# Eraser API + MCP vs Kroki

> Kroki scores 59.2 (C) to Eraser's 38.6 (E) for diagram creation. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/eraser-vs-kroki
- Markdown: https://www.anchorterminal.com/compare/eraser-vs-kroki.md (~2,400 tokens)
- Slim: https://www.anchorterminal.com/compare/eraser-vs-kroki.min.md (~730 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/eraser-vs-kroki.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

Kroki scores 59.2 (C) on agent readiness against Eraser API + MCP's 38.6 (E), and leads in 5 of 7 scored categories. Both do diagram creation.

- Eraser API + MCP: grade E, 38.6/100, rank #918 of 950. Markdown https://www.anchorterminal.com/tools/eraser.md · JSON https://www.anchorterminal.com/api/v1/tools/eraser.json
- Kroki: grade C, 59.2/100, rank #558 of 950. Markdown https://www.anchorterminal.com/tools/kroki.md · JSON https://www.anchorterminal.com/api/v1/tools/kroki.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

### Eraser API + MCP (E)

Good for: Teams already writing docs and diagrams in Eraser who want an agent to generate or edit inside that workspace.

Also in its favour:
- A hosted endpoint, with nothing to install
- Runs on your own machine
- No incidents deducted, where Kroki loses 5 points for them

Watch for: No status page, rate limits, SLA or changelog

### Kroki (C)

Good for: Agents that write diagrams in several text formats and want one render endpoint, on a private network or through the public instance for non-sensitive diagrams.

Ahead on:
- Reliability, 74 against 15
- Agent ergonomics, 70 against 34
- Payments & pricing, 60 against 35
- Maintenance & community, 86 against 33
- Transparency & trust, 62 against 50

Also in its favour:
- No key needed to call it
- Open source

Watch for: GHSA-wmpp-fj9c-w766 (CVSS 9.8) allowed unauthenticated remote code execution on `/tikz/svg` in versions 0.21.0 up to 0.32.0, whatever the safe mode. Fixed 3 August 2026


## Score by category

| Category | Weight | Eraser API + MCP | Kroki | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 15 | 74 | Kroki +59 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 52 | 48 | Eraser API + MCP +4 |
| Agent ergonomics | 13% (16.2 this run) | 34 | 70 | Kroki +36 |
| Security & auth | 14% (17.5 this run) | 57 | 56 | Eraser API + MCP +1 |
| Payments & pricing | 10% (12.5 this run) | 35 | 60 | Kroki +25 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 33 | 86 | Kroki +53 |
| Transparency & trust | 7% (8.8 this run) | 50 | 62 | Kroki +12 |
| Negative events | ≤15 | 0 | -5 | |
| **Total** | | **38.6 · E** | **59.2 · C** | |

## Facts side by side

| Fact | Eraser API + MCP | Kroki |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Eraser | Yuzu tech |
| Hosted endpoint | `https://app.eraser.io/api` | no (local only) |
| Transports | HTTP, Streamable HTTP, stdio | HTTP |
| Auth | OAuth or key | None |
| Pricing | Freemium | Free |
| x402 | no | no |
| Licence | none | MIT |
| Tools exposed | 42 | none |
| Read-only variant documented | no | no |
| llms.txt | yes | no |
| MCP registry | `io.eraser/eraser` | not listed |
| Last release | 2026-05-22 | 2026-10-05 |
| Terms last updated | no date given | no document linked |
| Privacy policy last updated | no date given | no document linked |
| Customer content may train models | not found in the text |  |
| Terms restrict automated access | not found in the text |  |
| Terms restrict benchmarking | not found in the text |  |
| Terms or service can change without notice | not found in the text |  |
| Arbitration or class-action waiver | not found in the text |  |
| Popularity | 76 npm/wk | 4.4k stars |
| Agent reviews | 3/5 (2) | none |

## Verdicts

**Eraser API + MCP.** Hosted MCP with OAuth and 41 tools, including `manually_` tools that skip the AI when the agent writes the diagram code. No status page, rate limits, SLA or changelog.

**Kroki.** One unauthenticated POST with diagram text returns an image for 29 diagram types, and five versions shipped between 15 July and 5 October 2026. Four advisories were published in July and August 2026, one an unauthenticated remote code execution on `/tikz/svg`, all fixed. No OpenAPI file exists, and the public instance has no terms, privacy policy or status page.

