diff --git a/frontend/popout.html b/frontend/popout.html
index ffac8ac..bfa4287 100644
--- a/frontend/popout.html
+++ b/frontend/popout.html
@@ -12,6 +12,64 @@
   <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.9.0/styles/github.min.css" id="hljs-theme-light" disabled>
   <script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.9.0/highlight.min.js"></script>
   <script src="https://unpkg.com/lucide@0.344.0/dist/umd/lucide.min.js"></script>
+  <script type="importmap">
+    {
+      "imports": {
+        "@codemirror/state": "https://esm.sh/@codemirror/state@6.2.0"
+      }
+    }
+  </script>
+  <script type="module">
+    import { EditorView, keymap, lineNumbers, highlightActiveLineGutter, highlightSpecialChars, drawSelection, dropCursor, rectangularSelection, crosshairCursor, highlightActiveLine } from "https://esm.sh/@codemirror/view@6.9.0?external=@codemirror/state";
+    import { EditorState } from "@codemirror/state";
+    import { defaultHighlightStyle, syntaxHighlighting, indentOnInput, bracketMatching, foldGutter, foldKeymap } from "https://esm.sh/@codemirror/language@6.6.0?external=@codemirror/state";
+    import { defaultKeymap, history, historyKeymap } from "https://esm.sh/@codemirror/commands@6.2.3?external=@codemirror/state";
+    import { searchKeymap, highlightSelectionMatches } from "https://esm.sh/@codemirror/search@6.3.0?external=@codemirror/state";
+    import { autocompletion, completionKeymap, closeBrackets, closeBracketsKeymap } from "https://esm.sh/@codemirror/autocomplete@6.5.0?external=@codemirror/state";
+    import { markdown } from "https://esm.sh/@codemirror/lang-markdown@6.1.0?external=@codemirror/state";
+    import { python } from "https://esm.sh/@codemirror/lang-python@6.1.3?external=@codemirror/state";
+    import { javascript } from "https://esm.sh/@codemirror/lang-javascript@6.1.7?external=@codemirror/state";
+    import { html } from "https://esm.sh/@codemirror/lang-html@6.4.3?external=@codemirror/state";
+    import { css } from "https://esm.sh/@codemirror/lang-css@6.2.0?external=@codemirror/state";
+    import { json } from "https://esm.sh/@codemirror/lang-json@6.0.1?external=@codemirror/state";
+    import { xml } from "https://esm.sh/@codemirror/lang-xml@6.0.2?external=@codemirror/state";
+    import { sql } from "https://esm.sh/@codemirror/lang-sql@6.5.0?external=@codemirror/state";
+    import { php } from "https://esm.sh/@codemirror/lang-php@6.0.1?external=@codemirror/state";
+    import { cpp } from "https://esm.sh/@codemirror/lang-cpp@6.0.2?external=@codemirror/state";
+    import { java } from "https://esm.sh/@codemirror/lang-java@6.0.1?external=@codemirror/state";
+    import { rust } from "https://esm.sh/@codemirror/lang-rust@6.0.1?external=@codemirror/state";
+    import { oneDark } from "https://esm.sh/@codemirror/theme-one-dark@6.1.0?external=@codemirror/state";
+
+    const basicSetup = [
+      lineNumbers(),
+      highlightActiveLineGutter(),
+      highlightSpecialChars(),
+      history(),
+      foldGutter(),
+      drawSelection(),
+      dropCursor(),
+      EditorState.allowMultipleSelections.of(true),
+      indentOnInput(),
+      syntaxHighlighting(defaultHighlightStyle, { fallback: true }),
+      bracketMatching(),
+      closeBrackets(),
+      autocompletion(),
+      rectangularSelection(),
+      crosshairCursor(),
+      highlightActiveLine(),
+      highlightSelectionMatches(),
+      keymap.of([
+        ...closeBracketsKeymap,
+        ...defaultKeymap,
+        ...searchKeymap,
+        ...historyKeymap,
+        ...foldKeymap,
+        ...completionKeymap,
+      ])
+    ];
+
+    window.CodeMirror = { EditorView, EditorState, basicSetup, markdown, python, javascript, html, css, json, xml, sql, php, cpp, java, rust, oneDark, keymap };
+  </script>
   <style>
     body, html {
       margin: 0;
@@ -36,6 +94,22 @@
 </head>
 <body class="popup-mode">
   <div class="popout-loading" id="loading">Chargement...</div>
+  <div class="editor-modal" id="editor-modal">
+    <div class="editor-container">
+      <div class="editor-header">
+        <div class="editor-title" id="editor-title">Édition</div>
+        <div class="editor-actions">
+          <button class="editor-btn" id="editor-cancel" title="Annuler" aria-label="Annuler">
+            <i data-lucide="x" style="width:16px;height:16px"></i>
+          </button>
+          <button class="editor-btn primary" id="editor-save" title="Sauvegarder" aria-label="Sauvegarder">
+            <i data-lucide="check" style="width:16px;height:16px"></i>
+          </button>
+        </div>
+      </div>
+      <div class="editor-body" id="editor-body"></div>
+    </div>
+  </div>
   
