diff --git a/public/js/myResources.js b/public/js/myResources.js
index b5793517..b494ef35 100644
--- a/public/js/myResources.js
+++ b/public/js/myResources.js
@@ -381,6 +381,29 @@
     var r = job.result || {};
     var g = r.grounding || {};
     var title = (r.resource && r.resource.title) || job.topic;
+    // A modification reports itself exactly as it did when the request waited for
+    // it; only where the answer arrives has changed.
+    if (job.kind === 'refine') {
+      // The model can return the document back unchanged. That is a failed
+      // modification, and saying "Applied" for it sent people off to download
+      // an identical file and conclude the feature was broken.
+      if (r.unchanged) {
+        status('“' + title + '”: the model returned it unchanged — nothing was modified. ' +
+               'Try naming the slide or section to change, and what to change about it.', 'bad');
+      } else {
+        // Whether it could see the slides is worth saying: it is the difference
+        // between "slide 4 looks crowded" being actionable and being guesswork,
+        // and it explains why this took longer.
+        status('“' + title + '” modified' +
+               (r.saw ? ', after looking at all ' + r.saw + ' slides' : '') +
+               (g.used ? ', using ' + g.count + ' library excerpt' + (g.count === 1 ? '' : 's') : '') +
+               '. Download it to see the result.', 'good');
+      }
+      reportSearches(r.searches);
+      showIllustrations(r.imageJobs || []);
+      reportImageFailures(r.imageFailures);
+      return;
+    }
     status('“' + title + '” is in your library. ' + (g.used
       ? 'Written from ' + g.count + ' library excerpt' + (g.count === 1 ? '' : 's') + '.'
       : 'Not grounded' + (g.reason ? ' — ' + g.reason : '') + '; written from the model alone.'),
@@ -415,11 +438,12 @@
       icon.style.color = busy ? 'var(--g600)' : job.status === 'done' ? 'var(--green)' : 'var(--red)';
       var label = document.createElement('span');
       label.style.cssText = 'flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;';
-      label.textContent = job.topic + ' · ' + (job.kind === 'article' ? 'article' : 'presentation');
+      label.textContent = job.topic + ' · ' + (job.kind === 'refine' ? 'modification'
+        : job.kind === 'article' ? 'article' : 'presentation');
       var state = document.createElement('span');
       state.style.cssText = 'color:var(--g600);white-space:nowrap;';
       state.textContent = job.status === 'queued' ? 'Queued'
-        : job.status === 'running' ? 'Writing… ' + elapsed(job)
+        : job.status === 'running' ? (job.kind === 'refine' ? 'Rewriting… ' : 'Writing… ') + elapsed(job)
         : job.status === 'done' ? 'Done'
         : 'Failed — ' + (job.error || 'Generation failed');
       row.appendChild(icon); row.appendChild(label); row.appendChild(state);
@@ -864,6 +888,11 @@
     if (btn) { btn.disabled = true; btn.innerHTML = '<i class="fas fa-spinner fa-spin"></i> Applying'; }
     clearResults();
     say('Rewriting…');
+    // Queued like a generation, not awaited. A revision restates the whole
+    // resource and can take minutes; a request held open that long is abandoned
+    // by the browser while the server carries on, which is exactly how a
+    // modification looked like it had failed and then really had been saved.
+    // The job list reports it, so leaving the page no longer loses the work.
     fetch('/api/my-resources/' + encodeURIComponent(id) + '/refine', {
       method: 'POST',
       headers: getAuthHeaders(),
@@ -879,29 +908,9 @@
       .then(function (r) { return r.json(); })
       .then(function (data) {
         if (!data.success) throw new Error(data.error || 'Could not apply the changes');
-        // Same reporting as generating: what it was written from, what was
-        // searched, and any figure that came back.
-        var g = data.grounding || {};
-        // The model can return the document back unchanged. That is a failed
-        // modification, and saying "Applied" for it sent people off to download
-        // an identical file and conclude the feature was broken.
-        if (data.unchanged) {
-          say('The model returned it unchanged — nothing was modified. ' +
-              'Try naming the slide or section to change, and what to change about it.', 'bad');
-        } else {
-          // Whether it could see the slides is worth saying: it is the
-          // difference between "slide 4 looks crowded" being actionable and
-          // being guesswork, and it explains why this took longer.
-          say('Applied' +
-              (data.saw ? ', after looking at all ' + data.saw + ' slides' : '') +
-              (g.used ? ', using ' + g.count + ' library excerpt' + (g.count === 1 ? '' : 's') : '') +
-              '. Download it to see the result.', 'good');
-        }
-        reportSearches(data.searches);
-        showIllustrations(data.imageJobs || []);
-        reportImageFailures(data.imageFailures);
-        if (box && !data.unchanged) box.value = '';
-        loadLibrary();
+        say('Rewriting in the background. You can leave this page — it keeps going.', 'good');
+        if (box) box.value = '';
+        refreshJobs();
       })
       .catch(function (err) { say(err.message, 'bad'); })
       .finally(function () {
diff --git a/src/routes/myResources.js b/src/routes/myResources.js
index 55e0184d..068726e2 100644
--- a/src/routes/myResources.js
+++ b/src/routes/myResources.js
@@ -574,15 +574,32 @@ function httpError(statusCode, message) {
 // job; a runaway click is not.
 var MAX_ACTIVE_JOBS = 3;
 
