fix: apply model extra params without overwriting stream (#732) (thanks @peschee)

src/agents/pi-embedded-runner-extraparams.live.test.ts

@@ -0,0 +1,63 @@
+import type { Model } from "@mariozechner/pi-ai";
+import { getModel, streamSimple } from "@mariozechner/pi-ai";
+import { describe, expect, it } from "vitest";
+import type { ClawdbotConfig } from "../config/config.js";
+import { applyExtraParamsToAgent } from "./pi-embedded-runner.js";
+
+const OPENAI_KEY = process.env.OPENAI_API_KEY ?? "";
+const LIVE = process.env.OPENAI_LIVE_TEST === "1" || process.env.LIVE === "1";
+
+const describeLive = LIVE && OPENAI_KEY ? describe : describe.skip;
+
+describeLive("pi embedded extra params (live)", () => {
+  it("applies config maxTokens to openai streamFn", async () => {
+    const model = getModel("openai", "gpt-5.2") as Model<"openai-completions">;
+
+    const cfg: ClawdbotConfig = {
+      agents: {
+        defaults: {
+          models: {
+            "openai/gpt-5.2": {
+              params: {
+                maxTokens: 8,
+              },
+            },
+          },
+        },
+      },
+    };
+
+    const agent = { streamFn: streamSimple };
+
+    applyExtraParamsToAgent(agent, cfg, "openai", model.id, "off");
+
+    const stream = agent.streamFn(
+      model,
+      {
+        messages: [
+          {
+            role: "user",
+            content:
+              "Write the alphabet letters A through Z as words separated by commas.",
+            timestamp: Date.now(),
+          },
+        ],
+      },
+      { apiKey: OPENAI_KEY },
+    );
+
+    let stopReason: string | undefined;
+    let outputTokens: number | undefined;
+    for await (const event of stream) {
+      if (event.type === "done") {
+        stopReason = event.reason;
+        outputTokens = event.message.usage.output;
+      }
+    }
+
+    expect(stopReason).toBeDefined();
+    expect(outputTokens).toBeDefined();
+    // Should respect maxTokens from config (8) — allow a small buffer for provider rounding.
+    expect(outputTokens ?? 0).toBeLessThanOrEqual(12);
+  }, 30_000);
+});