diff --git a/server/package.json b/server/package.json
index 6516136..7899a22 100644
--- a/server/package.json
+++ b/server/package.json
@@ -4,7 +4,8 @@
   "type": "module",
   "scripts": {
     "start": "node index.js",
-    "dev": "node --watch index.js"
+    "dev": "node --watch index.js",
+    "test": "node --test --test-reporter=spec 'test/**/*.test.js'"
   },
   "dependencies": {
     "@google/genai": "^1.41.0",
diff --git a/server/test/gemini-helpers.test.js b/server/test/gemini-helpers.test.js
new file mode 100644
index 0000000..e834b4a
--- /dev/null
+++ b/server/test/gemini-helpers.test.js
@@ -0,0 +1,131 @@
+import { test, describe } from "node:test";
+import { strict as assert } from "node:assert";
+import { PRICING, calcCost, buildAnalysisPrompt } from "../gemini-helpers.js";
+
+describe("PRICING table", () => {
+  test("includes all current production model slugs", () => {
+    assert.ok(PRICING["gemini-3-flash-preview"]);
+    assert.ok(PRICING["gemini-3-pro-preview"]);
+    assert.ok(PRICING["gemini-3.1-pro-preview"]);
+    assert.ok(PRICING["gemini-2.5-flash"]);
+  });
+
+  test("has a 'default' fallback row", () => {
+    assert.ok(PRICING["default"]);
+    assert.equal(typeof PRICING["default"].input, "number");
+  });
+
+  test("each row has input/output/thinking rates", () => {
+    for (const [model, rates] of Object.entries(PRICING)) {
+      assert.equal(typeof rates.input, "number", `${model}.input`);
+      assert.equal(typeof rates.output, "number", `${model}.output`);
+      assert.equal(typeof rates.thinking, "number", `${model}.thinking`);
+    }
+  });
+});
+
+describe("calcCost", () => {
+  test("uses model-specific rates when known", () => {
+    const cost = calcCost("gemini-3-flash-preview", {
+      promptTokenCount: 1_000_000,
+      candidatesTokenCount: 1_000_000,
+      thoughtsTokenCount: 0,
+    });
+    assert.equal(cost.inputTokens, 1_000_000);
+    assert.equal(cost.outputTokens, 1_000_000);
+    // 1M tokens × $0.50 input + 1M × $3.00 output = $3.50
+    assert.equal(parseFloat(cost.totalCost).toFixed(2), "3.50");
+  });
+
+  test("falls back to 'default' rates for unknown model", () => {
+    const cost = calcCost("invented-model-x", {
+      promptTokenCount: 1_000_000,
+      candidatesTokenCount: 0,
+      thoughtsTokenCount: 0,
+    });
+    // default input rate = $1.00 per 1M
+    assert.equal(parseFloat(cost.totalCost).toFixed(2), "1.00");
+  });
+
+  test("treats missing usage fields as zero", () => {
+    const cost = calcCost("gemini-3-flash-preview", {});
+    assert.equal(cost.inputTokens, 0);
+    assert.equal(cost.outputTokens, 0);
+    assert.equal(cost.thinkingTokens, 0);
+    assert.equal(parseFloat(cost.totalCost), 0);
+  });
+
+  test("formats sub-cent totals as ¢", () => {
+    const cost = calcCost("gemini-2.5-flash", {
+      promptTokenCount: 1000,
+      candidatesTokenCount: 1000,
+      thoughtsTokenCount: 0,
+    });
+    // tiny — display in ¢
+    assert.match(cost.totalCostDisplay, /¢$/);
+  });
+
+  test("formats >$0.01 totals as $X.XXXX", () => {
+    const cost = calcCost("gemini-3-pro-preview", {
+      promptTokenCount: 1_000_000,
+      candidatesTokenCount: 0,
+      thoughtsTokenCount: 0,
+    });
+    // $2.00
+    assert.match(cost.totalCostDisplay, /^\$\d+\.\d{4}$/);
+  });
+
+  test("totalTokens prefers usage.totalTokenCount when provided", () => {