+// One writer at a time, counted across generating and modifying alike: a
+// modification does the same library search and the same long model call as a
+// generation, so letting ten of them run at once is the cost the cap bounds.
+async function assertJobSlot(userId) {
+  var active = await db.get("SELECT COUNT(*)::int AS n FROM user_resource_jobs WHERE user_id = ? AND status IN ('queued', 'running')", [userId]);
+  if (active && active.n >= MAX_ACTIVE_JOBS) {
+    throw httpError(409, MAX_ACTIVE_JOBS + ' resources are already being written. Wait for one to finish.');
+  }
+}
+
 /** Run one queued job to its end and record how it ended. Never throws. */
-async function runResourceJob(jobId, userId, body) {
+async function runResourceJob(jobId, userId, body, kind, resourceId) {
   try {
     await db.run("UPDATE user_resource_jobs SET status = 'running', started_at = NOW() WHERE id = ?", [jobId]);
-    var result = await generateResource(userId, body);
+    // A modification needs the author, not just their id: the deck is rendered for
+    // sight and each figure is read back under their ownership. Loaded here rather
+    // than carried in the request, so the job holds no stale session.
+    var result = kind === 'refine'
+      ? await refineResource(await db.get('SELECT id, email, name, role, totp_enabled, disabled FROM users WHERE id = ?', [userId]), resourceId, body)
+      : await generateResource(userId, body);
     var summary = {
       resource: result.resource, grounding: result.grounding, imageJobs: result.imageJobs,
       imageFailures: result.imageFailures, searches: result.searches, review: result.review,
-      deckFallback: result.deckFallback, model: result.model
+      deckFallback: result.deckFallback, model: result.model,
+      // Read back by the page for a modification; absent for a generation.
+      unchanged: result.unchanged, saw: result.saw
     };
     await db.run("UPDATE user_resource_jobs SET status = 'done', finished_at = NOW(), resource_id = ?, result = ? WHERE id = ?",
       [result.resource.id, JSON.stringify(summary), jobId]);
@@ -614,10 +631,7 @@ router.post('/my-resources/generate', async function (req, res) {
   try {
     var topic = String(req.body.topic || '').trim();
     if (!topic) return res.status(400).json({ error: 'A topic is required' });
-    var active = await db.get("SELECT COUNT(*)::int AS n FROM user_resource_jobs WHERE user_id = ? AND status IN ('queued', 'running')", [req.user.id]);
-    if (active && active.n >= MAX_ACTIVE_JOBS) {
-      return res.status(409).json({ error: MAX_ACTIVE_JOBS + ' resources are already being written. Wait for one to finish.' });
-    }
+    await assertJobSlot(req.user.id);
     var count = await db.get('SELECT COUNT(*)::int AS n FROM user_resources WHERE user_id = ?', [req.user.id]);
     if (count && count.n >= MAX_PER_USER) {
       return res.status(409).json({ error: 'You have reached ' + MAX_PER_USER + ' saved resources. Delete one first.' });
@@ -626,7 +640,7 @@ router.post('/my-resources/generate', async function (req, res) {
       'INSERT INTO user_resource_jobs (user_id, topic, kind, request) VALUES (?, ?, ?, ?) ' +
       'RETURNING id, topic, kind, status, created_at',
       [req.user.id, topic.slice(0, 500), normalizeKind(req.body.kind), JSON.stringify(req.body || {})]);
-    runResourceJob(job.id, req.user.id, req.body || {});
+    runResourceJob(job.id, req.user.id, req.body || {}, 'generate', null);
     res.status(202).json({ success: true, job: job });
   } catch (err) {
     console.error('[my-resources] generate:', err.message);
@@ -1026,246 +1040,272 @@ router.put('/my-resources/:id/theme', async function (req, res) {
   }
 });
 
