The app's code in Dessn's cloud

Every Dessn project holds its app's whole repository: the Library and every frame are a checkout of it on a cloud sandbox. You can search it, read it and change copies of it through the Dessn MCP with no clone. The person sees each change as a live frame.

The loop

1. Find the project. dessn_projects_search({ query: '<project name>' }) gives its link. A link the person pasted goes to dessn_canvas_get.
2. Find the surface from their words. dessn_surfaces_list({ project, query }) matches a Library surface's name, its route and the words its picture shows, so "the Completed view" or "the empty state" finds it. Each surface has a route and a link.
3. Find the code behind it. Search for the exact words on the screen: dessn_files_list({ at: <project or surface link>, grep: 'No completed projects' }). It answers each file and line with the lines around it, which is enough to explain it and to write an edit. Find nothing? Try a shorter piece. Text may be split over elements, come from data (dessn.mocks/), or be uppercased by CSS. Then search for the component's name to find where it's used. path (a folder) and glob ('**/*.tsx') narrow a search; regex: true takes a pattern.
4. Read and explain. dessn_files_read({ at, path, from, to }) reads the lines around a match. as: 'outline' gives a long file's components and functions with their lines, and paths: [...] reads several files in one call. dessn_canvas_get on a frame lists its entryFiles (the files its picture renders). Explain what you found in the person's terms: which component, what decides when it shows, where its words and data come from. Name the files and lines so they can check.
5. Copy, always. Never edit the original: other people see it. Put the surface on a page and copy it:
   • dessn_pages_create({ project, title: '<the change>', private: true, key }) makes a page only they see (or use a page they named).
   • dessn_nodes_create({ page, key, items: [{ kind: 'frame', from: { surface: '<route>' }, x: 0, y: 0 }] }) adds the original.
   • dessn_nodes_create({ page, key, items: [{ kind: 'frame', from: { frame: <its id>, copy: true }, position: { rightOf: <its id> } }] }) adds the copy, on its own sandbox.
   • A change that shows only in a state (an empty list, a search with no results, another tab): give the original that state's route, and the copy keeps it (route: '/?view=completed&search=zzz' on the frame item), so the board itself shows before and after. If no route reaches the state, say so; change the app's sample data only when the person asks.
6. Edit the copy. dessn_files_write({ at: <the copy's link>, key, files: [{ path, edits: [{ oldString, newString }] }] }). Copy oldString exactly from the search's or the read's lines. The answer waits for the build and gives build (compile, runtime and type errors) and picture. A failed edit says why and shows the nearest lines; fix it and send it again.
7. Look. Check the write's picture (picture.landed, or its nextCall), or call dessn_canvas_screenshot({ target: <the copy's link> }). Compare it with the original. If the write's answer has fit, send its nextCall so the frame shows the whole page.
8. Put it on the board. The original and the copy sit side by side. Add a note above or beside them saying what changed and where, for example "Empty state message: src/views/Completed.tsx:42, 'No completed projects' → 'Nothing finished yet. Your wins will show up here'": dessn_nodes_create({ page, key, items: [{ kind: 'note', html: '<p>…</p>', position: { above: <copy id> } }] }). Give the person the page link and a picture of it.
9. Undo if it goes wrong. dessn_canvas_get on the copy lists its history (newest first, each with a seq). dessn_files_write({ at: <copy>, key, restore: <seq> }) brings that version back as a new entry, so nothing is lost. restore: 'undo' undoes the last restore.