refactor(providers): share openai compat defaults

src/agents/openai-completions-compat.ts

@@ -0,0 +1,58 @@
+import type { ProviderEndpointClass, ProviderRequestCapabilities } from "./provider-attribution.js";
+
+type OpenAICompletionsCompatDefaultsInput = {
+  provider?: string;
+  endpointClass: ProviderEndpointClass;
+  knownProviderFamily: string;
+};
+
+export type OpenAICompletionsCompatDefaults = {
+  supportsDeveloperRole: boolean;
+  supportsUsageInStreaming: boolean;
+  supportsStrictMode: boolean;
+};
+
+function isDefaultRouteProvider(provider: string | undefined, ...ids: string[]) {
+  return provider !== undefined && ids.includes(provider);
+}
+
+export function resolveOpenAICompletionsCompatDefaults(
+  input: OpenAICompletionsCompatDefaultsInput,
+): OpenAICompletionsCompatDefaults {
+  const { endpointClass, knownProviderFamily } = input;
+  const isDefaultRoute = endpointClass === "default";
+  const usesConfiguredNonOpenAIEndpoint =
+    endpointClass !== "default" && endpointClass !== "openai-public";
+  const isMoonshotLike =
+    knownProviderFamily === "moonshot" ||
+    knownProviderFamily === "modelstudio" ||
+    endpointClass === "moonshot-native" ||
+    endpointClass === "modelstudio-native";
+  const isZai =
+    endpointClass === "zai-native" ||
+    (isDefaultRoute && isDefaultRouteProvider(input.provider, "zai"));
+  const isNonStandard =
+    endpointClass === "cerebras-native" ||
+    endpointClass === "chutes-native" ||
+    endpointClass === "deepseek-native" ||
+    endpointClass === "mistral-public" ||
+    endpointClass === "opencode-native" ||
+    endpointClass === "xai-native" ||
+    isZai ||
+    (isDefaultRoute &&
+      isDefaultRouteProvider(input.provider, "cerebras", "chutes", "deepseek", "opencode", "xai"));
+
+  return {
+    supportsDeveloperRole: !isNonStandard && !isMoonshotLike && !usesConfiguredNonOpenAIEndpoint,
+    supportsUsageInStreaming: !isNonStandard && !usesConfiguredNonOpenAIEndpoint,
+    supportsStrictMode: !isZai && !usesConfiguredNonOpenAIEndpoint,
+  };
+}
+
+export function resolveOpenAICompletionsCompatDefaultsFromCapabilities(
+  input: Pick<ProviderRequestCapabilities, "endpointClass" | "knownProviderFamily"> & {
+    provider?: string;
+  },
+): OpenAICompletionsCompatDefaults {
+  return resolveOpenAICompletionsCompatDefaults(input);
+}

src/agents/openai-transport-stream.ts

@@ -19,6 +19,7 @@ import type {
   ResponseInputMessageContentList,
 } from "openai/resources/responses/responses.js";
 import { fetchWithSsrFGuard } from "../infra/net/fetch-guard.js";
+import { resolveOpenAICompletionsCompatDefaultsFromCapabilities } from "./openai-completions-compat.js";
 import { resolveProviderRequestCapabilities } from "./provider-attribution.js";
 import {
   buildProviderRequestDispatcherPolicy,
@@ -1341,30 +1342,13 @@ function detectCompat(model: OpenAIModeModel) {
   });
   const endpointClass = capabilities.endpointClass;
   const isDefaultRoute = endpointClass === "default";
-  const usesConfiguredNonOpenAIEndpoint =
-    endpointClass !== "default" && endpointClass !== "openai-public";
+  const compatDefaults = resolveOpenAICompletionsCompatDefaultsFromCapabilities({
+    provider,
+    ...capabilities,
+  });
   const isMistral =
     capabilities.knownProviderFamily === "mistral" || endpointClass === "mistral-public";
-  const isMoonshotLike =
-    capabilities.knownProviderFamily === "moonshot" ||
-    capabilities.knownProviderFamily === "modelstudio" ||
-    endpointClass === "moonshot-native" ||
-    endpointClass === "modelstudio-native";
   const isZai = endpointClass === "zai-native" || (isDefaultRoute && provider === "zai");
-  const isNonStandard =
-    endpointClass === "cerebras-native" ||
-    endpointClass === "chutes-native" ||
-    endpointClass === "deepseek-native" ||
-    isMistral ||
-    endpointClass === "opencode-native" ||
-    endpointClass === "xai-native" ||
-    isZai ||
-    (isDefaultRoute &&
-      (provider === "cerebras" ||
-        provider === "chutes" ||
-        provider === "deepseek" ||
-        provider === "opencode" ||
-        provider === "xai"));
   const useMaxTokens =
     endpointClass === "chutes-native" || (isDefaultRoute && provider === "chutes") || isMistral;
   const isGrok = endpointClass === "xai-native" || (isDefaultRoute && provider === "xai");
@@ -1380,11 +1364,26 @@ function detectCompat(model: OpenAIModeModel) {
         }
       : {};
   return {
-    supportsStore: !isNonStandard,
-    supportsDeveloperRole: !isNonStandard && !isMoonshotLike && !usesConfiguredNonOpenAIEndpoint,
+    supportsStore:
+      endpointClass !== "cerebras-native" &&
+      endpointClass !== "chutes-native" &&
+      endpointClass !== "deepseek-native" &&
+      !isMistral &&
+      endpointClass !== "opencode-native" &&
+      endpointClass !== "xai-native" &&
+      !isZai &&
+      !(
+        isDefaultRoute &&
+        (provider === "cerebras" ||
+          provider === "chutes" ||
+          provider === "deepseek" ||
+          provider === "opencode" ||
+          provider === "xai")
+      ),
+    supportsDeveloperRole: compatDefaults.supportsDeveloperRole,
     supportsReasoningEffort: !isGrok && !isMistral && !isZai,
     reasoningEffortMap,
-    supportsUsageInStreaming: !isNonStandard && !usesConfiguredNonOpenAIEndpoint,
+    supportsUsageInStreaming: compatDefaults.supportsUsageInStreaming,
     maxTokensField: useMaxTokens ? "max_tokens" : "max_completion_tokens",
     requiresToolResultName: false,
     requiresAssistantAfterToolResult: false,
@@ -1398,7 +1397,7 @@ function detectCompat(model: OpenAIModeModel) {
         : "openai",
     openRouterRouting: {},
     vercelGatewayRouting: {},
-    supportsStrictMode: !isZai && !usesConfiguredNonOpenAIEndpoint,
+    supportsStrictMode: compatDefaults.supportsStrictMode,
   };
 }
 