+// Modify a resource. The same shape as generating: the caller queues the work
+// and the page follows it as a job, so the tab can be closed while it runs.
+// Ownership is re-checked here rather than only at enqueue, because the
+// resource can be deleted while the job waits its turn.
+async function refineResource(user, resourceId, body) {
+  var instructions = String(body.instructions || '').trim();
+  if (!instructions) throw httpError(400, 'Say what to change');
+
+  var existing = await db.get(
+    'SELECT id, kind, topic, markdown, deck, image_ids, theme FROM user_resources WHERE id = ? AND user_id = ?',
+    [resourceId, user.id]
+  );
+  if (!existing) throw httpError(404, 'Not found');
+
+  // Modifying can reach for the same sources as generating: "add what the
+  // 2024 trial showed" is a request for material, not just a rewording, and
+  // without this it would be answered from the model's memory alone. The
+  // subject searched is the resource's own topic plus the instruction, so a
+  // request about something not in the original still finds it.
+  var subject = [existing.topic, instructions].filter(Boolean).join(' \u2014 ').slice(0, 500);
+  var sources = await gatherSources(subject, body, existing.topic || instructions);
+
+  var material = '';
+  if (sources.corpus.context) {
+    material += '\n\nLIBRARY EXCERPTS (prefer these over your own recall; add anything you use ' +
+      'to the References section):\n"""\n' + sources.corpus.context + '\n"""';
+  }
+  if (sources.literature) {
+    material += '\n\nPUBMED RESULTS (cite by PMID in the References section; cite nothing not ' +
+      'listed here):\n"""\n' + sources.literature + '\n"""';
+  }
+  if (sources.webFindings) {
+    material += '\n\nWEB RESULTS (list what you use in the References section by title and ' +
+      'URL):\n"""\n' + sources.webFindings + '\n"""';
+  }
+  if (sources.searchedAndFoundNothing) {
+    material += '\n\nThe search for this returned nothing. Do not invent a citation, a PMID or ' +
+      'a URL to fill the gap: leave the References section as it is.';
+  }
+
+  // A presentation with a stored deck is edited as a deck. Editing its
+  // markdown instead changed only the markdown: export renders from the deck,
+  // so a modification succeeded, said so, and produced an identical download.
+  //
+  // Declared here, above its first reader, and not further down where it used
+  // to sit. `var` hoisted it, so the illustration branch below read it as
+  // undefined and composed the markdown instruction for a deck: the model was
+  // told to return markdown and deck JSON in the same reply, the reply parsed
+  // as neither, and modifying a deck with illustration on failed outright.
+  var existingDeck = existing.deck
+    ? (typeof existing.deck === 'string' ? JSON.parse(existing.deck) : existing.deck) : null;
+  if (existingDeck && !(existingDeck.slides || []).length) existingDeck = null;
+
+  // How a figure is asked for depends on which thing is being edited. A deck
+  // places figures by declaring them on a slide; markdown has nowhere to put
+  // one, so it uses the tool. Offering the tool while editing a deck queued a
+  // figure that no slide referenced — it was generated, paid for, recorded
+  // against the resource, and never appeared in the export.
+  var illustration = !sources.wantsImages ? ''
+    : existingDeck
+      ? '\n\nThe author has asked for illustration. Add "image_prompt" to the slides that ' +
+        'should carry a figure — schematic or anatomical teaching artwork only, never a real ' +
+        'patient — and keep the "image_job" value of any slide that already has one. ' +
+        resourceImages.guidance(instructions)
+      : '\n\nAn illustration tool is available and the author has asked for illustration. ' +
+        resourceImages.guidance(instructions) + ' Schematic or anatomical teaching artwork only, ' +
+        'never a real patient. Returning the markdown is still required; a tool call is not a ' +
+        'substitute for it, and no image tag or URL goes into the markdown.';
+
+  // Let it look at the deck it is about to edit, when a vision model is
+  // configured. Measured before building this: the text model returned the
+  // deck unchanged for "make it better", and a stronger model fixed that
+  // without seeing anything — but sight is what makes the visual half of the
+  // instructions answerable at all, and that is most of what people ask for
+  // while modifying.
+  var visionModel = existingDeck
+    ? String(await db.getSetting('my_resources.review_model', '') || '') : '';
+  var slideViews = visionModel
+    ? await renderDeckForSight(existingDeck, existing.image_ids, user)
+    : [];
+  var sight = !slideViews.length ? '' :
+    '\n\nYou can see the deck as it renders now: ' + slideViews.length + ' image' +
+    (slideViews.length === 1 ? '' : 's') + ', one per slide, in order. The first image is ' +
+    'slide index 0 in the JSON below. Use them for anything the instruction says about how ' +
+    'a slide looks — crowded, empty, a figure in the wrong place, text running off the ' +
+    'bottom. The JSON is what you edit; the images only tell you what it currently ' +
+    'produces.';
+
+  var messages = [{ role: 'user', content: existingDeck
+    ? 'Revise the following slide deck according to the instruction. Return ONLY the ' +
+      'complete revised JSON object, in exactly the same shape, no commentary and no code ' +
+      'fences. Keep every slide that the instruction does not ask you to change, including ' +
+      'its layout and its "image_job" values, and keep any References slide last.\n\n' +
+      'INSTRUCTION: ' + instructions + illustration + material + sight +
+      '\n\nThe layouts available are:\n' + deckSchema.instructions(
+        (existingDeck.slides || []).length, 0) +
+      (existingDeck.format ? '\n\n' + deckFormats.instructions(existingDeck.format) : '') +
+      '\n\nDECK JSON:\n' + JSON.stringify({ slides: existingDeck.slides })
+    : 'Revise the following Pandoc markdown according to the instruction. ' +
+      'Return ONLY the complete revised markdown, no commentary, no code fences. ' +
+      'Keep the same overall structure unless the instruction asks otherwise, and keep any ' +
+      'References section at the end.\n\nINSTRUCTION: ' + instructions + illustration + material +
+      '\n\nMARKDOWN:\n"""\n' + existing.markdown + '\n"""' }];
+  // The reply restates the whole resource, so it needs room for one.
+  //
+  // The vision model does the editing when there is one — both because it is
+  // the only one that can act on what it sees, and because it follows a vague
+  // instruction better: measured on a real 20-slide deck, the text model
+  // echoed "make it better" back unchanged and the vision model did not.
+  // An explicit choice by the author still wins over both.
+  var options = {
+    model: body.model ? await resolveModel(body.model)
+      : (visionModel && slideViews.length ? visionModel : await resolveModel('')),
+    temperature: 0.2, maxTokens: 16000,
+    // A revision is writing. This is the call a thirteen-slide deck made the
+    // browser wait six minutes for: DeepSeek reasoned for a minute and a half
+    // and wrote nothing on the first attempt.
+    reasoningEffort: 'none'
+  };
+  if (slideViews.length) options.images = slideViews;
+  // Deck mode declares its figures; only the markdown path needs the tool.
+  var tools = sources.wantsImages && !existingDeck ? resourceImages.tools : [];
+  var callOptions = tools.length ? Object.assign({}, options, { tools: tools }) : options;
+  if (tools.length && resourceImages.requestedCount(instructions)) callOptions.toolChoice = 'required';
+
+  var ai = await callAI(messages, callOptions);
+  if (sources.wantsImages && !existingDeck) {
+    ai = await resourceImages.dispatch(ai, {
+      owner: user.id, body: body, subject: subject, imageModel: sources.imageModel,
+      messages: messages, options: options, callAI: callAI
+    });
+  }
+
+  var revisedDeck = existingDeck ? deckBuild.parse(ai && ai.content) : null;
+  if (existingDeck && !revisedDeck) {
+    // A reply that is not a deck would otherwise be saved as the markdown and
+    // silently drop every layout the deck held.
+    logRefine({ id: existing.id, path: 'deck', outcome: 'refused',
+                detail: 'the model did not return a usable deck', instructions: instructions });
+    throw httpError(502, 'That change could not be applied. Try wording it differently.');
+  }
+  if (revisedDeck) {
+    // Carried through rather than trusted from the reply.
+    revisedDeck.title = existingDeck.title;
+    revisedDeck.subtitle = existingDeck.subtitle;
+    revisedDeck.date = existingDeck.date;
+    // The look is the author's, not the model's: a modification never
+    // resets the theme. The column keeps it too, but the two should agree.
+    revisedDeck.theme = existingDeck.theme || existing.theme || revisedDeck.theme;
+    // And the shape it was written in.
+    revisedDeck.format = existingDeck.format || revisedDeck.format;
+    // Draw whatever the revised deck asked for, the same way generating does,
+    // so each new figure belongs to the slide that wanted it.
+    if (sources.wantsImages) {
+      var drawn = await deckBuild.drawFigures(revisedDeck, {
+        owner: user.id, body: body, subject: subject, imageModel: sources.imageModel
