diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..2642433
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,24 @@
+name: CI
+
+on:
+  pull_request:
+  push:
+    branches: [main]
+
+permissions:
+  contents: read
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - uses: pnpm/action-setup@v4
+        with:
+          version: "10.12.4"
+      - uses: actions/setup-node@v6
+        with:
+          node-version: "24"
+          cache: pnpm
+      - run: pnpm install --frozen-lockfile
+      - run: pnpm test
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index 5075cae..0916308 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -23,6 +23,7 @@ jobs:
           registry-url: "https://registry.npmjs.org"
           cache: pnpm
       - run: pnpm install --frozen-lockfile
+      - run: pnpm test
       - run: pnpm -r publish --access public --no-git-checks
         env:
           NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
diff --git a/package.json b/package.json
index 456af8e..a0113b5 100644
--- a/package.json
+++ b/package.json
@@ -14,6 +14,7 @@
     "url": "https://github.com/elkaix"
   },
   "scripts": {
+    "test": "node --test 'packages/*/test/*.test.js'",
     "publish:all": "pnpm -r publish --access public --no-git-checks"
   },
   "packageManager": "pnpm@10.12.4"
diff --git a/packages/dsh-tavily/README.md b/packages/dsh-tavily/README.md
index 55ce7c0..10ab6c7 100644
--- a/packages/dsh-tavily/README.md
+++ b/packages/dsh-tavily/README.md
@@ -86,7 +86,7 @@ If your profile's `cordis.patch.yml` already inserts its own Tavily MCP row (id
 | Ref                     | Meaning                                             |
 | ----------------------- | --------------------------------------------------- |
 | `TAVILY_API_KEY`        | Optional (search). Present = account quota; absent = keyless |
-| `TAVILY_SEARCH_ENABLED` | Present = on; unset = off                           |
+| `TAVILY_SEARCH_ENABLED` | `true` = on (the card writes `true`; `1` / `yes` / `on` also count); unset or any other value = off |
 
 The search key and toggle are stored on the credentials plane (`$DSH_HOME/.credentials.yaml`). The MCP bridge reads `TAVILY_API_KEY` from the launch environment instead, because MCP rows resolve before credentials are materialized. Do not commit real keys.
 
diff --git a/packages/dsh-tavily/test/index.test.js b/packages/dsh-tavily/test/index.test.js
new file mode 100644
index 0000000..447da4e
--- /dev/null
+++ b/packages/dsh-tavily/test/index.test.js
@@ -0,0 +1,135 @@
+import { afterEach, beforeEach, describe, it } from "node:test";
+import assert from "node:assert/strict";
+import { readFile } from "node:fs/promises";
+import { Readable } from "node:stream";
+import { createLaunchEnvironmentSnapshot } from "@deepseek-ai/dsh-launch-environment";
+import { apply, ENABLED_REF } from "../lib/index.js";
+
+const read = (path) => readFile(new URL(path, import.meta.url), "utf8");
+
+// A host context shaped like DSH's. The launch environment is an explicit empty
+// snapshot so real TAVILY_API_KEY / DEEPSEEK_API_KEY in process.env never leak in.
+function host({ creds = {}, withRegister = false } = {}) {
+  const seen = { providers: [], routes: [], effects: [], settings: [], disposed: 0 };
+  const launchEnvironment = createLaunchEnvironmentSnapshot([{ source: "process", values: {} }]);
+  const ctx = {
+    get: (name) => {
+      if (name === "credentials") return { resolve: async (ref) => ({ value: creds[ref] }) };
+      if (name === "launchEnvironment") return launchEnvironment;
+      return undefined;
+    },
+    web: { registerSearchProvider: (provider) => seen.providers.push(provider) },
+    webServer: {
+      register: (route) => {
+        seen.routes.push(route);
+        return () => seen.disposed++;
+      },
+    },
+    effect: (fn, label) => seen.effects.push({ label, result: fn() }),
+    // DSH <= 0.1.5 has settings.register; 0.1.7+ does not.
