# Excalidraw (slim)

> Excalidraw is a hand-drawn style whiteboard and diagram editor from Excalidraw s.r.o. in Brno. Agents reach it through the Excalidraw+ REST API and MCP server (public beta), a free keyless MCP App, and the open-source editor on npm (MIT).

- Full: https://www.anchorterminal.com/tools/excalidraw.md (~7,500 tokens) · this version ~1,730 tokens · JSON https://www.anchorterminal.com/tools/excalidraw.json · canonical https://www.anchorterminal.com/tools/excalidraw
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-10

**C · 54.5/100 · rank #683 of 950 · #9 in Diagramming · not agent-ready · confidence medium**


Assessment: Excalidraw+ keys carry read or full permission, route restrictions and an expiry, and the MCP server shows a key only the tools its routes allow. The API and MCP server are in public beta with breaking changes expected, sit behind the $6 Plus plan, and have no published OpenAPI file, SDK or idempotency keys.

## Facts

- Kind: HTTP API · vendor: Excalidraw s.r.o. · category: Diagramming · legal entity: Excalidraw s.r.o. · provenance 80/100
- Endpoint: `https://api.excalidraw.com/api/v1/mcp` (HTTP, Streamable HTTP)
- Auth: API key · pricing: Freemium · x402: no · licence: Excalidraw+ is a proprietary service under Excalidraw's terms of use. The editor and the MCP App on GitHub are MIT
- Probe metrics: not measured yet (probes haven't run)
- Surfaces: Excalidraw+ REST API at https://api.excalidraw.com/api/v1 and MCP server at `/api/v1/mcp` (both public beta, Plus plan). Free MCP App at https://mcp.excalidraw.com. Editor as the npm package `@excalidraw/excalidraw`
- REST API: 27 operations across collections, scenes, scene content, invites, users, workspace and logs. Scene content has `GET`, `PATCH` (merge by element version) and `PUT` (full replacement)
- MCP tools: 37 documented, among them `create_diagram`, `edit_scene_content`, `search_scene_content`, `get_scene_content`, `create_slide`, `add_image`, `take_screenshot` and three format guides. The low-level content write endpoints are not exposed as tools
- Free MCP App: Open source (MIT per README and package.json, no licence file), v0.3.2 of 9 February 2026, last commit 24 March 2026. Five tools. Checkpoints are kept in Redis for 30 days and inputs are capped at 5 MB. Export uploads an encrypted copy to excalidraw.com
- Credentials: Bearer API keys with `read` or `full` permission or specific routes, an expiry, rotation and soft delete. Personal keys (admin must enable) or workspace keys
- Rate limits: 600 requests a minute per IP, with `X-RateLimit-Limit`, `X-RateLimit-Remaining` and `X-RateLimit-Reset` headers
- Pagination: `offset` and `limit` (default 10, up to 100) with `hasNextPage`. Logs also take a cursor
- Errors: JSON with `statusCode`, `error` and `message`. Documented codes 400, 401, 403, 404, 429 and 500
- Export formats: PNG through the MCP `take_screenshot` tool. The editor exports PNG, SVG and `.excalidraw` JSON, and Excalidraw+ adds PDF and PPTX
- Audit: `GET /logs` returns workspace audit logs filtered by user, action, operation and date
- Free tier: Free plan with one scene saved in the browser and 10 AI requests a day. Plus has a 14-day trial
- Certifications: SOC 2 Type 1 and Type 2 and yearly penetration tests, per the security page. Report in the Vanta trust centre
- Editor package: `@excalidraw/excalidraw` 0.18.1 (20 April 2026), MIT, React 17 to 19, 133,534 GitHub stars
- Prices: Plus plan $6 per seat per month

- Scores: Reliability 50, Performance pending, Schema & documentation 65, Agent ergonomics 58, Security & auth 73, Payments & pricing 35, Task success pending, Maintenance & community 44, Transparency & trust 63 · negative events -2 · total over the 7 assessed categories
- Why: Reliability, Scored on the hosted lines for the Excalidraw+ API and MCP server. · Schema & documentation, The endpoint reference is generated from an OpenAPI schema, but no file is linked from the docs, and the MCP tool definitions could not be r… · Agent ergonomics, The docs list 37 MCP tools (5). · Security & auth, API keys are workspace-bound, take `read` or `full` permission or specific routes, carry an expiry and can be rotated or soft-deleted. · Payments & pricing, No x402, MPP or L402 (0). · Maintenance & community, The newest changelog entry is dated 1 September 2026, 38 days before the check (20). · Transparency & trust, The graded service is closed under public terms of use, while the editor and the MCP App are MIT (20).
- Sources: 15, open questions: 8, both in the full twin
- Capabilities: diagram.create, diagram.edit, diagram.export, diagram.as-code
- JSON: https://www.anchorterminal.com/api/v1/tools/excalidraw.json
- Verify (for the vendor): the badge `https://www.anchorterminal.com/badges/excalidraw.svg` or a link to https://www.anchorterminal.com/tools/excalidraw from a page on excalidraw.com or one of its subdomains, or the README of github.com/excalidraw/excalidraw, then `POST https://www.anchorterminal.com/api/v1/verify` `{"slug", "url"}` or `verify_listing` at /mcp; re-checked weekly, no effect on the grade. Snippets in the full twin.

## Before you call it

1. Send `Authorization: Bearer <API_KEY>` to https://api.excalidraw.com/api/v1. For MCP, use `POST /api/v1/mcp` only. The server is stateless and answers 405 to other methods
2. Use a personal key to reach the owner's private collection with the collection ID `private`. A workspace admin must enable personal keys first
3. Call `read_diagram_format`, `read_presentation_format` or `read_freeform_format` before the first scene write in a session
4. Write with `edit_scene_content` and bind arrows through `startBinding` and `endBinding` with `tempId` references. `PUT /scenes/{sceneId}/content` removes every element left out of the request
5. Stay under 600 requests a minute per IP and wait until `X-RateLimit-Reset` after a 429

## Connect

```bash
npm install react react-dom @excalidraw/excalidraw
```

```bash
curl https://api.excalidraw.com/api/v1/collections \
  -H "Authorization: Bearer <API_KEY>"
```
Full config and headless snippets are in the full page. Through letme (picks today, calling later): https://letme.dev/excalidraw

## Similar tools

| Tool | Grade | Score | Shared capabilities | Slim |
| --- | --- | --- | --- | --- |
| D2 | B | 65.3 | diagram.as-code, diagram.create, diagram.export, diagram.edit | https://www.anchorterminal.com/tools/d2.min.md |
| draw.io + MCP | B | 62.2 | diagram.create, diagram.as-code, diagram.edit, diagram.export | https://www.anchorterminal.com/tools/drawio.min.md |
| tldraw SDK + MCP | C | 60.7 | diagram.create, diagram.as-code, diagram.edit, diagram.export | https://www.anchorterminal.com/tools/tldraw.min.md |
| Lucid API + MCP | C | 60.6 | diagram.create, diagram.as-code, diagram.edit, diagram.export | https://www.anchorterminal.com/tools/lucid.min.md |
| Structurizr + MCP | C | 59.9 | diagram.create, diagram.as-code, diagram.edit, diagram.export | https://www.anchorterminal.com/tools/structurizr.min.md |


## Panel reviews (0, desk reviews from public material, no calls made)