diff --git a/open-sse/config/azureAi.ts b/open-sse/config/azureAi.ts
index fedbb99054..3daea87a2e 100644
--- a/open-sse/config/azureAi.ts
+++ b/open-sse/config/azureAi.ts
@@ -36,11 +36,59 @@ export function normalizeAzureAiBaseUrl(value: string | null | undefined): strin
   return normalized;
 }
 
+export type AzureUrlFormat = "foundry" | "classic";
+
+export function detectAzureUrlFormat(baseUrl: string | null | undefined): AzureUrlFormat {
+  if (!baseUrl || typeof baseUrl !== "string") return "foundry";
+  const trimmed = baseUrl.trim();
+  if (!trimmed) return "foundry";
+
+  try {
+    const urlStr =
+      trimmed.startsWith("http://") || trimmed.startsWith("https://")
+        ? trimmed
+        : `https://${trimmed}`;
+    const parsed = new URL(urlStr);
+    const host = parsed.hostname.toLowerCase();
+    const pathname = parsed.pathname.toLowerCase();
+
+    if (host.endsWith(".services.ai.azure.com")) {
+      return "foundry";
+    }
+
+    if (
+      (host.endsWith(".openai.azure.com") || host.endsWith(".cognitiveservices.azure.com")) &&
+      !pathname.includes("/v1")
+    ) {
+      return "classic";
+    }
+
+    if (pathname.includes("/v1")) {
+      return "foundry";
+    }
+
+    return "foundry";
+  } catch {
+    return "foundry";
+  }
+}
+
 export function buildAzureAiChatUrl(
   value: string | null | undefined,
-  apiType: "chat" | "responses" = "chat"
+  apiType: "chat" | "responses" = "chat",
+  model?: string,
+  apiVersion = "2024-12-01-preview"
 ): string {
+  const format = detectAzureUrlFormat(value);
   const normalized = normalizeAzureAiBaseUrl(value);
+
+  if (format === "classic" && model) {
+    const raw = stripTrailingSlashes((value || "").trim())
+      .replace(/\/openai$/i, "")
+      .replace(/\/openai\/deployments\/[^/]+\/chat\/completions[^/]*$/i, "");
+    return `${raw}/openai/deployments/${encodeURIComponent(model)}/chat/completions?api-version=${encodeURIComponent(apiVersion)}`;
+  }
+
   return `${normalized}/${apiType === "responses" ? "responses" : "chat/completions"}`;
 }
 
diff --git a/open-sse/executors/default.ts b/open-sse/executors/default.ts
index f7f76005f1..690bdea190 100644
--- a/open-sse/executors/default.ts
+++ b/open-sse/executors/default.ts
@@ -197,7 +197,12 @@ export class DefaultExecutor extends BaseExecutor {
             ? "responses"
             : "chat";
         const baseUrl = this.resolveBaseUrl(credentials);
-        return normalizeAzureAiChatUrl(baseUrl, apiType);
+        const apiVersion =
+          typeof credentials?.providerSpecificData?.apiVersion === "string" &&
+          credentials.providerSpecificData.apiVersion.trim()
+            ? credentials.providerSpecificData.apiVersion.trim()
+            : "2024-12-01-preview";
+        return normalizeAzureAiChatUrl(baseUrl, apiType, model, apiVersion);
       }
       case "watsonx": {
         const baseUrl = this.resolveBaseUrl(credentials);
diff --git a/open-sse/executors/default/urlNormalizers.ts b/open-sse/executors/default/urlNormalizers.ts
index a4a5ed4ae5..f2cf1a7294 100644
--- a/open-sse/executors/default/urlNormalizers.ts
+++ b/open-sse/executors/default/urlNormalizers.ts
@@ -17,8 +17,13 @@ export function normalizeDataRobotChatUrl(baseUrl) {
   return buildDataRobotChatUrl(baseUrl);
 }
 
