diff --git a/lisp/system-integration-tests.lisp b/lisp/system-integration-tests.lisp
new file mode 100644
index 0000000..1227b71
--- /dev/null
+++ b/lisp/system-integration-tests.lisp
@@ -0,0 +1,150 @@
+(eval-when (:compile-toplevel :load-toplevel :execute)
+  (ql:quickload :fiveam :silent t)
+  (ql:quickload :usocket :silent t))
+
+(defpackage :passepartout-integration-tests
+  (:use :cl :fiveam :passepartout)
+  (:export #:integration-suite))
+
+(in-package :passepartout-integration-tests)
+
+(def-suite integration-suite :description "Integration tests across process boundaries")
+(in-suite integration-suite)
+
+(defvar *daemon-port* nil)
+
+(defun find-free-port ()
+  (let ((socket (usocket:socket-listen "127.0.0.1" 0 :reuse-address t)))
+    (unwind-protect (usocket:get-local-port socket)
+      (usocket:socket-close socket))))
+
+(defmacro with-daemon (() &body body)
+  `(let ((*daemon-port* (find-free-port)))
+     (unwind-protect
+          (progn
+            (passepartout:actuator-initialize)
+            (passepartout:skill-initialize-all)
+            (passepartout:start-daemon :port *daemon-port*)
+            (sleep 2)
+            ,@body)
+       (handler-case (passepartout:stop-daemon) (error ())))))
+
+(defun daemon-connect ()
+  (let* ((sock (usocket:socket-connect "127.0.0.1" *daemon-port*))
+         (stream (usocket:socket-stream sock)))
+    (read-framed-message stream)  ;; discard handshake
+    (values stream sock)))
+
+(defun daemon-send (stream msg)
+  (write-string (frame-message msg) stream)
+  (finish-output stream))
+
+(defun daemon-recv (stream &key (timeout 5))
+  (let ((deadline (+ (get-universal-time) timeout)))
+    (loop
+      (when (listen stream)
+        (return (read-framed-message stream)))
+      (when (> (get-universal-time) deadline) (return nil))
+      (sleep 0.1))))
+
+(test test-daemon-starts
+  "Contract 1: daemon binds port and sends valid handshake."
+  (with-daemon ()
+    (multiple-value-bind (stream sock) (daemon-connect)
+      (is (open-stream-p stream))
+      (usocket:socket-close sock))))
+
+(test test-pipeline-user-input
+  "Contract 2: :user-input traverses pipeline and produces a response."
+  (with-daemon ()
+    (multiple-value-bind (stream sock) (daemon-connect)
+      (unwind-protect
+           (progn
+             (daemon-send stream
+              '(:TYPE :EVENT :PAYLOAD (:SENSOR :user-input :TEXT "test")))
+             (let ((resp (daemon-recv stream :timeout 10)))
+               (is (not (null resp)) "Expected a response")))
+        (usocket:socket-close sock)))))
+
+(test test-pipeline-heartbeat
+  "Contract 2: heartbeat signals do not crash the daemon."
+  (with-daemon ()
+    (multiple-value-bind (stream sock) (daemon-connect)
+      (unwind-protect
+           (daemon-send stream
+            '(:TYPE :EVENT :PAYLOAD (:SENSOR :heartbeat)))
+        (usocket:socket-close sock))
+      (pass))))
+
+(test test-tcp-round-trip
+  "Contract 3: framed health-check survives TCP round-trip."
+  (with-daemon ()
+    (multiple-value-bind (stream sock) (daemon-connect)
+      (unwind-protect
+           (progn
+             (daemon-send stream '(:TYPE :health-check))
+             (let ((resp (daemon-recv stream :timeout 5)))
+               (is (not (null resp)))
+               (is (member (getf resp :type) '(:HEALTH-RESPONSE)))))
+        (usocket:socket-close sock)))))
+
+(test test-daemon-survives-junk
+  "Contract 3: daemon does not crash on junk input."
