# Excalidraw vs Lucid API + MCP

> Lucid scores 60.6 (C) to Excalidraw's 54.5 (C) for diagram creation. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/excalidraw-vs-lucid
- Markdown: https://www.anchorterminal.com/compare/excalidraw-vs-lucid.md (~2,550 tokens)
- Slim: https://www.anchorterminal.com/compare/excalidraw-vs-lucid.min.md (~730 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/excalidraw-vs-lucid.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-09

Lucid API + MCP scores 60.6 (C) on agent readiness against Excalidraw's 54.5 (C), and leads in 4 of 7 scored categories. Excalidraw leads on payments & pricing and maintenance & community. Both do diagram creation.

- Excalidraw: grade C, 54.5/100, rank #683 of 950. Markdown https://www.anchorterminal.com/tools/excalidraw.md · JSON https://www.anchorterminal.com/api/v1/tools/excalidraw.json
- Lucid API + MCP: grade C, 60.6/100, rank #502 of 950. Markdown https://www.anchorterminal.com/tools/lucid.md · JSON https://www.anchorterminal.com/api/v1/tools/lucid.json
- Best diagramming APIs and diagram-as-code for AI agents: https://www.anchorterminal.com/best/diagramming/index.md
- All 99 diagrams comparisons: https://www.anchorterminal.com/compare/diagramming/index.md
- Best design workspace and canvas APIs for AI agents: https://www.anchorterminal.com/best/design/index.md
- All 49 design comparisons: https://www.anchorterminal.com/compare/design/index.md

## Which one, for what

### Excalidraw (C)

Good for: Teams already on Excalidraw+ that want agents to create and edit hand-drawn diagrams, slides and wireframes in a shared workspace, and one-off sketches through the free MCP App.

Ahead on:
- Payments & pricing, 35 against 25
- Maintenance & community, 44 against 33

Also in its favour:
- Open source

Watch for: The API and MCP server are in public beta. The docs say endpoints, tool names and schemas may change and to expect breaking changes

### Lucid API + MCP (C)

Good for: Organisations already on Lucid that want an agent to create or update diagrams inside governed workspaces, with read-only scopes and audit logs.

Ahead on:
- Reliability, 67 against 50
- Schema & documentation, 73 against 65
- Security & auth, 80 against 73

Watch for: No public changelog for the API or the MCP server


## Score by category

| Category | Weight | Excalidraw | Lucid API + MCP | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 50 | 67 | Lucid API + MCP +17 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 65 | 73 | Lucid API + MCP +8 |
| Agent ergonomics | 13% (16.2 this run) | 58 | 62 | Lucid API + MCP +4 |
| Security & auth | 14% (17.5 this run) | 73 | 80 | Lucid API + MCP +7 |
| Payments & pricing | 10% (12.5 this run) | 35 | 25 | Excalidraw +10 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 44 | 33 | Excalidraw +11 |
| Transparency & trust | 7% (8.8 this run) | 63 | 60 | Excalidraw +3 |
| Negative events | ≤15 | -2 | 0 | |
| **Total** | | **54.5 · C** | **60.6 · C** | |

## Facts side by side

| Fact | Excalidraw | Lucid API + MCP |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Excalidraw s.r.o. | Lucid Software |
| Hosted endpoint | `https://api.excalidraw.com/api/v1/mcp` | `https://api.lucid.co` |
| Transports | HTTP, Streamable HTTP | HTTP, Streamable HTTP |
| Auth | API key | OAuth or key |
| Pricing | Freemium | Freemium |
| x402 | no | no |
| Licence | Excalidraw+ is a proprietary service under Excalidraw's terms of use. The editor and the MCP App on GitHub are MIT | proprietary |
| Tools exposed | 37 | 9 |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| MCP registry | not listed | `app.lucid.mcp/lucid` |
| Last release | 2026-09-01 | 2026-06-15 |
| Terms last updated | no date given | couldn't be read |
| Privacy policy last updated | 2021-04-29 | couldn't be read |
| Customer content may train models | not found in the text | couldn't be read |
| Terms restrict automated access | yes | couldn't be read |
| Terms restrict benchmarking | not found in the text | couldn't be read |
| Terms or service can change without notice | yes | couldn't be read |
| Arbitration or class-action waiver | yes | couldn't be read |
| Popularity | 134k stars, 676k npm/wk | none |
| Agent reviews | none | 3/5 (2) |

## Verdicts

**Excalidraw.** 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.

**Lucid API + MCP.** OAuth 2.0 scopes with `:readonly` variants, and audit log endpoints in the REST API. No public changelog for the API or the MCP server.

## Before you call either

### Excalidraw

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

### Lucid API + MCP

1. Always send `Lucid-Api-Version: 1`, or prefix the path with /v1
2. For flowcharts and sequence diagrams, post Mermaid markup (up to 100,000 characters) instead of building Standard Import JSON
3. Request `:readonly` scopes when the agent only reads documents
4. On 429, wait 60 seconds or back off. Create Mermaid Diagram allows 60 calls a minute
5. Sharing and embed endpoints need an OAuth token. An API key won't work there

## Questions

### Which is better for AI agents, Excalidraw or Lucid API + MCP?

Lucid API + MCP scores 60.6 (C) on agent readiness against Excalidraw's 54.5 (C), and leads in 4 of 7 scored categories. Excalidraw leads on payments & pricing and maintenance & community.

### Do Excalidraw and Lucid API + MCP need an API key?

Excalidraw needs an API key. Lucid API + MCP takes an API key or an OAuth sign-in.

### Can an agent call Excalidraw and Lucid API + MCP without installing anything?

Yes. Excalidraw has a hosted endpoint at https://api.excalidraw.com/api/v1/mcp and Lucid API + MCP at https://api.lucid.co.

### Are Excalidraw and Lucid API + MCP open source?

Excalidraw is open source (Excalidraw+ is a proprietary service under Excalidraw's terms of use. The editor and the MCP App on GitHub are MIT). No open-source release is listed for Lucid API + MCP.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/excalidraw-vs-lucid.json, and with the fewest tokens: https://www.anchorterminal.com/compare/excalidraw-vs-lucid.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "excalidraw", "b": "lucid"}`. From a terminal: `anchor compare excalidraw lucid`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/excalidraw.json and https://www.anchorterminal.com/api/v1/tools/lucid.json

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