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https://github.com/1vav/embedded-editor-for-claude-code

Embedded visual workspace for Claude Code — Excalidraw, tldraw, and Markdown with MCP tools and inline PNG previews
https://github.com/1vav/embedded-editor-for-claude-code

anthropic claude-code claude-desktop excalidraw markdown tldraw

Last synced: about 2 months ago
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Embedded visual workspace for Claude Code — Excalidraw, tldraw, and Markdown with MCP tools and inline PNG previews

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README 

          
# Embedded Editor for Claude Code



An embedded visual workspace for Claude Code — edit Excalidraw diagrams, tldraw canvases, Markdown notes, and DuckDB tables in the browser preview pane, all linked together with `[[wikilinks]]`.



![ee.png](assets/ee.png)



Claude also gets **MCP tools** to create, query, and edit all four file types inline — including authentic PNG previews for diagrams and structured table data for DuckDB files.



---



## What it does



| | |

|---|---|

| **⬡ Excalidraw** | Rough hand-drawn diagrams. Claude creates and edits them via MCP tools and sees PNG previews inline. Also fully editable in the browser. |

| **◈ tldraw** | Infinite canvas with a full shape library. Browser-only — no MCP tools needed, just open and draw. |

| **¶ Markdown** | Full CommonMark with `[[wikilinks]]`, `![[diagram embeds]]`, images, tables, code blocks, strikethrough. Frontmatter panel, note style/color picker. |

| **🦆 DuckDB** | Real embedded analytical tables. Claude creates schemas, writes rows, runs SQL queries, and creates dynamic views via MCP tools. Embed live previews with `![[name.duckdb]]`. Click column headers to sort. Click the filename to rename in place. |

| **📄 PDF** | Drop in a `.pdf` file and open it in the browser — page-by-page viewer with zoom. |

| **📊 CSV** | `.csv` files open as read-only tables with the same column-sort UI as DuckDB. |



All editors are **live-synced** via SSE — Claude's edits appear in the browser immediately and vice versa.



---



## Quick start



### Global install (recommended)



Registers the MCP server and `/editor-start` · `/editor-stop` slash commands for every project:



```sh

npx embedded-editor-for-claude-code init --global

```



Restart Claude Code, then use the slash commands in any project:



```text

/editor-start    ← starts the viewer and opens it in the preview pane

/editor-stop     ← shuts it down

```



### Per-project install (optional)



Adds a full Excalidraw element reference to `CLAUDE.md` so Claude knows the diagram API without being told. Run inside the project you want to set up:



```sh

cd your-project

npx embedded-editor-for-claude-code init

```



### Update to latest version



```sh

npx embedded-editor-for-claude-code@latest init --global

```



> Re-run `init` after upgrading to refresh the API reference in `CLAUDE.md`.



### Manual MCP registration (alternative)



If you prefer not to use `init`, add the MCP server directly:



```sh

claude mcp add --transport stdio embedded-editor -- npx -y embedded-editor-for-claude-code

```



> **Desktop app users:** installation always requires a terminal step. Run any command above in a terminal, then switch to the desktop app — it picks up the configuration automatically without a restart.



### Ask Claude to draw



> "Draw an architecture diagram of this service"  

> "Sketch the auth flow as a sequence diagram"  

> "Add a database node to the existing diagram"



Claude calls the MCP tools and returns PNG previews inline as it builds the diagram.



### DuckDB tables with a live query pane



> "Create a table tracking sprint velocity — story points planned vs delivered"



Claude creates `velocity.duckdb`, defines the schema, and seeds it with rows. Open the file in the browser and you get a full table viewer with a **slideout SQL query pane**:



```

┌─────────────────────────────────────────────────────────────────┐

│  velocity.duckdb  · 4 rows  │ ⌘ Query │ ≡ Table │ ⊞ Cards │ ↓  │

├──────────┬───────────────────────────────────────────────────────┤

│ SQL·QUERY│  sprint  │ planned │ delivered │ pct   │ status      │

│          ├──────────┼─────────┼───────────┼───────┼─────────────│

│ SELECT   │  1       │ 34      │ 29        │ 85.3% │ ⚠ Below     │

│   sprint,│  2       │ 40      │ 38        │ 95.0% │ ✓           │

│   ...    │  3       │ 36      │ 36        │ 100%  │ ✓           │

│          │  4       │ 42      │ 31        │ 73.8% │ ⚠ Below     │

│ ▶ Run ⌘↵ │                                                       │

└──────────┴───────────────────────────────────────────────────────┘

```



Click **⌘ Query** to slide the SQL editor open. Write any SQL and hit `⌘↵` — results replace the table view instantly. Switch to **⊞ Cards** for a Kanban-style board that groups rows by any column (auto-detected from `status`, `state`, `stage`, etc.) with drag-to-regroup.