-export function normalizeAzureAiChatUrl(baseUrl: string, apiType: "chat" | "responses" = "chat") {
-  return buildAzureAiChatUrl(baseUrl, apiType);
+export function normalizeAzureAiChatUrl(
+  baseUrl: string,
+  apiType: "chat" | "responses" = "chat",
+  model?: string,
+  apiVersion?: string
+) {
+  return buildAzureAiChatUrl(baseUrl, apiType, model, apiVersion);
 }
 
 export function normalizeWatsonxChatUrl(baseUrl: string) {
diff --git a/src/app/api/providers/[id]/models/discovery/normalizers.ts b/src/app/api/providers/[id]/models/discovery/normalizers.ts
index 1b6e1c20df..ab6c06e477 100644
--- a/src/app/api/providers/[id]/models/discovery/normalizers.ts
+++ b/src/app/api/providers/[id]/models/discovery/normalizers.ts
@@ -232,3 +232,42 @@ export function normalizeSapModelsResponse(
     })
     .filter((value): value is { id: string; name: string; owned_by: string } => Boolean(value));
 }
+
+export function normalizeAzureModelsResponse(
+  data: unknown,
+  fallbackOwner = "azure-ai"
+): Array<{ id: string; name: string; owned_by: string }> {
+  const payload = asRecord(data);
+  const items = Array.isArray(data)
+    ? data
+    : Array.isArray(payload.data)
+      ? (payload.data as unknown[])
+      : Array.isArray(payload.models)
+        ? (payload.models as unknown[])
+        : Array.isArray(payload.value)
+          ? (payload.value as unknown[])
+          : Array.isArray(payload.deployments)
+            ? (payload.deployments as unknown[])
+            : [];
+
+  return items
+    .map((value) => {
+      const item = asRecord(value);
+      const id =
+        toNonEmptyString(item.id) ||
+        toNonEmptyString(item.deployment_name) ||
+        toNonEmptyString(item.deploymentName) ||
+        toNonEmptyString(item.name) ||
+        toNonEmptyString(item.model);
+      if (!id) return null;
+      const name =
+        toNonEmptyString(item.display_name) ||
+        toNonEmptyString(item.displayName) ||
+        toNonEmptyString(item.name) ||
+        id;
+      const ownedBy =
+        toNonEmptyString(item.owned_by) || toNonEmptyString(item.provider) || fallbackOwner;
+      return { id, name, owned_by: ownedBy };
+    })
+    .filter((value): value is { id: string; name: string; owned_by: string } => Boolean(value));
+}
diff --git a/src/app/api/providers/[id]/models/route.ts b/src/app/api/providers/[id]/models/route.ts
index f40cb6e5f3..b24c4b7cf5 100755
--- a/src/app/api/providers/[id]/models/route.ts
+++ b/src/app/api/providers/[id]/models/route.ts
@@ -107,6 +107,7 @@ import {
   normalizeDataRobotCatalogResponse,
   normalizeOpenAiLikeModelsResponse,
   normalizeSapModelsResponse,
+  normalizeAzureModelsResponse,
 } from "./discovery/normalizers";
 import { isNamedOpenAIStyleProvider } from "./discovery/providerSets";
 import { buildStaleEncryptionKeyResponse } from "./staleEncryptionGuard";
@@ -996,58 +997,63 @@ export async function GET(
         );
       }
 
-      const baseUrl =
+      const rawBaseUrl =
         getProviderBaseUrl(connection.providerSpecificData) || AZURE_AI_DEFAULT_BASE_URL;
-      const modelsUrl = buildAzureAiModelsUrl(baseUrl);
+      const baseUrl = normalizeAzureOpenAIBaseUrl(rawBaseUrl);
+      const apiVersion = encodeURIComponent(
+        getAzureOpenAIApiVersion(connection.providerSpecificData) || "2024-12-01-preview"
+      );
 