+    settings: withRegister ? { register: (...args) => seen.settings.push(args) } : {},
+  };
+  apply(ctx, {});
+  return seen;
+}
+
+let fetches;
+const realFetch = globalThis.fetch;
+beforeEach(() => {
+  fetches = [];
+  globalThis.fetch = async (url, init) => {
+    fetches.push({ url: String(url), headers: init?.headers ?? {} });
+    const body = { results: [{ url: "https://example.com", title: "Example", content: "text" }, { title: "no url" }] };
+    return new Response(JSON.stringify(body), { status: 200, headers: { "content-type": "application/json" } });
+  };
+});
+afterEach(() => {
+  globalThis.fetch = realFetch;
+});
+
+const tavilyCalls = () => fetches.filter((f) => f.url.startsWith("https://api.tavily.com/"));
+
+describe("apply()", () => {
+  it("boots on DSH 0.1.7+, where settings.register does not exist", () => {
+    const seen = host();
+    assert.equal(seen.providers.length, 1);
+    assert.equal(seen.providers[0].id, "tavily");
+  });
+
+  it("registers the Config namespace on DSH 0.1.5", () => {
+    const seen = host({ withRegister: true });
+    assert.equal(seen.settings[0][0], "web-search-tavily");
+  });
+
+  it("registers the probe route inside ctx.effect so a reload releases it", () => {
+    const seen = host();
+    assert.equal(seen.routes[0].path, "/api/tavily-probe");
+    const effect = seen.effects.find((e) => e.label === "tavily probe route");
+    assert.equal(typeof effect.result, "function");
+    effect.result();
+    assert.equal(seen.disposed, 1);
+  });
+});
+
+describe("search provider", () => {
+  it("searches Tavily keyless when enabled without a key", async () => {
+    const [provider] = host({ creds: { [ENABLED_REF]: "true" } }).providers;
+    const { sources } = await provider.search({ query: "q" });
+    const [call] = tavilyCalls();
+    assert.equal(call.url, "https://api.tavily.com/search");
+    assert.equal(call.headers["x-tavily-access-mode"], "keyless");
+    assert.equal(call.headers.authorization, undefined);
+    assert.deepEqual(sources.map((s) => s.url), ["https://example.com"]);
+  });
+
+  it("sends the saved key as a Bearer token", async () => {
+    const [provider] = host({ creds: { [ENABLED_REF]: "true", TAVILY_API_KEY: "tvly-test" } }).providers;
+    await provider.search({ query: "q" });
+    const [call] = tavilyCalls();
+    assert.equal(call.headers.authorization, "Bearer tvly-test");
+    assert.equal(call.headers["x-tavily-access-mode"], undefined);
+  });
+
+  for (const [label, creds] of [["unset", {}], ['"false"', { [ENABLED_REF]: "false" }]]) {
+    it(`falls back to official DeepSeek when the toggle is ${label}`, async () => {
+      const [provider] = host({ creds }).providers;
+      // No DeepSeek key here, so reaching the fallback shows up as its own
+      // missing-credential rejection.
+      await assert.rejects(provider.search({ query: "q" }), { code: "WEB_PROVIDER_CREDENTIAL_MISSING" });
+      assert.equal(tavilyCalls().length, 0);
+    });
+  }
+});
+
+describe("probe route", () => {
+  it("reports keyless mode when no key is saved", async () => {
+    const [route] = host().routes;
+    const req = Object.assign(Readable.from([Buffer.from("{}")]), { method: "POST" });
+    const res = {
+      writeHead(status) { this.status = status; },
+      end(body) { this.body = JSON.parse(body); },
+    };
+    await route.handler(req, res);
+    assert.equal(res.status, 200);
+    assert.deepEqual(res.body, { ok: true, mode: "keyless" });
+  });
+});
+
+describe("host compatibility", () => {
+  it("never loads the removed @deepseek-ai/dsh-client-runtime", async () => {
+    // Its presence blanked the settings card and tripped DSH Desktop's Safe Mode scan.
+    assert.doesNotMatch(await read("../lib/client.js"), /dsh-client-runtime/);
+    assert.doesNotMatch(await read("../package.json"), /dsh-client-runtime/);
+  });
+
+  it("renders the settings card in both the 0.1.5 and 0.1.7+ slots", async () => {
+    const client = await read("../lib/client.js");
+    assert.match(client, /"settings\.plugin\.item"/);
+    assert.match(client, /"plugins\.bundle\.config"/);
+  });
+
+  it("keeps dsh-base's fetchProvider in the web override", async () => {
+    // An id override replaces `config` wholesale; dropping fetchProvider breaks web fetch.
+    assert.match(await read("../cordis.patch.yml"), /- id: web\n\s+config:\n(?:\s+.*\n)*?\s+fetchProvider: http/);
+  });
+});