+      });
+      ai = Object.assign({}, ai, { imageJobs: drawn.jobs, imageFailures: drawn.failures });
+    } else {
+      // Illustration off: a figure the revision newly asks for keeps its
+      // place as an empty labelled frame; figures already drawn are kept.
+      await deckBuild.drawFigures(revisedDeck, { imageModel: '' });
+    }
+  }
+
+  // Look at the result. The edit was made against how the deck looked before
+  // it; a slide that gained two bullets now overflows, and only rendering it
+  // again shows that. Same reviewer as generation, which may reposition but
+  // is held to the same words — so a verification pass cannot quietly undo
+  // the change that was just asked for.
+  // Judged before the reviewer touches it. The question "did my instruction do
+  // anything" is about the model's edit; a reviewer that nudged a slide into
+  // two columns would otherwise mask an instruction that achieved nothing.
+  var echoedBack = revisedDeck
+    ? JSON.stringify(existingDeck.slides) === JSON.stringify(revisedDeck.slides)
+    : false;
+
+  var verified = { reviewed: false, reason: 'not attempted' };
+  if (revisedDeck && visionModel) {
+    verified = await deckReview.review(revisedDeck, {
+      model: visionModel,
+      reasoningEffort: options.reasoningEffort,
+      callAI: callAI,
+      extractJson: deckBuild.extractJson,
+      gotenberg: documentExport.GOTENBERG,
+      mime: documentExport.FORMATS.pptx.mime,
+      pptx: await documentExport.renderDeck(revisedDeck, [], figureIdList(existing.image_ids))
+    });
+    revisedDeck = verified.deck;
+  }
+
+  var revised = revisedDeck ? deckSchema.toMarkdown(revisedDeck)
+    : String((ai && ai.content) || '').trim();
+  if (!revised) throw httpError(502, 'The model returned nothing. Try again.');
+
+  // Figures from a modification are added to the ones already there, not
+  // swapped for them: "add two more diagrams" means more, not instead.
+  var added = (ai.imageJobs || []).map(function (job) { return job.jobId; }).filter(Boolean);
+  var row = await db.get(
+    'UPDATE user_resources SET markdown = ?, title = ?, updated_at = NOW(), ' +
+    'image_ids = image_ids || ?::jsonb, deck = COALESCE(?::jsonb, deck) ' +
+    'WHERE id = ? AND user_id = ? RETURNING id, title, updated_at',
+    [revised, firstHeading(revised), JSON.stringify(added),
+     revisedDeck ? JSON.stringify(revisedDeck) : null, existing.id, user.id]
+  );
+  // Said out loud, every time. A modification that changes nothing is the
+  // failure worth catching, and it is invisible from the response: the row
+  // updates, the title updates, and the file is identical.
+  // Computed once, because the caller is told this too. Logging it server-side
+  // while answering "Applied" left the one person who could do something about
+  // it — the person who asked for the change — reading a success message next
+  // to an identical file.
+  var unchanged = revisedDeck ? echoedBack
+    : revised.trim() === String(existing.markdown || '').trim();
+  logRefine({
+    id: existing.id,
+    path: revisedDeck ? 'deck' : 'markdown',
+    outcome: 'applied',
+    before: existingDeck ? (existingDeck.slides || []).length : existing.markdown.length,
+    after: revisedDeck ? (revisedDeck.slides || []).length : revised.length,
+    unchanged: unchanged,
+    figures: added.length,
+    model: ai && ai.model,
+    instructions: instructions
+  });
+
+  return {
+    success: true, resource: row, markdown: revised, unchanged: unchanged,
+    saw: slideViews.length,
+    review: { applied: verified.reviewed, reason: verified.reason },
+    grounding: { used: Boolean(sources.corpus.context), count: sources.corpus.sources.length,
+                 reason: sources.corpus.reason || null },
+    searches: sources.searches,
+    imageJobs: ai.imageJobs || [],
+    imageFailures: ai.imageFailures || [],
+    model: ai && ai.model
+  };
+}
+
+// Queue a modification and answer at once, exactly as generating does. The work
+// is a job on the server, so a browser that gives up waiting — Firefox abandons
+// a non-streaming fetch at five minutes — no longer takes the modification down
+// with it, and a reload loses nothing.
 router.post('/my-resources/:id/refine', async function (req, res) {
   try {
     var instructions = String(req.body.instructions || '').trim();
     if (!instructions) return res.status(400).json({ error: 'Say what to change' });
-
-    var existing = await db.get(
-      'SELECT id, kind, topic, markdown, deck, image_ids, theme FROM user_resources WHERE id = ? AND user_id = ?',
-      [parseInt(req.params.id, 10), req.user.id]
-    );
+    var resourceId = parseInt(req.params.id, 10);
+    var existing = await db.get('SELECT id, topic FROM user_resources WHERE id = ? AND user_id = ?',
+      [resourceId, req.user.id]);
     if (!existing) return res.status(404).json({ error: 'Not found' });
-
-    // Modifying can reach for the same sources as generating: "add what the
-    // 2024 trial showed" is a request for material, not just a rewording, and
-    // without this it would be answered from the model's memory alone. The
-    // subject searched is the resource's own topic plus the instruction, so a
-    // request about something not in the original still finds it.
-    var subject = [existing.topic, instructions].filter(Boolean).join(' \u2014 ').slice(0, 500);
-    var sources = await gatherSources(subject, req.body, existing.topic || instructions);
-
-    var material = '';
-    if (sources.corpus.context) {
-      material += '\n\nLIBRARY EXCERPTS (prefer these over your own recall; add anything you use ' +
-        'to the References section):\n"""\n' + sources.corpus.context + '\n"""';
-    }
-    if (sources.literature) {
-      material += '\n\nPUBMED RESULTS (cite by PMID in the References section; cite nothing not ' +
-        'listed here):\n"""\n' + sources.literature + '\n"""';
-    }
-    if (sources.webFindings) {
-      material += '\n\nWEB RESULTS (list what you use in the References section by title and ' +
-        'URL):\n"""\n' + sources.webFindings + '\n"""';
-    }
-    if (sources.searchedAndFoundNothing) {
-      material += '\n\nThe search for this returned nothing. Do not invent a citation, a PMID or ' +
-        'a URL to fill the gap: leave the References section as it is.';
-    }
-
-    // A presentation with a stored deck is edited as a deck. Editing its
-    // markdown instead changed only the markdown: export renders from the deck,
-    // so a modification succeeded, said so, and produced an identical download.
-    //
-    // Declared here, above its first reader, and not further down where it used
-    // to sit. `var` hoisted it, so the illustration branch below read it as
-    // undefined and composed the markdown instruction for a deck: the model was
-    // told to return markdown and deck JSON in the same reply, the reply parsed
-    // as neither, and modifying a deck with illustration on failed outright.
-    var existingDeck = existing.deck
-      ? (typeof existing.deck === 'string' ? JSON.parse(existing.deck) : existing.deck) : null;
-    if (existingDeck && !(existingDeck.slides || []).length) existingDeck = null;
-
-    // How a figure is asked for depends on which thing is being edited. A deck
-    // places figures by declaring them on a slide; markdown has nowhere to put
-    // one, so it uses the tool. Offering the tool while editing a deck queued a
-    // figure that no slide referenced — it was generated, paid for, recorded
-    // against the resource, and never appeared in the export.
-    var illustration = !sources.wantsImages ? ''
-      : existingDeck
-        ? '\n\nThe author has asked for illustration. Add "image_prompt" to the slides that ' +
-          'should carry a figure — schematic or anatomical teaching artwork only, never a real ' +
-          'patient — and keep the "image_job" value of any slide that already has one. ' +
-          resourceImages.guidance(instructions)
-        : '\n\nAn illustration tool is available and the author has asked for illustration. ' +
-          resourceImages.guidance(instructions) + ' Schematic or anatomical teaching artwork only, ' +
-          'never a real patient. Returning the markdown is still required; a tool call is not a ' +
-          'substitute for it, and no image tag or URL goes into the markdown.';
-
-    // Let it look at the deck it is about to edit, when a vision model is
-    // configured. Measured before building this: the text model returned the
-    // deck unchanged for "make it better", and a stronger model fixed that
-    // without seeing anything — but sight is what makes the visual half of the
-    // instructions answerable at all, and that is most of what people ask for
-    // while modifying.
-    var visionModel = existingDeck
-      ? String(await db.getSetting('my_resources.review_model', '') || '') : '';
-    var slideViews = visionModel
-      ? await renderDeckForSight(existingDeck, existing.image_ids, req.user)
-      : [];
-    var sight = !slideViews.length ? '' :
-      '\n\nYou can see the deck as it renders now: ' + slideViews.length + ' image' +
-      (slideViews.length === 1 ? '' : 's') + ', one per slide, in order. The first image is ' +
-      'slide index 0 in the JSON below. Use them for anything the instruction says about how ' +
-      'a slide looks — crowded, empty, a figure in the wrong place, text running off the ' +