-      let response: Response;
-      try {
-        response = await safeOutboundFetch(modelsUrl, {
-          ...SAFE_OUTBOUND_FETCH_PRESETS.modelsDiscovery,
-          guard: getProviderOutboundGuard(),
-          proxyConfig: proxy,
-          method: "GET",
-          headers: {
-            "Content-Type": "application/json",
-            "api-key": token,
-          },
-        });
-      } catch (error) {
-        const fallback = buildDiscoveryErrorFallbackResponse(error, {
-          cacheWarning: "Azure AI models API unavailable — using cached catalog",
-          localWarning: "Azure AI models API unavailable — using local catalog",
-        });
-        if (fallback) return fallback;
-        throw error;
+      const discoveryUrls = [
+        buildAzureAiModelsUrl(rawBaseUrl),
+        `${baseUrl}/deployments`,
+        `${baseUrl}/openai/deployments?api-version=${apiVersion}`,
+        `${baseUrl}/openai/models?api-version=${apiVersion}`,
+      ];
+
+      let lastStatus = 0;
+      for (const modelsUrl of discoveryUrls) {
+        let response: Response;
+        try {
+          response = await safeOutboundFetch(modelsUrl, {
+            ...SAFE_OUTBOUND_FETCH_PRESETS.modelsDiscovery,
+            guard: getProviderOutboundGuard(),
+            proxyConfig: proxy,
+            method: "GET",
+            headers: {
+              "Content-Type": "application/json",
+              "api-key": token,
+            },
+          });
+        } catch (error) {
+          const fallback = buildDiscoveryErrorFallbackResponse(error, {
+            cacheWarning: "Azure AI models API unavailable — using cached catalog",
+            localWarning: "Azure AI models API unavailable — using local catalog",
+          });
+          if (fallback) return fallback;
+          throw error;
+        }
+
+        if (response.ok) {
+          const normalized = normalizeAzureModelsResponse(await response.json(), "azure-ai");
+          if (normalized.length > 0) {
+            return buildApiDiscoveryResponse(normalized);
+          }
+        }
+
+        lastStatus = response.status;
+        if (response.status === 401 || response.status === 403) break;
       }
 
-      if (!response.ok) {
-        const fallback = buildDiscoveryFallbackResponse({
-          cacheWarning: `Models probe failed (${response.status}) — using cached catalog`,
-          localWarning: `Models probe failed (${response.status}) — using local catalog`,
-        });
-        if (fallback) return fallback;
-        return NextResponse.json(
-          { error: `Failed to fetch models: ${response.status}` },
-          { status: response.status }
-        );
-      }
-
-      const data = await response.json();
-      const models = (data.data || data.models || []).map((model: Record<string, unknown>) => ({
-        id:
-          (typeof model.id === "string" && model.id) ||
-          (typeof model.name === "string" && model.name) ||
-          "",
-        name:
-          (typeof model.display_name === "string" && model.display_name) ||
-          (typeof model.name === "string" && model.name) ||
-          (typeof model.id === "string" && model.id) ||
-          "",
-        owned_by: "azure-ai",
-      }));
-
-      return buildApiDiscoveryResponse(models.filter((model) => model.id));
+      const fallback = buildDiscoveryFallbackResponse({
+        cacheWarning: `Azure AI models probe failed (${lastStatus || "empty"}) — using cached catalog`,
+        localWarning: `Azure AI models probe failed (${lastStatus || "empty"}) — using local catalog`,
+      });
+      if (fallback) return fallback;
+      return NextResponse.json(
+        { error: `Failed to fetch models: ${lastStatus || "unknown"}` },
+        { status: lastStatus || 502 }
+      );
     }
 
     if (provider === "azure-openai") {
diff --git a/src/app/api/providers/[id]/test/route.ts b/src/app/api/providers/[id]/test/route.ts
index 8db4086671..9cae225cf5 100644
--- a/src/app/api/providers/[id]/test/route.ts
+++ b/src/app/api/providers/[id]/test/route.ts
@@ -615,6 +615,9 @@ async function testApiKeyConnection(connection: any) {
     error,
     warning: result.warning || null,
     diagnosis,
+    ...(Array.isArray((result as any).deployments)
+      ? { deployments: (result as any).deployments }
+      : {}),
   };
 }
 
diff --git a/src/lib/api/modelTestRunner.ts b/src/lib/api/modelTestRunner.ts
index edac46a909..be5411e64a 100644
--- a/src/lib/api/modelTestRunner.ts
+++ b/src/lib/api/modelTestRunner.ts
@@ -124,7 +124,11 @@ async function findCustomModelMetadata(providerId: string, modelId: string) {
   }
 }
 