Click any **column header** to sort (click again to reverse). The header turns amber and shows ▲/▼. Click the **filename** in the toolbar to rename the file in place — the tab bar, sidebar, and all wikilinks update automatically.



The toolbar also shows **"updated Xm ago"** — a timestamp updated after every `write_rows` call, equivalent to Jupyter's "last run" indicator.



Embed a live preview in any note with `![[velocity.duckdb]]` — it renders an inline table that updates whenever the data changes. The embed supports the same column sort.



---



## MCP tools



**Excalidraw diagrams**



| Tool | What it does |

|---|---|

| `list_diagrams` | List all `.excalidraw` files |

| `create_diagram` | Create a blank diagram; returns PNG preview |

| `read_diagram` | Return current JSON + PNG |

| `write_diagram` | Replace elements; returns PNG |

| `append_elements` | Add elements to existing diagram; returns PNG |

| `delete_diagram` | Delete a diagram file |



**Markdown notes**



| Tool | What it does |

|---|---|

| `list_notes` | List all `.md` notes |

| `create_note` | Create a blank note |

| `read_note` | Read note content |

| `write_note` | Write (replace) note content |

| `delete_note` | Delete a note |



**DuckDB tables**



| Tool | What it does |

|---|---|

| `list_tables` | List all `.duckdb` files |

| `create_table` | Create a new DuckDB file with an optional schema |

| `read_table` | Read rows from the first user table (returns markdown) |

| `write_rows` | Upsert rows into a table (batched — all rows in one SQL statement) |

| `delete_rows` | Delete rows matching a WHERE clause |

| `query_table` | Run arbitrary SQL; optional `save_as` inserts results into another table |

| `create_view` | Create a named DuckDB VIEW — a saved SQL query that re-executes dynamically on every read. Any column whose values match workspace file names gets a companion `_name` column with `[[wikilinks]]`; the browser renders those cells as clickable navigation links. |



**Workspace**



| Tool | What it does |

|---|---|

| `list_workspace` | List all files grouped by type in one call (diagrams, notes, tldraw, tables) |

| `rename_file` | Rename a file and rewrite all `[[wikilinks]]` |

| `get_backlinks` | Find all files that link to a given file |

| `list_history` | List saved snapshots for a diagram |

| `restore_snapshot` | Restore a diagram to a saved version |

| `list_tldraw` | List tldraw canvas files |

| `read_tldraw` | Read tldraw canvas JSON |



### How PNG rendering works



1. Claude calls `write_diagram` with Excalidraw JSON elements

2. The server writes the `.excalidraw` file

3. Excalidraw's `exportToSvg` runs in a jsdom shim — authentic SVG with rough.js strokes, hachure fills, real arrowheads

4. `@resvg/resvg-js` rasterizes to PNG

5. Returns `{type: "image", mimeType: "image/png", data: }` — Claude Code renders it inline



---



## Viewer features



- **File browser** — sidebar lists all `.excalidraw`, `.tldraw`, `.md`, `.duckdb`, `.pdf`, and `.csv` files; filter by type

- **Wikilinks** — `[[filename]]` in any editor navigates to that file as a new tab

- **Diagram embeds** — `![[diagram.excalidraw]]` in Markdown renders the diagram inline in preview

- **Image embeds** — `![alt](image.png)` works with local files; the server serves them from the project directory

- **Backlinks** — see which files link to the current one

- **Version history** — last 30 versions auto-saved; browse and restore from the history panel (`⟳`)

