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System Prompt Editor for Qwen Chat

Adds the ability to modify system prompts in the Qwen Chat interface to customize AI behavior.

  1. // ==UserScript==
  2. // @name           System Prompt Editor for Qwen Chat
  3. // @name:ru        Редактор системного промпта для Qwen Chat
  4. // @namespace      https://chat.qwen.ai/
  5. // @version        2025-06-19
  6. // @description    Adds the ability to modify system prompts in the Qwen Chat interface to customize AI behavior.
  7. // @description:ru Добавляет возможность изменения системных промптов в интерфейсе Qwen Chat для настройки поведения ИИ.
  8. // @author         Mikhail Zuenko
  9. // @match          https://chat.qwen.ai/*
  10. // @icon           https://www.google.com/s2/favicons?sz=64&domain=qwen.ai
  11. // @grant          unsafeWindow
  12. // ==/UserScript==
  13.  
  14. function generateUUID() {
  15.     return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, c => {
  16.         const r = Math.random() * 16 | 0;
  17.         const v = c === 'x' ? r : (r & 0x3) | 0x8;
  18.         return v.toString(16);
  19.     });
  20. }
  21.  
  22. function getSystemPromptMessage(data) {
  23.     const rootMessages = Object.values(data.chat.history.messages).filter(msg => msg.parentId === null);
  24.     const promptMessage = rootMessages.find(msg => msg.role === 'system');
  25.     return promptMessage || null;
  26. }
  27.  
  28. function setSystemPrompt(data, systemPrompt) {
  29.     const promptMessage = getSystemPromptMessage(data);
  30.     if (promptMessage) {
  31.         promptMessage.content = systemPrompt;
  32.         data.chat.messages.find(msg => msg.id === promptMessage.id).content = systemPrompt;
  33.     }
  34.     else {
  35.         const rootMessages = Object.values(data.chat.history.messages).filter(msg => msg.parentId === null);
  36.  
  37.         const promptMessage = {
  38.             id: generateUUID(),
  39.             parentId: null,
  40.             childrenIds: rootMessages.map(msg => msg.id),
  41.             role: 'system',
  42.             content: systemPrompt
  43.         };
  44.         for (const message of rootMessages) {
  45.             message.parentId = promptMessage.id;
  46.         }
  47.         data.chat.history.messages[promptMessage.id] = promptMessage;
  48.  
  49.         let firstIndex = null;
  50.         for (let msg = 0; msg < data.chat.messages.length; ++msg) {
  51.             if (data.chat.messages[msg].parentId === null) {
  52.                 data.chat.messages[msg].parentId = promptMessage.id;
  53.                 if (firstIndex === null) firstIndex = msg;
  54.             }
  55.         }
  56.         data.chat.messages.splice(firstIndex, 0, promptMessage);
  57.     }
  58. }
  59.  
  60. function deleteSystemPrompt(data) {
  61.     const promptMessage = getSystemPromptMessage(data);
  62.     if (!promptMessage) return;
  63.  
  64.     const children = promptMessage.childrenIds;
  65.     for (const childId of children) {
  66.         data.chat.history.messages[childId].parentId = null;
  67.     }
  68.     for (const message of data.chat.messages) {
  69.         if (children.includes(message.id)) message.parentId = null;
  70.     }
  71.     data.chat.messages.splice(data.chat.messages.findIndex(msg => msg.id === promptMessage.id), 1);
  72.     delete data.chat.history.messages[promptMessage.id];
  73. }
  74.  
  75. let origFetch = unsafeWindow.fetch;
  76. unsafeWindow.fetch = async (input, init) => {
  77.     if (init && init._noChange) return origFetch(input, init);
  78.     if (init && input === '/api/chat/completions') {
  79.         const body = JSON.parse(init.body);
  80.         const promptMessage = getSystemPromptMessage(await request('/api/v1/chats/' + body.chat_id));
  81.         if (promptMessage) {
  82.             body.messages.unshift({ role: 'system', content: promptMessage.content });
  83.             init.body = JSON.stringify(body);
  84.         }
  85.     }
  86.     else if (typeof input === 'string') {
  87.         if (/^\/api\/v1\/chats\/[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}\/?$/.test(input)) {
  88.             if (init && init.method === 'POST') {
  89.                 const promptMessage = getSystemPromptMessage(await request(input));
  90.                 if (promptMessage) {
  91.                     const body = JSON.parse(init.body);
  92.                     setSystemPrompt(body, promptMessage.content);
  93.                     init.body = JSON.stringify(body);
  94.                 }
  95.             }
  96.             const res = await origFetch(input, init);
  97.             const data = await res.json();
  98.             deleteSystemPrompt(data);
  99.             return new Response(JSON.stringify(data), {
  100.                 status: res.status,
  101.                 statusText: res.statusText,
  102.                 headers: res.headers
  103.             });
  104.         }
  105.     }
  106.     return origFetch(input, init);
  107. };
  108.  