-      'bottom. The JSON is what you edit; the images only tell you what it currently ' +
-      'produces.';
-
-    var messages = [{ role: 'user', content: existingDeck
-      ? 'Revise the following slide deck according to the instruction. Return ONLY the ' +
-        'complete revised JSON object, in exactly the same shape, no commentary and no code ' +
-        'fences. Keep every slide that the instruction does not ask you to change, including ' +
-        'its layout and its "image_job" values, and keep any References slide last.\n\n' +
-        'INSTRUCTION: ' + instructions + illustration + material + sight +
-        '\n\nThe layouts available are:\n' + deckSchema.instructions(
-          (existingDeck.slides || []).length, 0) +
-        (existingDeck.format ? '\n\n' + deckFormats.instructions(existingDeck.format) : '') +
-        '\n\nDECK JSON:\n' + JSON.stringify({ slides: existingDeck.slides })
-      : 'Revise the following Pandoc markdown according to the instruction. ' +
-        'Return ONLY the complete revised markdown, no commentary, no code fences. ' +
-        'Keep the same overall structure unless the instruction asks otherwise, and keep any ' +
-        'References section at the end.\n\nINSTRUCTION: ' + instructions + illustration + material +
-        '\n\nMARKDOWN:\n"""\n' + existing.markdown + '\n"""' }];
-    // The reply restates the whole resource, so it needs room for one.
-    //
-    // The vision model does the editing when there is one — both because it is
-    // the only one that can act on what it sees, and because it follows a vague
-    // instruction better: measured on a real 20-slide deck, the text model
-    // echoed "make it better" back unchanged and the vision model did not.
-    // An explicit choice by the author still wins over both.
-    var options = {
-      model: req.body.model ? await resolveModel(req.body.model)
-        : (visionModel && slideViews.length ? visionModel : await resolveModel('')),
-      temperature: 0.2, maxTokens: 16000,
-      // A revision is writing. This is the call a thirteen-slide deck made the
-      // browser wait six minutes for: DeepSeek reasoned for a minute and a half
-      // and wrote nothing on the first attempt.
-      reasoningEffort: 'none'
-    };
-    if (slideViews.length) options.images = slideViews;
-    // Deck mode declares its figures; only the markdown path needs the tool.
-    var tools = sources.wantsImages && !existingDeck ? resourceImages.tools : [];
-    var callOptions = tools.length ? Object.assign({}, options, { tools: tools }) : options;
-    if (tools.length && resourceImages.requestedCount(instructions)) callOptions.toolChoice = 'required';
-
-    var ai = await callAI(messages, callOptions);
-    if (sources.wantsImages && !existingDeck) {
-      ai = await resourceImages.dispatch(ai, {
-        owner: req.user.id, body: req.body, subject: subject, imageModel: sources.imageModel,
-        messages: messages, options: options, callAI: callAI
-      });
-    }
-
-    var revisedDeck = existingDeck ? deckBuild.parse(ai && ai.content) : null;
-    if (existingDeck && !revisedDeck) {
-      // A reply that is not a deck would otherwise be saved as the markdown and
-      // silently drop every layout the deck held.
-      logRefine({ id: existing.id, path: 'deck', outcome: 'refused',
-                  detail: 'the model did not return a usable deck', instructions: instructions });
-      return res.status(502).json({ error: 'That change could not be applied. Try wording it differently.' });
-    }
-    if (revisedDeck) {
-      // Carried through rather than trusted from the reply.
-      revisedDeck.title = existingDeck.title;
-      revisedDeck.subtitle = existingDeck.subtitle;
-      revisedDeck.date = existingDeck.date;
-      // The look is the author's, not the model's: a modification never
-      // resets the theme. The column keeps it too, but the two should agree.
-      revisedDeck.theme = existingDeck.theme || existing.theme || revisedDeck.theme;
-      // And the shape it was written in.
-      revisedDeck.format = existingDeck.format || revisedDeck.format;
-      // Draw whatever the revised deck asked for, the same way generating does,
-      // so each new figure belongs to the slide that wanted it.
-      if (sources.wantsImages) {
-        var drawn = await deckBuild.drawFigures(revisedDeck, {
-          owner: req.user.id, body: req.body, subject: subject, imageModel: sources.imageModel
-        });
-        ai = Object.assign({}, ai, { imageJobs: drawn.jobs, imageFailures: drawn.failures });
-      } else {
-        // Illustration off: a figure the revision newly asks for keeps its
-        // place as an empty labelled frame; figures already drawn are kept.
-        await deckBuild.drawFigures(revisedDeck, { imageModel: '' });
-      }
-    }
-
-    // Look at the result. The edit was made against how the deck looked before
-    // it; a slide that gained two bullets now overflows, and only rendering it
-    // again shows that. Same reviewer as generation, which may reposition but
-    // is held to the same words — so a verification pass cannot quietly undo
-    // the change that was just asked for.
-    // Judged before the reviewer touches it. The question "did my instruction do
-    // anything" is about the model's edit; a reviewer that nudged a slide into
-    // two columns would otherwise mask an instruction that achieved nothing.
-    var echoedBack = revisedDeck
-      ? JSON.stringify(existingDeck.slides) === JSON.stringify(revisedDeck.slides)
-      : false;
-
-    var verified = { reviewed: false, reason: 'not attempted' };
-    if (revisedDeck && visionModel) {
-      verified = await deckReview.review(revisedDeck, {
-        model: visionModel,
-        reasoningEffort: options.reasoningEffort,
-        callAI: callAI,
-        extractJson: deckBuild.extractJson,
-        gotenberg: documentExport.GOTENBERG,
-        mime: documentExport.FORMATS.pptx.mime,
-        pptx: await documentExport.renderDeck(revisedDeck, [], figureIdList(existing.image_ids))
-      });
-      revisedDeck = verified.deck;
-    }
-
-    var revised = revisedDeck ? deckSchema.toMarkdown(revisedDeck)
-      : String((ai && ai.content) || '').trim();
-    if (!revised) return res.status(502).json({ error: 'The model returned nothing. Try again.' });
-
-    // Figures from a modification are added to the ones already there, not
-    // swapped for them: "add two more diagrams" means more, not instead.
-    var added = (ai.imageJobs || []).map(function (job) { return job.jobId; }).filter(Boolean);
-    var row = await db.get(
-      'UPDATE user_resources SET markdown = ?, title = ?, updated_at = NOW(), ' +
-      'image_ids = image_ids || ?::jsonb, deck = COALESCE(?::jsonb, deck) ' +
-      'WHERE id = ? AND user_id = ? RETURNING id, title, updated_at',
-      [revised, firstHeading(revised), JSON.stringify(added),
-       revisedDeck ? JSON.stringify(revisedDeck) : null, existing.id, req.user.id]
-    );
-    // Said out loud, every time. A modification that changes nothing is the
-    // failure worth catching, and it is invisible from the response: the row
-    // updates, the title updates, and the file is identical.
-    // Computed once, because the caller is told this too. Logging it server-side
-    // while answering "Applied" left the one person who could do something about
-    // it — the person who asked for the change — reading a success message next
-    // to an identical file.
-    var unchanged = revisedDeck ? echoedBack
-      : revised.trim() === String(existing.markdown || '').trim();
-    logRefine({
-      id: existing.id,
-      path: revisedDeck ? 'deck' : 'markdown',
-      outcome: 'applied',
-      before: existingDeck ? (existingDeck.slides || []).length : existing.markdown.length,
-      after: revisedDeck ? (revisedDeck.slides || []).length : revised.length,
-      unchanged: unchanged,
-      figures: added.length,
-      model: ai && ai.model,
-      instructions: instructions
-    });
-
-    res.json({
-      success: true, resource: row, markdown: revised, unchanged: unchanged,
-      saw: slideViews.length,
-      review: { applied: verified.reviewed, reason: verified.reason },
-      grounding: { used: Boolean(sources.corpus.context), count: sources.corpus.sources.length,
-                   reason: sources.corpus.reason || null },
-      searches: sources.searches,
-      imageJobs: ai.imageJobs || [],
-      imageFailures: ai.imageFailures || [],
-      model: ai && ai.model
-    });
+    await assertJobSlot(req.user.id);
+    var job = await db.get(
+      'INSERT INTO user_resource_jobs (user_id, topic, kind, resource_id, request) VALUES (?, ?, ?, ?, ?) ' +
+      'RETURNING id, topic, kind, status, created_at',
+      [req.user.id, String(existing.topic || instructions).slice(0, 500), 'refine', resourceId,
+       JSON.stringify(req.body || {})]);
+    runResourceJob(job.id, req.user.id, req.body || {}, 'refine', resourceId);
+    res.status(202).json({ success: true, job: job });
   } catch (err) {
     console.error('[my-resources] refine:', err.message);
-    res.status(err.statusCode || 500).json({ error: err.statusCode ? err.message : 'Refinement failed' });
+    res.status(err.statusCode || 500).json({ error: err.statusCode ? err.message : 'Modification could not be started' });
   }
 });
 
