Sheaf Editor: think with agents

Work in docs inside your agentic coding app or your favourite code editor.
Strategy, research, specs and roadmaps, kept as files in the repo your agents can read at local lightning speeds.
_{VS Code · Kiro · Cursor · Windsurf · VSCodium}

Open source and MIT-licensed. Every line of Sheaf is in this repository, so you can read it, and so can your agent: ask it to check what the extension does before you install it. Each release is built by GitHub Actions and carries a build provenance attestation, which ties the published file to the commit it came from.

Sheaf shows the rendered document and lets you type straight into it. Headings look like headings, tables are grids, and the file on disk stays ordinary Markdown: an edit changes only what you typed, so the diff shows your change and nothing else.

Select a range, like a spreadsheet

Click a cell and type, drag across a range, or paste one in from Excel, Numbers or Sheets. Spreadsheet keys move you around, Cmd-click picks cells that are not next to each other, columns size to what they hold, and a long table keeps its header row in view. On disk it stays a Markdown table, and one edited cell is one changed line.

Filter and sort from the header

Name a CSV block and a view block elsewhere in the document shows it filtered, sorted and trimmed to the columns you want. Click a column header to sort or filter and Sheaf writes the line into the query for you. A view reads a named block in the document or a .csv file beside it, and a cell edited through the view changes that one field in the table behind it.

The same rows as a board

Add layout: board and group: status and the rows are cards in a column per value, with its count. Drag a card and its value changes in the table. The filtering and the sorting still apply, and a plain pipe table can be shown as a board from its own menu.

Every block, rendered as you write

Headings, callouts, task lists, maths, footnotes and code look like the finished page while you type into them. A slash menu, a toolbar over selected text, a right-click menu and a drag grip cover the block moves, Cmd+/ lists every shortcut, and find and replace reaches into tables and link addresses. Press Cmd+Alt+E on any block to see and edit its Markdown, or Open raw Markdown to drop the whole file back to plain text.

Diagrams drawn where you wrote them

A mermaid block is the diagram. It draws light or dark from the colours behind it, and the block still holds the Mermaid you typed.

Hand your agent the exact lines

Right-click any line. Copy ref and Send to terminal give your agent a quoted reference to exactly what you picked: the file, the lines and the text, and in a table the cells. Nothing runs until you press Enter.

See what your agent changed

When anything outside the editor writes the open file, Sheaf marks the lines it wrote with a bar in the margin and a tint across them, and beside the row number in a table. You read the change in the document rather than in source control. Edit the line and its mark goes; nothing is written to the file. If a write takes back what you just typed, Sheaf says so and one Cmd+Z brings it back.

Build the brain your agents read

Strategy, research, specs, roadmaps, decisions and the tables behind them, written as files in the repo. Every agent that opens the repo reads the lot, with no sync step, no retrieval layer and no account in the way. It travels with the code: clone the repo and you have it, branch and it branches with you.

Everything GitHub renders, and a little more

Sheaf reads the Markdown you already have and writes the same Markdown back. Everything GitHub draws, it draws: headings, emphasis, links, images, quotes, lists, task checkboxes, rules, code blocks, pipe tables, the five alerts from [!NOTE] to [!CAUTION], mermaid diagrams, $x$ and $$ maths, [^1] footnotes, emoji written by name like :warning:, and YAML front matter.

On top of that it adds six things. Each is a fenced block, an HTML comment or a file of its own, so the document still renders everywhere and an agent still reads the whole of it in one pass:

	Sheaf draws	Elsewhere
A highlight, `==like this==`	Marked up	The equals signs
A `csv` or `tsv` block	A spreadsheet grid	A code block
A `view` block	One table filtered, sorted and trimmed	A code block
A view with `layout: board`	Cards you drag	A code block
A `.csv` or `.tsv` file	A grid of its own	A table
An HTML comment	A note you can collapse	Hidden

It is still just a folder of Markdown (ish)

No import step. Your files, where they already are.
Only your changes change. git diff shows exactly what you did.
Every commit, forever. No plan tier expires your history.
Nothing to sign up for. No account, no database, no cloud.
The (ish). A csv or view block shows as a code block anywhere else.
Your .txt notes too. Right-click one and open it in Sheaf, read exactly as a .md. Double-clicking still gives you plain text.
Never locked in. Uninstall Sheaf and your documents are exactly as you left them.

Install

Editor	Where it installs from
VS Code	Visual Studio Marketplace
Cursor, Windsurf, Kiro, VSCodium	Open VSX

Every release goes to both as the same build. Install it, open any .md file, and there is nothing to configure.

Command	What it does
Open in Sheaf	Open the current file in Sheaf
Open as Raw Markdown (Text)	Open the plain text editor
Toggle Whole-Document Source Mode	Show the Markdown of every block at once
Open This Folder in a Browser	Serve the folder to a browser tab, with the same editor

The documentation has a page for every feature.

Making Sheaf the default, or not

Sheaf is the default editor for .md and .markdown files, so Markdown opens rendered as soon as it is installed. To open files in Sheaf one at a time instead, turn off Settings → Extensions → Sheaf → Use As Default Markdown Editor, or in settings.json:

"sheaf.useAsDefaultMarkdownEditor": false

Markdown then opens in the plain text editor, and you open a file in Sheaf with Open in Sheaf, on the Explorer's right-click menu, or with View: Reopen Editor With… → Sheaf (WYSIWYG). The setting maintains workbench.editorAssociations for you. If you have pointed *.md at another editor there, Sheaf leaves your choice alone.

Settings

Setting	Default	Description
`sheaf.useAsDefaultMarkdownEditor`	`true`	Open `.md` and `.markdown` files in Sheaf automatically.
`sheaf.contentWidth`	`708px`	Width of the centred text column. Any CSS length.
`sheaf.autoSave`	`true`	Save shortly after you stop typing.
`sheaf.revealSyntaxOnLine`	`false`	Show the Markdown of the block the cursor is in.
`sheaf.doubleClickToEditSource`	`false`	Double-click a rendered element to show its Markdown, instead of selecting a word.
`sheaf.tableOfContents`	`false`	Show a panel of the document's headings beside the text.

Verifying a release

An extension registry ships a bundled file, not source, so reading this repository tells you what the source says and nothing about the file running in your editor. Every release is built by GitHub Actions and carries a build provenance attestation recording the commit and the workflow that produced it. Both registries receive the same file, so one check covers either:

gh attestation verify sheafeditor-<version>.vsix --repo sheafeditor/sheafeditor

Download the .vsix from the releases page first. The command prints the commit and workflow the build came from. Anything else means the file did not come out of this repository's release pipeline.

Building from source

Sheaf is maintained by one person. Bug reports and ideas are welcome as issues; code contributions are not accepted.

npm install
npm run watch      # rebuilds the extension and the editor on change
# then press F5 in VS Code to launch the Extension Development Host

npm test runs the test suites and npm run package builds a .vsix.

See CONTRIBUTING.md for the full guide, including the one rule that is not negotiable: Sheaf never reserializes your Markdown.

Sheaf Editor: WYSIWYG Markdown

Sheaf Editor