diff --git a/node/clients/intsch/index.ts b/node/clients/intsch/index.ts
index b23fa0ea..39ef13a8 100644
--- a/node/clients/intsch/index.ts
+++ b/node/clients/intsch/index.ts
@@ -30,6 +30,7 @@ import { parseState } from '../../utils/searchState'
 import {
   filterUndefinedNonNull,
   filterByAllowedIntelligentSearchQueryKeys,
+  shouldInjectDPPreview,
 } from './utils'
 
 export class Intsch extends JanusClient implements IIntelligentSearchClient {
@@ -171,6 +172,10 @@ export class Intsch extends JanusClient implements IIntelligentSearchClient {
 
     const requestPath = `/api/intelligent-search/v1/product-search/${path}`
 
+    const dpPreview = shouldInjectDPPreview(this.context.production)
+      ? 'true'
+      : undefined
+
     const merged = filterUndefinedNonNull({
       sc: params.salesChannel ? params.salesChannel : segmentParams?.sc,
       regionId: params.regionId ?? segmentParams?.regionId,
@@ -208,6 +213,7 @@ export class Intsch extends JanusClient implements IIntelligentSearchClient {
           : undefined,
       simulationBehavior: params.simulationBehavior ?? undefined,
       variant: params.variant,
+      dpPreview,
       ...parseState(searchState),
     })
 
@@ -253,6 +259,10 @@ export class Intsch extends JanusClient implements IIntelligentSearchClient {
 
     const facetsPath = `/api/intelligent-search/v1/facets/${path}`
 
+    const dpPreview = shouldInjectDPPreview(this.context.production)
+      ? 'true'
+      : undefined
+
     const merged = filterUndefinedNonNull({
       sc: segmentParams?.sc,
       regionId: params.regionId ?? segmentParams?.regionId,
@@ -272,6 +282,7 @@ export class Intsch extends JanusClient implements IIntelligentSearchClient {
       locale: this.locale ?? segmentParams?.locale,
       bgy_leap: leap ? 'true' : undefined,
       variant: params.variant,
+      dpPreview,
       ...parseState(searchState),
     } as Record<string, unknown>)
 
diff --git a/node/clients/intsch/utils.test.ts b/node/clients/intsch/utils.test.ts
new file mode 100644
index 00000000..17cd69a4
--- /dev/null
+++ b/node/clients/intsch/utils.test.ts
@@ -0,0 +1,57 @@
+import {
+  filterByAllowedIntelligentSearchQueryKeys,
+  filterUndefinedNonNull,
+  shouldInjectDPPreview,
+} from './utils'
+
+describe('filterUndefinedNonNull', () => {
+  it('drops undefined and null values', () => {
+    expect(
+      filterUndefinedNonNull({ a: 1, b: undefined, c: null, d: 'x' })
+    ).toEqual({ a: 1, d: 'x' })
+  })
+
+  it('keeps falsy-but-meaningful values (false, "", 0)', () => {
+    expect(filterUndefinedNonNull({ a: false, b: '', c: 0 })).toEqual({
+      a: false,
+      b: '',
+      c: 0,
+    })
+  })
+})
+
+describe('filterByAllowedIntelligentSearchQueryKeys', () => {
+  it('keeps known IS API query keys and drops unknown ones', () => {
+    const result = filterByAllowedIntelligentSearchQueryKeys({
+      query: 'shoes',
+      foo: 'bar',
+      regionId: 'r1',
+    })
+    expect(result).toEqual({ query: 'shoes', regionId: 'r1' })
+  })
+
+  it('accepts the DPT-67 dpPreview key on the allowlist', () => {
+    const result = filterByAllowedIntelligentSearchQueryKeys({
+      dpPreview: 'true',
+      ignored: 'value',
+    })
+    expect(result).toEqual({ dpPreview: 'true' })
+  })
+})
+
+/**
+ * DPT-67: production-driven QA mode. The storefront emits `dpPreview=true` on
+ * non-production workspaces so the IS API activates the Delivery Promises code
+ * path without the store having to flip `deliveryPromisesEnabled`. Production
+ * traffic must never carry the param — including named workspaces promoted to
+ * production, not just `master`.
+ */
+describe('shouldInjectDPPreview', () => {
+  it('returns true for a non-production (QA/dev) workspace', () => {
+    expect(shouldInjectDPPreview(false)).toBe(true)
+  })
+
+  it('returns false for a production workspace', () => {
+    expect(shouldInjectDPPreview(true)).toBe(false)
+  })
+})
diff --git a/node/clients/intsch/utils.ts b/node/clients/intsch/utils.ts
index 075b353c..07fe1f91 100644
--- a/node/clients/intsch/utils.ts
+++ b/node/clients/intsch/utils.ts
@@ -90,8 +90,20 @@ export const INTELLIGENT_SEARCH_PRODUCT_QUERY_KEYS = new Set<string>([
   'priceTables',
   'simulationBehavior',
   'variant',
+  'dpPreview',
 ])
 
+/**
+ * Whether the IS API call should carry `dpPreview=true`. Non-production
+ * workspaces are treated as QA and get DP activated end-to-end without the
+ * store flipping `deliveryPromisesEnabled`. Production workspaces never carry
+ * the param — including named workspaces promoted to production, not just
+ * `master`.
+ */
+export function shouldInjectDPPreview(production: boolean): boolean {
+  return !production
+}
+
 export function filterByAllowedIntelligentSearchQueryKeys(
   obj: Record<string, unknown>,
   allowedKeys: Set<string> = INTELLIGENT_SEARCH_PRODUCT_QUERY_KEYS