+
 // ── Showing the deck to the model that is about to change it ────────────────
 // The model that writes a deck never sees it, and that is just as true when it
 // is editing one. Most of what people ask for while modifying is about the
@@ -1438,4 +1478,5 @@ module.exports = router;
 // The job runner's body, reachable for tests that exercise a generation
 // end to end without waiting on a detached job.
 module.exports.generateResource = generateResource;
+module.exports.refineResource = refineResource;
 module.exports.runResourceJob = runResourceJob;
diff --git a/test/deck-review.test.js b/test/deck-review.test.js
index 854e6eed..a2f27d20 100644
--- a/test/deck-review.test.js
+++ b/test/deck-review.test.js
@@ -148,7 +148,7 @@ test('the reviewer is admin-chosen, off by default, and runs once per change', (
   // rendered again — exactly the class of fault the reviewer exists for. The
   // old rule assumed refining was a text edit; it is a layout edit as often as
   // not.
-  const refine = route.slice(route.indexOf("router.post('/my-resources/:id/refine'"));
+  const refine = route.slice(route.indexOf("async function refineResource("));
   assert.match(refine, /deckReview\.review\(revisedDeck/);
   assert.match(refine, /if \(revisedDeck && visionModel\)/, 'and only when one is configured');
   // Still one pass. The verification runs on the result, never in a loop.
@@ -174,7 +174,7 @@ test('the review is asked without thinking when the caller says so', () => {
   const route = read('src/routes/myResources.js');
   const gen = route.slice(route.indexOf('async function generateResource('), route.indexOf('async function runResourceJob('));
   assert.match(gen, /reasoningEffort: options\.reasoningEffort,/, 'generation\u2019s review inherits the writing\u2019s rule');
-  const refine = route.slice(route.indexOf("router.post('/my-resources/:id/refine'"));
+  const refine = route.slice(route.indexOf("async function refineResource("));
   assert.match(refine, /reasoningEffort: 'none'/, 'a revision is writing');
   assert.equal((refine.match(/reasoningEffort: options\.reasoningEffort,/g) || []).length, 1,
     'and its review is asked the same way');
diff --git a/test/deck-themes.test.js b/test/deck-themes.test.js
index 6ee3de12..816d5409 100644
--- a/test/deck-themes.test.js
+++ b/test/deck-themes.test.js
@@ -93,7 +93,7 @@ test('a modification keeps the deck\'s theme', () => {
   // The model returns a new deck; the look was never its to choose. The
   // column keeps the theme regardless, but the deck field must agree with it.
   const route = read('src/routes/myResources.js');
-  const refine = route.slice(route.indexOf("router.post('/my-resources/:id/refine'"));
+  const refine = route.slice(route.indexOf("async function refineResource("));
   assert.match(refine, /revisedDeck\.theme = existingDeck\.theme \|\| existing\.theme \|\| revisedDeck\.theme/);
   assert.match(refine.slice(0, 2500), /SELECT id, kind, topic, markdown, deck, image_ids, theme FROM user_resources/);
 });
diff --git a/test/my-resources-refine.test.js b/test/my-resources-refine.test.js
index 587bfa38..fe09753d 100644
--- a/test/my-resources-refine.test.js
+++ b/test/my-resources-refine.test.js
@@ -120,7 +120,18 @@ function router(t, overrides = {}) {
   async function generate(body) {
     return module.exports.generateResource(7, body);
   }
-  return { request, generate, aiCalls, updates, reviewCalls, reviewOptions };
+  // Modifying is queued as a job too, so the tests that care what the writing
+  // does call its body directly, exactly as the generation tests do. The reply
+  // is shaped like the old synchronous one so the assertions stay about
+  // behaviour rather than about how the work is scheduled.
+  async function refine(body, id) {
+    try {
+      return { statusCode: 200, body: await module.exports.refineResource({ id: 7 }, id || 5, body) };
+    } catch (err) {
+      return { statusCode: err.statusCode || 500, body: { error: err.message } };
+    }
+  }
+  return { request, generate, refine, aiCalls, updates, reviewCalls, reviewOptions };
 }
 