-export function buildInternalChatRequest(testBody: Record<string, unknown>, signal: AbortSignal) {
+export function buildInternalChatRequest(
+  testBody: Record<string, unknown>,
+  signal: AbortSignal,
+  connectionId?: string
+) {
   return new Request(`${INTERNAL_ORIGIN}/v1/chat/completions`, {
     method: "POST",
     headers: {
@@ -136,13 +140,18 @@ export function buildInternalChatRequest(testBody: Record<string, unknown>, sign
       // Output Styles (e.g. "Ultra terse") leak a system prompt into a test-model call.
       "X-OmniRoute-Compression": "off",
       "X-Request-Id": `model-test-${randomUUID()}`,
+      ...(connectionId ? { "X-OmniRoute-Connection": connectionId } : {}),
     },
     body: JSON.stringify(testBody),
     signal,
   });
 }
 
-export function buildInternalRerankRequest(testBody: Record<string, unknown>, signal: AbortSignal) {
+export function buildInternalRerankRequest(
+  testBody: Record<string, unknown>,
+  signal: AbortSignal,
+  connectionId?: string
+) {
   return new Request(`${INTERNAL_ORIGIN}/v1/rerank`, {
     method: "POST",
     headers: {
@@ -151,6 +160,7 @@ export function buildInternalRerankRequest(testBody: Record<string, unknown>, si
       "X-OmniRoute-No-Cache": "true",
       "X-OmniRoute-Compression": "off",
       "X-Request-Id": `model-test-${randomUUID()}`,
+      ...(connectionId ? { "X-OmniRoute-Connection": connectionId } : {}),
     },
     body: JSON.stringify(testBody),
     signal,
@@ -308,9 +318,9 @@ export async function runSingleModelTest(
       );
     }
     if (isRerank) {
-      return postRerank(buildInternalRerankRequest(testBody, signal));
+      return postRerank(buildInternalRerankRequest(testBody, signal, connectionId));
     }
-    return postChatCompletion(buildInternalChatRequest(testBody, signal));
+    return postChatCompletion(buildInternalChatRequest(testBody, signal, connectionId));
   };
 
   let res: Response;
diff --git a/src/lib/providers/validation/cloudProviders.ts b/src/lib/providers/validation/cloudProviders.ts
index 0000d8cfba..776aeb883e 100644
--- a/src/lib/providers/validation/cloudProviders.ts
+++ b/src/lib/providers/validation/cloudProviders.ts
@@ -290,6 +290,56 @@ export async function validateAzureOpenAIProvider({ apiKey, providerSpecificData
   return { valid: false, error: `Validation failed: ${response.status}` };
 }
 
+function extractTargetDeployments(psd: Record<string, unknown>): string[] {
+  const deployments: string[] = [];
+
+  if (Array.isArray(psd.deployments)) {
+    for (const d of psd.deployments) {
+      if (typeof d === "string" && d.trim()) deployments.push(d.trim());
+      else if (
+        d &&
+        typeof d === "object" &&
+        typeof (d as any).id === "string" &&
+        (d as any).id.trim()
+      ) {
+        deployments.push((d as any).id.trim());
+      }
+    }
+  }
+
+  if (Array.isArray(psd.models)) {
+    for (const m of psd.models) {
+      if (typeof m === "string" && m.trim()) deployments.push(m.trim());
+      else if (
+        m &&
+        typeof m === "object" &&
+        typeof (m as any).id === "string" &&
+        (m as any).id.trim()
+      ) {
+        deployments.push((m as any).id.trim());
+      }
+    }
+  }
+
+  if (Array.isArray(psd.validationModelIds)) {
+    for (const id of psd.validationModelIds) {
+      if (typeof id === "string" && id.trim()) deployments.push(id.trim());
+    }
+  }
+
+  if (typeof psd.validationModelId === "string" && psd.validationModelId.trim()) {
+    const split = psd.validationModelId
+      .split(",")
+      .map((s) => s.trim())
+      .filter(Boolean);
+    for (const s of split) {
+      if (!deployments.includes(s)) deployments.push(s);
+    }
+  }
+
+  return Array.from(new Set(deployments));
+}
+
 export async function validateAzureAiProvider({ apiKey, providerSpecificData = {} }: any) {
   const rawBaseUrl = normalizeBaseUrl(providerSpecificData.baseUrl) || AZURE_AI_DEFAULT_BASE_URL;
   const modelsUrl = buildAzureAiModelsUrl(rawBaseUrl);
@@ -301,6 +351,7 @@ export async function validateAzureAiProvider({ apiKey, providerSpecificData = {
     providerSpecificData
   );
 
