLI client. Configured at boot by the
      # tea-login oneshot below if /state/forge-token is present, so
      # claude can `tea repos create`, `tea pulls create`, etc.
      tea
      # jq: JSON processing in shell — useful for parsing API responses,
      # forge REST calls, sqlite output, etc.
      jq
      # curl: HTTP client for forge REST API and other web requests.
      curl
      # hive-forge <verb>: CLI wrapping common Forgejo REST API operations
      # (view, pr, issue, comment, assign, close, labels, branches, etc.)
      (pkgs.callPackage ../packages/hive-forge-tools.nix { })
    ];

    # One-shot: tea config.yml from the seeded forge token. Shape
    # contract (always exit 0, no set -e, skip-silently, re-runnable):
    # docs/conventions.md::Best-effort oneshot services.
    # Take resolvconf + dhcpcd out of the /etc/resolv.conf loop so the
    # bridge resolver the oneshot below writes actually sticks. At their
    # NixOS defaults, resolvconf regenerates resolv.conf from host-tracking
    # *after* the oneshot has pointed it at the bridge (dhcpcd re-triggers
    # that when the veth comes up under isolation) — silently clobbering the
    # bridge nameserver back to the host resolver, which isn't authoritative
    # for the hive's own zones, so `forge.<domain>` stops resolving. We
    # disable resolvconf and tell dhcpcd not to touch resolv.conf (without
    # disabling dhcpcd itself, so the veth still gets its address); then
    # whoever wrote resolv.conf last owns it: the nixos-container host-copy
    # in shared netns, or the oneshot in isolated mode. (Same "take
    # resolvconf out of the loop" approach the matrix container uses.)
    networking.resolvconf.enable = false;
    networking.dhcpcd.extraConfig = "nohook resolv.conf";

    # Point resolv.conf at the hive bridge resolver when the container is
    # network-isolated. nixos-container copies the *host's* /etc/resolv.conf
    # into the container at every start — but the host resolver (e.g.
    # 127.0.0.53) is unreachable from a private netns and isn't
    # authoritative for the hive's own zones (forge.<domain> etc.). The
    # bridge dnsmasq (gateway IP) is. hive-priv drops the marker
    # `/etc/hyperhive-bridge-dns` (containing the gateway IP) only when
    # isolation is on, so this oneshot is inert in shared-netns mode — the
    # same shared container toplevel does the right thing in both modes.
    # Ordered before the first DNS consumer (tea-login) and the network
    # targets so name resolution works for the very first turn.
    systemd.services.hyperhive-isolated-dns = {
      description = "point resolv.conf at the hive bridge resolver (isolated containers)";
      wantedBy = [ "multi-user.target" ];
      after = [ "local-fs.target" ];
      # Ordered before every network consumer that does DNS on first
      # boot. `hive-ag3nt` (the harness) is the load-bearing one: its
      # first-turn api.anthropic.com lookup must not race the resolv.conf
      # rewrite (it only declares `after network.target`, so without this
      # edge the harness can start before we've fixed resolv.conf and the
      # first turn errors — self-heals next turn, but better not to flap).
      # `hive-matrix-daemon` likewise syncs over the network; the `before`
      # is a harmless no-op when matrix is disabled (the unit is absent).
      before = [
        "network-online.target"
        "tea-login.service"
        "hive-ag3nt.service"
        "hive-matrix-daemon.service"
      ];
      unitConfig.ConditionPathExists = "/etc/hyperhive-bridge-dns";
      serviceConfig = {
        Type = "oneshot";
        RemainAfterExit = true;
      };
      path = [ pkgs.coreutils ];
      script = ''
        set -eu
        gw=$(tr -d '[:space:]' < /etc/hyperhive-bridge-dns)
        if [ -z "$gw" ]; then
          echo "hyperhive-isolated-dns: empty marker; leaving resolv.conf as-is"
          exit 0
        fi
        # resolv.conf is a regular file copied from the host by
        # nixos-container; replace it (rm first in case it's a symlink).
        rm -f /etc/resolv.conf
        printf 'nameserver %s\n' "$gw" > /etc/resolv.conf
        echo "hyperhive-isolated-dns: resolv.conf -> nameserver $gw"
      '';
    };

