CreateEmbeddingsResponse has confusing type structure

[nitodeco]

The type for CreateEmbeddingsResponse is a union of CreateEmbeddingsResponseBody and string.

Source from createembeddings.d.ts:

/**
 * Embedding response
 */
export type CreateEmbeddingsResponseBody = {
    id?: string | undefined;
    object: ObjectT;
    data: Array<CreateEmbeddingsData>;
    model: string;
    usage?: Usage | undefined;
};
export type CreateEmbeddingsResponse = CreateEmbeddingsResponseBody | string;

This requires developers to handle both cases when implementing the sdk. Additionally, CreateEmbeddingsData is typed as string | number[], which again requires handling the string case.

Here is an example of this:

export const generateEmbeddingBad = async (text: string): Promise<number[]> => {
	const embedding = await openrouter.embeddings.generate({
		model: "google/gemini-embedding-001",
		input: text,
		encodingFormat: "float",
	});

	// Need to handle a string only response
	if (typeof embedding === "string") {
		throw new Error("Invalid embedding response");
	}

	// Need to ensure embedding is an array of numbers
	if (!Array.isArray(embedding.data[0].embedding)) {
		throw new Error("Invalid embedding response");
	}

	return embedding.data[0].embedding;
};

Ideally, using the sdk for embeddings would look more like this:

export const generateEmbeddingGood = async (text: string): Promise<number[]> => {
	const embedding = await openrouter.embeddings.generate({
		model: "google/gemini-embedding-001",
		input: text,
		encodingFormat: "float",
	});

	return embedding.data[0].embedding;
};