+  let modelsEndpointOk = false;
   try {
     const response = await validationRead(modelsUrl, {
       method: "GET",
@@ -308,83 +359,131 @@ export async function validateAzureAiProvider({ apiKey, providerSpecificData = {
     });
 
     if (response.ok) {
-      return { valid: true, error: null, method: "azure_ai_models" };
-    }
-
-    if (response.status === 401 || response.status === 403) {
+      modelsEndpointOk = true;
+    } else if (response.status === 401 || response.status === 403) {
       return { valid: false, error: "Invalid API key" };
-    }
-
-    if (response.status === 429) {
-      return {
-        valid: true,
-        error: null,
-        method: "azure_ai_models",
-        warning: "Rate limited, but credentials are valid",
-      };
+    } else if (response.status === 429) {
+      modelsEndpointOk = true;
     }
   } catch {
     // Fall through to chat probe when /models is unavailable.
   }
 
-  const validationModelId =
-    typeof providerSpecificData.validationModelId === "string"
-      ? providerSpecificData.validationModelId.trim()
-      : "";
+  const targetDeployments = extractTargetDeployments(providerSpecificData);
 
-  if (!validationModelId) {
+  if (targetDeployments.length === 0) {
+    if (modelsEndpointOk) {
+      return { valid: true, error: null, method: "azure_ai_models" };
+    }
     return {
       valid: false,
       error: "Endpoint /models unavailable. Provide a Model ID to validate via /chat/completions.",
     };
   }
 
-  const chatUrl = buildAzureAiChatUrl(
-    rawBaseUrl,
-    providerSpecificData.apiType === "responses" ? "responses" : "chat"
-  );
-  const chatBody =
-    providerSpecificData.apiType === "responses"
-      ? {
-          model: validationModelId,
-          input: "test",
-          max_output_tokens: 1,
-        }
+  const apiType = providerSpecificData.apiType === "responses" ? "responses" : "chat";
+  const apiVersion =
+    typeof providerSpecificData.apiVersion === "string" && providerSpecificData.apiVersion.trim()
+      ? providerSpecificData.apiVersion.trim()
+      : "2024-12-01-preview";
+
+  const probeOne = async (deploymentId: string) => {
+    const chatUrl = buildAzureAiChatUrl(rawBaseUrl, apiType, deploymentId, apiVersion);
+    const chatBody =
+      apiType === "responses"
+        ? {
+            model: deploymentId,
+            input: "test",
+            max_output_tokens: 1,
+          }
+        : {
+            model: deploymentId,
+            messages: [{ role: "user", content: "test" }],
+            max_tokens: 1,
+          };
+
+    try {
+      const response = await validationWrite(chatUrl, {
+        method: "POST",
+        headers,
+        body: JSON.stringify(chatBody),
+      });
+
+      if (
+        response.ok ||
+        response.status === 400 ||
+        response.status === 422 ||
+        response.status === 429
+      ) {
+        return { deploymentId, valid: true, status: "ok", error: null };
+      }
+
+      if (response.status === 401 || response.status === 403) {
+        return { deploymentId, valid: false, status: "auth_error", error: "Invalid API key" };
+      }
+
+      if (response.status === 404) {
+        return { deploymentId, valid: false, status: "not_found", error: "Deployment not found" };
+      }
+
+      return {
+        deploymentId,
+        valid: false,
+        status: "error",
+        error: `Provider unavailable (${response.status})`,
+      };
+    } catch (error: any) {
+      const errRes = toValidationErrorResult(error);
+      return {
+        deploymentId,
+        valid: false,
+        status: "error",
+        error: errRes.error || "Connection failed",
+      };
+    }
+  };
+
+  const settled = await Promise.allSettled(targetDeployments.map(probeOne));
+  const deploymentResults = settled.map((res, i) =>
+    res.status === "fulfilled"
+      ? res.value
       : {
-          model: validationModelId,
-          messages: [{ role: "user", content: "test" }],
-          max_tokens: 1,
-        };
+          deploymentId: targetDeployments[i],
+          valid: false,
+          status: "error",
+          error: "Connection test failed",
+        }
+  );
 
