diff --git a/.github/drivers/copilot_sdk_driver_sample_node.cjs b/.github/drivers/copilot_sdk_driver_sample_node.cjs
index cc20fdac5c3..0b65e83ede6 100644
--- a/.github/drivers/copilot_sdk_driver_sample_node.cjs
+++ b/.github/drivers/copilot_sdk_driver_sample_node.cjs
@@ -2,6 +2,7 @@
 "use strict";
 
 const fs = require("node:fs");
+const { isValidProviderConfig, isValidModelConfig, parseMultiProviderJson } = require("../../actions/setup/js/copilot_sdk_multi_provider.cjs");
 
 // Default timeout for a single sendAndWait call: 10 minutes.
 // Override via the COPILOT_SDK_SEND_TIMEOUT_MS environment variable.
@@ -43,31 +44,6 @@ function extractAssistantContent(message) {
   return "";
 }
 
-function isValidProviderConfig(p) {
-  return p && typeof p.name === "string" && typeof p.type === "string" && typeof p.baseUrl === "string";
-}
-
-function isValidModelConfig(m) {
-  return m && typeof m.id === "string" && typeof m.provider === "string";
-}
-
-function parseMultiProviderJson(raw) {
-  if (!raw) return null;
-  try {
-    const parsed = JSON.parse(raw);
-    if (!parsed || typeof parsed !== "object") return null;
-    if (!Array.isArray(parsed.providers) || parsed.providers.length < 1) return null;
-    if (!Array.isArray(parsed.models) || parsed.models.length < 1) return null;
-    // Validate minimal shape: providers must have name/type/baseUrl, models must have id/provider
-    if (!parsed.providers.every(isValidProviderConfig)) return null;
-    if (!parsed.models.every(isValidModelConfig)) return null;
-    const model = typeof parsed.model === "string" ? parsed.model.trim() : "";
-    return { model, providers: parsed.providers, models: parsed.models };
-  } catch {
-    return null;
-  }
-}
-
 function buildSessionConfig(model, onPermissionRequest) {
   const config = {
     onPermissionRequest,
diff --git a/actions/setup/js/copilot_sdk_driver.cjs b/actions/setup/js/copilot_sdk_driver.cjs
index 21b2797fc67..2e609e0462a 100644
--- a/actions/setup/js/copilot_sdk_driver.cjs
+++ b/actions/setup/js/copilot_sdk_driver.cjs
@@ -19,8 +19,9 @@
  * client connection, runs the session, and exits.
  *
  * Reusable helpers live in:
- *   copilot_sdk_permissions.cjs — permission config parsing and handler builder
- *   copilot_sdk_session.cjs     — session runner and JSONL event serialization
+ *   copilot_sdk_permissions.cjs    — permission config parsing and handler builder
+ *   copilot_sdk_session.cjs        — session runner and JSONL event serialization
+ *   copilot_sdk_multi_provider.cjs — multi-provider JSON parsing and validation
  */
 
 "use strict";
@@ -28,6 +29,7 @@
 const fs = require("fs");
 const { runWithCopilotSDK, extractPromptFromArgs } = require("./copilot_sdk_session.cjs");
 const { parsePermissionConfigFromServerArgs } = require("./copilot_sdk_permissions.cjs");
+const { parseMultiProviderJson } = require("./copilot_sdk_multi_provider.cjs");
 
 // Re-export the session and permission helpers so that existing callers that
 // require("./copilot_sdk_driver.cjs") (e.g. copilot_harness.cjs) continue to work.
@@ -45,45 +47,6 @@ function log(msg) {
   process.stderr.write(`[copilot-sdk-driver] ${msg}\n`);
 }
 
