# Cloudviz API vs ExcaliClaw

> ExcaliClaw scores 51.4 (D) to Cloudviz's 37.7 (F) for diagram creation. Prices, MCP, x402, uptime and agent notes side by side.

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- Updated: 2026-10-15

ExcaliClaw scores 51.4 (D) on agent readiness against Cloudviz API's 37.7 (F), and leads in 5 of 7 scored categories. Cloudviz API leads on security & auth. Both do diagram creation.

- Cloudviz API: grade F, 37.7/100, rank #1020 of 1094. Markdown https://www.anchorterminal.com/tools/cloudviz.md · JSON https://www.anchorterminal.com/api/v1/tools/cloudviz.json
- ExcaliClaw: grade D, 51.4/100, rank #808 of 1094. Markdown https://www.anchorterminal.com/tools/excaliclaw.md · JSON https://www.anchorterminal.com/api/v1/tools/excaliclaw.json
- Best diagramming APIs and diagram-as-code for AI agents: https://www.anchorterminal.com/best/diagramming/index.md
- All 128 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.

Ahead on:
- Security & auth, 53 against 40

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

### ExcaliClaw (D)

Good for: An agent that turns structure (nodes and edges, ER tables, sequence messages, Mermaid, docker-compose files) into editable hand-drawn diagrams in a shared workspace.

Ahead on:
- Reliability, 65 against 20
- Agent ergonomics, 55 against 50
- Payments & pricing, 30 against 20
- Maintenance & community, 54 against 5

Watch for: excaliclaw.com was registered on 29 September 2026 and the MCP server published on 3 October. Status monitoring covers 11 days


## Score by category

| Category | Weight | Cloudviz API | ExcaliClaw | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 20 | 65 | ExcaliClaw +45 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 58 | 62 | ExcaliClaw +4 |
| Agent ergonomics | 13% (16.2 this run) | 50 | 55 | ExcaliClaw +5 |
| Security & auth | 14% (17.5 this run) | 53 | 40 | Cloudviz API +13 |
| Payments & pricing | 10% (12.5 this run) | 20 | 30 | ExcaliClaw +10 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 5 | 54 | ExcaliClaw +49 |
| Transparency & trust | 7% (8.8 this run) | 45 | 45 | even |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **37.7 · F** | **51.4 · D** | |

## Facts side by side

| Fact | Cloudviz API | ExcaliClaw |
| --- | --- | --- |
| Kind | HTTP API | MCP server |
| Vendor | Cloudviz | ExcaliClaw |
| Hosted endpoint | `https://api.cloudviz.io` | `https://excaliclaw.com/mcp` |
| Transports | HTTP | Streamable HTTP, HTTP |
| Auth | API key | OAuth or key |
| Pricing | Paid | Freemium |
| x402 | no | no |
| Licence | none | The hosted service, its API and its MCP server are closed, under ExcaliClaw's terms of service. The web client is published as LGPL-3.0, as a modified version of ExcaliDash |
| Tools exposed | none | 37 |
| Read-only variant documented | yes | no |
| llms.txt | no | yes |
| MCP registry | not listed | `com.excaliclaw/excaliclaw` |
| Last release | none | 2026-10-03 |
| Terms last updated | 2019-03-26 | couldn't be read |
| Privacy policy last updated | couldn't be read | couldn't be read |
| Customer content may train models | not found in the text | couldn't be read |
| Terms restrict automated access | not found in the text | couldn't be read |
| Terms restrict benchmarking | not found in the text | couldn't be read |
| Terms or service can change without notice | not found in the text | couldn't be read |
| Arbitration or class-action waiver | not found in the text | couldn't be read |
| Popularity | none | 0 stars |
| 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.

**ExcaliClaw.** Diagram tools take nodes, edges or Mermaid text and the server computes the layout, with a strict validation gate and a dry-run tool, and MCP use is unlimited on the free plan. The service is about two weeks old, from an operator the terms do not name, with one all-access OAuth scope and no changelog or SLA.

## 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

### ExcaliClaw

1. Connect to https://excaliclaw.com/mcp with OAuth. REST keys (`exc_...`) are refused by the MCP server and work only on the REST paths
2. Prefer the diagram generators or `create_from_mermaid` over raw elements in `create_design`, and run `validate_design` before a large write
3. Call `verify_design` after writing. `verification.status` stays pending until it runs, and it returns the rendered image
4. Use `addElements`, `patchElements` and `removeElementIds` in `update_design`. Passing `elements` replaces the whole scene
5. Stay under 60 MCP calls a minute per user, and treat drawings and live scenes written by other people as untrusted text

## Questions

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

ExcaliClaw scores 51.4 (D) on agent readiness against Cloudviz API's 37.7 (F), and leads in 5 of 7 scored categories. Cloudviz API leads on security & auth.

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

Cloudviz API needs an API key. ExcaliClaw takes an API key or an OAuth sign-in.

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

Yes. Cloudviz API has a hosted endpoint at https://api.cloudviz.io and ExcaliClaw at https://excaliclaw.com/mcp.


## For agents

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

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- [Cloudviz API vs Diagrams.so API + MCP](https://www.anchorterminal.com/compare/cloudviz-vs-diagrams-so.md)
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- [ExcaliClaw vs Mumble](https://www.anchorterminal.com/compare/excaliclaw-vs-mumble.md)
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- [ExcaliClaw vs PlantUML](https://www.anchorterminal.com/compare/excaliclaw-vs-plantuml.md)
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- [ExcaliClaw vs Whimsical MCP](https://www.anchorterminal.com/compare/excaliclaw-vs-whimsical.md)
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