+    const cost = calcCost("gemini-3-flash-preview", {
+      promptTokenCount: 100,
+      candidatesTokenCount: 50,
+      thoughtsTokenCount: 25,
+      totalTokenCount: 200, // server-reported total may include hidden tokens
+    });
+    assert.equal(cost.totalTokens, 200);
+  });
+
+  test("totalTokens falls back to sum when totalTokenCount missing", () => {
+    const cost = calcCost("gemini-3-flash-preview", {
+      promptTokenCount: 100,
+      candidatesTokenCount: 50,
+      thoughtsTokenCount: 25,
+    });
+    assert.equal(cost.totalTokens, 175);
+  });
+});
+
+describe("buildAnalysisPrompt", () => {
+  test("numbers entries with timestamp + offset", () => {
+    const entries = [
+      { offset: 0, text: "Welcome", duration: 5 },
+      { offset: 30, text: "Topic two", duration: 60 },
+    ];
+    const prompt = buildAnalysisPrompt(entries);
+    assert.match(prompt, /\[0\] \(0:00\) Welcome/);
+    assert.match(prompt, /\[1\] \(0:30\) Topic two/);
+  });
+
+  test("substitutes the last segment index in the constraint", () => {
+    const entries = [{ offset: 0, text: "x", duration: 1 }];
+    const prompt = buildAnalysisPrompt(entries);
+    assert.match(prompt, /from 0 to 0 must belong/);
+  });
+
+  test("handles long-running content (hours)", () => {
+    const entries = [
+      { offset: 0, text: "start", duration: 1 },
+      { offset: 3661, text: "later", duration: 1 },
+    ];
+    const prompt = buildAnalysisPrompt(entries);
+    assert.match(prompt, /\(1:01:01\) later/);
+  });
+
+  test("emits a JSON-output instruction", () => {
+    const prompt = buildAnalysisPrompt([{ offset: 0, text: "x", duration: 1 }]);
+    assert.match(prompt, /Respond with ONLY valid JSON/);
+    assert.match(prompt, /"sections":/);
+    assert.match(prompt, /"startIndex":/);
+    assert.match(prompt, /"endIndex":/);
+  });
+});
diff --git a/server/test/history.test.js b/server/test/history.test.js
new file mode 100644
index 0000000..4e502c5
--- /dev/null
+++ b/server/test/history.test.js
@@ -0,0 +1,130 @@
+// Tests for server/history.js — file-backed session storage + meta.
+//
+// Each test mounts an isolated tmp dir as DATA_DIR and re-inits the
+// history module. We don't import the routes layer here — those need
+// an Express app and are covered better by an integration test later.
+
+import { test, describe, before, after } from "node:test";
+import { strict as assert } from "node:assert";
+import fs from "node:fs/promises";
+import os from "node:os";
+import path from "node:path";
+
+let tmpDir;
+let historyDir;
+let history;
+
+before(async () => {
+  tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), "recap-history-test-"));
+  historyDir = path.join(tmpDir, "history");
+  history = await import("../history.js");
+  await history.initHistory({ dataDir: tmpDir });
+});
+
+after(async () => {
+  await fs.rm(tmpDir, { recursive: true, force: true }).catch(() => {});
+});
+
+describe("initHistory + getHistoryDir", () => {
+  test("creates the history directory", async () => {
+    const stat = await fs.stat(historyDir);
+    assert.ok(stat.isDirectory());
+  });
+
+  test("getHistoryDir returns the configured path", () => {
+    assert.equal(history.getHistoryDir(), historyDir);
+  });
+
+  test("init is idempotent", async () => {
+    // Should not throw or wipe data.
