diff --git a/docs/sourceos-shell-integration.md b/docs/sourceos-shell-integration.md
index 50059b3..34f4985 100644
--- a/docs/sourceos-shell-integration.md
+++ b/docs/sourceos-shell-integration.md
@@ -11,6 +11,7 @@ This repository, `source-os`, carries the Linux realization surfaces required to
 - Nix/NixOS modules
 - profile wiring
 - machine-level integration hooks
+- derive-service runtime integration such as `docd`
 
 ## What does not belong here
 
diff --git a/docs/sourceos-shell-launcher-bridge.md b/docs/sourceos-shell-launcher-bridge.md
new file mode 100644
index 0000000..87287df
--- /dev/null
+++ b/docs/sourceos-shell-launcher-bridge.md
@@ -0,0 +1,28 @@
+# sourceos-shell launcher bridge note
+
+During the early shell rollout, launcher integration is tracked as temporary bridge work.
+
+## Routing rule
+
+Queries are routed by scope:
+
+- `apps` -> launcher or desktop-entry provider
+- `files` -> Linux-native file search only
+- `web` -> browser or web agent
+
+## Required invariant
+
+For `files` queries, Albert must not perform a second file-search pass in parallel with the Linux-native provider.
+
+## Realization scaffolds
+
+The Linux realization currently carries placeholder search-provider material at:
+
+- `linux/desktop/sourceos-search-provider.conf`
+- `/etc/sourceos-shell/search-provider.json` (realized by the shell Nix module scaffold)
+
+These capture the intended rollout mode and the provider choice for the Linux-native file search lane.
+
+## Lifecycle
+
+This bridge exists only until the shell's own command/search surface fully absorbs the routing behavior.
diff --git a/docs/sourceos-shell-service-graph.md b/docs/sourceos-shell-service-graph.md
new file mode 100644
index 0000000..e7df946
--- /dev/null
+++ b/docs/sourceos-shell-service-graph.md
@@ -0,0 +1,30 @@
+# sourceos-shell service graph note
+
+The Linux realization layer currently models the `sourceos-shell` runtime as a four-service graph:
+
+- `sourceos-shell`
+- `sourceos-router`
+- `sourceos-pdf-secure`
+- `sourceos-docd`
+
+These services are grouped by the `sourceos-shell.target` scaffold.
+
+## Intent
+
+This target is a Linux realization placeholder that captures the expected runtime grouping before the actual product/runtime repo exists.
+
+## Validation scaffold
+
+The current Linux realization adds a dedicated contract-style check at:
+
+- `tests/sourceos-shell-service-graph-contract.nix`
+
+This check verifies that:
+
+- `sourceos-shell.target` exists
+- the four runtime scaffold services are grouped beneath that target
+- the Nix module expresses the target and `partOf` relationships consistently
+
+## Follow-on
+
+Once `SourceOS-Linux/sourceos-shell` exists, the placeholder ExecStart values should be replaced with real package/service paths and the current scaffold checks should be upgraded into actual runtime/service-graph checks.
diff --git a/flake.nix b/flake.nix
index d06647a..18933e7 100644
--- a/flake.nix
+++ b/flake.nix
@@ -299,6 +299,7 @@
           mesh-package-contract = import ./tests/mesh-package-contract.nix { inherit pkgs; };
           mesh-host-runtime-contract = import ./tests/mesh-host-runtime-contract.nix { inherit pkgs; };
           sourceos-shell-module-contract = import ./tests/sourceos-shell-module-contract.nix { inherit pkgs; };
+ 
           sourceos-shell-pdf-stack-contract = import ./tests/sourceos-shell-pdf-stack-contract.nix { inherit pkgs; };
           sourceos-shell-pdf-config-contract = import ./tests/sourceos-shell-pdf-config-contract.nix { inherit pkgs; };
 