    systemd.services.tea-login = {
      description = "configure tea CLI from hive-forge token (best-effort)";
      wantedBy = [ "multi-user.target" ];
      after = [ "local-fs.target" ];
      serviceConfig = {
        Type = "oneshot";
        RemainAfterExit = true;
      };
      path = [
        pkgs.curl
        pkgs.python3
        pkgs.coreutils
      ];
      environment.HOME_DIR = homeDir;
      environment.AGENT_USER = userName;
      script = ''
                # No `set -e`: best-effort posture (see docs pointer above).
                FORGE_URL=${lib.escapeShellArg config.hyperhive.forge.url}
                # $HYPERHIVE_STATE_DIR is system-wide via the meta flake.
                TOKEN_FILE="$HYPERHIVE_STATE_DIR/forge-token"
                if [ ! -f "$TOKEN_FILE" ]; then
                  echo "tea-login: no forge-token at $TOKEN_FILE; skipping"
                  exit 0
                fi
                TOKEN=$(cat "$TOKEN_FILE")
                # Resolve the agent username from the forge API.
                USER=$(curl -sf --max-time 5 \
                  -H "Authorization: token $TOKEN" \
                  "$FORGE_URL/api/v1/user" \
                  | python3 -c 'import sys,json; print(json.load(sys.stdin).get("login",""))' \
                  2>/dev/null || true)
                if [ -z "$USER" ]; then
                  echo "tea-login: could not resolve username from forge API; skipping"
                  exit 0
                fi
                # Config under the agent user's home, chown'd to them;
                # service stays root-owned (see docs pointer above).
                CONFIG="$HOME_DIR/.config/tea/config.yml"
                mkdir -p "$(dirname "$CONFIG")" || true
                cat > "$CONFIG" << EOF
        logins:
            - name: forge
              url: $FORGE_URL
              token: $TOKEN
              default: true
              ssh_host: ""
              ssh_key: ""
              insecure: false
              ssh_agent: false
              user: $USER
        preferences:
            editor: false
            flag_defaults:
                remote: ""
        EOF
                chown -R "$AGENT_USER:$AGENT_USER" "$HOME_DIR/.config" 2>/dev/null || true
                echo "tea-login: configured for $FORGE_URL as $USER (config at $CONFIG)"
      '';
    };

    # Path-trigger sibling: re-fires forge-avatar-sync the moment
    # `<state>/forge-token` appears. Mirrors the matrix-avatar-sync
    # pattern — on first agent deployment the container boots before
    # hive-c0re has provisioned the forge-token, so the service fires
    # too early and exits with "no forge-token found". Without this path
    # unit, RemainAfterExit=true would prevent systemd from ever
    # re-running the service. See docs/persistence.md::forge-avatar-sync.
    systemd.paths.forge-avatar-sync = {
      description = "trigger forge-avatar-sync when forge-token appears";
      wantedBy = [ "multi-user.target" ];
      pathConfig.PathExistsGlob = "/agents/*/state/forge-token";
    };

    # One-shot: hyperhive.icon → Forgejo profile avatar. Shape contract:
    # docs/conventions.md::Best-effort oneshot services.
    # RemainAfterExit = false (unlike the old true) so the .path trigger
    # above can re-fire this unit when the forge-token arrives after boot.
    systemd.services.forge-avatar-sync = {
      description = "sync agent icon to Forgejo user avatar (best-effort)";
      wantedBy = [ "multi-user.target" ];
      after = [ "tea-login.service" ];
      serviceConfig = {
        Type = "oneshot";
        RemainAfterExit = false;
      };
      path = [
        pkgs.curl
        pkgs.coreutils
        pkgs.jq
        pkgs.librsvg
      ];
      script = ''
        ICON=/etc/hyperhive/icon.svg
        if [ ! -f "$ICON" ]; then
          echo "forge-avatar-sync: no icon configured; skipping"
          exit 0
        fi
        FORGE_URL=${lib.escapeShellArg config.hyperhive.forge.url}
        # $HYPERHIVE_STATE_DIR is set system-wide by the meta flake
        # (systemd.globalEnvironment) to `/agents/<name>/state`.
        TOKEN_FILE="$HYPERHIVE_STATE_DIR/forge-token"
        if [ ! -f "$TOKEN_FILE" ]; then
          echo "forge-avatar-sync: no forge-token found; skipping"
          exit 0
        fi
        TOKEN=$(cat "$TOKEN_FILE")
        # Rasterize SVG → PNG (Forgejo's Go image library can't decode SVG).
        PNG=$(mktemp --suffix=.png)
        if ! rsvg-convert -f png -w 512 -h 512 "$ICON" -o "$PNG" 2>/dev/null; then
          echo "forge-avatar-sync: rsvg-convert failed; skipping"
          rm -f "$PNG"
          exit 0
        fi
        IMAGE=$(base64 -w 0 < "$PNG")
        rm -f "$PNG"
        # Forgejo POST /user/avatar expects {"image":"<base64>"} — just the
        # raw base64 string, NOT a data URI (data:image/png;base64,...).
        # Use jq to build the payload so the large base64 value is safely quoted.
        PAYLOAD=$(jq -n --arg img "$IMAGE" '{image:$img}')
        RESP=$(curl -sf --max-time 10 \
          -X POST "$FORGE_URL/api/v1/user/avatar" \
          -H "Authorization: token $TOKEN" \
          -H "Content-Type: application/json" \
          -d "$PAYLOAD" \
          -w "\n%{http_code}" 2>/dev/null || true)
        CODE=$(printf '%s' "$RESP" | tail -1)
        if [ "$CODE" = "204" ] || [ "$CODE" = "200" ]; then
          echo "forge-avatar-sync: avatar uploaded (HTTP $CODE)"
        else
          echo "forge-avatar-sync: upload returned HTTP $CODE — skipping (non-fatal)"
        fi
      '';
    };

