diff --git a/runtime.md b/runtime.md
index e5520dfbd..b9c1b6458 100644
--- a/runtime.md
+++ b/runtime.md
@@ -1,5 +1,51 @@
 # Runtime and Lifecycle
 
+## State
+
+The runtime state for a container is persisted on disk so that external tools can consume and act on this information.
+The runtime state is stored in a JSON encoded file.
+It is recommended that this file is stored in a temporary filesystem so that it can be removed on a system reboot.
+On Linux based systems the state information is stored in `/run/oci`.
+The directory structure for a container is `<root>/<containerID>/state.json`.
+
+* **id** (string) ID is the container's ID.
+* **pid** (int) Pid is the main processes id within the container.
+* **root** (string) Root is the path to the container's root filesystem specified in the configuration.
+
+*Example*
+
+```json
+{
+    "id": "oci-container",
+    "pid": 4422,
+    "root": "/containers/redis"
+}
+```
+
+Linux systems add some platform specific information to the state.
+
+* **namespaces** Paths to the Linux namespaces setup for the container.
+* **cgrousps** Paths to the container's cgroups.
+* **externalFds** Paths to the container's main processes STDIO and other external fds.
+
+*Example Linux*
+
+```json
+{
+    "namespaces": {
+        "process": "/proc/33/ns/pid",
+        "net": "/proc/33/ns/net"
+    },
+    "cgroups": {
+        "device": "/sys/fs/cgroup/devices/oci-container",
+        "cpu": "/sys/fs/cgroup/cpu/oci-container"
+    },
+    "externalFds": [
+        "/proc/33/fd/1"
+    ]
+}
+```
+
 ## Lifecycle
 
 ### Create
diff --git a/spec_linux.go b/spec_linux.go
index eb28cbcf3..66750bf28 100644
--- a/spec_linux.go
+++ b/spec_linux.go
@@ -2,6 +2,9 @@
 
 package specs
 
+// LinuxStateDirectory holds the container's state information.
+const LinuxStateDirectory = "/run/oci"
+
 // LinuxSpec is the full specification for linux containers.
 type LinuxSpec struct {
 	Spec
@@ -150,3 +153,16 @@ type Resources struct {
 	// Network restriction configuration.
 	Network Network `json:"network"`
 }
+
+type LinuxState struct {
+	State
+	// Linux holds platform specific state information for linux.
+	Linux struct {
+		// Namespaces holds paths to the container's namespaces on disk.
+		Namespaces map[string]string `json:"namespaces"`
+		// Cgroups holds paths to the container's cgroup paths.
+		Cgroups map[string]string `json:"cgroups"`
+		// ExternalFds holds paths to the container's STDIO.
+		ExternalFds []string `json:"externalFds,omitempty"`
+	} `json:"linux"`
+}
diff --git a/state.go b/state.go
new file mode 100644
index 000000000..a4e814296
--- /dev/null
+++ b/state.go
@@ -0,0 +1,11 @@
+package specs
+
+// State holds information about the runtime information of the container.
+type State struct {
+	// ID is the container ID.
+	ID string `json:"id"`
+	// Pid is the process id for the container's main process.
+	Pid int `json:"pid"`
+	// Root path to the container's root filesystem.
+	Root string `json:"root"`
+}