diff --git a/linux/desktop/sourceos-keyboard-equivalence.conf b/linux/desktop/sourceos-keyboard-equivalence.conf
new file mode 100644
index 0000000..0576111
--- /dev/null
+++ b/linux/desktop/sourceos-keyboard-equivalence.conf
@@ -0,0 +1,23 @@
+# SourceOS shell keyboard-equivalence scaffold
+# Transitional Mac-on-Linux shortcut model.
+
+mode=kinto-bridge
+platform-model=mac-like
+terminal-model=mac-terminal-like
+
+# GUI lanes
+copy=Cmd-C
+paste=Cmd-V
+tab-next=Cmd-Shift-]
+tab-prev=Cmd-Shift-[
+window-switch=Cmd-Tab
+launcher=Cmd-Space
+
+# Terminal lanes
+interrupt=Ctrl-C
+terminal-copy=Cmd-C
+terminal-paste=Cmd-V
+word-left=Alt-Left
+word-right=Alt-Right
+
+invariant=gui_terminal_split_explicit
diff --git a/linux/systemd/sourceos-shell.target b/linux/systemd/sourceos-shell.target
new file mode 100644
index 0000000..d3a2937
--- /dev/null
+++ b/linux/systemd/sourceos-shell.target
@@ -0,0 +1,4 @@
+[Unit]
+Description=SourceOS shell service graph
+Wants=sourceos-shell.service sourceos-router.service sourceos-pdf-secure.service sourceos-docd.service
+After=network-online.target
diff --git a/tests/sourceos-shell-keyboard-equivalence-contract.nix b/tests/sourceos-shell-keyboard-equivalence-contract.nix
new file mode 100644
index 0000000..481fe64
--- /dev/null
+++ b/tests/sourceos-shell-keyboard-equivalence-contract.nix
@@ -0,0 +1,14 @@
+{ pkgs ? import <nixpkgs> {} }:
+pkgs.runCommand "sourceos-shell-keyboard-equivalence-contract" {
+  nativeBuildInputs = [ pkgs.gnugrep ];
+} ''
+  test -f ${../linux/desktop/sourceos-keyboard-equivalence.conf}
+  grep -q 'mode=kinto-bridge' ${../linux/desktop/sourceos-keyboard-equivalence.conf}
+  grep -q 'platform-model=mac-like' ${../linux/desktop/sourceos-keyboard-equivalence.conf}
+  grep -q 'terminal-model=mac-terminal-like' ${../linux/desktop/sourceos-keyboard-equivalence.conf}
+  grep -q '# GUI lanes' ${../linux/desktop/sourceos-keyboard-equivalence.conf}
+  grep -q '# Terminal lanes' ${../linux/desktop/sourceos-keyboard-equivalence.conf}
+  grep -q 'invariant=gui_terminal_split_explicit' ${../linux/desktop/sourceos-keyboard-equivalence.conf}
+  mkdir -p $out
+  echo validated > $out/result.txt
+''
diff --git a/tests/sourceos-shell-service-graph-contract.nix b/tests/sourceos-shell-service-graph-contract.nix
new file mode 100644
index 0000000..adac31a
--- /dev/null
+++ b/tests/sourceos-shell-service-graph-contract.nix
@@ -0,0 +1,12 @@
+{ pkgs ? import <nixpkgs> {} }:
+pkgs.runCommand "sourceos-shell-service-graph-contract" {
+  nativeBuildInputs = [ pkgs.gnugrep ];
+} ''
+  test -f ${../linux/systemd/sourceos-shell.target}
+  grep -q 'sourceos-shell.service sourceos-router.service sourceos-pdf-secure.service sourceos-docd.service' ${../linux/systemd/sourceos-shell.target}
+  grep -q 'systemd.targets.sourceos-shell' ${../modules/nixos/sourceos-shell/default.nix}
+  grep -q 'partOf = \[ "sourceos-shell.target" \]' ${../modules/nixos/sourceos-shell/default.nix}
+  grep -q 'sourceos-shell.target' ${../docs/sourceos-shell-service-graph.md}
+  mkdir -p $out
+  echo validated > $out/result.txt
+''