diff --git a/javascript/sentry-conventions/src/attributes.ts b/javascript/sentry-conventions/src/attributes.ts
index 8e7aa029..375fe4a8 100644
--- a/javascript/sentry-conventions/src/attributes.ts
+++ b/javascript/sentry-conventions/src/attributes.ts
@@ -1157,6 +1157,26 @@ export const APP_VITALS_START_COLD_VALUE = 'app.vitals.start.cold.value';
  */
 export type APP_VITALS_START_COLD_VALUE_TYPE = number;
 
+// Path: model/attributes/app/app__vitals__start__prewarmed.json
+
+/**
+ * Whether the app start was prewarmed. `app.vitals.start.prewarmed`
+ *
+ * Attribute Value Type: `boolean` {@link APP_VITALS_START_PREWARMED_TYPE}
+ *
+ * Contains PII: false
+ *
+ * Attribute defined in OTEL: No
+ *
+ * @example true
+ */
+export const APP_VITALS_START_PREWARMED = 'app.vitals.start.prewarmed';
+
+/**
+ * Type for {@link APP_VITALS_START_PREWARMED} app.vitals.start.prewarmed
+ */
+export type APP_VITALS_START_PREWARMED_TYPE = boolean;
+
 // Path: model/attributes/app/app__vitals__start__reason.json
 
 /**
@@ -12008,6 +12028,7 @@ export const ATTRIBUTE_TYPE: Record<string, AttributeType> = {
   [APP_VITALS_FRAMES_SLOW_COUNT]: 'integer',
   [APP_VITALS_FRAMES_TOTAL_COUNT]: 'integer',
   [APP_VITALS_START_COLD_VALUE]: 'double',
+  [APP_VITALS_START_PREWARMED]: 'boolean',
   [APP_VITALS_START_REASON]: 'string',
   [APP_VITALS_START_SCREEN]: 'string',
   [APP_VITALS_START_TYPE]: 'string',
@@ -12578,6 +12599,7 @@ export type AttributeName =
   | typeof APP_VITALS_FRAMES_SLOW_COUNT
   | typeof APP_VITALS_FRAMES_TOTAL_COUNT
   | typeof APP_VITALS_START_COLD_VALUE
+  | typeof APP_VITALS_START_PREWARMED
   | typeof APP_VITALS_START_REASON
   | typeof APP_VITALS_START_SCREEN
   | typeof APP_VITALS_START_TYPE
@@ -13892,6 +13914,17 @@ export const ATTRIBUTE_METADATA: Record<AttributeName, AttributeMetadata> = {
     sdks: ['sentry.cocoa', 'sentry.java.android', 'sentry.javascript.react-native', 'sentry.dart.flutter'],
     changelog: [{ version: '0.5.0', prs: [313], description: 'Added app.vitals.start.cold.value attribute' }],
   },
+  [APP_VITALS_START_PREWARMED]: {
+    brief: 'Whether the app start was prewarmed.',
+    type: 'boolean',
+    pii: {
+      isPii: 'false',
+    },
+    isInOtel: false,
+    example: true,
+    sdks: ['sentry.cocoa'],
+    changelog: [{ version: 'next', prs: [379], description: 'Added app.vitals.start.prewarmed attribute' }],
+  },
   [APP_VITALS_START_REASON]: {
     brief: 'The reason that triggered the app start.',
     type: 'string',
@@ -20124,6 +20157,7 @@ export type Attributes = {
   [APP_VITALS_FRAMES_SLOW_COUNT]?: APP_VITALS_FRAMES_SLOW_COUNT_TYPE;
   [APP_VITALS_FRAMES_TOTAL_COUNT]?: APP_VITALS_FRAMES_TOTAL_COUNT_TYPE;
   [APP_VITALS_START_COLD_VALUE]?: APP_VITALS_START_COLD_VALUE_TYPE;
+  [APP_VITALS_START_PREWARMED]?: APP_VITALS_START_PREWARMED_TYPE;
   [APP_VITALS_START_REASON]?: APP_VITALS_START_REASON_TYPE;
   [APP_VITALS_START_SCREEN]?: APP_VITALS_START_SCREEN_TYPE;
   [APP_VITALS_START_TYPE]?: APP_VITALS_START_TYPE_TYPE;
diff --git a/model/attributes/app/app__vitals__start__prewarmed.json b/model/attributes/app/app__vitals__start__prewarmed.json
new file mode 100644
index 00000000..c767c319
--- /dev/null
+++ b/model/attributes/app/app__vitals__start__prewarmed.json
@@ -0,0 +1,18 @@
+{
+  "key": "app.vitals.start.prewarmed",
+  "brief": "Whether the app start was prewarmed.",
+  "type": "boolean",
+  "pii": {
+    "key": "false"
+  },
+  "is_in_otel": false,
+  "example": true,
+  "sdks": ["sentry.cocoa"],
+  "changelog": [
+    {
+      "version": "next",
+      "prs": [379],
+      "description": "Added app.vitals.start.prewarmed attribute"
+    }
+  ]
+}
diff --git a/python/src/sentry_conventions/attributes.py b/python/src/sentry_conventions/attributes.py
index 4100b101..6478f6c7 100644
--- a/python/src/sentry_conventions/attributes.py
+++ b/python/src/sentry_conventions/attributes.py
@@ -831,6 +831,18 @@ class ATTRIBUTE_NAMES(metaclass=_AttributeNamesMeta):
     Example: 1234.56
     """
 
+    # Path: model/attributes/app/app__vitals__start__prewarmed.json
+    APP_VITALS_START_PREWARMED: Literal["app.vitals.start.prewarmed"] = (
+        "app.vitals.start.prewarmed"
+    )
+    """Whether the app start was prewarmed.
+
+    Type: bool
+    Contains PII: false
+    Defined in OTEL: No
+    Example: true
+    """
+
     # Path: model/attributes/app/app__vitals__start__reason.json
     APP_VITALS_START_REASON: Literal["app.vitals.start.reason"] = (
         "app.vitals.start.reason"
@@ -7408,6 +7420,21 @@ class ATTRIBUTE_NAMES(metaclass=_AttributeNamesMeta):
             ),
         ],
     ),
+    "app.vitals.start.prewarmed": AttributeMetadata(
+        brief="Whether the app start was prewarmed.",
+        type=AttributeType.BOOLEAN,
+        pii=PiiInfo(isPii=IsPii.FALSE),
+        is_in_otel=False,
+        example=True,
+        sdks=["sentry.cocoa"],
+        changelog=[
+            ChangelogEntry(
+                version="next",
+                prs=[379],
+                description="Added app.vitals.start.prewarmed attribute",
+            ),
+        ],
+    ),
     "app.vitals.start.reason": AttributeMetadata(
         brief="The reason that triggered the app start.",
         type=AttributeType.STRING,
@@ -13984,6 +14011,7 @@ class ATTRIBUTE_NAMES(metaclass=_AttributeNamesMeta):
         "app.vitals.frames.slow.count": int,
         "app.vitals.frames.total.count": int,
         "app.vitals.start.cold.value": float,
+        "app.vitals.start.prewarmed": bool,
         "app.vitals.start.reason": str,
         "app.vitals.start.screen": str,
         "app.vitals.start.type": str,