From 47e7b0087a81a8eaddffc35ddb55ffc2dee12749 Mon Sep 17 00:00:00 2001
From: Denver Coneybeare <dconeybe@google.com>
Date: Fri, 31 Jul 2026 09:52:40 -0400
Subject: [PATCH 1/2] data-connect-api-client-internal.ts: add
 "x-firebase-sqlconnect-affinity" header

---
 src/data-connect/data-connect-api-client-internal.ts        | 6 ++++--
 .../data-connect/data-connect-api-client-internal.spec.ts   | 3 +++
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/data-connect/data-connect-api-client-internal.ts b/src/data-connect/data-connect-api-client-internal.ts
index b200eb120e..54dcee6f1e 100644
--- a/src/data-connect/data-connect-api-client-internal.ts
+++ b/src/data-connect/data-connect-api-client-internal.ts
@@ -70,11 +70,12 @@ const IMPERSONATE_MUTATION_ENDPOINT = 'impersonateMutation';
 /** @internal The maximum number of items allowed in the @allow directive's maxCount argument. */
 export const ALLOW_DIRECTIVE_MAX_COUNT = 10_000;
 
-function getHeaders(isUsingGen: boolean): { [key: string]: string } {
+function getHeaders(projectId: string, serviceId: string, isUsingGen: boolean): { [key: string]: string } {
   const headerValue = {
     'X-Firebase-Client': `fire-admin-node/${utils.getSdkVersion()}`,
     'X-Goog-Api-Client': utils.getMetricsHeader(),
     'X-Client-Version': `node/${utils.getSdkVersion()}`,
+    'X-Firebase-Sqlconnect-Affinity': `${projectId}${serviceId}`,
   };
   if (isUsingGen) {
     headerValue['X-Goog-Api-Client'] += ' admin-js/gen';
@@ -386,10 +387,11 @@ export class DataConnectApiClient {
    */
   private async makeGqlRequest<GraphqlResponse>(url: string, data: object): 
   Promise<ExecuteGraphqlResponse<GraphqlResponse>> {
+    const projectId = await this.getProjectId();
     const request: HttpRequestConfig = {
       method: 'POST',
       url,
-      headers: getHeaders(this.isUsingGen),
+      headers: getHeaders(projectId, this.connectorConfig.serviceId, this.isUsingGen),
       data,
     };
     const resp = await this.httpClient.send(request);
diff --git a/test/unit/data-connect/data-connect-api-client-internal.spec.ts b/test/unit/data-connect/data-connect-api-client-internal.spec.ts
index cfc51e5b38..eb9b7d111c 100644
--- a/test/unit/data-connect/data-connect-api-client-internal.spec.ts
+++ b/test/unit/data-connect/data-connect-api-client-internal.spec.ts
@@ -54,6 +54,7 @@ describe('DataConnectApiClient', () => {
     'X-Firebase-Client': `fire-admin-node/${getSdkVersion()}`,
     'X-Goog-Api-Client': getMetricsHeader(),
     'X-Client-Version': `node/${getSdkVersion()}`,
+    'X-Firebase-Sqlconnect-Affinity': 'test-projectmy-service',
   };
 
   const EXPECTED_HEADERS_WITH_GEN = {
@@ -61,6 +62,7 @@ describe('DataConnectApiClient', () => {
     'X-Firebase-Client': `fire-admin-node/${getSdkVersion()}`,
     'X-Goog-Api-Client': getMetricsHeader() + ' admin-js/gen',
     'X-Client-Version': `node/${getSdkVersion()}`,
+    'X-Firebase-Sqlconnect-Affinity': 'test-projectmy-service',
   };
 
   const EMULATOR_EXPECTED_HEADERS = {
@@ -68,6 +70,7 @@ describe('DataConnectApiClient', () => {
     'X-Firebase-Client': `fire-admin-node/${getSdkVersion()}`,
     'X-Goog-Api-Client': getMetricsHeader(),
     'X-Client-Version': `node/${getSdkVersion()}`,
+    'X-Firebase-Sqlconnect-Affinity': 'test-projectmy-service',
   };
 
   const noProjectId = 'Failed to determine project ID. Initialize the SDK with service '

From 99549fa7a07a823b09c8b202afe3664aa32e5977 Mon Sep 17 00:00:00 2001
From: Denver Coneybeare <dconeybe@google.com>
Date: Fri, 31 Jul 2026 10:09:59 -0400
Subject: [PATCH 2/2] data-connect-api-client-internal.ts: GetHeadersParameters
 added, to reduce the chance that the caller will invert the two string
 arguments.

---
 .../data-connect-api-client-internal.ts           | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/data-connect/data-connect-api-client-internal.ts b/src/data-connect/data-connect-api-client-internal.ts
index 54dcee6f1e..89f863b5e4 100644
--- a/src/data-connect/data-connect-api-client-internal.ts
+++ b/src/data-connect/data-connect-api-client-internal.ts
@@ -70,7 +70,14 @@ const IMPERSONATE_MUTATION_ENDPOINT = 'impersonateMutation';
 /** @internal The maximum number of items allowed in the @allow directive's maxCount argument. */
 export const ALLOW_DIRECTIVE_MAX_COUNT = 10_000;
 
-function getHeaders(projectId: string, serviceId: string, isUsingGen: boolean): { [key: string]: string } {
+interface GetHeadersParameters {
+  projectId: string;
+  serviceId: string;
+  isUsingGen: boolean;
+}
+
+function getHeaders(parameters: GetHeadersParameters): { [key: string]: string } {
+  const { projectId, serviceId, isUsingGen } = parameters;
   const headerValue = {
     'X-Firebase-Client': `fire-admin-node/${utils.getSdkVersion()}`,
     'X-Goog-Api-Client': utils.getMetricsHeader(),
@@ -391,7 +398,11 @@ export class DataConnectApiClient {
     const request: HttpRequestConfig = {
       method: 'POST',
       url,
-      headers: getHeaders(projectId, this.connectorConfig.serviceId, this.isUsingGen),
+      headers: getHeaders({
+        projectId,
+        serviceId: this.connectorConfig.serviceId,
+        isUsingGen: this.isUsingGen,
+      }),
       data,
     };
     const resp = await this.httpClient.send(request);