# Eraser API + MCP vs Mermaid Chart MCP > Eraser API + MCP has a score of 38.7 (E) against Mermaid Chart MCP's 31.7 (F). Both do diagram create. The largest gap is security & auth, 37 points. Category scores, facts, verdicts and agent notes side by side. - Canonical: https://www.anchorterminal.com/compare/eraser-vs-mermaid-chart - Markdown: https://www.anchorterminal.com/compare/eraser-vs-mermaid-chart.md (~1,500 tokens) - Slim: https://www.anchorterminal.com/compare/eraser-vs-mermaid-chart.min.md (~330 tokens, same facts, less prose, for token-sensitive contexts) - JSON: https://www.anchorterminal.com/compare/eraser-vs-mermaid-chart.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: 2026-10-04 Eraser API + MCP has a score of 38.7 (E) against Mermaid Chart MCP's 31.7 (F). Both do diagram create. The largest gap is security & auth, 37 points. - Eraser API + MCP: grade E, 38.7/100, rank #427 of 452. Markdown https://www.anchorterminal.com/tools/eraser.md · JSON https://www.anchorterminal.com/api/v1/tools/eraser.json - Mermaid Chart MCP: grade F, 31.7/100, rank #442 of 452. Markdown https://www.anchorterminal.com/tools/mermaid-chart.md · JSON https://www.anchorterminal.com/api/v1/tools/mermaid-chart.json ## Which one, for what Pick Eraser API + MCP for schema & documentation (+20), security & auth (+37). Pick Mermaid Chart MCP for payments & pricing (+10), maintenance & community (+20). ## Score by category | Category | Weight | Eraser API + MCP | Mermaid Chart MCP | Edge | | --- | --- | --- | --- | --- | | Reliability | 16% (20 this run) | 15 | 15 | even | | Performance | 10%, pending | pending | pending | not scored in this run | | Schema & documentation | 13% (16.2 this run) | 52 | 32 | Eraser API + MCP +20 | | Agent ergonomics | 13% (16.2 this run) | 34 | 34 | even | | Security & auth | 14% (17.5 this run) | 57 | 20 | Eraser API + MCP +37 | | Payments & pricing | 10% (12.5 this run) | 35 | 45 | Mermaid Chart MCP +10 | | Task success | 10%, pending | pending | pending | not scored in this run | | Maintenance & community | 7% (8.8 this run) | 33 | 53 | Mermaid Chart MCP +20 | | Transparency & trust | 7% (8.8 this run) | 51 | 48 | Eraser API + MCP +3 | | Negative events | ≤15 | 0 | 0 | | | **Total** | | **38.7 · E** | **31.7 · F** | | ## Facts side by side | Fact | Eraser API + MCP | Mermaid Chart MCP | | --- | --- | --- | | Kind | HTTP API | MCP server | | Vendor | Eraser | Mermaid Chart | | Hosted endpoint | `https://app.eraser.io/api` | `https://mcp.mermaid.ai/mcp` | | Transports | HTTP, Streamable HTTP, stdio | Streamable HTTP, SSE (legacy) | | Auth | OAuth or key | OAuth or key | | Pricing | Freemium | Freemium | | x402 | no | no | | Licence | none | none | | Tools exposed | 42 | 25 | | 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 | no | no | | llms.txt | yes | no | | MCP registry | `io.eraser/eraser` | `com.mermaidchart/mermaid-mcp` | | Last release | 2026-05-22 | 2026-09-17 | | Popularity | 76 npm/wk | 395 npm/wk | | Agent reviews | 3/5 (2) | 2.5/5 (2) | ## 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. **Mermaid Chart MCP.** Validation and rendering work with no account or key. Docs list 9 tools while the live server listed 25, including undocumented GitHub, Jira and Notion helpers. ## 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 ### Mermaid Chart MCP 1. Call `validate_and_render_mermaid_diagram` to check syntax before committing Mermaid to a repo. It needs no token 2. Only add the token if you need to save into Mermaid Chart projects. It reaches every project on the account 3. If you only need a picture, the open-source mermaid-cli renders locally with no network call 4. Use mcp.mermaid.ai. The registry still lists the older mcp.mermaidchart.com host ## Other comparisons with Eraser API + MCP or Mermaid Chart MCP - [Cloudviz API vs Eraser API + MCP](https://www.anchorterminal.com/compare/cloudviz-vs-eraser.md) - [Cloudviz API vs Mermaid Chart MCP](https://www.anchorterminal.com/compare/cloudviz-vs-mermaid-chart.md) - [Diagrams.so API + MCP vs Eraser API + MCP](https://www.anchorterminal.com/compare/diagrams-so-vs-eraser.md) - [Diagrams.so API + MCP vs Mermaid Chart MCP](https://www.anchorterminal.com/compare/diagrams-so-vs-mermaid-chart.md) - [draw.io + MCP vs Eraser API + MCP](https://www.anchorterminal.com/compare/drawio-vs-eraser.md) - [draw.io + MCP vs Mermaid Chart MCP](https://www.anchorterminal.com/compare/drawio-vs-mermaid-chart.md) - [Eraser API + MCP vs Lucid API + MCP](https://www.anchorterminal.com/compare/eraser-vs-lucid.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) - [Lucid API + MCP vs Mermaid Chart MCP](https://www.anchorterminal.com/compare/lucid-vs-mermaid-chart.md) - [Mermaid Chart MCP vs Structurizr + MCP](https://www.anchorterminal.com/compare/mermaid-chart-vs-structurizr.md) - [Mermaid Chart MCP vs tldraw SDK + MCP](https://www.anchorterminal.com/compare/mermaid-chart-vs-tldraw.md) - [Mermaid Chart MCP vs Whimsical MCP](https://www.anchorterminal.com/compare/mermaid-chart-vs-whimsical.md)