+    await history.initHistory({ dataDir: tmpDir });
+    await history.initHistory({ dataDir: tmpDir });
+  });
+});
+
+describe("saveToHistory", () => {
+  test("returns an id and writes a file with the expected shape", async () => {
+    const id = await history.saveToHistory(
+      "videoId123",
+      "https://youtu.be/videoId123",
+      "My title",
+      [{ title: "Topic 1" }],
+      [{ offset: 0, text: "hello" }],
+      [{ message: "started" }],
+      "20260101",
+      "youtube"
+    );
+    assert.match(id, /^\d+-videoId123$/);
+
+    const raw = await fs.readFile(path.join(historyDir, `${id}.json`), "utf-8");
+    const record = JSON.parse(raw);
+    assert.equal(record.id, id);
+    assert.equal(record.videoId, "videoId123");
+    assert.equal(record.url, "https://youtu.be/videoId123");
+    assert.equal(record.title, "My title");
+    assert.equal(record.type, "youtube");
+    assert.equal(record.topicCount, 1);
+    assert.equal(record.segmentCount, 1);
+    assert.equal(record.uploadDate, "20260101");
+    assert.deepEqual(record.chunks, [{ title: "Topic 1" }]);
+    assert.deepEqual(record.entries, [{ offset: 0, text: "hello" }]);
+    assert.deepEqual(record.logs, [{ message: "started" }]);
+    assert.ok(record.createdAt);
+  });
+
+  test("falls back to 'Untitled' when title is empty", async () => {
+    const id = await history.saveToHistory(
+      "noTitleX",
+      "url",
+      "",
+      [],
+      [],
+      [],
+      "",
+      "youtube"
+    );
+    const raw = await fs.readFile(path.join(historyDir, `${id}.json`), "utf-8");
+    const record = JSON.parse(raw);
+    assert.equal(record.title, "Untitled");
+  });
+
+  test("defaults type to 'youtube' when not specified", async () => {
+    const id = await history.saveToHistory("vid", "url", "t", [], [], [], "", null);
+    const raw = await fs.readFile(path.join(historyDir, `${id}.json`), "utf-8");
+    assert.equal(JSON.parse(raw).type, "youtube");
+  });
+
+  test("encodes long podcast guids into a base64-truncated id suffix", async () => {
+    const longGuid = "https://example.com/podcasts/feed.xml#episode-uuid-very-long-string";
+    const id = await history.saveToHistory(longGuid, longGuid, "ep", [], [], [], "", "podcast");
+    // suffix should be 16 base64 chars, not the raw URL
+    assert.ok(!id.includes("https"));
+    assert.match(id, /^\d+-[A-Za-z0-9_-]{16}$/);
+  });
+});
+
+describe("loadMeta + saveMeta", () => {
+  test("loadMeta returns default empty shape when file missing", async () => {
+    // Use a fresh sub-history to ensure no prior _meta.json
+    const meta = await history.loadMeta();
+    assert.ok(Array.isArray(meta.folders));
+    assert.ok(Array.isArray(meta.uncategorized));
+  });
+
+  test("saveMeta + loadMeta round-trips", async () => {
+    const original = {
+      folders: [{ id: "f1", name: "Bitcoin podcasts", collapsed: false, items: ["s1", "s2"] }],
+      uncategorized: ["s3"],
+    };
+    await history.saveMeta(original);
+    const loaded = await history.loadMeta();
+    assert.deepEqual(loaded, original);
+  });
+
+  test("loadMeta returns default when _meta.json is corrupt", async () => {
+    await fs.writeFile(path.join(historyDir, "_meta.json"), "{ this is not json");
+    const loaded = await history.loadMeta();
+    assert.deepEqual(loaded.folders, []);
+    assert.deepEqual(loaded.uncategorized, []);
+  });
+});
diff --git a/server/test/license.test.js b/server/test/license.test.js
new file mode 100644
index 0000000..fe84e2c
--- /dev/null
+++ b/server/test/license.test.js
@@ -0,0 +1,180 @@
+// Tests for server/license.js — the offline Ed25519 verifier wrapper.
+//
+// license.js reads its paths (LICENSE_PATH, STARTOS_CONFIG_PATH) at module
+// load time from env vars. To isolate test fixtures, we set RECAP_LICENSE_
+// KEY_PATH + DATA_DIR to a tmp dir BEFORE importing the module — which is
+// why this file uses dynamic import().
+
+import { test, describe, before, after } from "node:test";
+import { strict as assert } from "node:assert";
+import fs from "node:fs/promises";
+import os from "node:os";
+import path from "node:path";
+
+let tmpDir;
+let licensePath;
+let licenseModule;
+
+before(async () => {
+  tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), "recap-license-test-"));
+  licensePath = path.join(tmpDir, "license.txt");
+  process.env.DATA_DIR = tmpDir;
+  process.env.RECAP_LICENSE_KEY_PATH = licensePath;
+  // Make sure config dir exists so the fallback read in readLicenseString
+  // doesn't fail on a missing parent.
+  await fs.mkdir(path.join(tmpDir, "config"), { recursive: true });
+  // Dynamic import after env vars are in place.
