diff --git a/docs/design/schemas/client-diagnostics/v1/attr-registry.json b/docs/design/schemas/client-diagnostics/v1/attr-registry.json
index 25b710b7..d22be55b 100644
--- a/docs/design/schemas/client-diagnostics/v1/attr-registry.json
+++ b/docs/design/schemas/client-diagnostics/v1/attr-registry.json
@@ -39,6 +39,22 @@
       "audio_underruns": {
         "type": "integer",
         "description": "Audio underrun count."
+      },
+      "session_id": {
+        "type": "string",
+        "description": "Playback session identifier for correlation with operational logs."
+      },
+      "play_method": {
+        "type": "string",
+        "description": "Selected playback delivery method such as direct, remux, or transcode."
+      },
+      "reason": {
+        "type": "string",
+        "description": "Playback route, interruption, or lifecycle reason."
+      },
+      "position_ms": {
+        "type": "integer",
+        "description": "Current playback position in milliseconds."
       }
     },
     "focus": {
@@ -67,12 +83,44 @@
       "duration_ms": {
         "type": "integer",
         "description": "Request duration in milliseconds."
+      },
+      "outcome": {
+        "type": "string",
+        "description": "Request outcome such as success, http_error, transport_error, or cancelled."
+      },
+      "error_code": {
+        "type": "string",
+        "description": "Stable error classification for a failed request."
+      },
+      "attempt": {
+        "type": "integer",
+        "description": "Attempt ordinal for a retried request."
       }
     },
     "lifecycle": {
       "state": {
         "type": "string",
         "description": "App lifecycle state."
+      },
+      "phase": {
+        "type": "string",
+        "description": "Startup or lifecycle phase identifier."
+      },
+      "duration_ms": {
+        "type": "integer",
+        "description": "Elapsed duration for the phase in milliseconds."
+      },
+      "outcome": {
+        "type": "string",
+        "description": "Result of the phase, such as success, failure, or skipped."
+      },
+      "reason": {
+        "type": "string",
+        "description": "Classification for the phase outcome."
+      },
+      "launch_type": {
+        "type": "string",
+        "description": "Launch classification, such as cold or warm."
       }
     },
     "crash": {
diff --git a/internal/diagnostics/contract/contract.go b/internal/diagnostics/contract/contract.go
index 6709f049..ff0114be 100644
--- a/internal/diagnostics/contract/contract.go
+++ b/internal/diagnostics/contract/contract.go
@@ -259,6 +259,10 @@ var attrRegistry = map[string]map[string]attrValueType{
 		"bitrate_kbps":    attrInteger,
 		"dropped_frames":  attrInteger,
 		"audio_underruns": attrInteger,
+		"session_id":      attrString,
+		"play_method":     attrString,
+		"reason":          attrString,
+		"position_ms":     attrInteger,
 	},
 	"focus": {
 		"target": attrString,
@@ -269,9 +273,17 @@ var attrRegistry = map[string]map[string]attrValueType{
 		"path":        attrString,
 		"status":      attrInteger,
 		"duration_ms": attrInteger,
+		"outcome":     attrString,
+		"error_code":  attrString,
+		"attempt":     attrInteger,
 	},
 	"lifecycle": {
-		"state": attrString,
+		"state":       attrString,
+		"phase":       attrString,
+		"duration_ms": attrInteger,
+		"outcome":     attrString,
+		"reason":      attrString,
+		"launch_type": attrString,
 	},
 	"crash": {
 		"fingerprint": attrString,