diff --git a/scripts/lib/preprocess.mjs b/scripts/lib/preprocess.mjs
index ef6f41f..45e9847 100644
--- a/scripts/lib/preprocess.mjs
+++ b/scripts/lib/preprocess.mjs
@@ -346,7 +346,7 @@ export function relaxResponseEnumsInSpec(spec) {
     if (/^[a-z]/.test(name)) return false;
     if (/(Request|Params)$/.test(name)) return false;
     return (
-      /(Dto|Response)$/.test(name) ||
+      /(Dto|Response|DisplayConfig)$/.test(name) ||
       /^(SingleValueResponse|TableValueResult|CursorPage)/.test(name)
     );
   }
@@ -447,10 +447,12 @@ export function relaxResponseStrict(source) {
   const strictRe = /\.strict\(\)/g;
 
   function isResponseShape(name) {
+    // Nested response-only metadata (*DisplayConfig) must be tolerant too —
+    // parent *Dto `.passthrough()` does not relax nested `.strict()` objects.
     if (/^[a-z]/.test(name)) return false;
     if (/(Request|Params)$/.test(name)) return false;
     return (
-      /(Dto|Response)$/.test(name) ||
+      /(Dto|Response|DisplayConfig)$/.test(name) ||
       /^(SingleValueResponse|TableValueResult|CursorPage)/.test(name)
     );
   }
diff --git a/src/lib/api-zod.generated.ts b/src/lib/api-zod.generated.ts
index 53163f9..cbd263a 100644
--- a/src/lib/api-zod.generated.ts
+++ b/src/lib/api-zod.generated.ts
@@ -1445,7 +1445,7 @@ const AlertChannelDisplayConfig = z
     projectKey: z.string().nullable(),
   })
   .partial()
-  .strict();
+  .passthrough();
 const AlertChannelDto = z
   .object({
     id: z.string().uuid(),
diff --git a/test/lib/display-config-passthrough.test.ts b/test/lib/display-config-passthrough.test.ts
new file mode 100644
index 0000000..c79f956
--- /dev/null
+++ b/test/lib/display-config-passthrough.test.ts
@@ -0,0 +1,19 @@
+import {describe, expect, it} from 'vitest'
+import {schemas} from '../../src/lib/api-zod.generated.js'
+
+describe('AlertChannelDisplayConfig Postel tolerance', () => {
+  it('accepts additive SMS/phone keys unknown to this CLI pin', () => {
+    const parsed = schemas.AlertChannelDisplayConfig.parse({
+      recipients: ['ops@example.com'],
+      phoneNumber: '+14155550123',
+      verifiedPhoneNumberId: 7,
+      phoneNumbers: ['+14155550123'],
+      voiceLanguage: 'en-US',
+      preferredLanguage: 'de-DE',
+      futureCarrierField: 'kept',
+    })
+    expect(parsed.recipients).toEqual(['ops@example.com'])
+    expect((parsed as {phoneNumber?: string}).phoneNumber).toBe('+14155550123')
+    expect((parsed as {futureCarrierField?: string}).futureCarrierField).toBe('kept')
+  })
+})