    # Long-running matrix-sdk client + sync per agent. Holds the unix
    # socket the stdio `hive-matrix-mcp` bridge connects to + emits
    # hyperhive wake signals on incoming room events via
    # `/run/hive/mcp.sock`. See
    # `docs/persistence.md::Matrix per-agent daemon + token-arrival
    # trigger` for the socket-path / first-boot-ordering rationale.
    systemd.services.hive-matrix-daemon = lib.mkIf config.hyperhive.matrix.enable {
      description = "long-running matrix-sdk Client + MCP daemon socket";
      wantedBy = [ "multi-user.target" ];
      after = [ "network-online.target" ];
      wants = [ "network-online.target" ];
      environment = {
        HIVE_MATRIX_SOCKET = "/run/hive-matrix/socket";
        RUST_LOG = "info";
      }
      # Homeserver URL: by default the daemon inherits the host-forwarded
      # HIVE_MATRIX_URL (set isolation-aware by hive-c0re: `matrix.<domain>`
      # via the gateway under private-netns isolation, loopback otherwise),
      # falling back to the daemon's built-in localhost default if the
      # forward is absent. A per-agent `hyperhive.matrix.url` override
      # (non-default) is set unit-level so it wins over the forwarded value;
      # at the default we deliberately DON'T set it so the forwarded
      # isolation-aware value isn't shadowed.
      // lib.optionalAttrs (config.hyperhive.matrix.url != matrixUrlDefault) {
        HIVE_MATRIX_URL = config.hyperhive.matrix.url;
      }
      # Multi-account: serialize the *extra* accounts to the JSON the
      # daemon parses (`accounts::configured`). Only set when extras are
      # declared; the daemon always synthesizes the primary `main`
      # (hive-internal) account itself from the per-agent paths and
      # prepends it, so we emit extras only. Each entry is in the
      # daemon's `AccountCfg` serde shape: name (the attr key) /
      # token_file / state_dir / optional homeserver.
      // lib.optionalAttrs (config.hyperhive.matrixAccounts != { }) {
        HIVE_MATRIX_ACCOUNTS = builtins.toJSON (
          lib.mapAttrsToList (
            name: a:
            {
              inherit name;
              token_file = a.tokenFile;
              state_dir = a.sessionDir;
            }
            // lib.optionalAttrs (a.homeserver != null) { inherit (a) homeserver; }
          ) config.hyperhive.matrixAccounts
        );
      };
      serviceConfig = {
        ExecStart = "${pkgs.hyperhive}/bin/hive-matrix-daemon";
        Restart = "on-failure";
        RestartSec = 5;
        User = userName;
        Group = userName;
        RuntimeDirectory = "hive-matrix";
        # Keep /run/hive-matrix across restarts. With the default
        # `RuntimeDirectoryPreserve=no`, a `switch-to-configuration`
        # restart races the outgoing instance's stop-time cleanup
        # (which deletes the dir) against the incoming instance's
        # start (which creates it + binds the socket inside it). The
        # cleanup can win and delete the dir out from under the fresh
        # daemon, which then fails to mkdir under root-owned /run and
        # exits — looping on Restart=on-failure until the next boot.
        # `yes` stops systemd removing it on stop; it still creates it
        # on first start, and it lives on tmpfs so it's gone at
        # container reboot regardless. See hive-bash-daemon below.
        RuntimeDirectoryPreserve = "yes";
      };
    };