-  try {
-    const response = await validationWrite(chatUrl, {
-      method: "POST",
-      headers,
-      body: JSON.stringify(chatBody),
-    });
+  const validCount = deploymentResults.filter((r) => r.valid).length;
+  const totalCount = deploymentResults.length;
+  const hasAnyValid = validCount > 0 || modelsEndpointOk;
 
-    if (
-      response.ok ||
-      response.status === 400 ||
-      response.status === 404 ||
-      response.status === 422 ||
-      response.status === 429
-    ) {
-      return { valid: true, error: null, method: "azure_ai_chat_probe" };
-    }
-
-    if (response.status === 401 || response.status === 403) {
-      return { valid: false, error: "Invalid API key" };
-    }
-
-    if (response.status >= 500) {
-      return { valid: false, error: `Provider unavailable (${response.status})` };
-    }
-  } catch (error: any) {
-    return toValidationErrorResult(error);
+  if (!hasAnyValid) {
+    const firstErr = deploymentResults.find((r) => r.error)?.error || "Connection failed";
+    return {
+      valid: false,
+      error: firstErr,
+      method: "azure_ai_chat_probe",
+      deployments: deploymentResults,
+    };
   }
 
-  return { valid: false, error: "Connection failed while testing Azure AI Foundry" };
+  const warning =
+    validCount < totalCount
+      ? `${totalCount - validCount} of ${totalCount} deployment(s) failed connection test.`
+      : null;
+
+  return {
+    valid: true,
+    error: null,
+    warning,
+    method:
+      modelsEndpointOk && targetDeployments.length === 0
+        ? "azure_ai_models"
+        : "azure_ai_chat_probe",
+    deployments: deploymentResults,
+  };
 }
 
 export async function validateWatsonxProvider({ apiKey, providerSpecificData = {} }: any) {
@@ -666,4 +765,3 @@ export async function validateSapProvider({ apiKey, providerSpecificData = {} }:
 
