fix(embeddings): forward Gemini output dimensions (#1366)

Co-authored-by: GoClaw Operator <operator@goclaw>

open-sse/handlers/embeddingProviders/gemini.js

@@ -13,12 +13,24 @@ export default {
     return `${BASE}/${path}:${op}?key=${encodeURIComponent(apiKey)}`;
   },
   buildHeaders: () => ({ "Content-Type": "application/json" }),
-  buildBody: (model, { input }) => {
+  buildBody: (model, { input, dimensions }) => {
     const m = modelPath(model);
+    const outputDimensionality = Number(dimensions);
+    const hasOutputDimensionality = Number.isFinite(outputDimensionality) && outputDimensionality > 0;
     if (Array.isArray(input)) {
-      return { requests: input.map((text) => ({ model: m, content: { parts: [{ text: String(text) }] } })) };
+      return {
+        requests: input.map((text) => ({
+          model: m,
+          content: { parts: [{ text: String(text) }] },
+          ...(hasOutputDimensionality ? { outputDimensionality } : {}),
+        })),
+      };
     }
-    return { model: m, content: { parts: [{ text: String(input) }] } };
+    return {
+      model: m,
+      content: { parts: [{ text: String(input) }] },
+      ...(hasOutputDimensionality ? { outputDimensionality } : {}),
+    };
   },
   normalize: (responseBody, model) => {
     if (responseBody.object === "list" && Array.isArray(responseBody.data)) return responseBody;

tests/unit/embeddingsCore.test.js

@@ -141,6 +141,51 @@ describe("buildEmbeddingsBody", () => {
     const sent = JSON.parse(init.body);
     expect(sent.encoding_format).toBe("float");
   });
+
+  it("gemini single input forwards dimensions as outputDimensionality", async () => {
+    vi.mocked(fetch).mockResolvedValueOnce(makeProviderResponse({
+      embedding: { values: [0.1, 0.2, 0.3] },
+    }));
+
+    await handleEmbeddingsCore(makeOptions({
+      body: {
+        model: "gemini/gemini-embedding-2-preview",
+        input: "test",
+        dimensions: 1536,
+      },
+      modelInfo: { provider: "gemini", model: "gemini-embedding-2-preview" },
+      credentials: { apiKey: "gemini-key" },
+    }));
+
+    const [, init] = vi.mocked(fetch).mock.calls[0];
+    const sent = JSON.parse(init.body);
+    expect(sent.outputDimensionality).toBe(1536);
+  });
+
+  it("gemini batch input forwards dimensions on each request", async () => {
+    vi.mocked(fetch).mockResolvedValueOnce(makeProviderResponse({
+      embeddings: [
+        { values: [0.1, 0.2, 0.3] },
+        { values: [0.4, 0.5, 0.6] },
+      ],
+    }));
+
+    await handleEmbeddingsCore(makeOptions({
+      body: {
+        model: "gemini/gemini-embedding-2-preview",
+        input: ["hello", "world"],
+        dimensions: 1536,
+      },
+      modelInfo: { provider: "gemini", model: "gemini-embedding-2-preview" },
+      credentials: { apiKey: "gemini-key" },
+    }));
+
+    const [, init] = vi.mocked(fetch).mock.calls[0];
+    const sent = JSON.parse(init.body);
+    expect(sent.requests).toHaveLength(2);
+    expect(sent.requests[0].outputDimensionality).toBe(1536);
+    expect(sent.requests[1].outputDimensionality).toBe(1536);
+  });
 });
 
 // ─── Test: buildEmbeddingsUrl ────────────────────────────────────────────────