fix(ollama): restore catalog-driven num_ctx for native /api/chat

extensions/ollama/src/stream-runtime.test.ts

@@ -208,7 +208,7 @@ describe("createConfiguredOllamaCompatStreamWrapper", () => {
         };
         expect(requestBody.think).toBe(false);
         expect(requestBody.options?.think).toBeUndefined();
-        expect(requestBody.options?.num_ctx).toBeUndefined();
+        expect(requestBody.options?.num_ctx).toBe(131072);
       },
     );
   });
@@ -310,7 +310,7 @@ describe("createConfiguredOllamaCompatStreamWrapper", () => {
         };
         expect(requestBody.think).toBe("low");
         expect(requestBody.options?.think).toBeUndefined();
-        expect(requestBody.options?.num_ctx).toBeUndefined();
+        expect(requestBody.options?.num_ctx).toBe(131072);
       },
     );
   });
@@ -405,7 +405,7 @@ describe("createConfiguredOllamaCompatStreamWrapper", () => {
         };
         expect(requestBody.think).toBe("high");
         expect(requestBody.options?.think).toBeUndefined();
-        expect(requestBody.options?.num_ctx).toBeUndefined();
+        expect(requestBody.options?.num_ctx).toBe(131072);
       },
     );
   });
@@ -1602,7 +1602,9 @@ describe("createOllamaStreamFn", () => {
         if (!requestBody.options) {
           throw new Error("Expected Ollama request options");
         }
-        expect(requestBody.options?.num_ctx).toBeUndefined();
+        // Catalog `contextWindow` flows through as `num_ctx` so the request
+        // does not silently truncate to Ollama's small Modelfile default.
+        expect(requestBody.options?.num_ctx).toBe(131072);
         expect(requestBody.options.num_predict).toBe(123);
       },
     );
@@ -1657,6 +1659,60 @@ describe("createOllamaStreamFn", () => {
     );
   });
 
+  it("omits num_ctx when the model has no params.num_ctx and no catalog window", async () => {
+    await withMockNdjsonFetch(
+      [
+        '{"model":"m","created_at":"t","message":{"role":"assistant","content":"ok"},"done":false}',
+        '{"model":"m","created_at":"t","message":{"role":"assistant","content":""},"done":true,"prompt_eval_count":1,"eval_count":1}',
+      ],
+      async (fetchMock) => {
+        const stream = await createOllamaTestStream({
+          baseUrl: "http://ollama-host:11434",
+          // Override the helper default contextWindow back to undefined so the
+          // request body should leave Ollama's Modelfile to decide num_ctx.
+          model: { contextWindow: undefined },
+        });
+
+        await collectStreamEvents(stream);
+
+        const requestInit = getGuardedFetchCall(fetchMock).init ?? {};
+        if (typeof requestInit.body !== "string") {
+          throw new Error("Expected string request body");
+        }
+        const requestBody = JSON.parse(requestInit.body) as {
+          options?: { num_ctx?: number };
+        };
+        expect(requestBody.options?.num_ctx).toBeUndefined();
+      },
+    );
+  });
+
+  it("falls back to catalog contextWindow as num_ctx when params.num_ctx is unset", async () => {
+    await withMockNdjsonFetch(
+      [
+        '{"model":"m","created_at":"t","message":{"role":"assistant","content":"ok"},"done":false}',
+        '{"model":"m","created_at":"t","message":{"role":"assistant","content":""},"done":true,"prompt_eval_count":1,"eval_count":1}',
+      ],
+      async (fetchMock) => {
+        const stream = await createOllamaTestStream({
+          baseUrl: "http://ollama-host:11434",
+          model: { contextWindow: 32768 },
+        });
+
+        await collectStreamEvents(stream);
+
+        const requestInit = getGuardedFetchCall(fetchMock).init ?? {};
+        if (typeof requestInit.body !== "string") {
+          throw new Error("Expected string request body");
+        }
+        const requestBody = JSON.parse(requestInit.body) as {
+          options?: { num_ctx?: number };
+        };
+        expect(requestBody.options?.num_ctx).toBe(32768);
+      },
+    );
+  });
+
   it("maps configured native Ollama params.thinking=max to the stable top-level think value", async () => {
     await withMockNdjsonFetch(
       [

extensions/ollama/src/stream.ts

@@ -290,6 +290,34 @@ function resolveOllamaNumCtx(model: ProviderRuntimeModel): number {
   );
 }
 
+/**
+ * Resolves num_ctx for native /api/chat requests:
+ *  1. explicit `params.num_ctx` set on the model wins,
+ *  2. otherwise the catalog `contextWindow` / `maxTokens` is forwarded so
+ *     OpenClaw's known model windows survive the trip and `/api/chat` does
+ *     not silently truncate to Ollama's small Modelfile default (typically
+ *     2048 tokens) — which is too small for a system prompt plus tool
+ *     definitions and produces "model picks wrong tools / says nonsense"
+ *     symptoms on agent turns,
+ *  3. when neither is known, return undefined so the Modelfile decides.
+ *
+ * This intentionally differs from `resolveOllamaNumCtx` by not falling back
+ * to `DEFAULT_CONTEXT_TOKENS`: that constant is a sane wrapper-side guess for
+ * the OpenAI-compat path, but on the native path we prefer to leave num_ctx
+ * absent rather than guess a window for an unknown model.
+ */
+function resolveOllamaNativeNumCtx(model: ProviderRuntimeModel): number | undefined {
+  const configured = resolveOllamaConfiguredNumCtx(model);
+  if (configured !== undefined) {
+    return configured;
+  }
+  const catalog = model.contextWindow ?? model.maxTokens;
+  if (typeof catalog === "number" && Number.isFinite(catalog) && catalog > 0) {
+    return Math.floor(catalog);
+  }
+  return undefined;
+}
+
 function resolveOllamaModelOptions(model: ProviderRuntimeModel): Record<string, unknown> {
   const options: Record<string, unknown> = {};
   const params = model.params;
@@ -303,7 +331,7 @@ function resolveOllamaModelOptions(model: ProviderRuntimeModel): Record<string,
       }
     }
   }
-  const numCtx = resolveOllamaConfiguredNumCtx(model);
+  const numCtx = resolveOllamaNativeNumCtx(model);
   if (numCtx !== undefined) {
     options.num_ctx = numCtx;
   }