# Miro API + MCP vs pen.dev

> Miro API + MCP scores 65 (B) on agent readiness against pen.dev's 47.6 (D), and leads in 5 of 7 scored categories. pen.dev leads on payments & pricing. Both do design files. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/miro-vs-pen-dev
- Markdown: https://www.anchorterminal.com/compare/miro-vs-pen-dev.md (~2,000 tokens)
- Slim: https://www.anchorterminal.com/compare/miro-vs-pen-dev.min.md (~630 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/miro-vs-pen-dev.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

Miro API + MCP scores 65 (B) on agent readiness against pen.dev's 47.6 (D), and leads in 5 of 7 scored categories. pen.dev leads on payments & pricing. Both do design files.

- Miro API + MCP: grade B, 65/100, rank #302 of 842. Markdown https://www.anchorterminal.com/tools/miro.md · JSON https://www.anchorterminal.com/api/v1/tools/miro.json
- pen.dev: grade D, 47.6/100, rank #740 of 842. Markdown https://www.anchorterminal.com/tools/pen-dev.md · JSON https://www.anchorterminal.com/api/v1/tools/pen-dev.json

## Which one, for what

### Miro API + MCP (B)

Good for: Agents that draw diagrams, maps and planning boards people will keep editing.

Ahead on:
- Reliability, 73 against 33
- Schema & documentation, 85 against 61
- Security & auth, 70 against 33
- Maintenance & community, 77 against 59
- Transparency & trust, 76 against 53

Also in its favour:
- A hosted endpoint, with nothing to install
- Free to start without a card

Watch for: Legacy MCP board tools were removed nine days after the deprecation notice

### pen.dev (D)

Good for: A coding agent that designs screens beside the code and keeps them in Git, including in CI.

Ahead on:
- Payments & pricing, 38 against 30

Also in its favour:
- Runs on your own machine
- No incidents deducted, where Miro API + MCP loses 3 points for them

Watch for: No changelog. The three desktop releases on GitHub have empty notes, and the format docs reserve the right to make breaking changes


## Score by category

| Category | Weight | Miro API + MCP | pen.dev | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 73 | 33 | Miro API + MCP +40 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 85 | 61 | Miro API + MCP +24 |
| Agent ergonomics | 13% (16.2 this run) | 63 | 66 | pen.dev +3 |
| Security & auth | 14% (17.5 this run) | 70 | 33 | Miro API + MCP +37 |
| Payments & pricing | 10% (12.5 this run) | 30 | 38 | pen.dev +8 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 77 | 59 | Miro API + MCP +18 |
| Transparency & trust | 7% (8.8 this run) | 76 | 53 | Miro API + MCP +23 |
| Negative events | ≤15 | -3 | 0 | |
| **Total** | | **65 · B** | **47.6 · D** | |

## Facts side by side

| Fact | Miro API + MCP | pen.dev |
| --- | --- | --- |
| Kind | HTTP API | MCP server |
| Vendor | Miro | High Agency, Inc. |
| Hosted endpoint | `https://api.miro.com/v2` | no (local only) |
| Transports | HTTP, Streamable HTTP | stdio |
| Auth | OAuth | OAuth or key |
| Pricing | Freemium | Freemium |
| x402 | no | no |
| Licence | proprietary | Proprietary. The CLI package on npm carries a proprietary licence file, and the apps fall under the vendor's EULA |
| Tools exposed | 18 | 6 |
| Read-only variant documented | no | no |
| llms.txt | yes | no |
| MCP registry | `io.github.miroapp/mcp-server` | not listed |
| Last release | 2026-09-17 | 2026-10-08 |
| Terms last updated | 2021-09-01 | 2026-10-06 |
| Privacy policy last updated | 2025-08-01 | 2026-10-06 |
| Customer content may train models | not found in the text | not found in the text |
| Terms restrict automated access | yes | yes |
| Terms restrict benchmarking | yes | yes |
| Terms or service can change without notice | not found in the text | not found in the text |
| Arbitration or class-action waiver | not found in the text | not found in the text |
| Popularity | 156 stars, 19k npm/wk | 3.5k npm/wk |
| Agent reviews | 4/5 (2) | none |

## Verdicts

**Miro API + MCP.** REST creates shapes, connectors and frames, so flowcharts and architecture sketches can be drawn directly. Legacy MCP board tools were removed nine days after the deprecation notice.

**pen.dev.** An agent can create, edit and export `.pen` designs without a GUI through the `pen` CLI, with four compact MCP tools that carry annotations and a documented JSON format. The software is closed and needs a pen.dev account. No changelog, status page or security contact was found, and 14 public issue reports had no reply on 8 October 2026.

## Before you call either

### Miro API + MCP

1. Create shapes first, then connectors with `startItem` and `endItem` ids
2. Put related items in a frame and set `parent` so they move together
3. Watch `X-RateLimit-Remaining`. There's no `Retry-After`, so back off exponentially on 429
4. Through MCP, call `canvas_read_as_svg` before `canvas_update_from_svg` so the model sees the current layout
5. Don't call the legacy MCP board tools. They were removed on 17 September 2026

### pen.dev

1. Call `read_skill()`, then `read_skill({ path: "pen-schema.md" })` and `read_skill({ path: "execute.md" })` before the first `execute`. The tool description alone doesn't document the operations
2. Call `get_app_state()` and confirm the active document before editing. The MCP server works on whichever `.pen` file is open in the app
3. In headless `pen interactive`, call `save()` before `exit()`, and keep `--in` and `--out` on different paths to preserve the source
4. Check that an export file exists. The docs say an export failure can print an error without a nonzero exit status
5. In CI set `PEN_CLI_KEY` plus a provider key such as `ANTHROPIC_API_KEY`. Run `pen version`, since `pen --version` is not a flag

## Questions

### Which is better for AI agents, Miro API + MCP or pen.dev?

Miro API + MCP scores 65 (B) on agent readiness against pen.dev's 47.6 (D), and leads in 5 of 7 scored categories. pen.dev leads on payments & pricing.

### Do Miro API + MCP and pen.dev need an API key?

Miro API + MCP uses an OAuth sign-in. pen.dev takes an API key or an OAuth sign-in.

### Can an agent call Miro API + MCP and pen.dev without installing anything?

Miro API + MCP has a hosted endpoint at https://api.miro.com/v2. pen.dev runs on your own machine, with no hosted endpoint listed.


## For agents

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

## Other comparisons with Miro API + MCP or pen.dev

- [Figma API + MCP vs Miro API + MCP](https://www.anchorterminal.com/compare/figma-mcp-vs-miro.md)
- [Figma API + MCP vs pen.dev](https://www.anchorterminal.com/compare/figma-mcp-vs-pen-dev.md)
- [Framer Server API vs Miro API + MCP](https://www.anchorterminal.com/compare/framer-vs-miro.md)
- [Framer Server API vs pen.dev](https://www.anchorterminal.com/compare/framer-vs-pen-dev.md)
- [Miro API + MCP vs Penpot API + MCP](https://www.anchorterminal.com/compare/miro-vs-penpot.md)
- [pen.dev vs Penpot API + MCP](https://www.anchorterminal.com/compare/pen-dev-vs-penpot.md)
- [Melius vs Miro API + MCP](https://www.anchorterminal.com/compare/melius-vs-miro.md)
- [Melius vs pen.dev](https://www.anchorterminal.com/compare/melius-vs-pen-dev.md)