diff --git a/app/src/renderer/src/session-timeline-presentation.mjs b/app/src/renderer/src/session-timeline-presentation.mjs
index fee7471..976fe57 100644
--- a/app/src/renderer/src/session-timeline-presentation.mjs
+++ b/app/src/renderer/src/session-timeline-presentation.mjs
@@ -21,7 +21,7 @@ function formatToolInput(toolCall) {
   }
 }
 
-function renderFileContent(text) {
+function renderFileContent(text, label = 'File contents') {
   let lines = text.split('\n');
   const hasLineNums = lines.length > 1 && lines.slice(0, 5).every(line => /^\s*\d+\t/.test(line) || line === '');
   let gutter;
@@ -38,7 +38,7 @@ function renderFileContent(text) {
   const total = lines.length;
   const collapsed = total > 12;
   return `<div class="file-content">
-    <div class="file-content-head"><span class="label">File contents</span><span class="meta">${total} lines</span></div>
+    <div class="file-content-head"><span class="label">${escapeHtml(label)}</span><span class="meta">${total} lines</span></div>
     <div class="file-content-body ${collapsed ? 'collapsed' : ''}"><div class="gutter">${gutter}</div><div class="code">${escapeHtml(lines.join('\n'))}</div></div>
     ${collapsed ? `<button class="file-content-expand" onclick="this.previousElementSibling.classList.toggle('collapsed');this.textContent=this.previousElementSibling.classList.contains('collapsed')?'Show all ${total} lines':'Collapse'">Show all ${total} lines</button>` : ''}
   </div>`;
@@ -226,7 +226,10 @@ export function renderPrettyTool(toolCall) {
 
   const terminal = renderTerminalTool(toolCall.name, args, output, isError);
   if (terminal !== null) return terminal;
-  return `<div class="body-section"><div class="body-label">Input</div>${renderFieldGrid(args)}</div>`
+  const input = typeof args === 'string'
+    ? renderFileContent(args, 'Input')
+    : `<div class="body-section"><div class="body-label">Input</div>${renderFieldGrid(args)}</div>`;
+  return input
     + (output ? `<div class="body-section" style="margin-top:12px;"><div class="body-label">Output</div>${renderOutput(output, isError)}</div>` : '');
 }
 
diff --git a/tests/app-tool-renderer.test.mjs b/tests/app-tool-renderer.test.mjs
index d72657a..abd4ba4 100644
--- a/tests/app-tool-renderer.test.mjs
+++ b/tests/app-tool-renderer.test.mjs
@@ -2,6 +2,7 @@ import test from 'node:test';
 import assert from 'node:assert/strict';
 
 import { getArgPreview, getToolIcon, renderTerminalTool } from '../app/src/renderer/src/tool-renderer.js';
+import { renderPrettyTool } from '../app/src/renderer/src/session-timeline-presentation.mjs';
 
 test('Codex exec renders source and decoded result instead of a Bash terminal', () => {
   const output = JSON.stringify([
@@ -110,3 +111,38 @@ test('Codex exec preview uses its string input', () => {
 test('Codex exec uses the Claude Bash terminal icon', () => {
   assert.equal(getToolIcon('exec'), getToolIcon('Bash'));
 });
+
+test('Codex apply_patch renders its string input as one multiline block', () => {
+  const patch = [
+    '*** Begin Patch',
+    '*** Update File: app.css',
+    '@@',
+    '-old',
+    '+new <value>',
+    '*** End Patch',
+  ].join('\n');
+  const html = renderPrettyTool({
+    name: 'apply_patch',
+    input_json: JSON.stringify(patch),
+    result: { content: 'Done!', is_error: 0 },
+  });
+
+  assert.match(html, /class="file-content"/);
+  assert.match(html, /<span class="label">Input<\/span><span class="meta">6 lines<\/span>/);
+  assert.match(html, /\*\*\* Begin Patch\n\*\*\* Update File: app\.css\n@@\n-old\n\+new &lt;value&gt;\n\*\*\* End Patch/);
+  assert.doesNotMatch(html, /<div class="field-(?:grid|key)">/);
+  assert.doesNotMatch(html, /<value>/);
+});
+
+test('generic object tool input continues to render as a field grid', () => {
+  const html = renderPrettyTool({
+    name: 'custom_tool',
+    input_json: JSON.stringify({ path: 'app.css', recursive: true }),
+    result: {},
+  });
+
+  assert.match(html, /class="field-grid"/);
+  assert.match(html, /class="field-key">path</);
+  assert.match(html, /class="field-key">recursive</);
+  assert.doesNotMatch(html, /class="file-content"/);
+});