diff --git a/ui/src/lib/editor/JsonEditor.svelte b/ui/src/lib/editor/JsonEditor.svelte
index 6ac0609..9ed833c 100644
--- a/ui/src/lib/editor/JsonEditor.svelte
+++ b/ui/src/lib/editor/JsonEditor.svelte
@@ -60,6 +60,7 @@
         guides: { indentation: false },
         automaticLayout: true,
         scrollBeyondLastLine: false,
+        wordWrap: 'on',
         fontSize: 13,
         tabSize: 2,
         fixedOverflowWidgets: true,
diff --git a/ui/src/lib/pages/JobPage.svelte b/ui/src/lib/pages/JobPage.svelte
index 68e9e58..8c4f9eb 100644
--- a/ui/src/lib/pages/JobPage.svelte
+++ b/ui/src/lib/pages/JobPage.svelte
@@ -23,6 +23,7 @@
   } from '../runstate'
   import { stepProgress } from '../progress'
   import FlowView from '../editor/FlowView.svelte'
+  import JsonEditor from '../editor/JsonEditor.svelte'
   import CopyButton from '../CopyButton.svelte'
   import DownloadLink from '../DownloadLink.svelte'
   import { notify } from '../toast'
@@ -39,6 +40,13 @@
   // a workflow that pins its seed to a literal or names none at all -
   // neither can be handed a different one, so the button stays away.
   let seedVariable = $state<string | null>(null)
+  // Whether `definition` is the realized copy the run itself wrote (every
+  // mutable input pinned) or the definition as submitted - the run predates
+  // run tracking, or its run directory is gone. Named beside the JSON view.
+  let realized = $state(false)
+  // The JSON view of that definition - off until asked, since the flow graph
+  // already answers "what did this run do" for most readers
+  let showJson = $state(false)
   let events = $state<JobEvent[]>([])
   let error = $state('')
   // arrival clocks for pipeline_step events, for the ETA estimate
@@ -51,6 +59,8 @@
     events = []
     definition = null
     seedVariable = null
+    realized = false
+    showJson = false
     // Under the flat output layout two runs write the same file names, so
     // a map keyed by name would show the last job's recipe for this one
     fileMeta = {}
@@ -64,6 +74,7 @@
         if (stopped) return
         definition = result.definition
         seedVariable = result.seed_variable
+        realized = result.realized
       })
       .catch(() => {
         /* no definition on file - the graph just does not appear */
@@ -440,7 +451,27 @@
 
   {#if definition}
     <section class="flowsection">
-      <h2>Workflow</h2>
+      <div class="flowhead">
+        <h2>Workflow</h2>
+        <span
+          class="muted jsonmark"
+          title={realized
+            ? 'this is the realized copy the run itself wrote - every mutable input pinned to the value it used'
+            : 'this is the definition as submitted - no realized copy of this run is on file'}
+          >{realized ? 'realized' : 'as submitted'}</span
+        >
+        <span class="flex"></span>
+        <button
+          class="bare"
+          onclick={() => (showJson = !showJson)}
+          aria-expanded={showJson}
+          title={showJson
+            ? 'hide the workflow this job ran'
+            : 'show the workflow this job ran, as JSON'}
+        >
+          {showJson ? 'hide' : 'show'} JSON
+        </button>
+      </div>
       <FlowView
         workflow={definition}
         activeStep={running ? activeNode : undefined}
@@ -448,6 +479,15 @@
         activeMember={activeMemberStep}
         doneMembers={finishedMemberSteps}
       />
+      {#if showJson}
+        <div class="json">
+          <JsonEditor
+            value={JSON.stringify(definition, null, 2)}
+            readonly
+            height="520px"
+          />
+        </div>
+      {/if}
     </section>
   {/if}
 
