diff --git a/src/lib/seam/connect/models/events/common.ts b/src/lib/seam/connect/models/events/common.ts
index e43aaa90..de1ea928 100644
--- a/src/lib/seam/connect/models/events/common.ts
+++ b/src/lib/seam/connect/models/events/common.ts
@@ -60,3 +60,18 @@ export const common_event_warning = z
   .describe(
     'Warning associated with the resource, including the warning code, message, and creation timestamp.',
   )
+
+export const lock_access_denied_reason = z
+  .enum([
+    'unknown_code',
+    'expired_code',
+    'blocklisted_code',
+    'too_many_attempts',
+    'blocked_by_privacy_mode',
+    'credential_error',
+  ])
+  .describe(
+    'Normalized reason a lock denied access. Provider-agnostic; not all providers report every value.',
+  )
+
+export type LockAccessDeniedReason = z.infer<typeof lock_access_denied_reason>
diff --git a/src/lib/seam/connect/models/events/devices.ts b/src/lib/seam/connect/models/events/devices.ts
index 3ecd242b..056ac402 100644
--- a/src/lib/seam/connect/models/events/devices.ts
+++ b/src/lib/seam/connect/models/events/devices.ts
@@ -6,6 +6,7 @@ import {
   common_event,
   common_event_error,
   common_event_warning,
+  lock_access_denied_reason,
 } from './common.js'
 
 const device_event = common_event.extend({
@@ -549,6 +550,17 @@ export const lock_access_denied_event = device_event.extend({
     .uuid()
     .optional()
     .describe('ID of the affected device.'),
+  reason: z
+    .object({
+      reason_code: lock_access_denied_reason,
+      message: z
+        .string()
+        .describe('Human-readable explanation of why access was denied.'),
+    })
+    .optional()
+    .describe(
+      'Why access was denied, when the provider reports a determinable cause. Omitted when unknown.',
+    ),
 }).describe(`
   ---
   route_path: /locks
diff --git a/src/lib/seam/connect/openapi.ts b/src/lib/seam/connect/openapi.ts
index df3ffa78..3b4e0c16 100644
--- a/src/lib/seam/connect/openapi.ts
+++ b/src/lib/seam/connect/openapi.ts
@@ -26164,6 +26164,32 @@ const openapi: OpenAPISpec = {
                 format: 'date-time',
                 type: 'string',
               },
+              reason: {
+                description:
+                  'Why access was denied, when the provider reports a determinable cause. Omitted when unknown.',
+                properties: {
+                  message: {
+                    description:
+                      'Human-readable explanation of why access was denied.',
+                    type: 'string',
+                  },
+                  reason_code: {
+                    description:
+                      'Normalized reason a lock denied access. Provider-agnostic; not all providers report every value.',
+                    enum: [
+                      'unknown_code',
+                      'expired_code',
+                      'blocklisted_code',
+                      'too_many_attempts',
+                      'blocked_by_privacy_mode',
+                      'credential_error',
+                    ],
+                    type: 'string',
+                  },
+                },
+                required: ['reason_code', 'message'],
+                type: 'object',
+              },
               user_identity_id: {
                 description:
                   '\n      undocumented: Unreleased.\n      ---\n      ID of the user identity associated with the access-denied event.\n    ',
diff --git a/src/lib/seam/connect/route-types.ts b/src/lib/seam/connect/route-types.ts
index 5e88756c..36b150e9 100644
--- a/src/lib/seam/connect/route-types.ts
+++ b/src/lib/seam/connect/route-types.ts
@@ -57707,6 +57707,21 @@ export type Routes = {
               ID of the ACS entrance associated with the access-denied event.
              */
                 acs_entrance_id?: string | undefined
+                /** Why access was denied, when the provider reports a determinable cause. Omitted when unknown. */
+                reason?:
+                  | {
+                      /** Normalized reason a lock denied access. Provider-agnostic; not all providers report every value. */
+                      reason_code:
+                        | 'unknown_code'
+                        | 'expired_code'
+                        | 'blocklisted_code'
+                        | 'too_many_attempts'
+                        | 'blocked_by_privacy_mode'
+                        | 'credential_error'
+                      /** Human-readable explanation of why access was denied. */
+                      message: string
+                    }
+                  | undefined
               }
             | {
                 /** ID of the event. */
@@ -61570,6 +61585,21 @@ export type Routes = {
               ID of the ACS entrance associated with the access-denied event.
              */
             acs_entrance_id?: string | undefined
+            /** Why access was denied, when the provider reports a determinable cause. Omitted when unknown. */
+            reason?:
+              | {
+                  /** Normalized reason a lock denied access. Provider-agnostic; not all providers report every value. */
+                  reason_code:
+                    | 'unknown_code'
+                    | 'expired_code'
+                    | 'blocklisted_code'
+                    | 'too_many_attempts'
+                    | 'blocked_by_privacy_mode'
+                    | 'credential_error'
+                  /** Human-readable explanation of why access was denied. */
+                  message: string
+                }
+              | undefined
           }
         | {
             /** ID of the event. */
@@ -96959,6 +96989,21 @@ export type Routes = {
               ID of the ACS entrance associated with the access-denied event.
              */
             acs_entrance_id?: string | undefined
+            /** Why access was denied, when the provider reports a determinable cause. Omitted when unknown. */
+            reason?:
+              | {
+                  /** Normalized reason a lock denied access. Provider-agnostic; not all providers report every value. */
+                  reason_code:
+                    | 'unknown_code'
+                    | 'expired_code'
+                    | 'blocklisted_code'
+                    | 'too_many_attempts'
+                    | 'blocked_by_privacy_mode'
+                    | 'credential_error'
+                  /** Human-readable explanation of why access was denied. */
+                  message: string
+                }
+              | undefined
           }
         | {
             /** ID of the event. */
@@ -141912,6 +141957,21 @@ export type Routes = {
                   ID of the ACS entrance associated with the access-denied event.
                  */
                   acs_entrance_id?: string | undefined
+                  /** Why access was denied, when the provider reports a determinable cause. Omitted when unknown. */
+                  reason?:
+                    | {
+                        /** Normalized reason a lock denied access. Provider-agnostic; not all providers report every value. */
+                        reason_code:
+                          | 'unknown_code'
+                          | 'expired_code'
+                          | 'blocklisted_code'
+                          | 'too_many_attempts'
+                          | 'blocked_by_privacy_mode'
+                          | 'credential_error'
+                        /** Human-readable explanation of why access was denied. */
+                        message: string
+                      }
+                    | undefined
                 }
               | {
                   /** ID of the event. */