   <div class="main-layout" style="height: 100vh; display: flex; position: relative; overflow: hidden;">
     <main class="content-area" id="content-area" style="margin-top: 15px; flex: 1; overflow-y: auto; overflow-x: hidden;">
@@ -81,20 +155,26 @@
     }
 
     let rightSidebarVisible = false;
-let rightSidebarWidth = 280;
-let headingsCache = [];
-let activeHeadingId = null;
+    let rightSidebarWidth = 280;
+    let headingsCache = [];
+    let activeHeadingId = null;
+    let showingSource = false;
+    let cachedRawSource = null;
+    let editorView = null;
+    let fallbackEditorEl = null;
+    let editorVault = null;
+    let editorPath = null;
 
-function el(tag, attrs, children) {
-  const e = document.createElement(tag);
-  if (attrs) { for (let k in attrs) { if (k === "class") e.className = attrs[k]; else e.setAttribute(k, attrs[k]); } }
-  if (children) { children.forEach(c => { if (typeof c === "string") e.appendChild(document.createTextNode(c)); else e.appendChild(c); }); }
-  return e;
-}
+    function el(tag, attrs, children) {
+      const e = document.createElement(tag);
+      if (attrs) { for (let k in attrs) { if (k === "class") e.className = attrs[k]; else e.setAttribute(k, attrs[k]); } }
+      if (children) { children.forEach(c => { if (typeof c === "string") e.appendChild(document.createTextNode(c)); else e.appendChild(c); }); }
+      return e;
+    }
 
-function safeCreateIcons() { if (window.lucide) window.lucide.createIcons(); }
+    function safeCreateIcons() { if (window.lucide) window.lucide.createIcons(); }
 
-const OutlineManager = {
+    const OutlineManager = {
     /**
      * Slugify text to create valid IDs
      */
@@ -506,6 +586,8 @@ const RightSidebarManager = {
       const pathParts = window.location.pathname.split('/');
       const vault = decodeURIComponent(pathParts[2]);
       const path = decodeURIComponent(pathParts.slice(3).join('/'));
+      showingSource = false;
+      cachedRawSource = null;
 
       if (!vault || !path) {
         document.getElementById('loading').textContent = "Paramètres invalides";
@@ -580,6 +662,36 @@ const RightSidebarManager = {
         });
         actionsDiv.appendChild(copyBtn);
 
