feat: log llm runtime responses

src/lib/llm/__tests__/client.test.ts

@@ -10,6 +10,8 @@ describe("generateValidatedJson", () => {
   afterEach(() => {
     process.env.LLM_PROVIDER = originalProvider;
     process.env.DEEPSEEK_API_KEY = originalDeepSeekKey;
+    delete process.env.LLM_LOG_RAW_LIMIT;
+    delete process.env.DEEPSEEK_MODEL;
     client.setGenerateJsonForValidation(client.generateJson);
     vi.restoreAllMocks();
   });
@@ -103,6 +105,88 @@ describe("generateValidatedJson", () => {
     );
     expect(warnSpy).toHaveBeenCalledWith(expect.stringContaining("value"));
   });
+
+  it("logs provider, model, task, raw response snippet, and validation success", async () => {
+    process.env.LLM_PROVIDER = "deepseek";
+    process.env.DEEPSEEK_API_KEY = "test-key";
+    process.env.DEEPSEEK_MODEL = "deepseek-test";
+    process.env.LLM_LOG_RAW_LIMIT = "80";
+    const infoSpy = vi.spyOn(console, "info").mockImplementation(() => {});
+    const warnSpy = vi.spyOn(console, "warn").mockImplementation(() => {});
+    client.setGenerateJsonForValidation(async () => ({
+      value: "from-llm",
+      longField: "x".repeat(200),
+    }));
+
+    const result = await client.generateValidatedJson({
+      schema: z.object({ value: z.string(), longField: z.string() }),
+      task: "article_optimizer",
+      prompt: "Return JSON.",
+    });
+
+    expect(result?.value).toBe("from-llm");
+    expect(infoSpy).toHaveBeenCalledWith(
+      expect.stringContaining(
+        "[llm:start] provider=deepseek model=deepseek-test task=article_optimizer",
+      ),
+    );
+    expect(infoSpy).toHaveBeenCalledWith(
+      expect.stringContaining("[llm:response] task=article_optimizer"),
+    );
+    expect(infoSpy).toHaveBeenCalledWith(
+      expect.stringContaining('"value":"from-llm"'),
+    );
+    expect(infoSpy).toHaveBeenCalledWith(
+      expect.stringContaining("[llm:validated] task=article_optimizer ok=true"),
+    );
+    expect(warnSpy).not.toHaveBeenCalled();
+  });
+
+  it("logs validation failure without leaking provider secrets", async () => {
+    process.env.LLM_PROVIDER = "deepseek";
+    process.env.DEEPSEEK_API_KEY = "super-secret-key";
+    process.env.DEEPSEEK_MODEL = "deepseek-test";
+    const infoSpy = vi.spyOn(console, "info").mockImplementation(() => {});
+    const warnSpy = vi.spyOn(console, "warn").mockImplementation(() => {});
+    client.setGenerateJsonForValidation(async () => ({ value: 42 }));
+
+    const result = await client.generateValidatedJson({
+      schema: z.object({ value: z.string() }),
+      task: "fact_extractor",
+      prompt: "Return JSON.",
+    });
+
+    const allLogs = [...infoSpy.mock.calls, ...warnSpy.mock.calls]
+      .flat()
+      .join("\n");
+    expect(result).toBeNull();
+    expect(allLogs).toContain("[llm:validated] task=fact_extractor ok=false");
+    expect(allLogs).toContain("zod_error=");
+    expect(allLogs).not.toContain("super-secret-key");
+  });
+
+  it("logs provider call failure for validated JSON calls", async () => {
+    process.env.LLM_PROVIDER = "deepseek";
+    process.env.DEEPSEEK_API_KEY = "test-key";
+    const warnSpy = vi.spyOn(console, "warn").mockImplementation(() => {});
+    client.setGenerateJsonForValidation(async () => {
+      throw new Error("provider unavailable");
+    });
+
+    const result = await client.generateValidatedJson({
+      schema: z.object({ value: z.string() }),
+      task: "quality_inspector",
+      prompt: "Return JSON.",
+    });
+
+    expect(result).toBeNull();
+    expect(warnSpy).toHaveBeenCalledWith(
+      expect.stringContaining("[llm:error] task=quality_inspector"),
+    );
+    expect(warnSpy).toHaveBeenCalledWith(
+      expect.stringContaining("provider unavailable"),
+    );
+  });
 });
 
 describe("generateJson logging", () => {

src/lib/llm/client.ts

@@ -1,12 +1,19 @@
 import OpenAI from "openai";
 import type { z } from "zod";
 
+export type LlmTaskName =
+  | "unknown"
+  | "fact_extractor"
+  | "article_optimizer"
+  | "quality_inspector"
+  | "targeted_rewriter";
+
 export interface GenerateInput {
   system?: string;
   prompt: string;
   model?: string;
   temperature?: number;
-  task?: string;
+  task?: LlmTaskName;
 }
 
 export interface GenerateValidatedJsonInput<T> extends GenerateInput {
@@ -77,7 +84,16 @@ function getTask(input: GenerateInput) {
   return input.task?.trim() || "unknown";
 }
 
-function truncateRaw(value: string, maxLength = 4000) {
+function getRawLogLimit() {
+  const parsed = Number(process.env.LLM_LOG_RAW_LIMIT ?? "4000");
+  return Number.isFinite(parsed) && parsed >= 0 ? parsed : 4000;
+}
+
+function stringifyForLog(value: unknown) {
+  return typeof value === "string" ? value : JSON.stringify(value);
+}
+
+function truncateRaw(value: string, maxLength = getRawLogLimit()) {
   return value.length > maxLength
     ? `${value.slice(0, maxLength)}...[truncated ${value.length - maxLength} chars]`
     : value;
@@ -195,8 +211,17 @@ export async function generateValidatedJson<T>({
     return null;
   }
 
+  const status = getLlmProviderStatus();
+  const startedAt = Date.now();
+  console.info(
+    `[llm:start] provider=${status.provider} model=${input.model ?? status.model} task=${task}`,
+  );
+
   try {
     const generated = await generateJsonForValidation<unknown>(input);
+    console.info(
+      `[llm:response] task=${task} duration_ms=${Date.now() - startedAt} raw=${truncateRaw(stringifyForLog(generated))}`,
+    );
     const parsed = schema.safeParse(generated);
     if (parsed.success) {
       console.info(`[llm:validated] task=${task} ok=true`);
@@ -206,8 +231,12 @@ export async function generateValidatedJson<T>({
       `[llm:validated] task=${task} ok=false zod_error=${quoteLogValue(summarizeZodError(parsed.error))}`,
     );
     return null;
-  } catch {
+  } catch (error) {
     console.info(`[llm:validated] task=${task} ok=false reason=provider_error`);
+    const message = error instanceof Error ? error.message : String(error);
+    console.warn(
+      `[llm:error] task=${task} duration_ms=${Date.now() - startedAt} message=${quoteLogValue(message)}`,
+    );
     return null;
   }
 }