diff --git a/tests/runner-e2e/CHAT-FEATURES.md b/tests/runner-e2e/CHAT-FEATURES.md
index 9a04d43973c..a66cf38a374 100644
--- a/tests/runner-e2e/CHAT-FEATURES.md
+++ b/tests/runner-e2e/CHAT-FEATURES.md
@@ -239,6 +239,12 @@ Initial setup uses the existing workflow operations:
    independent checks, private-evidence receipts and cleanup. Inspect screenshots
    through authenticated private-history retrieval. Retain earlier failed attempts.
 
+Launch preflight searches use TestOps' typed name filter, encoded as Base64 of
+UTF-8 JSON in the `search` query parameter. Plain name text returns HTTP 400.
+The backlog and completion launchers share this encoding; the full-catalog
+launcher uses the completion adapter. Existing nonce and once-only guards still
+apply before a plan-run request.
+
 The runtime accepts only `operation`, `ALLURE_JOB_RUN_ID` and reserved username
 metadata. It rejects arbitrary source/model/budget selectors, branch workflows,
 replays and foreign cases. All secret-bearing jobs recheck actual GitHub run and
diff --git a/tests/runner-e2e/chat-completion-testops-api.mjs b/tests/runner-e2e/chat-completion-testops-api.mjs
index e6eba6bc284..5b9f883c935 100644
--- a/tests/runner-e2e/chat-completion-testops-api.mjs
+++ b/tests/runner-e2e/chat-completion-testops-api.mjs
@@ -1,4 +1,4 @@
-import { testopsClient, endpoint } from './chat-feature-testops-api.mjs';
+import { testopsClient, endpoint, launchNameSearch } from './chat-feature-testops-api.mjs';
 import { cases, planName, positive, reject, validateSelection, catalogDefinition } from './chat-completion-testops-contract.mjs';
 
 import { reconcileFullCatalog } from './chat-full-catalog-testops-reconcile.mjs';
@@ -225,7 +225,7 @@ export async function launchPilotPlan(api, env, context, workflowId, markOnce) {
   if (!Array.isArray(assignments) || assignments.length !== 1 || assignments[0].job?.id !== binding.jobId
     || assignments[0].testCasesCount !== cases.length) reject('plan_job_mismatch');
   const name = `${planName} · ${env.CHAT_COMPLETION_TESTOPS_LAUNCH_NONCE}`;
-  const existing = pageRows(await api(`/api/launch?${new URLSearchParams({ projectId: '1', search: name, page: '0', size: '100' })}`));
+  const existing = pageRows(await api(`/api/launch?${new URLSearchParams({ projectId: '1', search: launchNameSearch(name), page: '0', size: '100' })}`));
   if (existing.length) reject('launch_already_requested');
   await markOnce('launch_plan');
   const launched = await api(`/api/testplan/${binding.planId}/run`, 'POST', { launchName: name });
diff --git a/tests/runner-e2e/chat-completion-testops-api.test.mjs b/tests/runner-e2e/chat-completion-testops-api.test.mjs
index 40a1da85cc2..4ee58ebe003 100644
--- a/tests/runner-e2e/chat-completion-testops-api.test.mjs
+++ b/tests/runner-e2e/chat-completion-testops-api.test.mjs
@@ -128,6 +128,22 @@ test('the fenced launcher requests one exact three-case TestOps launch', async (
     launchName: `${planName} · ${operatorEnv.CHAT_COMPLETION_TESTOPS_LAUNCH_NONCE}` } }]);
 });
 
