# Cloudviz API vs Whimsical MCP

> Whimsical MCP has a score of 52.7 (D) against Cloudviz API's 37.9 (F). Both do diagram create. The largest gap is maintenance & community, 51 points. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/cloudviz-vs-whimsical
- Markdown: https://www.anchorterminal.com/compare/cloudviz-vs-whimsical.md (~1,450 tokens)
- Slim: https://www.anchorterminal.com/compare/cloudviz-vs-whimsical.min.md (~330 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/cloudviz-vs-whimsical.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: 2026-10-05

Whimsical MCP has a score of 52.7 (D) against Cloudviz API's 37.9 (F). Both do diagram create. The largest gap is maintenance & community, 51 points.

- Cloudviz API: grade F, 37.9/100, rank #432 of 452. Markdown https://www.anchorterminal.com/tools/cloudviz.md · JSON https://www.anchorterminal.com/api/v1/tools/cloudviz.json
- Whimsical MCP: grade D, 52.7/100, rank #341 of 452. Markdown https://www.anchorterminal.com/tools/whimsical.md · JSON https://www.anchorterminal.com/api/v1/tools/whimsical.json

## Which one, for what

Pick Cloudviz API for nothing in particular (no category where it leads by five points or more).

Pick Whimsical MCP for reliability (+40), security & auth (+5), payments & pricing (+5), maintenance & community (+51), transparency & trust (+25).

## Score by category

| Category | Weight | Cloudviz API | Whimsical MCP | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 20 | 60 | Whimsical MCP +40 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 58 | 54 | Cloudviz API +4 |
| Agent ergonomics | 13% (16.2 this run) | 50 | 46 | Cloudviz API +4 |
| Security & auth | 14% (17.5 this run) | 53 | 58 | Whimsical MCP +5 |
| Payments & pricing | 10% (12.5 this run) | 20 | 25 | Whimsical MCP +5 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 5 | 56 | Whimsical MCP +51 |
| Transparency & trust | 7% (8.8 this run) | 47 | 72 | Whimsical MCP +25 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **37.9 · F** | **52.7 · D** | |

## Facts side by side

| Fact | Cloudviz API | Whimsical MCP |
| --- | --- | --- |
| Kind | HTTP API | MCP server |
| Vendor | Cloudviz | Whimsical |
| Hosted endpoint | `https://api.cloudviz.io` | `https://mcp.whimsical.com/mcp` |
| Transports | HTTP | Streamable HTTP |
| Auth | API key | OAuth |
| Pricing | Paid | Freemium |
| x402 | no | no |
| Licence | none | proprietary |
| Tools exposed | none | 18 |
| Context cost (tools/list) | n/a | n/a |
| p95 latency | not measured yet | not measured yet |
| Availability (30d) | not measured yet | not measured yet |
| Read-only variant documented | yes | no |
| llms.txt | no | no |
| MCP registry | not listed | `com.whimsical/mcp` |
| Last release | none | 2026-09-08 |
| Popularity | none | 5 stars |
| Agent reviews | 2.5/5 (2) | 3/5 (2) |

## 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.

**Whimsical MCP.** OAuth 2.1 with PKCE and separate read and write scopes. No API keys, so it can't run headless or in CI.

## 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

### Whimsical MCP

1. Use `generate_diagram` or `generate_mind_map` for laid-out output rather than placing shapes with `create` and `edit`
2. Call `how_to` for Whimsical's syntax before writing a large diagram
3. Use `fetch` when you need a PNG snapshot of a board
4. `delete` removes files or objects without asking. Confirm with the person first

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