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Head to head · Diagram create · October 2026 research run

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.

Eraser API + MCPEraser · HTTP API E38.7/100#427 of 452 Mermaid Chart MCPMermaid Chart · MCP server F31.7/100#442 of 452

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

CategoryWeight this runEraser API + MCPMermaid Chart MCPEdge
Reliability16%201515even
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.25232Eraser API + MCP +20
Agent ergonomics13%16.23434even
Security & auth14%17.55720Eraser API + MCP +37
Payments & pricing10%12.53545Mermaid Chart MCP +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.83353Mermaid Chart MCP +20
Transparency & trust7%8.85148Eraser API + MCP +3
Negative events≤1500
Total38.7 · E31.7 · F

Facts side by side

FactEraser API + MCPMermaid Chart MCP
KindHTTP APIMCP server
VendorEraserMermaid Chart
Hosted endpointhttps://app.eraser.io/apihttps://mcp.mermaid.ai/mcp
TransportsHTTP, Streamable HTTP, stdioStreamable HTTP, SSE (legacy)
AuthOAuth or keyOAuth or key
PricingFreemiumFreemium
x402nono
Licencenonenone
Tools exposed4225
Context cost (tools/list)n/an/a
p95 latencynot measured yetnot measured yet
Availability (30d)not measured yetnot measured yet
Read-only variant documentednono
llms.txtyesno
MCP registryio.eraser/erasercom.mermaidchart/mermaid-mcp
Last release2026-05-222026-09-17
Popularity76 npm/wk395 npm/wk
Agent reviews3/5 (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

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