fix: add openai_custom to error message and make ?provider= case-insensitive (#80)

* fix: add openai_custom to error message and make ?provider= case-insensitive

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* fix: accept custom_openai as alias for openai_custom in ?provider= param

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* squash: Add tests.

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: bgrozev

src/server.ts

@@ -265,7 +265,7 @@ export function handleWebSocketConnection(ws: WebSocket, parameters: ISessionPar
 		if (requestedProvider) {
 			// Provider specified in URL
 			if (!isValidProvider(requestedProvider)) {
-				const errorMessage = `Invalid provider: ${requestedProvider}. Valid providers are: openai, gemini, deepgram, dummy`;
+				const errorMessage = `Invalid provider: ${requestedProvider}. Valid providers are: openai, openai_custom, gemini, deepgram, dummy`;
 				logger.error(`[WS-${connectionId}] ${errorMessage}`);
 				ws.close(1002, errorMessage);
 				return;

src/utils.ts

@@ -45,7 +45,8 @@ export function extractSessionParameters(url: string): ISessionParameters {
 	const sendBack = parsedUrl.searchParams.get('sendBack');
 	const sendBackInterim = parsedUrl.searchParams.get('sendBackInterim');
 	const lang = parsedUrl.searchParams.get('lang');
-	const provider = parsedUrl.searchParams.get('provider');
+	const rawProvider = parsedUrl.searchParams.get('provider')?.toLowerCase();
+	const provider = rawProvider === 'custom_openai' ? 'openai_custom' : rawProvider;
 	const encodingParam = parsedUrl.searchParams.get('encoding');
 	let encoding: AudioEncoding;
 	if (encodingParam === null || encodingParam === 'opus') {

test/unit/utils.test.ts

@@ -51,6 +51,24 @@ describe('extractSessionParameters', () => {
 			expect(params.tags).toEqual(['production', 'region-us']);
 		});
 
+		it('should normalize provider to lowercase', () => {
+			const url = 'ws://localhost:8080/transcribe?provider=Deepgram';
+			const params = extractSessionParameters(url);
+			expect(params.provider).toBe('deepgram');
+		});
+
+		it('should map custom_openai alias to openai_custom', () => {
+			const url = 'ws://localhost:8080/transcribe?provider=custom_openai';
+			const params = extractSessionParameters(url);
+			expect(params.provider).toBe('openai_custom');
+		});
+
+		it('should map CUSTOM_OPENAI alias case-insensitively to openai_custom', () => {
+			const url = 'ws://localhost:8080/transcribe?provider=CUSTOM_OPENAI';
+			const params = extractSessionParameters(url);
+			expect(params.provider).toBe('openai_custom');
+		});
+
 		it('should filter out empty tag values', () => {
 			const url = 'ws://localhost:8080/transcribe?sessionId=test&tag=&tag=valid';
 			const params = extractSessionParameters(url);