- **Live rename** — renaming rewrites all `[[wikilinks]]` across the project

- **Live sync** — SSE events push changes to all open tabs instantly

- **Light/dark** — follows your OS preference

- **Note style picker** — font style (Serif · Sans · Literary · Compact · Mono) and color profile (Auto · Sepia · Paper · Night · Forest) selectors in the Markdown toolbar; each setting is independent and persists across sessions

- **Frontmatter panel** — YAML front matter in notes renders as a collapsible property panel; dates, URLs, and booleans get styled display

- **External links** — because the preview pane only allows `localhost` navigation, clicking any external link copies its URL to the clipboard (a "link copied" toast confirms it)

- **Drag-to-reorder** — grab handles appear on hover for paragraphs, table rows, list items, headings (with their sections), and whole tables; drag to reorder

- **Column sort** — click any column header in DuckDB or CSV views to sort asc/desc (▲/▼); click again to reverse; numeric values sort numerically

- **Inline rename** — click the filename in a DuckDB tab or embed header to rename it in place; all wikilinks update via the server



### Slash commands



In the Markdown note editor, type `/` at the start of a line to open the command palette:



![slash_commands.png](assets/slash_commands.png)



| Command | What it does |

|---|---|

| `/diagram [description]` | Creates a new Excalidraw diagram, embeds it as `![[name.excalidraw]]`, and pre-fills the prompt bar with your description so Claude populates it |

| `/canvas [description]` | Creates a new tldraw canvas and embeds it as `![[name.tldraw]]` |

| `/note [description]` | Creates a new linked Markdown note, embeds it as `[[name]]`, and pre-fills the prompt bar for Claude to write its content |

| `/table [description]` | Creates a new DuckDB table file with a slug-based name derived from the description (e.g. `/table sprint velocity` → `sprint-velocity-a3f.duckdb`), embeds it, and pre-fills the prompt bar so Claude defines the schema |

| `/query [description]` | Creates a new DuckDB file as a query result target with a slug-based name, embeds it, and pre-fills Claude to write the query SQL |

| `/link` | Opens a searchable picker of all existing files and inserts a wikilink |



**How it works:**



1. Type `/diagram` (or `/d` to narrow) — the palette shows matching commands

2. Press `Space` and type a description — the option updates to show your text

3. Press `Tab` or `Enter` to accept — the file is created instantly, the slash command is replaced with the wikilink embed, and the prompt bar below is pre-filled with your description ready to send to Claude



Example: typing `/diagram show the auth flow` then pressing Tab creates `diagram-abc123.excalidraw`, inserts `![[diagram-abc123.excalidraw]]` in the note, and pre-fills:



```

show the auth flow



Diagram file: [[diagram-abc123.excalidraw]] (already created). Use the write_diagram MCP tool to populate it.

```



Copy that into Claude and it draws the diagram directly into the linked file.



---



## Architecture



### Excalidraw



![[architecture.excalidraw]]



### tldraw



![[architecture.tldraw]]



---



## Diagram API knowledge



Running `npx embedded-editor-for-claude-code init` writes a complete **Excalidraw element reference** into your `CLAUDE.md`, including:



- All element types (`rectangle`, `ellipse`, `diamond`, `arrow`, `text`, …)

- Every valid prop value (colors, fill styles, roughness levels, stroke styles)

- Arrow binding syntax

- Copy-pasteable minimal examples



The guide is stamped with the exact package versions it was generated from. Re-run `init` after upgrading `embedded-editor` to refresh it.



---



## Requirements



- **Node.js 18+**

- **[`@resvg/resvg-js`](https://github.com/yisibl/resvg-js)** — prebuilt binaries for macOS (arm64/x64), Linux (x64/arm64), Windows (x64). No compilation needed on these platforms.



---



## Development



```sh

git clone https://github.com/1vav/embedded-editor-for-claude-code.git

cd embedded-editor-for-claude-code

npm install

npm run build          # generate vendor/ bundles



# Rebuild after changing src/viewer/entry.jsx

node scripts/build-viewer-bundle.mjs



# Rebuild after bumping @excalidraw/excalidraw

node scripts/build-excalidraw-bundle.mjs



# Smoke test (MCP stdio protocol happy path)

node scripts/smoke-stdio.mjs

```



See [CONTRIBUTING.md](./CONTRIBUTING.md) for full contribution guidelines.



---



## License



MIT — see [LICENSE](./LICENSE)