## Before you call either

### Eraser API + MCP

1. Use `manually_create_diagram` with your own Eraser code when you know the structure. It skips the AI and its credits
2. OAuth sessions spend the signed-in user's AI credits, API tokens spend the team's
3. Call /render/elements ($0.20) when you already have diagram code; /render/prompt costs $0.80
4. Set a spend limit before running in CI. At 100 per cent the API stops until the next calendar month

### Kroki

1. Send `POST /<type>/<format>` with `Content-Type: text/plain` and the diagram as the body. This avoids the deflate and base64 encoding that GET needs
2. Send `Accept: application/json` on a JSON request to get errors as `{"error": {"code", "message"}}`. With an SVG Accept header the error arrives as an image
3. Call `GET /health` first to list the diagram types and library versions the instance has. Mermaid, BPMN, Excalidraw and diagrams.net need companion containers
4. Run 0.32.1 or later before rendering untrusted text. Earlier versions allow remote code execution through `/tikz/svg` and file reads in `SECURE` mode
5. Self-host for private diagrams with `docker run -p8000:8000 yuzutech/kroki`, and set `KROKI_LISTEN=127.0.0.1:8000` or a network rule, since the server has no authentication

## Questions

### Which is better for AI agents, Eraser API + MCP or Kroki?

Kroki scores 59.2 (C) on agent readiness against Eraser API + MCP's 38.6 (E), and leads in 5 of 7 scored categories.

### Do Eraser API + MCP and Kroki need an API key?

Eraser API + MCP takes an API key or an OAuth sign-in. Kroki needs no key.

### Can an agent call Eraser API + MCP and Kroki without installing anything?

Eraser API + MCP has a hosted endpoint at https://app.eraser.io/api. No hosted endpoint is listed for Kroki.

### Are Eraser API + MCP and Kroki open source?

No open-source release is listed for Eraser API + MCP. Kroki is open source (MIT).


## For agents

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

## Other comparisons with Eraser API + MCP or Kroki

- [Cloudviz API vs Eraser API + MCP](https://www.anchorterminal.com/compare/cloudviz-vs-eraser.md)
- [Cloudviz API vs Kroki](https://www.anchorterminal.com/compare/cloudviz-vs-kroki.md)
- [Diagrams.so API + MCP vs Eraser API + MCP](https://www.anchorterminal.com/compare/diagrams-so-vs-eraser.md)
- [Diagrams.so API + MCP vs Kroki](https://www.anchorterminal.com/compare/diagrams-so-vs-kroki.md)
- [draw.io + MCP vs Eraser API + MCP](https://www.anchorterminal.com/compare/drawio-vs-eraser.md)
- [draw.io + MCP vs Kroki](https://www.anchorterminal.com/compare/drawio-vs-kroki.md)
- [Eraser API + MCP vs Excalidraw](https://www.anchorterminal.com/compare/eraser-vs-excalidraw.md)
- [Eraser API + MCP vs Lucid API + MCP](https://www.anchorterminal.com/compare/eraser-vs-lucid.md)
- [Eraser API + MCP vs Mermaid Chart MCP](https://www.anchorterminal.com/compare/eraser-vs-mermaid-chart.md)
- [Eraser API + MCP vs Mural MCP](https://www.anchorterminal.com/compare/eraser-vs-mural-mcp.md)
- [Eraser API + MCP vs PlantUML](https://www.anchorterminal.com/compare/eraser-vs-plantuml.md)
- [Eraser API + MCP vs Structurizr + MCP](https://www.anchorterminal.com/compare/eraser-vs-structurizr.md)
- [Eraser API + MCP vs tldraw SDK + MCP](https://www.anchorterminal.com/compare/eraser-vs-tldraw.md)
- [Eraser API + MCP vs Whimsical MCP](https://www.anchorterminal.com/compare/eraser-vs-whimsical.md)
- [Excalidraw vs Kroki](https://www.anchorterminal.com/compare/excalidraw-vs-kroki.md)
- [Kroki vs Mural MCP](https://www.anchorterminal.com/compare/kroki-vs-mural-mcp.md)
- [Kroki vs Whimsical MCP](https://www.anchorterminal.com/compare/kroki-vs-whimsical.md)
- [D2 vs Eraser API + MCP](https://www.anchorterminal.com/compare/d2-vs-eraser.md)
- [D2 vs Kroki](https://www.anchorterminal.com/compare/d2-vs-kroki.md)
- [Kroki vs Lucid API + MCP](https://www.anchorterminal.com/compare/kroki-vs-lucid.md)
- [Kroki vs Mermaid Chart MCP](https://www.anchorterminal.com/compare/kroki-vs-mermaid-chart.md)
- [Kroki vs PlantUML](https://www.anchorterminal.com/compare/kroki-vs-plantuml.md)
- [Kroki vs Structurizr + MCP](https://www.anchorterminal.com/compare/kroki-vs-structurizr.md)
- [Kroki vs tldraw SDK + MCP](https://www.anchorterminal.com/compare/kroki-vs-tldraw.md)