diff --git a/commands/trekendsession.md b/commands/trekendsession.md
index c00af26..57810d2 100644
--- a/commands/trekendsession.md
+++ b/commands/trekendsession.md
@@ -114,7 +114,7 @@ Under `node --input-type=module -e "<script>" arg1 arg2 arg3`, Node sets
 `process.argv[1]`. Adjust the destructure if your Node version differs.
 
 This phase ALSO writes a sibling `NEXT-SESSION-PROMPT.local.md` in the
-project directory with YAML frontmatter (`produced_by: ultraplan-end-session-local`,
+project directory with YAML frontmatter (`produced_by: trekendsession`,
 `produced_at: <ISO-8601>`, `project: <project-dir>`). Both files are written
 in a single ESM block so the writes succeed or fail together:
 
@@ -129,7 +129,7 @@ const stateObj = { schema_version: 1, project: dir, next_session_brief_path: bri
 const stateFile = path.join(dir, '.session-state.local.json');
 atomicWriteJson(stateFile, stateObj);
 const promptFile = path.join(dir, 'NEXT-SESSION-PROMPT.local.md');
-const promptBody = '---\\nproduced_by: ultraplan-end-session-local\\nproduced_at: ' + now + '\\nproject: ' + dir + '\\n---\\n\\n# ' + label + '\\n\\nResume via /ultracontinue.\\n';
+const promptBody = '---\\nproduced_by: trekendsession\\nproduced_at: ' + now + '\\nproject: ' + dir + '\\n---\\n\\n# ' + label + '\\n\\nResume via /ultracontinue.\\n';
 writeFileSync(promptFile, promptBody);
 console.log(stateFile);
 console.log(promptFile);
diff --git a/commands/trekexecute.md b/commands/trekexecute.md
index 512587c..e9d3b2b 100644
--- a/commands/trekexecute.md
+++ b/commands/trekexecute.md
@@ -415,7 +415,7 @@ Verify with `node lib/validators/session-state-validator.mjs --json
 to stderr but do NOT block the stop; `progress.json` is still authoritative.
 
 **Also write sibling `NEXT-SESSION-PROMPT.local.md`** with frontmatter
-(`produced_by: ultraexecute-local`, `produced_at: <ISO-8601>`,
+(`produced_by: trekexecute`, `produced_at: <ISO-8601>`,
 `status: stopped`) so the next-session producer-mismatch check has both
 candidates available. Use the same combined ESM block pattern as Phase 8.
 
@@ -904,7 +904,7 @@ write pattern + validator check as Phase 2.55. On validator failure, warn
 but do not block.
 
 **Also write sibling `NEXT-SESSION-PROMPT.local.md`** with frontmatter
-(`produced_by: ultraexecute-local`, `produced_at: <ISO-8601>`,
+(`produced_by: trekexecute`, `produced_at: <ISO-8601>`,
 `status: stopped`) — same combined ESM pattern as Phase 8 — so Phase 1.5
 of `/ultracontinue` can compare project-dir and plugin-root candidates.
 
@@ -1352,7 +1352,7 @@ to stderr but do NOT block — Phase 8 must always reach the final report.
 