 test('modifying a deck asks for a deck, even when illustration is on', async () => {
@@ -133,7 +144,7 @@ test('modifying a deck asks for a deck, even when illustration is on', async ()
   const r = router(null, {
     reply: JSON.stringify({ slides: [DECK.slides[0], { type: 'bullets', title: 'Features', bullets: ['Barking cough', 'Stridor', 'Hoarse voice'] }] })
   });
-  const res = await r.request('post', '/my-resources/:id/refine', {
+  const res = await r.refine( {
     instructions: 'add a third feature', withImages: 'true'
   });
 
@@ -154,7 +165,7 @@ test('a modification the model returned unchanged says so instead of claiming su
   // logged server-side, where the person who could reword the instruction
   // could not see it.
   const r = router(null, { reply: JSON.stringify({ slides: DECK.slides }) });
-  const res = await r.request('post', '/my-resources/:id/refine', { instructions: 'make it better' });
+  const res = await r.refine( { instructions: 'make it better' });
 
   assert.equal(res.statusCode, 200);
   assert.equal(res.body.unchanged, true, 'the caller is told the deck came back identical');
@@ -164,7 +175,7 @@ test('a modification that did change the deck reports itself as changed', async
   const r = router(null, {
     reply: JSON.stringify({ slides: [DECK.slides[0], { type: 'bullets', title: 'Features', bullets: ['Barking cough', 'Stridor', 'Hoarse voice'] }] })
   });
-  const res = await r.request('post', '/my-resources/:id/refine', { instructions: 'add a third feature' });
+  const res = await r.refine( { instructions: 'add a third feature' });
 
   assert.equal(res.body.unchanged, false);
   assert.equal(r.updates.length, 1, 'and the row is written');
@@ -173,7 +184,7 @@ test('a modification that did change the deck reports itself as changed', async
 
 test('a presentation with no deck still modifies, through the markdown path', async () => {
   const r = router(null, { row: { deck: null }, reply: '# Croup\n\n- Barking cough\n- Stridor\n- Hoarse voice\n' });
-  const res = await r.request('post', '/my-resources/:id/refine', {
+  const res = await r.refine( {
     instructions: 'add a third feature', withImages: 'true'
   });
 
@@ -195,7 +206,9 @@ test('the library says which presentations carry a deck, and the row shows when
   assert.match(ui, /row\.updated_at \? new Date\(row\.updated_at\)/);
   assert.match(ui, /edited \? 'modified '/);
   assert.match(ui, /has_deck === false \? ' · plain text, no slide layout' : ''/);
-  assert.match(ui, /if \(data\.unchanged\) \{/);
+  // A modification reports from the job list now that it runs in the background,
+  // so "it came back unchanged" still reaches the person who asked for it.
+  assert.match(ui, /if \(r\.unchanged\) \{/);
 });
 