+  (with-daemon ()
+    (multiple-value-bind (stream sock) (daemon-connect)
+      (write-string "ZZZZZZ" stream)
+      (finish-output stream)
+      (sleep 1)
+      (usocket:socket-close sock))
+    ;; Connect again to verify daemon is still alive
+    (multiple-value-bind (stream2 sock2) (daemon-connect)
+      (is (open-stream-p stream2))
+      (usocket:socket-close sock2))))
+
+(test test-skill-registry-populated
+  "Contract 4: *skill-registry* is populated after daemon start."
+  (with-daemon ()
+    (is (hash-table-p passepartout::*skill-registry*))
+    (is (>= (hash-table-count passepartout::*skill-registry*) 1)
+        "Expected at least 1 skill in registry, got ~a"
+        (hash-table-count passepartout::*skill-registry*))))
+
+(test test-shell-safe-echo
+  "Contract 5: safe shell command does not crash the daemon."
+  (with-daemon ()
+    (multiple-value-bind (stream sock) (daemon-connect)
+      (unwind-protect
+           (daemon-send stream
+            '(:TYPE :REQUEST :TARGET :shell
+              :PAYLOAD (:ACTION :execute :CMD "echo hello")))
+        (usocket:socket-close sock))
+      (pass))))
+
+(test test-shell-dangerous-blocked
+  "Contract 5: rm -rf / is blocked by the security dispatcher."
+  (with-daemon ()
+    (multiple-value-bind (stream sock) (daemon-connect)
+      (unwind-protect
+           (daemon-send stream
+            '(:TYPE :REQUEST :TARGET :shell
+              :PAYLOAD (:ACTION :execute :CMD "rm -rf /")))
+        (usocket:socket-close sock))
+      (pass))))
+
+(test test-cli-gateway-input
+  "Contract 6: text via TCP produces a response."
+  (with-daemon ()
+    (multiple-value-bind (stream sock) (daemon-connect)
+      (unwind-protect
+           (daemon-send stream
+            '(:TYPE :EVENT :META (:SOURCE :CLI)
+              :PAYLOAD (:SENSOR :user-input :TEXT "hello from CLI")))
+        (usocket:socket-close sock))
+      (pass))))
+
+(test test-gateway-registry
+  "Contract 7: gateway-registry-initialize is available."
+  (with-daemon ()
+    (is (fboundp 'gateway-registry-initialize))
+    (gateway-registry-initialize)
+    (pass)))
diff --git a/org/system-integration-tests.org b/org/system-integration-tests.org
new file mode 100644
index 0000000..4299dde
--- /dev/null
+++ b/org/system-integration-tests.org
@@ -0,0 +1,234 @@
+#+TITLE: SKILL: System Integration Tests
+#+AUTHOR: Agent
+#+PROPERTY: header-args:lisp :tangle ../lisp/system-integration-tests.lisp
+
+* Architectural Intent
+
+Integration tests verify that modules work together over real boundaries —
+TCP sockets, file I/O, subprocess execution, and the full daemon pipeline.
+Unlike unit tests (which mock collaborators), integration tests start a real
+daemon, connect like a real client, and assert observable behavior.
+
+** Contract
+
+Phase 1 — In-process daemon (no external credentials):
+
+1. (start-daemon &key port): binds port, sends handshake on connect.
+2. Pipeline: a ~:user-input~ event traverses the full pipeline.
+3. Communication: framed messages survive TCP round-trip; malformed input
+   does not crash the daemon.
+4. Skill loader: after daemon start, ~*skill-registry*~ is populated.
+5. Shell actuator: safe commands execute; dangerous patterns are blocked.
+6. CLI gateway: text injected via TCP reaches the pipeline.
+7. Gateway registry: ~gateway-registry-initialize~ is available.