src/plugins/provider-model-compat.ts

@@ -1,4 +1,5 @@
 import type { Api, Model } from "@mariozechner/pi-ai";
+import { resolveOpenAICompletionsCompatDefaultsFromCapabilities } from "../agents/openai-completions-compat.js";
 import { resolveProviderRequestCapabilities } from "../agents/provider-attribution.js";
 import type { ModelCompatConfig } from "../config/types.models.js";
 
@@ -92,21 +93,30 @@ export function normalizeModelCompat(model: Model<Api>): Model<Api> {
   }
 
   const compat = model.compat ?? undefined;
-  const needsForce = baseUrl
-    ? resolveProviderRequestCapabilities({
+  const detectedCompatDefaults = baseUrl
+    ? resolveOpenAICompletionsCompatDefaultsFromCapabilities({
         provider: typeof model.provider === "string" ? model.provider : undefined,
-        api: model.api,
-        baseUrl,
-        capability: "llm",
-        transport: "stream",
-      }).endpointClass !== "openai-public"
-    : false;
+        ...resolveProviderRequestCapabilities({
+          provider: typeof model.provider === "string" ? model.provider : undefined,
+          api: model.api,
+          baseUrl,
+          capability: "llm",
+          transport: "stream",
+        }),
+      })
+    : undefined;
+  const needsForce = Boolean(
+    detectedCompatDefaults &&
+    (!detectedCompatDefaults.supportsDeveloperRole ||
+      !detectedCompatDefaults.supportsUsageInStreaming ||
+      !detectedCompatDefaults.supportsStrictMode),
+  );
   if (!needsForce) {
     return model;
   }
   const forcedDeveloperRole = compat?.supportsDeveloperRole === true;
   const hasStreamingUsageOverride = compat?.supportsUsageInStreaming !== undefined;
-  const targetStrictMode = compat?.supportsStrictMode ?? false;
+  const targetStrictMode = compat?.supportsStrictMode ?? detectedCompatDefaults?.supportsStrictMode;
   if (
     compat?.supportsDeveloperRole !== undefined &&
     hasStreamingUsageOverride &&
@@ -121,13 +131,17 @@ export function normalizeModelCompat(model: Model<Api>): Model<Api> {
       ? {
           ...compat,
           supportsDeveloperRole: forcedDeveloperRole || false,
-          ...(hasStreamingUsageOverride ? {} : { supportsUsageInStreaming: false }),
+          ...(hasStreamingUsageOverride
+            ? {}
+            : {
+                supportsUsageInStreaming: detectedCompatDefaults?.supportsUsageInStreaming ?? false,
+              }),
           supportsStrictMode: targetStrictMode,
         }
       : {
           supportsDeveloperRole: false,
-          supportsUsageInStreaming: false,
-          supportsStrictMode: false,
+          supportsUsageInStreaming: detectedCompatDefaults?.supportsUsageInStreaming ?? false,
+          supportsStrictMode: detectedCompatDefaults?.supportsStrictMode ?? false,
         },
   } as typeof model;
 }