  109. function getIdFromUrl() {
  110.     const path = location.pathname.match(/^\/c\/([0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12})\/?$/);
  111.     return path ? path[1] : null;
  112. }
  113. function request(input, init) {
  114.     return unsafeWindow.fetch(input, { _noChange: true, ...init }).then(res => res.json());
  115. }
  116.  
  117. function $E(tag, props, children) {
  118.     const elem = document.createElement(tag);
  119.     for (const prop in props) {
  120.         if (prop.startsWith('on')) elem.addEventListener(prop.slice(2).toLowerCase(), props[prop]);
  121.         else if (prop === 'classes') elem.classList.add(props[prop]);
  122.         else {
  123.             const snakeProp = prop.replace(/([A-Z])/g, '-$1').toLowerCase();
  124.             if (props[prop] === true) elem.setAttribute(snakeProp, '');
  125.             else elem.setAttribute(snakeProp, props[prop]);
  126.         }
  127.     }
  128.     elem.append(...children);
  129.     return elem;
  130. }
  131. function $T(text) {
  132.     return document.createTextNode(text || '');
  133. }
  134.  
  135. const textarea = $E('textarea', {
  136.     class: 'block w-full h-[200px] p-2 bg-white dark:bg-[#2A2A2A] text-[#2C2C36] dark:text-[#FAFAFC] rounded-lg resize-none',
  137.     placeholder: 'How should I answer you?'
  138. }, [])
  139.  
  140. const button = $E(
  141.     'button',
  142.     {
  143.         class: 'ml-1',
  144.         async onClick() {
  145.             const id = getIdFromUrl();
  146.             if (id) {
  147.                 const data = await request('/api/v1/chats/' + id);
  148.                 const promptMessage = getSystemPromptMessage(data);
  149.                 textarea.value = promptMessage ? promptMessage.content : '';
  150.  
  151.                 document.body.append(editor);
  152.                 document.addEventListener('keydown', escCloseEditor);
  153.             }
  154.         }
  155.     },
  156.     [$E('i', { class: 'iconfont leading-none icon-line-message-circle-02 w-[32px] h-[32px] chat-input-feature-btn !mr-[0]' }, [])]
  157. );
  158.  
  159. const editor = $E('div', {
  160.     class: 'modal fixed inset-0 z-[9999] flex h-full w-full items-center justify-center overflow-hidden bg-black/60',
  161.     onMousedown: closeEditor
  162. }, [
  163.     $E('div', {
  164.         class: 'm-auto max-w-full w-[480px] mx-2 shadow-3xl scrollbar-hidden max-h-[90vh] overflow-y-auto bg-gray-50 dark:bg-gray-900 rounded-2xl',
  165.         onMousedown: event => event.stopPropagation()
  166.     }, [
  167.         $E('div', { class: 'flex justify-between px-5 pb-1 pt-4 dark:text-gray-300' }, [
  168.             $E('div', { class: 'self-center text-lg font-medium' }, [$T('System Prompt')]),
  169.             $E('button', {
  170.                 class: 'self-center',
  171.                 onClick: closeEditor
  172.             }, [
  173.                 $E('i', { class: 'iconfont leading-none icon-line-x-02 font-bold' }, [])
  174.             ])
  175.         ]),
  176.         $E('div', { class: 'px-4 pt-1' }, [textarea]),
  177.         $E('div', { class: 'flex justify-end p-4 pt-3 text-sm font-medium' }, [
  178.             $E('button', {
  179.                 class: 'dark:purple-500 dark:hover:purple-400 rounded-full bg-purple-500 px-3.5 py-1.5 text-sm font-medium text-white transition hover:bg-purple-400',
  180.                 async onClick() {
  181.                     closeEditor();
  182.  
  183.                     const id = getIdFromUrl();
  184.                     if (id) {
  185.                         const data = await request('/api/v1/chats/' + id);
  186.  
  187.                         if (textarea.value === '') deleteSystemPrompt(data);
  188.                         else setSystemPrompt(data, textarea.value);
  189.  
  190.                         request('/api/v1/chats/' + id, {
  191.                             method: 'POST',
  192.                             headers: { 'Content-Type': 'application/json' },
  193.                             body: JSON.stringify(data)
  194.                         });
  195.                     }
  196.                 }
  197.             }, [$T('Save')])
  198.         ])
  199.     ])
  200. ]);
  201.  
  202. function closeEditor() {
  203.     editor.remove();
  204.     document.removeEventListener('keydown', escCloseEditor);
  205. }
  206. function escCloseEditor(event) {
  207.     if (event.code === 'Escape') closeEditor();
  208. }
  209.  
  210. let lastId = getIdFromUrl();
  211. addEventListener('popstate', () => {
  212.     const newId = getIdFromUrl();
  213.     if (lastId === newId) return;
  214.     closeEditor();
  215.     lastId = newId;
  216. });
  217.  
  218. new MutationObserver(() => {
  219.     const elem = document.querySelector('div:has(>.operationBtn)>:first-child');
  220.     if (document.getElementById('messages-container') && elem && button.parentNode !== elem) {
  221.         elem.append(button);
  222.     }
  223. }).observe(document.body, { childList: true, subtree: true });