   return { valid: false, error: "Connection failed while testing SAP Generative AI Hub" };
 }
-
diff --git a/tests/unit/azureAiMultiModelTest.test.ts b/tests/unit/azureAiMultiModelTest.test.ts
new file mode 100644
index 0000000000..de8be64ee3
--- /dev/null
+++ b/tests/unit/azureAiMultiModelTest.test.ts
@@ -0,0 +1,189 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+import { detectAzureUrlFormat, buildAzureAiChatUrl } from "../../open-sse/config/azureAi.ts";
+import {
+  normalizeOpenAiLikeModelsResponse,
+  normalizeAzureModelsResponse,
+} from "../../src/app/api/providers/[id]/models/discovery/normalizers";
+import { validateAzureAiProvider } from "../../src/lib/providers/validation/cloudProviders.ts";
+import { buildInternalChatRequest } from "../../src/lib/api/modelTestRunner";
+
+test("detectAzureUrlFormat correctly identifies foundry vs classic Azure URL formats", () => {
+  // Foundry format (.services.ai.azure.com or explicit /v1 path)
+  assert.equal(
+    detectAzureUrlFormat("https://my-foundry.services.ai.azure.com/openai/v1"),
+    "foundry"
+  );
+  assert.equal(detectAzureUrlFormat("https://my-foundry.services.ai.azure.com"), "foundry");
+  assert.equal(detectAzureUrlFormat("https://custom-gateway.internal/openai/v1"), "foundry");
+
+  // Classic Azure OpenAI format (.openai.azure.com / .cognitiveservices.azure.com without /v1)
+  assert.equal(detectAzureUrlFormat("https://my-resource.openai.azure.com"), "classic");
+  assert.equal(detectAzureUrlFormat("https://my-resource.cognitiveservices.azure.com"), "classic");
+
+  // Classic domain with explicit /v1 path returns foundry
+  assert.equal(detectAzureUrlFormat("https://my-resource.openai.azure.com/openai/v1"), "foundry");
+
+  // Fallbacks for empty / null / unknown domain
+  assert.equal(detectAzureUrlFormat(""), "foundry");
+  assert.equal(detectAzureUrlFormat(null), "foundry");
+  assert.equal(detectAzureUrlFormat(undefined), "foundry");
+  assert.equal(detectAzureUrlFormat("https://unknown-proxy.company.com"), "foundry");
+});
+
+test("buildAzureAiChatUrl builds appropriate chat URLs based on detected format", () => {
+  // Classic format with model
+  const classicUrl = buildAzureAiChatUrl(
+    "https://my-resource.openai.azure.com",
+    "chat",
+    "gpt-4o-mini",
+    "2024-12-01-preview"
+  );
+  assert.equal(
+    classicUrl,
+    "https://my-resource.openai.azure.com/openai/deployments/gpt-4o-mini/chat/completions?api-version=2024-12-01-preview"
+  );
+
+  // Foundry format
+  const foundryUrl = buildAzureAiChatUrl(
+    "https://my-resource.services.ai.azure.com/openai/v1",
+    "chat",
+    "gpt-4o-mini"
+  );
+  assert.equal(foundryUrl, "https://my-resource.services.ai.azure.com/openai/v1/chat/completions");
+});
+
+test("normalizeOpenAiLikeModelsResponse regression test for standard OpenAI-compatible providers", () => {
+  // Standard OpenAI response format (openai, together, openrouter, etc.)
+  const openaiPayload = {
+    object: "list",
+    data: [
+      { id: "gpt-4o", object: "model", owned_by: "system" },
+      { id: "gpt-4o-mini", object: "model", owned_by: "system" },
+    ],
+  };
+
+  const normalizedOpenAI = normalizeOpenAiLikeModelsResponse(openaiPayload, "openai");
+  assert.equal(normalizedOpenAI.length, 2);
+  assert.equal(normalizedOpenAI[0].id, "gpt-4o");
+  assert.equal(normalizedOpenAI[0].owned_by, "system");
+  assert.equal(normalizedOpenAI[1].id, "gpt-4o-mini");
+
+  // Together AI format
+  const togetherPayload = {
+    data: [{ id: "meta-llama/Llama-3-70b-chat-hf", name: "Llama-3-70b", provider: "together" }],
+  };
+
+  const normalizedTogether = normalizeOpenAiLikeModelsResponse(togetherPayload, "together");
+  assert.equal(normalizedTogether.length, 1);
+  assert.equal(normalizedTogether[0].id, "meta-llama/Llama-3-70b-chat-hf");
+  assert.equal(normalizedTogether[0].owned_by, "together");
+});
+
+test("normalizeAzureModelsResponse handles Azure-specific deployment response formats", () => {
+  // Azure REST value array