 **Also write sibling `NEXT-SESSION-PROMPT.local.md`** (Bug 3 frontmatter
 contract — see `docs/HANDOVER-CONTRACTS.md` § Handover 7 Lifecycle) in the
-project directory. The frontmatter MUST contain `produced_by: ultraexecute-local`
+project directory. The frontmatter MUST contain `produced_by: trekexecute`
 and `produced_at: <ISO-8601>` so `/ultracontinue` Phase 1.5 can detect
 producer drift between project-dir and plugin-root candidates. Use a single
 ESM inline block so state-file + prompt-file writes succeed or fail together:
@@ -1366,7 +1366,7 @@ const [, dir, briefPath, label, status] = process.argv;
 const now = new Date().toISOString();
 const stateObj = { schema_version: 1, project: dir, next_session_brief_path: briefPath, next_session_label: label, status, updated_at: now };
 atomicWriteJson(path.join(dir, '.session-state.local.json'), stateObj);
-const promptBody = '---\\nproduced_by: ultraexecute-local\\nproduced_at: ' + now + '\\nproject: ' + dir + '\\nstatus: ' + status + '\\n---\\n\\n# ' + label + '\\n\\nResume via /ultracontinue.\\n';
+const promptBody = '---\\nproduced_by: trekexecute\\nproduced_at: ' + now + '\\nproject: ' + dir + '\\nstatus: ' + status + '\\n---\\n\\n# ' + label + '\\n\\nResume via /ultracontinue.\\n';
 writeFileSync(path.join(dir, 'NEXT-SESSION-PROMPT.local.md'), promptBody);
 " '{project_dir}' '{next_session_brief_path}' '{next_session_label}' '{status}'`
 ```
diff --git a/docs/HANDOVER-CONTRACTS.md b/docs/HANDOVER-CONTRACTS.md
index 3b19b7c..1150124 100644
--- a/docs/HANDOVER-CONTRACTS.md
+++ b/docs/HANDOVER-CONTRACTS.md
@@ -429,7 +429,7 @@ The state file follows a producer/consumer separation that keeps responsibilitie
 
 **Frontmatter contract for `NEXT-SESSION-PROMPT.local.md`:** Producers MUST write a YAML frontmatter block on the prompt file with at minimum:
 
-- `produced_by:` — string identifying the producer (e.g. `ultraplan-local-A4-session`, `ultraexecute-local-phase-8`, `ultraplan-end-session-local`)
+- `produced_by:` — string identifying the producer (e.g. `trekplan-A4-session`, `trekexecute-phase-8`, `trekendsession`)
 - `produced_at:` — ISO-8601 timestamp of when the file was written
 
 The `next-session-prompt-validator` (`lib/validators/next-session-prompt-validator.mjs`) cross-checks `produced_at` against the sibling state file's `updated_at` and emits a `NEXT_SESSION_PROMPT_INCONSISTENT` error when the prompt is older than the state — that means the prompt has not been refreshed for the current session and is stale. Files **without** any frontmatter are tolerated (warning, not error) for backwards compatibility with v3.3.x and earlier hand-rolled prompt files; this is consistent with Handover 3's drift-WARN posture.
diff --git a/lib/validators/next-session-prompt-validator.mjs b/lib/validators/next-session-prompt-validator.mjs
index 931e0fc..e4cd708 100644
--- a/lib/validators/next-session-prompt-validator.mjs
+++ b/lib/validators/next-session-prompt-validator.mjs
@@ -1,8 +1,8 @@
 // lib/validators/next-session-prompt-validator.mjs
 // Validate NEXT-SESSION-PROMPT.local.md frontmatter (Bug 3 contract).
 //
-// Producers (ultraexecute-local Phase 8/2.55/4, ultraplan-end-session-local
-// Phase 3) MUST write `produced_by:` and `produced_at:` (ISO-8601) frontmatter.
+// Producers (trekexecute Phase 8/2.55/4, trekendsession Phase 3) MUST write
+// `produced_by:` and `produced_at:` (ISO-8601) frontmatter.
 // Consumers (/ultracontinue Phase 1.5) compare two candidate files and refuse
 // when producers disagree on a non-stale pair.
 //
diff --git a/tests/commands/trekcontinue.test.mjs b/tests/commands/trekcontinue.test.mjs
index 7195043..7ec6e5f 100644
--- a/tests/commands/trekcontinue.test.mjs
+++ b/tests/commands/trekcontinue.test.mjs
@@ -210,7 +210,7 @@ test('ultracontinue Bug 3 (e) — CLI consistency mode flags producer mismatch i