+  licenseModule = await import("../license.js");
+});
+
+after(async () => {
+  delete process.env.RECAP_LICENSE_KEY_PATH;
+  delete process.env.DATA_DIR;
+  await fs.rm(tmpDir, { recursive: true, force: true }).catch(() => {});
+});
+
+describe("checkLicense", () => {
+  test("returns 'unlicensed' when no key file exists", async () => {
+    await fs.unlink(licensePath).catch(() => {});
+    const state = licenseModule.checkLicense();
+    assert.equal(state.state, "unlicensed");
+    assert.equal(state.reason, null);
+    assert.deepEqual([...state.entitlements], []);
+  });
+
+  test("returns 'invalid' for a malformed key", async () => {
+    await fs.writeFile(licensePath, "garbage-not-a-license");
+    const state = licenseModule.checkLicense();
+    assert.equal(state.state, "invalid");
+    assert.ok(state.reason, "should have a reason");
+  });
+
+  test("returns 'invalid' for a LIC1 prefix without valid base32 body", async () => {
+    await fs.writeFile(licensePath, "LIC1-not-real-key");
+    const state = licenseModule.checkLicense();
+    assert.equal(state.state, "invalid");
+  });
+
+  test("falls back to startos-config.json when license.txt is missing", async () => {
+    await fs.unlink(licensePath).catch(() => {});
+    const cfgPath = path.join(tmpDir, "config", "startos-config.json");
+    await fs.writeFile(cfgPath, JSON.stringify({ recap_license_key: "LIC1-bad-but-detected" }));
+    const state = licenseModule.checkLicense();
+    // Will be 'invalid' (bad key) but NOT 'unlicensed' — proves the fallback ran.
+    assert.equal(state.state, "invalid");
+    await fs.unlink(cfgPath).catch(() => {});
+  });
+
+  test("license.txt takes priority over startos-config.json", async () => {
+    await fs.writeFile(licensePath, "LIC1-from-license-txt");
+    const cfgPath = path.join(tmpDir, "config", "startos-config.json");
+    await fs.writeFile(cfgPath, JSON.stringify({ recap_license_key: "LIC1-from-config" }));
+    const state = licenseModule.checkLicense();
+    // Both are bad, but the reason should reflect license.txt's content,
+    // not the config's. We can't easily distinguish without a real key,
+    // but we can confirm it returns 'invalid' (no precedence-related crash).
+    assert.equal(state.state, "invalid");
+    await fs.unlink(cfgPath).catch(() => {});
+    await fs.unlink(licensePath).catch(() => {});
+  });
+});
+
+describe("activate / deactivate", () => {
+  test("activate rejects keys missing the LIC1- prefix", () => {
+    assert.throws(() => licenseModule.activate("not-a-license"), { code: "bad_format" });
+    assert.throws(() => licenseModule.activate(""), { code: "bad_format" });
+    assert.throws(() => licenseModule.activate(null), { code: "bad_format" });
+  });
+
+  test("activate writes a LIC1-prefixed string to license.txt", async () => {
+    const fake = "LIC1-fake-but-shaped-correctly";
+    const state = licenseModule.activate(fake);
+    const written = (await fs.readFile(licensePath, "utf-8")).trim();
+    assert.equal(written, fake);
+    // Returned state will be 'invalid' (signature fails) — not our concern here.
+    assert.ok(["invalid", "licensed"].includes(state.state));
+  });
+
+  test("deactivate removes license.txt and the state sidecar", async () => {
+    await fs.writeFile(licensePath, "LIC1-anything");
+    licenseModule.deactivate();
+    await assert.rejects(fs.access(licensePath), /ENOENT/);
+    const state = licenseModule.checkLicense();
+    assert.equal(state.state, "unlicensed");
+  });
+
+  test("deactivate is idempotent on a clean slate", () => {
+    // No file → should not throw
+    licenseModule.deactivate();
+    licenseModule.deactivate();
+  });
+});
+
+describe("publicView", () => {
+  test("never includes the raw license key", () => {
+    const state = licenseModule.checkLicense();
+    const view = licenseModule.publicView(state);
+    // The public view should not contain anything that looks like a license string
+    const flat = JSON.stringify(view);
+    assert.ok(!flat.includes("LIC1-"));
+  });
+
+  test("converts entitlements Set to a sorted array", () => {
+    const view = licenseModule.publicView({
+      state: "licensed",
+      reason: null,
+      licenseId: "abc",
+      entitlements: new Set(["library", "core", "history"]),
+      expiresAt: null,
