[ResponsesAPI] Provider in model + clean input (#1588)

Some tweaks to make it work in a demo:
- provider can be passed like this
`model="cohere@CohereLabs/c4ai-command-a-03-2025"`
- clean up input message if empty message (not supported by some
providers)
- check tools calls is not an empty list

Author: Wauplin

packages/responses-server/src/routes/responses.ts

@@ -45,46 +45,53 @@ export const postCreateResponse = async (
 
 	if (Array.isArray(req.body.input)) {
 		messages.push(
-			...req.body.input.map((item) => ({
-				role: item.role,
-				content:
-					typeof item.content === "string"
-						? item.content
-						: item.content
-								.map((content) => {
-									switch (content.type) {
-										case "input_image":
-											return {
-												type: "image_url" as ChatCompletionInputMessageChunkType,
-												image_url: {
-													url: content.image_url,
-												},
-											};
-										case "output_text":
-											return {
-												type: "text" as ChatCompletionInputMessageChunkType,
-												text: content.text,
-											};
-										case "refusal":
-											return undefined;
-										case "input_text":
-											return {
-												type: "text" as ChatCompletionInputMessageChunkType,
-												text: content.text,
-											};
-									}
-								})
-								.filter((item) => item !== undefined),
-			}))
+			...req.body.input
+				.map((item) => ({
+					role: item.role,
+					content:
+						typeof item.content === "string"
+							? item.content
+							: item.content
+									.map((content) => {
+										switch (content.type) {
+											case "input_image":
+												return {
+													type: "image_url" as ChatCompletionInputMessageChunkType,
+													image_url: {
+														url: content.image_url,
+													},
+												};
+											case "output_text":
+												return content.text
+													? {
+															type: "text" as ChatCompletionInputMessageChunkType,
+															text: content.text,
+													  }
+													: undefined;
+											case "refusal":
+												return undefined;
+											case "input_text":
+												return {
+													type: "text" as ChatCompletionInputMessageChunkType,
+													text: content.text,
+												};
+										}
+									})
+									.filter((item) => item !== undefined),
+				}))
+				.filter((message) => message.content?.length !== 0)
 		);
 	} else {
 		messages.push({ role: "user", content: req.body.input });
 	}
 
+	const model = req.body.model.includes("@") ? req.body.model.split("@")[1] : req.body.model;
+	const provider = req.body.model.includes("@") ? req.body.model.split("@")[0] : undefined;
+
 	const payload: ChatCompletionInput = {
 		// main params
-		model: req.body.model,
-		provider: req.body.provider,
+		model: model,
+		provider: provider,
 		messages: messages,
 		stream: req.body.stream,
 		// options
@@ -239,7 +246,7 @@ export const postCreateResponse = async (
 						delta: chunk.choices[0].delta.content,
 						sequence_number: sequenceNumber++,
 					});
-				} else if (chunk.choices[0].delta.tool_calls) {
+				} else if (chunk.choices[0].delta.tool_calls && chunk.choices[0].delta.tool_calls.length > 0) {
 					if (chunk.choices[0].delta.tool_calls.length > 1) {
 						throw new StreamingError("Not implemented: only single tool call is supported in streaming mode.");
 					}

packages/responses-server/src/schemas.ts

@@ -84,7 +84,6 @@ export const createResponseParamsSchema = z.object({
 		.default(null),
 	model: z.string(),
 	// parallel_tool_calls: z.boolean().default(true), // TODO: how to handle this if chat completion doesn't?
-	provider: z.string().optional(),
 	// previous_response_id: z.string().nullable().default(null),
 	// reasoning: z.object({
 	// 	effort: z.enum(["low", "medium", "high"]).default("medium"),