     // Project-dir prompt: produced_by ultraexecute-local at T-1
     const projectPrompt = join(projectDir, 'NEXT-SESSION-PROMPT.local.md');
     writeFileSync(projectPrompt,
-      '---\nproduced_by: ultraexecute-local\nproduced_at: 2026-05-04T15:30:00.000Z\n---\n\n# Session 2\n');
+      '---\nproduced_by: trekexecute\nproduced_at: 2026-05-04T15:30:00.000Z\n---\n\n# Session 2\n');
 
     // Plugin-root prompt: produced_by graceful-handoff at T-0 (newer)
     const pluginPrompt = join(root, 'NEXT-SESSION-PROMPT.local.md');
@@ -303,7 +303,7 @@ test('ultracontinue Bug 4 (f-1) dry-run lists candidates without deleting', asyn
       updated_at: '2026-05-04T16:00:00.000Z',
     }, null, 2));
     writeFileSync(join(dir, 'NEXT-SESSION-PROMPT.local.md'),
-      '---\nproduced_by: ultraexecute-local\nproduced_at: 2026-05-04T16:00:00.000Z\n---\n\n# Done\n');
+      '---\nproduced_by: trekexecute\nproduced_at: 2026-05-04T16:00:00.000Z\n---\n\n# Done\n');
     const r = cleanupProject(dir, { dryRun: true });
     assert.equal(r.valid, true, JSON.stringify(r.errors));
     assert.equal(r.parsed.wouldDelete.length, 2);
@@ -330,7 +330,7 @@ test('ultracontinue Bug 4 (f-2) confirm deletes and (f-3) idempotent re-run hand
       updated_at: '2026-05-04T16:00:00.000Z',
     }, null, 2));
     writeFileSync(join(dir, 'NEXT-SESSION-PROMPT.local.md'),
-      '---\nproduced_by: ultraexecute-local\nproduced_at: 2026-05-04T16:00:00.000Z\n---\n\n# Done\n');
+      '---\nproduced_by: trekexecute\nproduced_at: 2026-05-04T16:00:00.000Z\n---\n\n# Done\n');
 
     // f-2: confirm deletes
     const r2 = cleanupProject(dir, { dryRun: false, confirm: true });
diff --git a/tests/lib/cleanup.test.mjs b/tests/lib/cleanup.test.mjs
index b8d7f3e..3f7bb04 100644
--- a/tests/lib/cleanup.test.mjs
+++ b/tests/lib/cleanup.test.mjs
@@ -20,7 +20,7 @@ function buildProject(dir, status) {
   };
   writeFileSync(join(dir, '.session-state.local.json'), JSON.stringify(stateObj, null, 2));
   writeFileSync(join(dir, 'NEXT-SESSION-PROMPT.local.md'),
-    `---\nproduced_by: ultraexecute-local\nproduced_at: 2026-05-04T16:00:00.000Z\n---\n\n# Done\n`);
+    `---\nproduced_by: trekexecute\nproduced_at: 2026-05-04T16:00:00.000Z\n---\n\n# Done\n`);
   return dir;
 }
 
diff --git a/tests/validators/next-session-prompt-validator.test.mjs b/tests/validators/next-session-prompt-validator.test.mjs
index 299aae6..3b3af97 100644
--- a/tests/validators/next-session-prompt-validator.test.mjs
+++ b/tests/validators/next-session-prompt-validator.test.mjs
@@ -21,10 +21,10 @@ function frontmatter(producedBy, producedAt, extra = '') {
 }
 
 test('validateNextSessionPromptContent — both consistent producers (valid)', () => {
-  const text = frontmatter('ultraexecute-local', '2026-05-04T16:00:00.000Z');
+  const text = frontmatter('trekexecute', '2026-05-04T16:00:00.000Z');
   const r = validateNextSessionPromptContent(text);
   assert.equal(r.valid, true, JSON.stringify(r.errors));
-  assert.equal(r.parsed.produced_by, 'ultraexecute-local');
+  assert.equal(r.parsed.produced_by, 'trekexecute');
 });
 
 test('validateNextSessionPromptObject — missing produced_by is invalid', () => {
@@ -34,7 +34,7 @@ test('validateNextSessionPromptObject — missing produced_by is invalid', () =>
 });
 
 test('validateNextSessionPromptObject — missing produced_at is invalid', () => {
-  const r = validateNextSessionPromptObject({ produced_by: 'ultraexecute-local' });
+  const r = validateNextSessionPromptObject({ produced_by: 'trekexecute' });
   assert.equal(r.valid, false);
   assert.ok(r.errors.find(e => e.code === 'NEXT_SESSION_PROMPT_MISSING_FIELD' && /produced_at/.test(e.message)));
 });
@@ -52,7 +52,7 @@ test('validateNextSessionPromptContent — no frontmatter downgrades to warning
 });
 
 test('validateNextSessionPromptConsistency — producer mismatch with both fresh fails', () => {