+      isTrial: false,
+    });
+    assert.deepEqual(view.entitlements, ["core", "history", "library"]);
+  });
+
+  test("ISO-formats expiresAt and graceUntil", () => {
+    const expiresAt = new Date("2027-01-01T00:00:00.000Z");
+    const view = licenseModule.publicView({
+      state: "licensed",
+      reason: null,
+      licenseId: null,
+      entitlements: new Set(),
+      expiresAt,
+      isTrial: false,
+    });
+    assert.equal(view.expiresAt, "2027-01-01T00:00:00.000Z");
+  });
+
+  test("always exposes productSlug = 'recap'", () => {
+    const view = licenseModule.publicView({
+      state: "unlicensed",
+      reason: null,
+      licenseId: null,
+      entitlements: new Set(),
+      expiresAt: null,
+      isTrial: false,
+    });
+    assert.equal(view.productSlug, "recap");
+  });
+});
+
+describe("has(state, entitlement)", () => {
+  test("returns true when entitlement present", () => {
+    assert.equal(
+      licenseModule.has({ entitlements: new Set(["core"]) }, "core"),
+      true
+    );
+  });
+
+  test("returns false when entitlement absent", () => {
+    assert.equal(
+      licenseModule.has({ entitlements: new Set(["core"]) }, "subscriptions"),
+      false
+    );
+  });
+
+  test("returns falsy on null state", () => {
+    assert.ok(!licenseModule.has(null, "core"));
+    assert.ok(!licenseModule.has(undefined, "core"));
+    assert.ok(!licenseModule.has({}, "core"));
+  });
+});
diff --git a/server/test/util.test.js b/server/test/util.test.js
new file mode 100644
index 0000000..c416793
--- /dev/null
+++ b/server/test/util.test.js
@@ -0,0 +1,230 @@
+import { test, describe } from "node:test";
+import { strict as assert } from "node:assert";
+import {
+  sendEvent,
+  extractVideoId,
+  formatTime,
+  parseTimestampedTranscript,
+  safeText,
+  retryGemini,
+} from "../util.js";
+
+describe("extractVideoId", () => {
+  test("extracts from standard watch URL", () => {
+    assert.equal(extractVideoId("https://www.youtube.com/watch?v=dQw4w9WgXcQ"), "dQw4w9WgXcQ");
+  });
+
+  test("extracts from youtu.be short URL", () => {
+    assert.equal(extractVideoId("https://youtu.be/dQw4w9WgXcQ"), "dQw4w9WgXcQ");
+  });
+
+  test("extracts from /embed/ URL", () => {
+    assert.equal(extractVideoId("https://www.youtube.com/embed/dQw4w9WgXcQ"), "dQw4w9WgXcQ");
+  });
+
+  test("accepts a bare 11-character id", () => {
+    assert.equal(extractVideoId("dQw4w9WgXcQ"), "dQw4w9WgXcQ");
+  });
+
+  test("returns null for non-YouTube URL", () => {
+    assert.equal(extractVideoId("https://example.com/video"), null);
+  });
+
+  test("returns null for empty / null input", () => {
+    assert.equal(extractVideoId(""), null);
+    assert.equal(extractVideoId(null), null);
+    assert.equal(extractVideoId(undefined), null);
+  });
+
+  test("returns null for too-short id", () => {
+    assert.equal(extractVideoId("dQw4w9W"), null);
+  });
+});
+
+describe("formatTime", () => {
+  test("formats sub-minute as M:SS", () => {
+    assert.equal(formatTime(0), "0:00");
+    assert.equal(formatTime(5), "0:05");
+    assert.equal(formatTime(59), "0:59");
+  });
+
+  test("formats minutes as M:SS", () => {
+    assert.equal(formatTime(60), "1:00");
+    assert.equal(formatTime(125), "2:05");
+    assert.equal(formatTime(3599), "59:59");
+  });
+
+  test("formats hours+ as H:MM:SS", () => {
+    assert.equal(formatTime(3600), "1:00:00");
+    assert.equal(formatTime(3661), "1:01:01");
+    assert.equal(formatTime(7325), "2:02:05");
+  });
+
+  test("floors fractional seconds", () => {
+    assert.equal(formatTime(60.9), "1:00");
+  });
+});
+
+describe("parseTimestampedTranscript", () => {
+  test("parses [M:SS] format", () => {
+    const entries = parseTimestampedTranscript(
+      "[0:00] Welcome\n[0:05] Today we're talking about\n[0:30] Topic two"
+    );
+    assert.equal(entries.length, 3);
+    assert.deepEqual(entries[0], { text: "Welcome", offset: 0, duration: 5 });
+    assert.equal(entries[1].offset, 5);
+    assert.equal(entries[1].duration, 25);
+    // Last entry gets default 15s duration
+    assert.equal(entries[2].offset, 30);
+    assert.equal(entries[2].duration, 15);
+  });
+
+  test("parses H:MM:SS format", () => {
+    const entries = parseTimestampedTranscript("[1:02:30] Hello");
