fix: validate openai speech speeds

extensions/openai/speech-provider.test.ts

@@ -97,6 +97,64 @@ describe("buildOpenAISpeechProvider", () => {
     });
   });
 
+  it("drops malformed speech speed values", () => {
+    const provider = buildOpenAISpeechProvider();
+    const resolved = provider.resolveConfig?.({
+      cfg: {} as never,
+      timeoutMs: 30_000,
+      rawConfig: {
+        providers: {
+          openai: {
+            speed: 4.5,
+          },
+        },
+      },
+    });
+
+    expect(resolved?.speed).toBeUndefined();
+  });
+
+  it("passes custom endpoint speech speeds through", () => {
+    const provider = buildOpenAISpeechProvider();
+    const resolved = provider.resolveConfig?.({
+      cfg: {} as never,
+      timeoutMs: 30_000,
+      rawConfig: {
+        providers: {
+          openai: {
+            baseUrl: "https://tts.example.com/v1",
+            speed: 4.5,
+          },
+        },
+      },
+    });
+
+    expect(resolved?.speed).toBe(4.5);
+  });
+
+  it("uses talk base url overrides when validating speech speed", () => {
+    const provider = buildOpenAISpeechProvider();
+
+    const resolvedConfig = provider.resolveTalkConfig?.({
+      cfg: {} as never,
+      timeoutMs: 30_000,
+      baseTtsConfig: {
+        providers: {
+          openai: {
+            apiKey: "sk-base",
+          },
+        },
+      },
+      talkProviderConfig: {
+        baseUrl: "https://tts.example.com/v1",
+        speed: 4.5,
+      },
+    });
+
+    expect(resolvedConfig?.baseUrl).toBe("https://tts.example.com/v1");
+    expect(resolvedConfig?.speed).toBe(4.5);
+  });
+
   it("parses OpenAI directive tokens against the resolved base url", () => {
     const provider = buildOpenAISpeechProvider();
 

extensions/openai/speech-provider.ts

@@ -105,24 +105,36 @@ function readExtraBody(value: unknown): Record<string, unknown> | undefined {
   return body;
 }
 
+function normalizeOpenAISpeechSpeed(value: unknown, baseUrl?: string): number | undefined {
+  const speed = asFiniteNumber(value);
+  if (speed === undefined) {
+    return undefined;
+  }
+  if (baseUrl !== undefined && normalizeOpenAITtsBaseUrl(baseUrl) !== DEFAULT_OPENAI_BASE_URL) {
+    return speed;
+  }
+  return speed >= 0.25 && speed <= 4 ? speed : undefined;
+}
+
 function normalizeOpenAIProviderConfig(
   rawConfig: Record<string, unknown>,
 ): OpenAITtsProviderConfig {
   const raw = resolveOpenAIProviderConfigRecord(rawConfig);
   const extraBody = readExtraBody(raw?.extraBody) ?? readExtraBody(raw?.extra_body);
+  const baseUrl = normalizeOpenAITtsBaseUrl(
+    trimToUndefined(raw?.baseUrl) ??
+      trimToUndefined(process.env.OPENAI_TTS_BASE_URL) ??
+      DEFAULT_OPENAI_BASE_URL,
+  );
   return {
     apiKey: normalizeResolvedSecretInputString({
       value: raw?.apiKey,
       path: "messages.tts.providers.openai.apiKey",
     }),
-    baseUrl: normalizeOpenAITtsBaseUrl(
-      trimToUndefined(raw?.baseUrl) ??
-        trimToUndefined(process.env.OPENAI_TTS_BASE_URL) ??
-        DEFAULT_OPENAI_BASE_URL,
-    ),
+    baseUrl,
     model: trimToUndefined(raw?.model) ?? "gpt-4o-mini-tts",
     voice: trimToUndefined(raw?.voice) ?? "coral",
-    speed: asFiniteNumber(raw?.speed),
+    speed: normalizeOpenAISpeechSpeed(raw?.speed, baseUrl),
     instructions: trimToUndefined(raw?.instructions),
     responseFormat: normalizeOpenAISpeechResponseFormat(raw?.responseFormat),
     extraBody,
@@ -136,7 +148,11 @@ function readOpenAIProviderConfig(config: SpeechProviderConfig): OpenAITtsProvid
     baseUrl: trimToUndefined(config.baseUrl) ?? normalized.baseUrl,
     model: trimToUndefined(config.model) ?? normalized.model,
     voice: trimToUndefined(config.voice) ?? normalized.voice,
-    speed: asFiniteNumber(config.speed) ?? normalized.speed,
+    speed:
+      normalizeOpenAISpeechSpeed(
+        config.speed,
+        trimToUndefined(config.baseUrl) ?? normalized.baseUrl,
+      ) ?? normalized.speed,
     instructions: trimToUndefined(config.instructions) ?? normalized.instructions,
     responseFormat:
       normalizeOpenAISpeechResponseFormat(config.responseFormat) ?? normalized.responseFormat,
@@ -146,6 +162,7 @@ function readOpenAIProviderConfig(config: SpeechProviderConfig): OpenAITtsProvid
 