-  const a = { path: '/a', parsed: { produced_by: 'ultraexecute-local', produced_at: '2026-05-04T16:00:00.000Z' } };
+  const a = { path: '/a', parsed: { produced_by: 'trekexecute', produced_at: '2026-05-04T16:00:00.000Z' } };
   const b = { path: '/b', parsed: { produced_by: 'graceful-handoff', produced_at: '2026-05-04T16:05:00.000Z' } };
   const state = { updated_at: '2026-05-04T15:00:00.000Z' };
   const r = validateNextSessionPromptConsistency(a, b, { state, now: Date.parse('2026-05-04T16:30:00.000Z') });
@@ -62,7 +62,7 @@ test('validateNextSessionPromptConsistency — producer mismatch with both fresh
 
 test('validateNextSessionPromptConsistency — state-anchored stale candidate ignored', () => {
   const a = { path: '/a', parsed: { produced_by: 'graceful-handoff', produced_at: '2026-05-03T10:00:00.000Z' } };
-  const b = { path: '/b', parsed: { produced_by: 'ultraexecute-local', produced_at: '2026-05-04T16:05:00.000Z' } };
+  const b = { path: '/b', parsed: { produced_by: 'trekexecute', produced_at: '2026-05-04T16:05:00.000Z' } };
   const state = { updated_at: '2026-05-04T16:00:00.000Z' };
   const r = validateNextSessionPromptConsistency(a, b, { state, now: Date.parse('2026-05-04T16:30:00.000Z') });
   assert.equal(r.valid, true, JSON.stringify(r.errors));
@@ -70,16 +70,16 @@ test('validateNextSessionPromptConsistency — state-anchored stale candidate ig
 });
 
 test('validateNextSessionPromptConsistency — 24h wall-clock drift emits soft warning', () => {
-  const a = { path: '/a', parsed: { produced_by: 'ultraexecute-local', produced_at: '2026-05-01T16:00:00.000Z' } };
-  const b = { path: '/b', parsed: { produced_by: 'ultraexecute-local', produced_at: '2026-05-01T16:00:00.000Z' } };
+  const a = { path: '/a', parsed: { produced_by: 'trekexecute', produced_at: '2026-05-01T16:00:00.000Z' } };
+  const b = { path: '/b', parsed: { produced_by: 'trekexecute', produced_at: '2026-05-01T16:00:00.000Z' } };
   const r = validateNextSessionPromptConsistency(a, b, { now: Date.parse('2026-05-04T16:30:00.000Z') });
   assert.equal(r.valid, true);
   assert.ok(r.warnings.find(w => w.code === 'NEXT_SESSION_PROMPT_WALL_CLOCK_DRIFT'));
 });
 
 test('validateNextSessionPromptConsistency — same producer, both fresh, no errors', () => {
-  const a = { path: '/a', parsed: { produced_by: 'ultraexecute-local', produced_at: '2026-05-04T16:00:00.000Z' } };
-  const b = { path: '/b', parsed: { produced_by: 'ultraexecute-local', produced_at: '2026-05-04T16:01:00.000Z' } };
+  const a = { path: '/a', parsed: { produced_by: 'trekexecute', produced_at: '2026-05-04T16:00:00.000Z' } };
+  const b = { path: '/b', parsed: { produced_by: 'trekexecute', produced_at: '2026-05-04T16:01:00.000Z' } };
   const r = validateNextSessionPromptConsistency(a, b, { now: Date.parse('2026-05-04T16:30:00.000Z') });
   assert.equal(r.valid, true);
   assert.deepEqual(r.errors, []);
@@ -91,7 +91,7 @@ test('CLI shim — single-file mode returns JSON for valid file', () => {
   const dir = mkdtempSync(join(tmpdir(), 'nspv-cli-'));
   try {
     const file = join(dir, 'NEXT-SESSION-PROMPT.local.md');
-    writeFileSync(file, frontmatter('ultraexecute-local', '2026-05-04T16:00:00.000Z'));
+    writeFileSync(file, frontmatter('trekexecute', '2026-05-04T16:00:00.000Z'));
     const out = execFileSync(process.execPath, [
       'lib/validators/next-session-prompt-validator.mjs',
       '--json',
@@ -109,7 +109,7 @@ test('CLI shim — consistency mode flags producer mismatch', () => {
   try {
     const a = join(dir, 'a.md');
     const b = join(dir, 'b.md');
-    writeFileSync(a, frontmatter('ultraexecute-local', '2026-05-04T16:00:00.000Z'));
+    writeFileSync(a, frontmatter('trekexecute', '2026-05-04T16:00:00.000Z'));
     writeFileSync(b, frontmatter('graceful-handoff', '2026-05-04T16:01:00.000Z'));
     let exitCode = 0;
     let out = '';