+test('completion launch preflight sends the typed UTF-8 name filter required by TestOps', async () => {
+  const f = mutationApi({ assignments: [{ job, testCasesCount: 3 }] });
+  const api = async (route, ...args) => {
+    if (route.startsWith('/api/launch?')) {
+      const wire = new URL(route, 'https://paperclip.testops.cloud').searchParams.get('search');
+      let filters;
+      try { filters = JSON.parse(Buffer.from(wire, 'base64').toString('utf8')); }
+      catch { throw new Error('TestOps HTTP 400: typed launch search required'); }
+      assert.deepEqual(filters, [{ id: 'name', type: 'string', value: `${planName} · ${operatorEnv.CHAT_COMPLETION_TESTOPS_LAUNCH_NONCE}` }]);
+    }
+    return f.api(route, ...args);
+  };
+  await launchPilotPlan(api, operatorEnv, context, 999, async () => {});
+  assert.equal(f.calls.filter(row => row.method === 'POST').length, 1);
+});
+
 for (const changed of [{ GITHUB_RUN_NUMBER: '6' }, { CHAT_COMPLETION_TESTOPS_LAUNCH_NONCE: 'not-a-nonce' }, { CHAT_COMPLETION_TESTOPS_LAUNCH_RUN_NUMBER: '' }]) {
   test(`launcher rejects its invalid fence before requests: ${Object.keys(changed)[0]}`, async () => {
     const f = mutationApi();
diff --git a/tests/runner-e2e/chat-feature-testops-api.mjs b/tests/runner-e2e/chat-feature-testops-api.mjs
index 8be6bc63fc3..2b4a4f1d049 100644
--- a/tests/runner-e2e/chat-feature-testops-api.mjs
+++ b/tests/runner-e2e/chat-feature-testops-api.mjs
@@ -2,6 +2,10 @@ export const endpoint = 'https://paperclip.testops.cloud';
 export const planName = 'Chat feature evals';
 export const fullName = 'paperclip.Product E2E.chat-features.create-backlog';
 export const aliases = [fullName, 'paperclip.Product E2E.chat-features.tasks.create-backlog'];
+export function launchNameSearch(name) {
+  // TestOps search uses the UI's typed filter carrier, not plain search text.
+  return Buffer.from(JSON.stringify([{ id: 'name', type: 'string', value: name }]), 'utf8').toString('base64');
+}
 class SetupFailure extends Error {
   constructor(code, status = null) { super(code); this.code = code; this.status = status; }
 }
@@ -348,7 +352,7 @@ export async function launchChatPlan(api, env, markOnce, admission) {
   const assignments = await api(`/api/testplan/${known.planId}/job`);
   if (!Array.isArray(assignments) || assignments.length > 1 || assignments.some(row => row.job?.id !== known.jobId || row.testCasesCount !== 1)) fail('chat_testops_plan_job_mismatch');
   const launchName = `${planName} · ${nonce}`;
-  const existing = rows(await api(`/api/launch?${new URLSearchParams({ projectId: '1', search: launchName, page: '0', size: '100' })}`));
+  const existing = rows(await api(`/api/launch?${new URLSearchParams({ projectId: '1', search: launchNameSearch(launchName), page: '0', size: '100' })}`));
   if (existing.length) {
     if (existing.length !== 1 || existing[0].name !== launchName || !id(existing[0].id)) fail('chat_testops_nonce_conflict');
     return { schema: 'paperclip.chat-feature-testops-launch/v1', ...source, nonce, planId: known.planId,
diff --git a/tests/runner-e2e/chat-feature-testops-api.test.mjs b/tests/runner-e2e/chat-feature-testops-api.test.mjs
index 292411c1d22..318c616208c 100644
--- a/tests/runner-e2e/chat-feature-testops-api.test.mjs
+++ b/tests/runner-e2e/chat-feature-testops-api.test.mjs
@@ -196,6 +196,22 @@ test('launch configures only the exact registered public job/plan then issues on
   assert.ok(!server.calls.some(row => /jobrun.*rerun|dispatches/.test(row.route)));
 });
 
+test('backlog launch preflight sends the typed UTF-8 name filter required by TestOps', async () => {
+  const server = launchServer();
+  const api = async (route, ...args) => {
+    if (route.startsWith('/api/launch?')) {
+      const wire = new URL(route, 'https://paperclip.testops.cloud').searchParams.get('search');
+      let filters;
+      try { filters = JSON.parse(Buffer.from(wire, 'base64').toString('utf8')); }
+      catch { throw new Error('TestOps HTTP 400: typed launch search required'); }
+      assert.deepEqual(filters, [{ id: 'name', type: 'string', value: `Chat feature evals · ${launchEnv.CHAT_TESTOPS_LAUNCH_NONCE}` }]);
+    }
+    return server.api(route, ...args);
+  };
+  await launchChatPlan(api, launchEnv, async () => {}, await fence());
+  assert.equal(server.requests(), 1);
+});
+
 test('observed launch nonce prevents a second run request across separate local entry attempts', async () => {
   const server = launchServer(); await launchChatPlan(server.api, launchEnv, async () => {}, await fence());
   const result = await launchChatPlan(server.api, launchEnv, () => assert.fail('existing launch must not mark or write'), await fence());