diff --git a/src/plugins/provider-catalog.test.ts b/src/plugins/provider-catalog.test.ts
index 84e1c824456..34e4c7b1a98 100644
--- a/src/plugins/provider-catalog.test.ts
+++ b/src/plugins/provider-catalog.test.ts
@@ -121,6 +121,36 @@ describe("buildSingleProviderApiKeyCatalog", () => {
     });
   });
 
+  it("matches explicit base url config across canonical provider aliases", async () => {
+    const result = await buildSingleProviderApiKeyCatalog({
+      ctx: createCatalogContext({
+        apiKeys: { zai: "secret-key" },
+        config: {
+          models: {
+            providers: {
+              "z.ai": {
+                baseUrl: " https://api.z.ai/custom ",
+                models: [],
+              },
+            },
+          },
+        },
+      }),
+      providerId: "z-ai",
+      buildProvider: () => createProviderConfig({ baseUrl: "https://default.example/zai" }),
+      allowExplicitBaseUrl: true,
+    });
+
+    expect(result).toEqual({
+      provider: {
+        api: "openai-completions",
+        baseUrl: "https://api.z.ai/custom",
+        models: [],
+        apiKey: "secret-key",
+      },
+    });
+  });
+
   it("adds api key to each paired provider", async () => {
     const result = await buildPairedProviderApiKeyCatalog({
       ctx: createCatalogContext({
diff --git a/src/plugins/provider-catalog.ts b/src/plugins/provider-catalog.ts
index a8934fa6c0a..cf38fb12a92 100644
--- a/src/plugins/provider-catalog.ts
+++ b/src/plugins/provider-catalog.ts
@@ -24,14 +24,18 @@ export async function buildSingleProviderApiKeyCatalog(params: {
   buildProvider: () => ModelProviderConfig | Promise<ModelProviderConfig>;
   allowExplicitBaseUrl?: boolean;
 }): Promise<ProviderCatalogResult> {
-  const apiKey = params.ctx.resolveProviderApiKey(params.providerId).apiKey;
+  const providerId = normalizeProviderId(params.providerId);
+  const apiKey = params.ctx.resolveProviderApiKey(providerId).apiKey;
   if (!apiKey) {
     return null;
   }
 
-  const explicitProvider = params.allowExplicitBaseUrl
-    ? params.ctx.config.models?.providers?.[params.providerId]
-    : undefined;
+  const explicitProvider =
+    params.allowExplicitBaseUrl && params.ctx.config.models?.providers
+      ? Object.entries(params.ctx.config.models.providers).find(
+          ([configuredProviderId]) => normalizeProviderId(configuredProviderId) === providerId,
+        )?.[1]
+      : undefined;
   const explicitBaseUrl =
     typeof explicitProvider?.baseUrl === "string" ? explicitProvider.baseUrl.trim() : "";
 
@@ -51,7 +55,7 @@ export async function buildPairedProviderApiKeyCatalog(params: {
     | Record<string, ModelProviderConfig>
     | Promise<Record<string, ModelProviderConfig>>;
 }): Promise<ProviderCatalogResult> {
-  const apiKey = params.ctx.resolveProviderApiKey(params.providerId).apiKey;
+  const apiKey = params.ctx.resolveProviderApiKey(normalizeProviderId(params.providerId)).apiKey;
   if (!apiKey) {
     return null;
   }