+        const sourceBtn = document.createElement("button");
+        sourceBtn.className = "btn-action";
+        sourceBtn.title = "Voir la source";
+        sourceBtn.innerHTML = '<i data-lucide="code" style="width:14px;height:14px"></i> Source';
+        sourceBtn.addEventListener("click", async () => {
+          const rendered = document.getElementById("file-rendered-content");
+          const raw = document.getElementById("file-raw-content");
+          if (!rendered || !raw) return;
+
+          showingSource = !showingSource;
+          if (showingSource) {
+            sourceBtn.classList.add("active");
+            if (!cachedRawSource) {
+              const rawUrl = `/api/file/${encodeURIComponent(vault)}/raw?path=${encodeURIComponent(path)}`;
+              const rawResponse = await fetch(rawUrl, { credentials: 'include' });
+              if (!rawResponse.ok) throw new Error("Erreur lors du chargement de la source");
+              const rawData = await rawResponse.json();
+              cachedRawSource = rawData.raw;
+            }
+            raw.textContent = cachedRawSource;
+            rendered.style.display = "none";
+            raw.style.display = "block";
+          } else {
+            sourceBtn.classList.remove("active");
+            rendered.style.display = "block";
+            raw.style.display = "none";
+          }
+        });
+        actionsDiv.appendChild(sourceBtn);
+
         const dlBtn = document.createElement("button");
         dlBtn.className = "btn-action";
         dlBtn.title = "Télécharger";
@@ -594,6 +706,15 @@ const RightSidebarManager = {
         });
         actionsDiv.appendChild(dlBtn);
 
+        const editBtn = document.createElement("button");
+        editBtn.className = "btn-action";
+        editBtn.title = "Éditer";
+        editBtn.innerHTML = '<i data-lucide="edit" style="width:14px;height:14px"></i> Éditer';
+        editBtn.addEventListener("click", () => {
+          openEditor(vault, path);
+        });
+        actionsDiv.appendChild(editBtn);
+
         const tocBtn = document.createElement("button");
         tocBtn.className = "btn-action";
         tocBtn.id = "toc-toggle-btn";
@@ -618,6 +739,12 @@ const RightSidebarManager = {
         mdDiv.innerHTML = data.html;
         area.appendChild(mdDiv);
 
+        const rawDiv = document.createElement("div");
+        rawDiv.className = "raw-source-view";
+        rawDiv.id = "file-raw-content";
+        rawDiv.style.display = "none";
+        area.appendChild(rawDiv);
+
         // Render lucide icons
         if (window.lucide) {
           window.lucide.createIcons();
@@ -641,6 +768,171 @@ const RightSidebarManager = {
       }
     }
 