+  const azureValuePayload = {
+    value: [
+      { id: "dep-gpt4", name: "GPT 4 Deployment" },
+      { deployment_name: "dep-phi3", display_name: "Phi-3 Mini" },
+    ],
+  };
+
+  const normalizedValue = normalizeAzureModelsResponse(azureValuePayload, "azure-ai");
+  assert.equal(normalizedValue.length, 2);
+  assert.equal(normalizedValue[0].id, "dep-gpt4");
+  assert.equal(normalizedValue[0].name, "GPT 4 Deployment");
+  assert.equal(normalizedValue[1].id, "dep-phi3");
+  assert.equal(normalizedValue[1].name, "Phi-3 Mini");
+
+  // Azure deployments array
+  const azureDeploymentsPayload = {
+    deployments: [{ deploymentName: "dep-mistral", model: "mistral-large" }],
+  };
+
+  const normalizedDeployments = normalizeAzureModelsResponse(azureDeploymentsPayload, "azure-ai");
+  assert.equal(normalizedDeployments.length, 1);
+  assert.equal(normalizedDeployments[0].id, "dep-mistral");
+});
+
+test("buildInternalChatRequest sets X-OmniRoute-Connection header when connectionId is provided", () => {
+  const reqWithConn = buildInternalChatRequest(
+    { model: "azure-ai/gpt-4o" },
+    new AbortController().signal,
+    "conn-azure-123"
+  );
+  assert.equal(reqWithConn.headers.get("X-OmniRoute-Connection"), "conn-azure-123");
+
+  const reqWithoutConn = buildInternalChatRequest(
+    { model: "azure-ai/gpt-4o" },
+    new AbortController().signal
+  );
+  assert.equal(reqWithoutConn.headers.get("X-OmniRoute-Connection"), null);
+});
+
+test("validateAzureAiProvider evaluates multi-deployment connections with granular per-deployment results", async () => {
+  const originalFetch = globalThis.fetch;
+  globalThis.fetch = (async (url: string | URL | Request, options?: RequestInit) => {
+    const urlStr = String(url);
+    const bodyStr = String(options?.body || "");
+    if (urlStr.includes("/models")) {
+      return new Response(JSON.stringify({ error: "models unavailable" }), { status: 404 });
+    }
+    if (urlStr.includes("dep-ok") || bodyStr.includes("dep-ok")) {
+      return new Response(JSON.stringify({ id: "dep-ok" }), { status: 200 });
+    }
+    if (urlStr.includes("dep-auth-err") || bodyStr.includes("dep-auth-err")) {
+      return new Response(JSON.stringify({ error: "unauthorized" }), { status: 401 });
+    }
+    if (urlStr.includes("dep-timeout") || bodyStr.includes("dep-timeout")) {
+      throw new Error("Connection test timed out");
+    }
+    return new Response(JSON.stringify({ ok: true }), { status: 200 });
+  }) as typeof globalThis.fetch;
+
+  try {
+    const psd = {
+      baseUrl: "https://example.com/openai/v1",
+      deployments: ["dep-ok", "dep-auth-err", "dep-timeout"],
+    };
+
+    const result = await validateAzureAiProvider({
+      apiKey: "test-api-key",
+      providerSpecificData: psd,
+    });
+
+    assert.equal(typeof result, "object");
+    assert.equal(result.valid, true);
+    assert.ok(Array.isArray(result.deployments));
+    assert.equal(result.deployments.length, 3);
+
+    type DeploymentResult = {
+      deploymentId: string;
+      valid: boolean;
+      status: string;
+      error?: string | null;
+    };
+    const deployments = result.deployments as DeploymentResult[];
+    const depOk = deployments.find((d) => d.deploymentId === "dep-ok");
+    const depAuth = deployments.find((d) => d.deploymentId === "dep-auth-err");
+    const depTimeout = deployments.find((d) => d.deploymentId === "dep-timeout");
+
+    assert.ok(depOk);
+    assert.equal(depOk.valid, true);
+    assert.equal(depOk.status, "ok");
+
+    assert.ok(depAuth);
+    assert.equal(depAuth.valid, false);
+    assert.equal(depAuth.status, "auth_error");
+
+    assert.ok(depTimeout);
+    assert.equal(depTimeout.valid, false);
+    assert.equal(depTimeout.status, "error");
+
+    // 1 failed/error deployment does not block the other deployments or invalidate the connection completely
+    assert.equal(typeof result.warning, "string");
+  } finally {
+    globalThis.fetch = originalFetch;
+  }
+});