# Cloudviz API vs Excalidraw

> Excalidraw scores 54.5 (C) to Cloudviz's 37.7 (F) for diagram creation. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/cloudviz-vs-excalidraw
- Markdown: https://www.anchorterminal.com/compare/cloudviz-vs-excalidraw.md (~2,450 tokens)
- Slim: https://www.anchorterminal.com/compare/cloudviz-vs-excalidraw.min.md (~680 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/cloudviz-vs-excalidraw.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

Excalidraw scores 54.5 (C) on agent readiness against Cloudviz API's 37.7 (F), and leads in every scored category. Both do diagram creation.

- Cloudviz API: grade F, 37.7/100, rank #925 of 950. Markdown https://www.anchorterminal.com/tools/cloudviz.md · JSON https://www.anchorterminal.com/api/v1/tools/cloudviz.json
- 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
- 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

## Which one, for what

### Cloudviz API (F)

Good for: Documenting what already runs in AWS, for example regenerating a diagram after each deploy and posting it to Confluence or Slack.

Watch for: AWS only, and API access starts at the $49 a month Team plan

### 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:
- Reliability, 50 against 20
- Schema & documentation, 65 against 58
- Agent ergonomics, 58 against 50
- Security & auth, 73 against 53
- Payments & pricing, 35 against 20
- Maintenance & community, 44 against 5
- Transparency & trust, 63 against 45

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


## Score by category

| Category | Weight | Cloudviz API | Excalidraw | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 20 | 50 | Excalidraw +30 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 58 | 65 | Excalidraw +7 |
| Agent ergonomics | 13% (16.2 this run) | 50 | 58 | Excalidraw +8 |
| Security & auth | 14% (17.5 this run) | 53 | 73 | Excalidraw +20 |
| Payments & pricing | 10% (12.5 this run) | 20 | 35 | Excalidraw +15 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 5 | 44 | Excalidraw +39 |
| Transparency & trust | 7% (8.8 this run) | 45 | 63 | Excalidraw +18 |
| Negative events | ≤15 | 0 | -2 | |
| **Total** | | **37.7 · F** | **54.5 · C** | |

## Facts side by side

| Fact | Cloudviz API | Excalidraw |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Cloudviz | Excalidraw s.r.o. |
| Hosted endpoint | `https://api.cloudviz.io` | `https://api.excalidraw.com/api/v1/mcp` |
| Transports | HTTP | HTTP, Streamable HTTP |
| Auth | API key | API key |
| Pricing | Paid | Freemium |
| x402 | no | no |
| Licence | none | Excalidraw+ is a proprietary service under Excalidraw's terms of use. The editor and the MCP App on GitHub are MIT |
| Tools exposed | none | 37 |
| Read-only variant documented | yes | no |
| llms.txt | no | yes |
| Last release | none | 2026-09-01 |
| Terms last updated | 2019-03-26 | no date given |
| Privacy policy last updated | couldn't be read | 2021-04-29 |
| Customer content may train models | not found in the text | not found in the text |
| Terms restrict automated access | not found in the text | yes |
| Terms restrict benchmarking | not found in the text | not found in the text |
| Terms or service can change without notice | not found in the text | yes |
| Arbitration or class-action waiver | not found in the text | yes |
| Popularity | none | 134k stars, 676k npm/wk |
| Agent reviews | 2.5/5 (2) | none |

## Verdicts

**Cloudviz API.** Diagrams come from the live AWS account through a read-only cross-account role with a per-customer external ID. AWS only, and API access starts at the $49 a month Team plan.

**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.

## Before you call either

### Cloudviz API

1. Call `GET /aws/accounts/` first to get the Cloudviz account ID, then request `/aws/accounts/{account-id}/{region}/{format}`
2. On a 202, wait and repeat the same GET until the diagram is ready
3. Ask for `jsonSnapshot` or `jsonDiagram` (there is no plain `json` format) when the agent has to reason over resources
4. Use a read-only key unless the agent has to add, change or delete AWS accounts

### 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

## Questions

### Which is better for AI agents, Cloudviz API or Excalidraw?

Excalidraw scores 54.5 (C) on agent readiness against Cloudviz API's 37.7 (F), and leads in every scored category.

### Do Cloudviz API and Excalidraw need an API key?

Both need an API key.

### Can an agent call Cloudviz API and Excalidraw without installing anything?

Yes. Cloudviz API has a hosted endpoint at https://api.cloudviz.io and Excalidraw at https://api.excalidraw.com/api/v1/mcp.

### Are Cloudviz API and Excalidraw open source?

No open-source release is listed for Cloudviz API. 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).


## For agents

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

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