+    assert.equal(entries[0].offset, 1 * 3600 + 2 * 60 + 30);
+  });
+
+  test("parses (M:SS) format", () => {
+    const entries = parseTimestampedTranscript("(0:00) Welcome");
+    assert.equal(entries.length, 1);
+    assert.equal(entries[0].text, "Welcome");
+  });
+
+  test("strips markdown bold markers", () => {
+    const entries = parseTimestampedTranscript("**[0:00]** Hello world");
+    assert.equal(entries[0].text, "Hello world");
+  });
+
+  test("ignores blank lines", () => {
+    const entries = parseTimestampedTranscript("\n[0:00] one\n\n[0:05] two\n");
+    assert.equal(entries.length, 2);
+  });
+
+  test("returns empty array for unparseable input", () => {
+    assert.deepEqual(parseTimestampedTranscript(""), []);
+    assert.deepEqual(parseTimestampedTranscript("no timestamps here"), []);
+  });
+});
+
+describe("safeText", () => {
+  test("returns .text when accessible", () => {
+    assert.equal(safeText({ text: "hello" }), "hello");
+  });
+
+  test("falls back to candidates[0].content.parts when .text throws", () => {
+    const fake = {
+      get text() { throw new Error("nope"); },
+      candidates: [{ content: { parts: [{ text: "from " }, { text: "parts" }] } }],
+    };
+    assert.equal(safeText(fake), "from parts");
+  });
+
+  test("returns empty string when neither path yields text", () => {
+    assert.equal(safeText({}), "");
+    assert.equal(safeText({ candidates: [] }), "");
+  });
+
+  test("does not throw on null / weird shapes", () => {
+    assert.equal(safeText({ candidates: [{ content: null }] }), "");
+  });
+});
+
+describe("retryGemini", () => {
+  test("returns successful result on first try", async () => {
+    const result = await retryGemini(async () => "ok", { retries: 3, delayMs: 1 });
+    assert.equal(result, "ok");
+  });
+
+  test("retries on 503 and eventually succeeds", async () => {
+    let attempts = 0;
+    const result = await retryGemini(
+      async () => {
+        attempts++;
+        if (attempts < 3) {
+          const err = new Error("temporary");
+          err.status = 503;
+          throw err;
+        }
+        return "ok";
+      },
+      { retries: 5, delayMs: 1 }
+    );
+    assert.equal(result, "ok");
+    assert.equal(attempts, 3);
+  });
+
+  test("retries on network error patterns", async () => {
+    let attempts = 0;
+    const result = await retryGemini(
+      async () => {
+        attempts++;
+        if (attempts < 2) throw new Error("fetch failed");
+        return "ok";
+      },
+      { retries: 3, delayMs: 1 }
+    );
+    assert.equal(result, "ok");
+    assert.equal(attempts, 2);
+  });
+
+  test("does NOT retry on non-retryable errors", async () => {
+    let attempts = 0;
+    await assert.rejects(
+      retryGemini(
+        async () => {
+          attempts++;
+          throw new Error("bad request: invalid argument");
+        },
+        { retries: 5, delayMs: 1 }
+      )
+    );
+    assert.equal(attempts, 1);
+  });
+
+  test("throws after exhausting retries", async () => {
+    let attempts = 0;
+    await assert.rejects(
+      retryGemini(
+        async () => {
+          attempts++;
+          const err = new Error("still 503");
+          err.status = 503;
+          throw err;
+        },
+        { retries: 3, delayMs: 1 }
+      )
+    );
+    assert.equal(attempts, 3);
+  });
+
+  test("calls log function on retries", async () => {
+    const logs = [];
+    await retryGemini(
+      async () => {
+        const err = new Error("503");
+        err.status = 503;
+        throw err;
+      },
+      { retries: 2, delayMs: 1, label: "test", log: (msg) => logs.push(msg) }
+    ).catch(() => {});
+    assert.equal(logs.length, 1);
+    assert.match(logs[0], /test/);
+    assert.match(logs[0], /retrying/);
+  });
+});
+
+describe("sendEvent", () => {
+  test("writes a properly formatted SSE frame", () => {
+    let written = "";
+    const fakeRes = { write: (chunk) => { written += chunk; } };
+    sendEvent(fakeRes, "result", { foo: "bar" });
+    assert.equal(written, 'event: result\ndata: {"foo":"bar"}\n\n');
+  });
+
+  test("handles primitive data", () => {
+    let written = "";
+    const fakeRes = { write: (chunk) => { written += chunk; } };
+    sendEvent(fakeRes, "ping", null);
+    assert.equal(written, "event: ping\ndata: null\n\n");
+  });
+});