Markdown and text files

Schreibzeug opens Markdown notes (.md) and plain text files (.txt) in an editor of their own, creates them from "Neu", and saves them as what they are: the same encoding, the same line endings, no own format. A file nobody edited is never written.

Writing Markdown

The editor is CodeMirror 6 (MIT), in packages/text-editor. It keeps the text as Markdown and only shows it formatted; there is no rich-text model that would write the Markdown anew on every save (lists, blank lines and tables stay as they were typed). Three views, remembered per browser:

View	What it shows
Live	Headings, bold, italic, code, links, quotes, bullets and task boxes formatted; the marks (#, **, the link's address …) appear in the lines the cursor is in. Tables and code blocks stay as source, in monospace.
Geteilt	The source on the left, a preview on the right, rendered from the same parser (@lezer/markdown with GitHub's tables, task lists and strikethrough).
Quelltext	The source alone, in monospace.

The toolbar and the "Format" menu write Markdown into the text, as typing it would: a heading level for the line, ** around the selection (taken away again inside bold), -, 1. or - [ ] before the selected lines, a link, a table with a header row, a rule. Ticking a task's box in the live view writes [x]. Strg+B and Strg+I work as in the other editors; Enter continues a list or a quote. The commands are pure functions over CodeMirror's state (src/commands.ts), tested without a browser.

The preview escapes every text: raw HTML in the Markdown shows as text, and links and images only go to http(s), mailto or a relative address (src/preview.ts).

A .txt file opens in the same editor in monospace, without toolbar, preview or Markdown.

Keeping the file as it is

src/codec.ts reads the bytes and writes them back:

• Encoding: a byte order mark decides (UTF-8, UTF-16 LE/BE); without one, UTF-8 when the bytes are valid UTF-8, else Windows-1252, which older German text files from Windows use. A character the file's encoding has no byte for (an emoji in a Windows-1252 file) is not dropped: the save fails with a message naming it.
• Byte order mark: kept when there was one; a new file has none.
• Line endings: the editor works with \n; the save writes the ending most lines had (LF, CRLF or CR), also for lines pasted with another one. A new file uses LF.

The status bar shows the cursor, the encoding, the line ending and the kind of file. An unchanged text with one kind of line ending encodes to the same bytes it was read from (test/codec.test.ts); in a file whose lines end in different ways, a save gives them all the most common ending. That is why an unchanged file is never written: saving without a change stores nothing, and write_text appends to the bytes as they are.

Saving

A text file has no editing session and no relay: the editor saves the whole file, by hand or two seconds after the last change (15 seconds after a failed save). Every save is made over the version it was made from: it sends If-Match: "<sha256>", the SHA-256 of the bytes it opened or last stored, and the server stores it only while that is still the newest version (apps/server/src/files/repository.ts addVersion, checked in the same transaction; on the desktop the bytes on disk, so a write by another program counts too). Otherwise it answers 409 with CHANGED_SINCE, and the editor stops saving on its own and asks:

• Neue Fassung laden throws this text away and opens the newest version;
• Als Kopie speichern keeps this text as "… (Kopie).md" beside it and opens that.

Two windows on one note therefore never overwrite each other unnoticed. Real-time co-editing of text files, with the others' cursors, would need a relay of its own (Yjs over a WebSocket route); it is not part of this yet.

Versions, restoring, sharing, links, copies and renaming work as for every other file (files).

Claude and other MCP clients

read_document reads .md and .txt, upload_file with text creates a note, and write_text replaces or appends to the text of a note or text file in the file's own encoding and line endings, made over the version it read (MCP server).

Tests

• packages/text-editor/test: encoding, byte order mark and line endings round trip; the toolbar's commands; the preview and its escaping; the editor's "modified" state and views (happy-dom).
• apps/server/test/files.test.ts, apps/local/test/files.test.ts: empty notes and text files, saves over a version, a refused save leaving the file as it was, two saves over the same version.
• apps/server/test/mcp-create.test.ts: write_text in a Windows-1252 file with CRLF.
• e2e/text.spec.ts: a note created from "Neu", formatted from the toolbar and saved on its own; the split view; a Windows file kept byte for byte; two windows on one note.