diff --git a/src/workflow/__tests__/selectors.test.ts b/src/workflow/__tests__/selectors.test.ts
index c67cc5d55..fca0179a4 100644
--- a/src/workflow/__tests__/selectors.test.ts
+++ b/src/workflow/__tests__/selectors.test.ts
@@ -63,6 +63,57 @@ test('mergePhases: actual but undeclared phase appended to the end', () => {
   expect(mergePhases(r).map(p => p.title)).toEqual(['Find', 'Adhoc'])
 })
 
+// Regression: scripts that pass opts.phase directly to agent() without a phase() hook call
+// (the ultracode canonical pipeline pattern). phase_started is never emitted for those phases,
+// so run.phases lacks them. The sidebar used to show them as pending forever while agents were
+// clearly running under them — and worse, the previous phase stayed "running" because phase_done
+// only fires on the next phase() call. Derive status from agents when no actual record exists.
+test('mergePhases: derives status from agents when phase_started was never emitted', () => {
+  // Mirrors the real .claude/workflow-runs/wnxct9u3q/script.js shape:
+  // phase('Map') called, 8 Map agents done; pipeline stage with phase:'Find' running (1/4);
+  // Verify / Synthesize declared but not started; phase('Synthesize') not yet reached so
+  // phase_done Map has not fired either — actual Map is still 'running'.
+  const r = run({
+    declaredPhases: ['Map', 'Find', 'Verify', 'Synthesize'],
+    phases: [{ title: 'Map', status: 'running' }],
+    agents: [
+      ...Array.from({ length: 8 }, (_, i) => ({
+        id: i,
+        phase: 'Map',
+        status: 'done' as const,
+        resultKind: 'ok',
+      })),
+      { id: 100, phase: 'Find', status: 'done', resultKind: 'ok' },
+      { id: 101, phase: 'Find', status: 'running' },
+      { id: 102, phase: 'Find', status: 'running' },
+      { id: 103, phase: 'Find', status: 'running' },
+    ],
+  })
+  expect(mergePhases(r)).toEqual([
+    { title: 'Map', status: 'done', done: 8, total: 8 },
+    { title: 'Find', status: 'running', done: 1, total: 4 },
+    { title: 'Verify', status: 'pending', done: 0, total: 0 },
+    { title: 'Synthesize', status: 'pending', done: 0, total: 0 },
+  ])
+})
+
+// A phase that appears only on agents (not in declaredPhases, not in run.phases) is still
+// surfaced so the user sees it in the sidebar.
+test('mergePhases: phase only present on agents is appended and derived from agent states', () => {
+  const r = run({
+    declaredPhases: ['Scan'],
+    phases: [],
+    agents: [
+      { id: 1, phase: 'AdhocFromAgent', status: 'running' },
+      { id: 2, phase: 'AdhocFromAgent', status: 'done', resultKind: 'ok' },
+    ],
+  })
+  expect(mergePhases(r)).toEqual([
+    { title: 'Scan', status: 'pending', done: 0, total: 0 },
+    { title: 'AdhocFromAgent', status: 'running', done: 1, total: 2 },
+  ])
+})
+
 test('filterAgentsByPhase: All / undefined → all; specified → only that phase', () => {
   const agents: AgentProgress[] = [
     { id: 1, phase: 'A', status: 'running' },
diff --git a/src/workflow/panel/selectors.ts b/src/workflow/panel/selectors.ts
index 0d18eddf5..b7d7345c9 100644
--- a/src/workflow/panel/selectors.ts
+++ b/src/workflow/panel/selectors.ts
@@ -13,9 +13,40 @@ export type MergedPhase = {
 }
 
 /**
- * Merge declaredPhases (declared by meta) and run.phases (actually running/done):
- * - Declared order takes priority; phases present in actual but not declared are appended at the end.
- * - No actual record -> pending; otherwise take the actual status.
+ * Derive a phase's sidebar status from the actual record + the agents grouped under it.
+ *
+ * The actual record comes from `phase_started`/`phase_done` events. Scripts that follow the
+ * ultracode canonical pipeline pattern pass `opts.phase` directly to `agent()` inside
+ * `pipeline()`/`parallel()` stages and never call `phase()` for those phases — so no
+ * `phase_started` ever fires and `run.phases` lacks them. Worse, because `phase_done` only
+ * emits when the *next* `phase()` runs, the previous phase stays "running" in `run.phases`
+ * even after all its agents finish.
+ *
+ * Rules (checked in order):
+ * 1. `phase_done` already fired → done is authoritative, respect it.
+ * 2. Agents exist under this phase → derive from their states
+ *    (all done → done; otherwise → running). This is what the user actually sees.
+ * 3. No agents yet → fall back to the actual record
+ *    (`running` if `phase()` was called and is still active, else pending).
+ */
+function derivePhaseStatus(
+  actual: { status: 'running' | 'done' } | undefined,
+  inPhase: AgentProgress[],
+): PhaseStatus {
+  if (actual?.status === 'done') return 'done'
+  if (inPhase.length > 0) {
+    return inPhase.every(a => a.status === 'done') ? 'done' : 'running'
+  }
+  return actual?.status === 'running' ? 'running' : 'pending'
+}
+
+/**
+ * Merge declaredPhases (declared by meta), run.phases (actually running/done),
+ * and phases that appear only on agents:
+ * - Declared order takes priority; then actual-but-undeclared; then agent-only phases.
+ *   Agent-only phases surface in the sidebar even when the script never called `phase()`
+ *   for them — otherwise the user sees agents running under a phase that isn't listed.
+ * - Status is derived via {@link derivePhaseStatus}.
  * - done/total = done under that phase / total agents under that phase.
  */
 export function mergePhases(
@@ -28,17 +59,22 @@ export function mergePhases(
     if (seen.has(title)) return
     seen.add(title)
     const actual = actualByTitle.get(title)
-    const status: PhaseStatus = !actual ? 'pending' : actual.status
     const inPhase = run.agents.filter(a => a.phase === title)
     out.push({
       title,
-      status,
+      status: derivePhaseStatus(actual, inPhase),
       done: inPhase.filter(a => a.status === 'done').length,
       total: inPhase.length,
     })
   }
   for (const t of run.declaredPhases) push(t)
   for (const p of run.phases) push(p.title)
+  // Scripts that pass opts.phase directly to agent() (the ultracode pipeline pattern)
+  // may have agents grouped under phases that never got a phase() call — surface them
+  // so the sidebar reflects every phase the user can actually observe agents running in.
+  for (const a of run.agents) {
+    if (a.phase) push(a.phase)
+  }
   return out
 }