 // ── Generating a deck ──────────────────────────────────────────────────────
@@ -271,7 +284,7 @@ test('modifying a resource is writing too, and is asked without thinking', async
   // a thirteen-slide deck it reasoned for a minute and a half before writing a
   // word, which is past the point a browser waits for the request.
   const r = router(null, { reply: JSON.stringify({ slides: DECK.slides }) });
-  const res = await r.request('post', '/my-resources/:id/refine', { instructions: 'make it better' });
+  const res = await r.refine( { instructions: 'make it better' });
 
   assert.equal(res.statusCode, 200);
   assert.equal(r.aiCalls[0].options.reasoningEffort, 'none');
@@ -329,7 +342,7 @@ test('modifying a deck shows the model what the deck currently looks like', asyn
   // "that slide is crowded", "the diagram is in the wrong place" — and none of
   // it is answerable from the JSON alone.
   const r = router(null, { visionModel: 'seeing-model', slideImages: TWO_PNGS, replies: [EDITED] });
-  const res = await r.request('post', '/my-resources/:id/refine', {
+  const res = await r.refine( {
     instructions: 'slide 2 looks crowded, split it'
   });
 
@@ -346,7 +359,7 @@ test('the edited deck is rendered again and checked', async () => {
   // The edit was made against how the deck looked *before* it. A slide that
   // gained two bullets only overflows once it is rendered again.
   const r = router(null, { visionModel: 'seeing-model', slideImages: TWO_PNGS, replies: [EDITED] });
-  const res = await r.request('post', '/my-resources/:id/refine', { instructions: 'add a feature' });
+  const res = await r.refine( { instructions: 'add a feature' });
 
   assert.equal(r.reviewCalls.length, 1, 'the result goes back past the reviewer');
   assert.equal(res.body.review.applied, true);
@@ -356,7 +369,7 @@ test('with no vision model configured, modify still works and never renders', as
   // Sight is an upgrade, not a dependency. Nothing here may become a new way
   // for a modification to fail.
   const r = router(null, { replies: [EDITED] });
-  const res = await r.request('post', '/my-resources/:id/refine', { instructions: 'add a feature' });
+  const res = await r.refine( { instructions: 'add a feature' });
 
   assert.equal(res.statusCode, 200);
   assert.equal(res.body.saw, 0);
@@ -368,7 +381,7 @@ test('a render that fails falls through to editing blind rather than failing', a
   // Gotenberg down, LibreOffice wedged, a deck too big: none of them may cost
   // the author their modification.
   const r = router(null, { visionModel: 'seeing-model', slideImages: [], replies: [EDITED] });
-  const res = await r.request('post', '/my-resources/:id/refine', { instructions: 'add a feature' });
+  const res = await r.refine( { instructions: 'add a feature' });
 
   assert.equal(res.statusCode, 200);
   assert.equal(res.body.saw, 0);
@@ -382,7 +395,7 @@ test('an echo is still reported as an echo, even when the reviewer moved somethi
   // achieved nothing look like it had worked.
   const r = router(null, { visionModel: 'seeing-model', slideImages: TWO_PNGS,
                            replies: [JSON.stringify({ slides: DECK.slides })] });
-  const res = await r.request('post', '/my-resources/:id/refine', { instructions: 'make it better' });
+  const res = await r.refine( { instructions: 'make it better' });
 
   assert.equal(res.body.unchanged, true, 'judged on the model edit, before the reviewer ran');
 });
diff --git a/test/my-resources.test.js b/test/my-resources.test.js
index e7351f4c..2ab4b802 100644
--- a/test/my-resources.test.js
+++ b/test/my-resources.test.js
@@ -184,7 +184,7 @@ test('illustration is opt-in, with its own dispatcher rather than the assistant
   assert.match(read('public/js/generatedImages.js'), /my_resources: '\/api\/my-resources\/image\/jobs\/'/);
   // And it renders where the person is looking, rather than pointing them at an
   // image history this feature does not have.
-  assert.match(read('public/js/myResources.js'), /showIllustrations\(data\.imageJobs \|\| \[\]\)/);
+  assert.match(read('public/js/myResources.js'), /showIllustrations\(r\.imageJobs \|\| \[\]\)/);
   assert.match(read('public/components/my-resources.html'), /id="mr-images"/);
   assert.match(route, /imageJobs: ai\.imageJobs \|\| \[\]/, 'and reported back');
 
diff --git a/test/resource-sharing.test.js b/test/resource-sharing.test.js
index 36cd45dc..c1963c49 100644
--- a/test/resource-sharing.test.js
+++ b/test/resource-sharing.test.js
@@ -14,7 +14,7 @@ test('every read route goes through the reader rule; every write route still fil
     const body = route.slice(route.indexOf(marker), route.indexOf('\n});', route.indexOf(marker)));
     assert.match(body, /await readableResource\(req\.params\.id, req\.user\.id/, marker + ' reads through the rule');
   }
-  for (const marker of ["router.put('/my-resources/:id/theme'", "router.post('/my-resources/:id/refine'", "router.delete('/my-resources/:id'", "router.put('/my-resources/:id'"]) {
+  for (const marker of ["router.put('/my-resources/:id/theme'", "async function refineResource(", "router.delete('/my-resources/:id'", "router.put('/my-resources/:id'"]) {
     const body = route.slice(route.indexOf(marker), route.indexOf('\n});', route.indexOf(marker)));
     assert.match(body, /AND user_id = \?/, marker + ' stays the owner\'s');
     assert.doesNotMatch(body, /readableResource/, marker + ' is not opened to readers');
diff --git a/test/web-search.test.js b/test/web-search.test.js
index 69e8540b..ac45e308 100644
--- a/test/web-search.test.js
+++ b/test/web-search.test.js
@@ -107,7 +107,7 @@ test('searching is the route\u2019s job, not something the model is asked to do'
   // different sources or searching them differently.
   assert.match(route, /async function gatherSources\(subject, body, keywords\)/);
   assert.match(route, /var sources = await gatherSources\(topic, body\);/, 'generate');
-  assert.match(route, /var sources = await gatherSources\(subject, req\.body, existing\.topic \|\| instructions\);/,
+  assert.match(route, /var sources = await gatherSources\(subject, body, existing\.topic \|\| instructions\);/,
     'and modify, whose library search gets the instruction for context and whose keyword searches do not');
 
   // Declared before they are used. They were not, once: `var` hoisting made