-function isValidProviderConfig(p) {
-  return p && typeof p.name === "string" && typeof p.type === "string" && typeof p.baseUrl === "string";
-}
-
-function isValidModelConfig(m) {
-  return m && typeof m.id === "string" && typeof m.provider === "string";
-}
-
-/**
- * Parse the GH_AW_COPILOT_SDK_MULTI_PROVIDER_JSON env var.
- *
- * Returns `null` when the env var is unset or contains invalid JSON.
- * On success returns `{ model, providers, models }` where the shapes match the
- * Copilot SDK `NamedProviderConfig` / `ProviderModelConfig` types.
- *
- * @param {string | undefined} value
- * @returns {{
- *   model: string,
- *   providers: import("@github/copilot-sdk").NamedProviderConfig[],
- *   models: import("@github/copilot-sdk").ProviderModelConfig[],
- * } | null}
- */
-function parseMultiProviderJson(value) {
-  if (!value) return null;
-  try {
-    const parsed = JSON.parse(value);
-    if (!parsed || typeof parsed !== "object") return null;
-    if (!Array.isArray(parsed.providers) || parsed.providers.length < 1) return null;
-    if (!Array.isArray(parsed.models) || parsed.models.length < 1) return null;
-    // Validate minimal shape: providers must have name/type/baseUrl, models must have id/provider
-    if (!parsed.providers.every(isValidProviderConfig)) return null;
-    if (!parsed.models.every(isValidModelConfig)) return null;
-    const model = typeof parsed.model === "string" ? parsed.model.trim() : "";
-    return { model, providers: parsed.providers, models: parsed.models };
-  } catch {
-    return null;
-  }
-}
-
 /**
  * Entry point when the driver is run directly with Node:
  *   node copilot_sdk_driver.cjs
diff --git a/actions/setup/js/copilot_sdk_multi_provider.cjs b/actions/setup/js/copilot_sdk_multi_provider.cjs
new file mode 100644
index 00000000000..f5eda347657
--- /dev/null
+++ b/actions/setup/js/copilot_sdk_multi_provider.cjs
@@ -0,0 +1,65 @@
+// @ts-check
+
+/**
+ * Copilot SDK Multi-Provider Helpers
+ *
+ * Shared parsing and validation utilities for the GH_AW_COPILOT_SDK_MULTI_PROVIDER_JSON
+ * environment variable.  Consumed by both the production SDK driver
+ * (copilot_sdk_driver.cjs) and any custom driver (e.g. the Node sample driver
+ * under .github/drivers/) so that the validation logic stays in one place.
+ */
+
+"use strict";
+
+/**
+ * @param {any} p
+ * @returns {boolean}
+ */
+function isValidProviderConfig(p) {
+  return p && typeof p.name === "string" && typeof p.type === "string" && typeof p.baseUrl === "string";
+}
+
+/**
+ * @param {any} m
+ * @returns {boolean}
+ */
+function isValidModelConfig(m) {
+  return m && typeof m.id === "string" && typeof m.provider === "string";
+}
+
+/**
+ * Parse the GH_AW_COPILOT_SDK_MULTI_PROVIDER_JSON env var.
+ *
+ * Returns `null` when the env var is unset or contains invalid JSON.
+ * On success returns `{ model, providers, models }` where the shapes match the
+ * Copilot SDK `NamedProviderConfig` / `ProviderModelConfig` types.
+ *
+ * @param {string | undefined} value
+ * @returns {{
+ *   model: string,
+ *   providers: import("@github/copilot-sdk").NamedProviderConfig[],
+ *   models: import("@github/copilot-sdk").ProviderModelConfig[],
+ * } | null}
+ */
+function parseMultiProviderJson(value) {
+  if (!value) return null;
+  try {
+    const parsed = JSON.parse(value);
+    if (!parsed || typeof parsed !== "object") return null;
+    if (!Array.isArray(parsed.providers) || parsed.providers.length < 1) return null;
+    if (!Array.isArray(parsed.models) || parsed.models.length < 1) return null;
+    // Validate minimal shape: providers must have name/type/baseUrl, models must have id/provider
+    if (!parsed.providers.every(isValidProviderConfig)) return null;
+    if (!parsed.models.every(isValidModelConfig)) return null;
+    const model = typeof parsed.model === "string" ? parsed.model.trim() : "";
+    return { model, providers: parsed.providers, models: parsed.models };
+  } catch {
+    return null;
+  }
+}
+
+module.exports = {
+  isValidProviderConfig,
+  isValidModelConfig,
+  parseMultiProviderJson,
+};