    # Bash task runner daemon — long-running process that owns subprocess
    # monitoring + completion wake signals. Always enabled (every agent
    # needs bash tools). The stdio MCP bridge `hive-bash-mcp` connects
    # to this daemon's socket per turn.
    # Socket dir: /run/hive-bash/ — RuntimeDirectory keeps it on tmpfs.
    systemd.services.hive-bash-daemon = {
      description = "bash task runner daemon for hive-bash-mcp";
      wantedBy = [ "multi-user.target" ];
      # The daemon runs every bash task via `Command::new("bash")` and the
      # commands themselves (hive-forge, git, jq, …) resolve from PATH.
      # Pre-split this ran inside hive-ag3nt.service and inherited the
      # agent's PATH; the standalone daemon needs the same or `bash` itself
      # isn't found (spawn fails with ENOENT, the task is marked done in
      # 0s with no output / no .out/.err). Mirror the harness unit's PATH:
      # NixOS appends `/bin` to each entry → /run/wrappers/bin (setuid
      # sudo) + /run/current-system/sw/bin (bash, coreutils, hive-forge, …).
      path = [
        "/run/wrappers"
        "/run/current-system/sw"
      ];
      environment = {
        HIVE_BASH_SOCKET = "/run/hive-bash/socket";
        HIVE_CONTROL_SOCKET = "/run/hive/mcp.sock";
        RUST_LOG = "info";
        # HYPERHIVE_HARNESS_DIR and HYPERHIVE_STATE_DIR are already
        # injected via systemd.globalEnvironment by the meta flake
        # (set to /agents/<name>/harness and /agents/<name>/state
        # respectively). Listed here for explicitness — the daemon
        # uses these to derive its task + loose-ends dir paths.
        # Without them the daemon falls back to deriving harness/ as a
        # sibling of state/, which produces the same value but is
        # less robust if the two vars ever diverge.
      };
      serviceConfig = {
        ExecStart = "${pkgs.hyperhive}/bin/hive-bash-daemon";
        Restart = "on-failure";
        RestartSec = 3;
        User = userName;
        Group = userName;
        RuntimeDirectory = "hive-bash";
        # See the matching note on hive-matrix-daemon. Without this, a
        # post-rebuild restart races stop-time dir cleanup against the
        # fresh daemon's socket-dir creation; the daemon loses, fails
        # `mkdir /run/hive-bash` (Permission denied, non-root in /run),
        # and loops on Restart=on-failure until the next container
        # boot — i.e. the bash daemon "doesn't come up post-rebuild".
        RuntimeDirectoryPreserve = "yes";
      };
    };

    # Re-fire the daemon when the matrix token appears (hive-c0re
    # provisions it after agent containers come up). Without this
    # the daemon would exit 0 silently on first boot and the MCP
    # would have no backend until next restart. See
    # `docs/persistence.md` (same section as above).
    systemd.paths.hive-matrix-daemon = lib.mkIf config.hyperhive.matrix.enable {
      description = "trigger hive-matrix-daemon when a matrix token appears";
      wantedBy = [ "multi-user.target" ];
      # `matrix-token*` (not just `matrix-token`) so a secondary
      # multi-account token (e.g. `matrix-token-ccc`) landing also
      # re-fires the daemon to pick up the freshly-provisioned account.
      pathConfig.PathExistsGlob = "/agents/*/state/matrix-token*";
    };

    # Path-trigger sibling: re-fires matrix-avatar-sync the moment
    # `<state>/matrix-token` appears. Same first-boot-ordering pattern
    # as hive-matrix-daemon above.
    systemd.paths.matrix-avatar-sync = {
      description = "trigger matrix-avatar-sync when matrix-token appears";
      wantedBy = [ "multi-user.target" ];
      pathConfig.PathExistsGlob = "/agents/*/state/matrix-token";
    };

