# Lucid API + MCP vs Mermaid Chart MCP

> Lucid API + MCP has a score of 60.9 (C) against Mermaid Chart MCP's 31.7 (F). Both do diagram create. The largest gap is security & auth, 60 points. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/lucid-vs-mermaid-chart
- Markdown: https://www.anchorterminal.com/compare/lucid-vs-mermaid-chart.md (~1,500 tokens)
- Slim: https://www.anchorterminal.com/compare/lucid-vs-mermaid-chart.min.md (~380 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/lucid-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: 2026-10-05

Lucid API + MCP has a score of 60.9 (C) against Mermaid Chart MCP's 31.7 (F). Both do diagram create. The largest gap is security & auth, 60 points.

- Lucid API + MCP: grade C, 60.9/100, rank #238 of 452. Markdown https://www.anchorterminal.com/tools/lucid.md · JSON https://www.anchorterminal.com/api/v1/tools/lucid.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 Lucid API + MCP for reliability (+52), schema & documentation (+41), agent ergonomics (+28), security & auth (+60), transparency & trust (+15).

Pick Mermaid Chart MCP for payments & pricing (+20), maintenance & community (+20).

## Score by category

| Category | Weight | Lucid API + MCP | Mermaid Chart MCP | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 67 | 15 | Lucid API + MCP +52 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 73 | 32 | Lucid API + MCP +41 |
| Agent ergonomics | 13% (16.2 this run) | 62 | 34 | Lucid API + MCP +28 |
| Security & auth | 14% (17.5 this run) | 80 | 20 | Lucid API + MCP +60 |
| Payments & pricing | 10% (12.5 this run) | 25 | 45 | Mermaid Chart MCP +20 |
| 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) | 63 | 48 | Lucid API + MCP +15 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **60.9 · C** | **31.7 · F** | |

## Facts side by side

| Fact | Lucid API + MCP | Mermaid Chart MCP |
| --- | --- | --- |
| Kind | HTTP API | MCP server |
| Vendor | Lucid Software | Mermaid Chart |
| Hosted endpoint | `https://api.lucid.co` | `https://mcp.mermaid.ai/mcp` |
| Transports | HTTP, Streamable HTTP | Streamable HTTP, SSE (legacy) |
| Auth | OAuth or key | OAuth or key |
| Pricing | Freemium | Freemium |
| x402 | no | no |
| Licence | proprietary | none |
| Tools exposed | 9 | 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 | `app.lucid.mcp/lucid` | `com.mermaidchart/mermaid-mcp` |
| Last release | 2026-06-15 | 2026-09-17 |
| Popularity | none | 395 npm/wk |
| Agent reviews | 3/5 (2) | 2.5/5 (2) |

## Verdicts

**Lucid API + MCP.** OAuth 2.0 scopes with `:readonly` variants, and audit log endpoints in the REST API. No public changelog for the API or the MCP server.

**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

### Lucid API + MCP

1. Always send `Lucid-Api-Version: 1`, or prefix the path with /v1
2. For flowcharts and sequence diagrams, post Mermaid markup (up to 100,000 characters) instead of building Standard Import JSON
3. Request `:readonly` scopes when the agent only reads documents
4. On 429, wait 60 seconds or back off. Create Mermaid Diagram allows 60 calls a minute
5. Sharing and embed endpoints need an OAuth token. An API key won't work there

### 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

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