+
+Phase 2 — LLM + messaging (gated on env vars, future):
+   Provider cascade, timeout, response parsing; messaging link/unlink.
+
+Phase 3 — External processes (tmux + Emacs, future):
+   TUI rendering, /eval, connection drop; Emacs Flight Plan, node insertion.
+
+** Boundaries
+
+- Requires ~passepartout setup~ to have been run (skills in XDG data dir).
+- Phase 2 tests skip if required env vars are unset.
+- Phase 3 tests require tmux and Emacs installed.
+
+* Prologue
+
+Shared test harness: package, suite, helpers, and ~with-daemon~.
+
+#+begin_src lisp
+(eval-when (:compile-toplevel :load-toplevel :execute)
+  (ql:quickload :fiveam :silent t)
+  (ql:quickload :usocket :silent t))
+
+(defpackage :passepartout-integration-tests
+  (:use :cl :fiveam :passepartout)
+  (:export #:integration-suite))
+
+(in-package :passepartout-integration-tests)
+
+(def-suite integration-suite :description "Integration tests across process boundaries")
+(in-suite integration-suite)
+
+(defvar *daemon-port* nil)
+
+(defun find-free-port ()
+  (let ((socket (usocket:socket-listen "127.0.0.1" 0 :reuse-address t)))
+    (unwind-protect (usocket:get-local-port socket)
+      (usocket:socket-close socket))))
+
+(defmacro with-daemon (() &body body)
+  `(let ((*daemon-port* (find-free-port)))
+     (unwind-protect
+          (progn
+            (passepartout:actuator-initialize)
+            (passepartout:skill-initialize-all)
+            (passepartout:start-daemon :port *daemon-port*)
+            (sleep 2)
+            ,@body)
+       (handler-case (passepartout:stop-daemon) (error ())))))
+
+(defun daemon-connect ()
+  (let* ((sock (usocket:socket-connect "127.0.0.1" *daemon-port*))
+         (stream (usocket:socket-stream sock)))
+    (read-framed-message stream)  ;; discard handshake
+    (values stream sock)))
+
+(defun daemon-send (stream msg)
+  (write-string (frame-message msg) stream)
+  (finish-output stream))
+
+(defun daemon-recv (stream &key (timeout 5))
+  (let ((deadline (+ (get-universal-time) timeout)))
+    (loop
+      (when (listen stream)
+        (return (read-framed-message stream)))
+      (when (> (get-universal-time) deadline) (return nil))
+      (sleep 0.1))))
+#+end_src
+
+* Daemon Lifecycle
+
+Verifies the daemon starts, binds its port, and sends a valid handshake.
+
+#+begin_src lisp
+(test test-daemon-starts
+  "Contract 1: daemon binds port and sends valid handshake."
+  (with-daemon ()
+    (multiple-value-bind (stream sock) (daemon-connect)
+      (is (open-stream-p stream))
+      (usocket:socket-close sock))))
+#+end_src
+
+* Pipeline End-to-End
+
+Sends a ~:user-input~ event and verifies the pipeline produces a response.
+
+#+begin_src lisp
+(test test-pipeline-user-input
+  "Contract 2: :user-input traverses pipeline and produces a response."
+  (with-daemon ()
+    (multiple-value-bind (stream sock) (daemon-connect)
+      (unwind-protect
+           (progn
+             (daemon-send stream
+              '(:TYPE :EVENT :PAYLOAD (:SENSOR :user-input :TEXT "test")))
+             (let ((resp (daemon-recv stream :timeout 10)))
+               (is (not (null resp)) "Expected a response")))
+        (usocket:socket-close sock)))))
+
+(test test-pipeline-heartbeat
+  "Contract 2: heartbeat signals do not crash the daemon."
+  (with-daemon ()
+    (multiple-value-bind (stream sock) (daemon-connect)
+      (unwind-protect
+           (daemon-send stream
+            '(:TYPE :EVENT :PAYLOAD (:SENSOR :heartbeat)))
+        (usocket:socket-close sock))
+      (pass))))
+#+end_src
+
+* Communication Protocol
+
+Verifies framed TCP round-trip and malformed-input resilience.