    # One-shot: hyperhive.icon → matrix profile avatar (two-step media
    # upload + set avatar_url). Shape contract:
    # docs/conventions.md::Best-effort oneshot services. Protocol +
    # why RemainAfterExit = false:
    # docs/persistence.md::matrix-avatar-sync.
    systemd.services.matrix-avatar-sync = {
      description = "sync agent icon to matrix profile avatar (best-effort)";
      wantedBy = [ "multi-user.target" ];
      # No `after = [ "tea-login.service" ]` — matrix has no
      # equivalent prerequisite; we just need the homeserver up.
      serviceConfig = {
        Type = "oneshot";
        # RemainAfterExit = false so the .path trigger can re-fire
        # the unit (see docs/persistence.md::matrix-avatar-sync).
        RemainAfterExit = false;
      };
      path = [
        pkgs.curl
        pkgs.coreutils
        pkgs.jq
        pkgs.librsvg
      ];
      script = ''
        ICON=/etc/hyperhive/icon.svg
        if [ ! -f "$ICON" ]; then
          echo "matrix-avatar-sync: no icon configured; skipping"
          exit 0
        fi
        # Token written by `hive-c0re::matrix::ensure_user_for` to the
        # agent's bind-mounted state dir. $HYPERHIVE_STATE_DIR is set
        # system-wide by the meta flake (systemd.globalEnvironment) to
        # `/agents/<name>/state`.
        TOKEN_FILE="$HYPERHIVE_STATE_DIR/matrix-token"
        if [ ! -f "$TOKEN_FILE" ]; then
          echo "matrix-avatar-sync: no matrix-token at $TOKEN_FILE; skipping"
          exit 0
        fi
        # Hash-based idempotency: skip the upload if the icon hasn't
        # changed since the last successful sync. Every upload mints a
        # new mxc:// URI which triggers a profile state event in every
        # joined room — uploading the same bytes again produces timeline
        # spam without changing the visible avatar. The hash file lives
        # in $HYPERHIVE_STATE_DIR (survives restart, wiped on purge so
        # purge + re-provision gets a fresh upload). Delete to force
        # re-upload.
        HASH_FILE="$HYPERHIVE_STATE_DIR/matrix-avatar-icon-hash"
        CURRENT_HASH=$(sha256sum "$ICON" | cut -d' ' -f1)
        if [ -f "$HASH_FILE" ] && [ "$(cat "$HASH_FILE" 2>/dev/null)" = "$CURRENT_HASH" ]; then
          echo "matrix-avatar-sync: icon unchanged (hash matches); skipping"
          exit 0
        fi
        TOKEN=$(cat "$TOKEN_FILE")
        # Local tuwunel reachable on shared host netns at the
        # default matrix-spec port. Override via
        # `hyperhive.matrix.url` if the operator runs the
        # homeserver elsewhere.
        MATRIX_URL=http://localhost:8008
        # whoami → user_id. Needed to scope the avatar set call.
        # Tolerant of the homeserver being unreachable (`-f` makes
        # curl fail on 4xx/5xx; `|| true` swallows the exit).
        USER_ID=$(curl -sf --max-time 5 \
          -H "Authorization: Bearer $TOKEN" \
          "$MATRIX_URL/_matrix/client/v3/account/whoami" 2>/dev/null \
          | jq -r '.user_id // empty' || true)
        if [ -z "$USER_ID" ]; then
          echo "matrix-avatar-sync: whoami failed or homeserver unreachable; skipping"
          exit 0
        fi
        # Rasterize SVG → PNG (matrix media accepts any image type
        # but we already standardise on PNG for the forge sync).
        PNG=$(mktemp --suffix=.png)
        if ! rsvg-convert -f png -w 512 -h 512 "$ICON" -o "$PNG" 2>/dev/null; then
          echo "matrix-avatar-sync: rsvg-convert failed; skipping"
          rm -f "$PNG"
          exit 0
        fi
        # Step 1: upload bytes → mxc:// URI.
        MXC=$(curl -sf --max-time 10 \
          -X POST "$MATRIX_URL/_matrix/media/v3/upload" \
          -H "Authorization: Bearer $TOKEN" \
          -H "Content-Type: image/png" \
          --data-binary "@$PNG" 2>/dev/null \
          | jq -r '.content_uri // empty' || true)
        rm -f "$PNG"
        if [ -z "$MXC" ]; then
          echo "matrix-avatar-sync: media upload failed; skipping"
          exit 0
        fi
        # Step 2: set avatar_url on the profile.
        PAYLOAD=$(jq -n --arg url "$MXC" '{avatar_url:$url}')
        CODE=$(curl -s --max-time 10 \
          -X PUT "$MATRIX_URL/_matrix/client/v3/profile/$USER_ID/avatar_url" \
          -H "Authorization: Bearer $TOKEN" \
          -H "Content-Type: application/json" \
          -d "$PAYLOAD" \
          -o /dev/null -w "%{http_code}" 2>/dev/null || true)
        if [ "$CODE" = "200" ]; then
          echo "matrix-avatar-sync: avatar set on $USER_ID"
          # Persist hash so subsequent runs skip the upload when the
          # icon hasn't changed.
          echo "$CURRENT_HASH" > "$HASH_FILE"
        else
          echo "matrix-avatar-sync: avatar PUT returned HTTP $CODE — skipping (non-fatal)"
        fi
      '';
    };