 function readOpenAIOverrides(
   overrides: SpeechProviderOverrides | undefined,
+  baseUrl: string,
 ): OpenAITtsProviderOverrides {
   if (!overrides) {
     return {};
@@ -153,7 +170,7 @@ function readOpenAIOverrides(
   return {
     model: trimToUndefined(overrides.model),
     voice: trimToUndefined(overrides.voice),
-    speed: asFiniteNumber(overrides.speed),
+    speed: normalizeOpenAISpeechSpeed(overrides.speed, baseUrl),
   };
 }
 
@@ -232,6 +249,8 @@ export function buildOpenAISpeechProvider(): SpeechProviderPlugin {
     resolveTalkConfig: ({ baseTtsConfig, talkProviderConfig }) => {
       const base = normalizeOpenAIProviderConfig(baseTtsConfig);
       const responseFormat = normalizeOpenAISpeechResponseFormat(talkProviderConfig.responseFormat);
+      const baseUrl = trimToUndefined(talkProviderConfig.baseUrl) ?? base.baseUrl;
+      const speed = normalizeOpenAISpeechSpeed(talkProviderConfig.speed, baseUrl);
       return {
         ...base,
         ...(talkProviderConfig.apiKey === undefined
@@ -242,18 +261,14 @@ export function buildOpenAISpeechProvider(): SpeechProviderPlugin {
                 path: "talk.providers.openai.apiKey",
               }),
             }),
-        ...(trimToUndefined(talkProviderConfig.baseUrl) == null
-          ? {}
-          : { baseUrl: trimToUndefined(talkProviderConfig.baseUrl) }),
+        ...(trimToUndefined(talkProviderConfig.baseUrl) == null ? {} : { baseUrl }),
         ...(trimToUndefined(talkProviderConfig.modelId) == null
           ? {}
           : { model: trimToUndefined(talkProviderConfig.modelId) }),
         ...(trimToUndefined(talkProviderConfig.voiceId) == null
           ? {}
           : { voice: trimToUndefined(talkProviderConfig.voiceId) }),
-        ...(asFiniteNumber(talkProviderConfig.speed) == null
-          ? {}
-          : { speed: asFiniteNumber(talkProviderConfig.speed) }),
+        ...(speed == null ? {} : { speed }),
         ...(trimToUndefined(talkProviderConfig.instructions) == null
           ? {}
           : { instructions: trimToUndefined(talkProviderConfig.instructions) }),
@@ -291,7 +306,7 @@ export function buildOpenAISpeechProvider(): SpeechProviderPlugin {
     },
     synthesize: async (req) => {
       const config = readOpenAIProviderConfig(req.providerConfig);
-      const overrides = readOpenAIOverrides(req.providerOverrides);
+      const overrides = readOpenAIOverrides(req.providerOverrides, config.baseUrl);
       const apiKey = config.apiKey || process.env.OPENAI_API_KEY;
       if (!apiKey) {
         throw new Error("OpenAI API key missing");
@@ -322,7 +337,7 @@ export function buildOpenAISpeechProvider(): SpeechProviderPlugin {
     },
     synthesizeTelephony: async (req) => {
       const config = readOpenAIProviderConfig(req.providerConfig);
-      const overrides = readOpenAIOverrides(req.providerOverrides);
+      const overrides = readOpenAIOverrides(req.providerOverrides, config.baseUrl);
       const apiKey = config.apiKey || process.env.OPENAI_API_KEY;
       if (!apiKey) {
         throw new Error("OpenAI API key missing");