+    async function waitForCodeMirror() {
+      let attempts = 0;
+      while (!window.CodeMirror && attempts < 50) {
+        await new Promise((resolve) => setTimeout(resolve, 100));
+        attempts++;
+      }
+      if (!window.CodeMirror) {
+        throw new Error("CodeMirror failed to load");
+      }
+    }
+
+    async function openEditor(vaultName, filePath) {
+      editorVault = vaultName;
+      editorPath = filePath;
+
+      const modal = document.getElementById("editor-modal");
+      const titleEl = document.getElementById("editor-title");
+      const bodyEl = document.getElementById("editor-body");
+
+      titleEl.textContent = `Édition: ${filePath.split("/").pop()}`;
+
+      const rawUrl = `/api/file/${encodeURIComponent(vaultName)}/raw?path=${encodeURIComponent(filePath)}`;
+      const rawResponse = await fetch(rawUrl, { credentials: 'include' });
+      if (!rawResponse.ok) {
+        throw new Error("Erreur lors du chargement du contenu à éditer");
+      }
+      const rawData = await rawResponse.json();
+      cachedRawSource = rawData.raw;
+
+      bodyEl.innerHTML = "";
+      if (editorView) {
+        editorView.destroy();
+        editorView = null;
+      }
+      fallbackEditorEl = null;
+
+      try {
+        await waitForCodeMirror();
+
+        const { EditorView, EditorState, basicSetup, markdown, python, javascript, html, css, json, xml, sql, php, cpp, java, rust, oneDark, keymap } = window.CodeMirror;
+        const currentTheme = document.documentElement.getAttribute("data-theme");
+        const fileExt = filePath.split(".").pop().toLowerCase();
+        const extensions = [
+          basicSetup,
+          keymap.of([
+            {
+              key: "Mod-s",
+              run: () => {
+                saveFile();
+                return true;
+              },
+            },
+          ]),
+          EditorView.lineWrapping,
+        ];
+        const langMap = {
+          md: markdown,
+          markdown: markdown,
+          py: python,
+          js: javascript,
+          jsx: javascript,
+          ts: javascript,
+          tsx: javascript,
+          mjs: javascript,
+          cjs: javascript,
+          html: html,
+          htm: html,
+          css: css,
+          scss: css,
+          less: css,
+          json: json,
+          xml: xml,
+          svg: xml,
+          sql: sql,
+          php: php,
+          cpp: cpp,
+          cc: cpp,
+          cxx: cpp,
+          c: cpp,
+          h: cpp,
+          hpp: cpp,
+          java: java,
+          rs: rust,
+          sh: javascript,
+          bash: javascript,
+          zsh: javascript,
+        };
+        const langMode = langMap[fileExt];
+        if (langMode) {
+          extensions.push(langMode());
+        }
+        if (currentTheme === "dark") {
+          extensions.push(oneDark);
+        }
+        const state = EditorState.create({
+          doc: rawData.raw,
+          extensions: extensions,
+        });
+        editorView = new EditorView({
+          state: state,
+          parent: bodyEl,
+        });
+      } catch (err) {
+        console.error("CodeMirror init failed, falling back to textarea:", err);
+        fallbackEditorEl = document.createElement("textarea");
+        fallbackEditorEl.className = "fallback-editor";
+        fallbackEditorEl.value = rawData.raw;
+        bodyEl.appendChild(fallbackEditorEl);
+      }
+
+      modal.classList.add("active");
+      safeCreateIcons();
+    }
+
+    function closeEditor() {
+      const modal = document.getElementById("editor-modal");
+      modal.classList.remove("active");
+      if (editorView) {
+        editorView.destroy();
+        editorView = null;
+      }
+      fallbackEditorEl = null;
+      editorVault = null;
+      editorPath = null;
+    }
+
+    async function saveFile() {
+      if ((!editorView && !fallbackEditorEl) || !editorVault || !editorPath) return;
+
+      const content = editorView ? editorView.state.doc.toString() : fallbackEditorEl.value;
+      const saveBtn = document.getElementById("editor-save");
+      const originalHTML = saveBtn.innerHTML;
+
+      try {
+        saveBtn.disabled = true;
+        saveBtn.innerHTML = '<i data-lucide="loader" style="width:16px;height:16px"></i>';
+        safeCreateIcons();
+
+        const response = await fetch(`/api/file/${encodeURIComponent(editorVault)}/save?path=${encodeURIComponent(editorPath)}`, {
+          method: "PUT",
+          headers: { "Content-Type": "application/json" },
+          body: JSON.stringify({ content }),
+          credentials: 'include'
+        });
+
+        if (!response.ok) {
+          const error = await response.json();
+          throw new Error(error.detail || "Erreur de sauvegarde");
+        }
+
+        saveBtn.innerHTML = '<i data-lucide="check" style="width:16px;height:16px"></i>';
+        safeCreateIcons();
+
+        closeEditor();
+        await initPopout();
+      } catch (err) {
+        console.error("Save error:", err);
+        saveBtn.innerHTML = originalHTML;
+        safeCreateIcons();
+        alert(err.message || "Erreur lors de la sauvegarde");
+      } finally {
+        saveBtn.disabled = false;
+      }
+    }
+
     function createBreadcrumbSep() {
       const sep = document.createElement("span");
       sep.className = "sep";
@@ -841,6 +1133,8 @@ const RightSidebarManager = {
         applyTheme(event.newValue);
       }
     });
+    document.getElementById("editor-cancel").addEventListener("click", closeEditor);
+    document.getElementById("editor-save").addEventListener("click", saveFile);
     initPopout();
   </script>
 </body>