@@ -618,9 +658,21 @@
   .flowsection {
     margin-bottom: 1rem;
   }
-  .flowsection h2 {
+  .flowhead {
+    display: flex;
+    flex-wrap: wrap;
+    align-items: center;
+    gap: 0.4rem 1rem;
     margin-bottom: var(--space-2);
   }
+  .flowhead h2 {
+    margin: 0;
+  }
+  /* Which copy the definition is - what the engine resolves, so mono */
+  .jsonmark {
+    font-family: var(--font-mono);
+    font-size: var(--t-xs);
+  }
   .warnings {
     color: var(--warn);
   }
diff --git a/ui/src/lib/pages/JobPage.test.ts b/ui/src/lib/pages/JobPage.test.ts
index eb0d654..fe39904 100644
--- a/ui/src/lib/pages/JobPage.test.ts
+++ b/ui/src/lib/pages/JobPage.test.ts
@@ -1,4 +1,4 @@
-import { cleanup, render, screen, waitFor } from '@testing-library/svelte'
+import { cleanup, fireEvent, render, screen, waitFor } from '@testing-library/svelte'
 import { afterEach, expect, it, vi } from 'vitest'
 import JobPage from './JobPage.svelte'
 import { api } from '../api'
@@ -13,9 +13,17 @@ const stream = vi.hoisted(() => ({
 const metadata = vi.hoisted(() => ({
   byFile: {} as Record<string, Record<string, unknown>>,
 }))
-// The definition the job ran, for the flow view and the unsaved reasons
+// The definition the job ran, for the flow view and the unsaved reasons,
+// and whether it is the realized copy or the definition as submitted
 const ran = vi.hoisted(() => ({
   definition: null as Record<string, any> | null,
+  realized: true,
+}))
+
+// Monaco cannot boot in jsdom; the page's JSON view is tested through this
+// stub, which renders the value it was handed as plain text
+vi.mock('../editor/JsonEditor.svelte', async () => ({
+  default: (await import('./JsonEditorStub.svelte')).default,
 }))
 
 vi.mock('../api', () => ({
@@ -23,7 +31,11 @@ vi.mock('../api', () => ({
   api: {
     getJob: vi.fn(() => Promise.resolve(detail.job)),
     getJobWorkflow: vi.fn(() =>
-      Promise.resolve({ definition: ran.definition, seed_variable: null }),
+      Promise.resolve({
+        definition: ran.definition,
+        realized: ran.realized,
+        seed_variable: null,
+      }),
     ),
     galleryMetadata: vi.fn((name: string) =>
       Promise.resolve({
@@ -67,6 +79,7 @@ afterEach(() => {
   stream.onEvent = null
   metadata.byFile = {}
   ran.definition = null
+  ran.realized = true
   vi.mocked(api.galleryMetadata).mockClear()
 })
 
@@ -351,3 +364,23 @@ it('says nothing about an acknowledgement a run did not carry', async () => {
   await waitFor(() => expect(screen.getByText('j1')).toBeTruthy())
   expect(screen.queryByText(/acknowledged/)).toBeNull()
 })
+
+it('offers the workflow JSON behind a toggle, labelled as the realized copy', async () => {
+  ran.definition = { steps: [{ name: 'base', pipeline: {} }] }
+  render(JobPage, { jobId: 'j1' })
+  await waitFor(() => expect(screen.getByText('realized')).toBeTruthy())
+  // The JSON is for the curious, not the default view
+  expect(screen.queryByTestId('json-editor')).toBeNull()
+  await fireEvent.click(screen.getByRole('button', { name: 'show JSON' }))
+  const shown = await screen.findByTestId('json-editor')
+  // What the viewer is handed is the definition the page fetched
+  expect(shown.textContent).toContain('"name": "base"')
+  expect(screen.getByRole('button', { name: 'hide JSON' })).toBeTruthy()
+})
+
+it('labels a definition with no realized copy on file as submitted', async () => {
+  ran.definition = { steps: [{ name: 'base', pipeline: {} }] }
+  ran.realized = false
+  render(JobPage, { jobId: 'j1' })
+  await waitFor(() => expect(screen.getByText('as submitted')).toBeTruthy())
+})
diff --git a/ui/src/lib/pages/JsonEditorStub.svelte b/ui/src/lib/pages/JsonEditorStub.svelte
new file mode 100644
index 0000000..b023d69
--- /dev/null
+++ b/ui/src/lib/pages/JsonEditorStub.svelte
@@ -0,0 +1,8 @@
+<script lang="ts">
+  // Test stand-in for the Monaco-backed JsonEditor: renders the value as
+  // plain text so a test can assert what the page handed the viewer
+  // without booting Monaco in jsdom.
+  let { value }: { value: string } = $props()
+</script>
+
+<pre data-testid="json-editor">{value}</pre>
\ No newline at end of file