    # Write declared dashboardLinks to the state dir so hive-c0re can
    # read them without accessing the container's /etc/ from the host.
    # Best-effort oneshot (always exit 0):
    # docs/conventions.md::Best-effort oneshot services.
    systemd.services.hive-dashboard-links = lib.mkIf (config.hyperhive.dashboardLinks != [ ]) {
      description = "write declarative dashboardLinks to agent state dir";
      wantedBy = [ "multi-user.target" ];
      serviceConfig = {
        Type = "oneshot";
        RemainAfterExit = true;
      };
      environment.LINKS_JSON = builtins.toJSON config.hyperhive.dashboardLinks;
      script = ''
        # Sub-agents have their state dir bind-mounted at /agents/<name>/state.
        # Use a glob — exactly one match per container at runtime.
        STATE_DIR=$(echo /agents/*/state)
        if [ ! -d "$STATE_DIR" ]; then
          echo "hive-dashboard-links: no state dir found at /agents/*/state; skipping"
          exit 0
        fi
        printf '%s' "$LINKS_JSON" > "$STATE_DIR/hyperhive-dashboard-links.json"
        echo "hive-dashboard-links: wrote $(printf '%s' "$LINKS_JSON" | wc -c) bytes to $STATE_DIR/hyperhive-dashboard-links.json"
      '';
    };

    # Git is needed by claude's Bash tool (for the agent <-> manager config
    # request flow) and by hive-c0re's own setup_applied / setup_proposed.
    # The per-agent `applied/<name>/flake.nix` overrides `user.name` and
    # `user.email` with the agent's identity — values here are `mkDefault`
    # so the per-agent override wins without needing `mkForce`.
    programs.git = {
      enable = true;
      config = {
        user = {
          name = lib.mkDefault "hyperhive";
          email = lib.mkDefault "hyperhive@local";
        };
        init.defaultBranch = lib.mkDefault "main";
      };
    };

    # Harness systemd unit. Unit shape (PATH wrapper-dir trick, env vars,
    # RuntimeDirectory, User=, standalone-eval fallbacks):
    # docs/agent-hierarchy.md::Harness systemd unit shape. PATH /bin
    # auto-append behaviour: docs/gotchas.md::systemd.services.*.path
    # appends /bin to every entry.
    systemd.services.hive-ag3nt =
      let
        binary = "hive";
      in
      {
        description = "${binary} harness";
        wantedBy = [ "multi-user.target" ];
        after = [ "network.target" ];
        # `/run/wrappers` before `/run/current-system/sw` so setuid
        # `sudo` resolves first. Passing the bare prefixes (no trailing
        # `/bin`) is intentional — see docs pointer above.
        path = [
          "/run/wrappers"
          "/run/current-system/sw"
        ];
        environment = {
          SHELL = "${pkgs.bashInteractive}/bin/bash";
          HOME = homeDir;
          HIVE_STATIC_DIR = "${config.hyperhive.frontend.mergedDist}";
          HIVE_ASSETS_DIR = "${pkgs.hyperhive-assets}/share/hyperhive";
          # Unix-socket path for the harness web UI. All agents always bind
          # here; TCP fallback is removed. Path matches
          # `hive_c0re::agent_sockets::socket_path_for(name)` so lifecycle
          # bind-mounts and gateway upstream config stay in sync.
          HIVE_WEB_SOCKET = "/run/hive-agent/${userName}/web.sock";
        };
        serviceConfig = {
          ExecStart = "${pkgs.hyperhive}/bin/${binary} serve";
          Restart = "on-failure";
          RestartSec = 2;
          # Per-service runtime dir owned by `User=` below; the harness
          # writes its regenerated claude-{mcp-config,settings,system-prompt}
          # files here (`paths::config_dir`). Separate from /run/hive,
          # which holds hive-c0re's mcp.sock.
          RuntimeDirectory = "hive-config";
          User = userName;
          Group = userName;
        };
      };

    system.stateVersion = "25.11";
  };
}