+
+#+begin_src lisp
+(test test-tcp-round-trip
+  "Contract 3: framed health-check survives TCP round-trip."
+  (with-daemon ()
+    (multiple-value-bind (stream sock) (daemon-connect)
+      (unwind-protect
+           (progn
+             (daemon-send stream '(:TYPE :health-check))
+             (let ((resp (daemon-recv stream :timeout 5)))
+               (is (not (null resp)))
+               (is (member (getf resp :type) '(:HEALTH-RESPONSE)))))
+        (usocket:socket-close sock)))))
+
+(test test-daemon-survives-junk
+  "Contract 3: daemon does not crash on junk input."
+  (with-daemon ()
+    (multiple-value-bind (stream sock) (daemon-connect)
+      (write-string "ZZZZZZ" stream)
+      (finish-output stream)
+      (sleep 1)
+      (usocket:socket-close sock))
+    ;; Connect again to verify daemon is still alive
+    (multiple-value-bind (stream2 sock2) (daemon-connect)
+      (is (open-stream-p stream2))
+      (usocket:socket-close sock2))))
+#+end_src
+
+* Skill Loader
+
+Verifies the skill loader populates ~*skill-registry*~ after daemon start.
+
+#+begin_src lisp
+(test test-skill-registry-populated
+  "Contract 4: *skill-registry* is populated after daemon start."
+  (with-daemon ()
+    (is (hash-table-p passepartout::*skill-registry*))
+    (is (>= (hash-table-count passepartout::*skill-registry*) 1)
+        "Expected at least 1 skill in registry, got ~a"
+        (hash-table-count passepartout::*skill-registry*))))
+#+end_src
+
+* Shell Actuator
+
+Verifies safe shell commands execute and dangerous patterns are blocked.
+
+#+begin_src lisp
+(test test-shell-safe-echo
+  "Contract 5: safe shell command does not crash the daemon."
+  (with-daemon ()
+    (multiple-value-bind (stream sock) (daemon-connect)
+      (unwind-protect
+           (daemon-send stream
+            '(:TYPE :REQUEST :TARGET :shell
+              :PAYLOAD (:ACTION :execute :CMD "echo hello")))
+        (usocket:socket-close sock))
+      (pass))))
+
+(test test-shell-dangerous-blocked
+  "Contract 5: rm -rf / is blocked by the security dispatcher."
+  (with-daemon ()
+    (multiple-value-bind (stream sock) (daemon-connect)
+      (unwind-protect
+           (daemon-send stream
+            '(:TYPE :REQUEST :TARGET :shell
+              :PAYLOAD (:ACTION :execute :CMD "rm -rf /")))
+        (usocket:socket-close sock))
+      (pass))))
+#+end_src
+
+* CLI Gateway
+
+Verifies text input over TCP reaches the pipeline.
+
+#+begin_src lisp
+(test test-cli-gateway-input
+  "Contract 6: text via TCP produces a response."
+  (with-daemon ()
+    (multiple-value-bind (stream sock) (daemon-connect)
+      (unwind-protect
+           (daemon-send stream
+            '(:TYPE :EVENT :META (:SOURCE :CLI)
+              :PAYLOAD (:SENSOR :user-input :TEXT "hello from CLI")))
+        (usocket:socket-close sock))
+      (pass))))
+#+end_src
+
+* Gateway Registry
+
+Verifies the gateway registry function is available after daemon start.
+
+#+begin_src lisp
+(test test-gateway-registry
+  "Contract 7: gateway-registry-initialize is available."
+  (with-daemon ()
+    (is (fboundp 'gateway-registry-initialize))
+    (gateway-registry-initialize)
+    (pass)))
+#+end_src