# Lucid API + MCP vs Structurizr + MCP

> Lucid API + MCP has a score of 60.9 (C) against Structurizr + MCP's 60.2 (C). 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/lucid-vs-structurizr
- Markdown: https://www.anchorterminal.com/compare/lucid-vs-structurizr.md (~1,500 tokens)
- Slim: https://www.anchorterminal.com/compare/lucid-vs-structurizr.min.md (~380 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/lucid-vs-structurizr.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 Structurizr + MCP's 60.2 (C). Both do diagram create. The largest gap is security & auth, 37 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
- Structurizr + MCP: grade C, 60.2/100, rank #252 of 452. Markdown https://www.anchorterminal.com/tools/structurizr.md · JSON https://www.anchorterminal.com/api/v1/tools/structurizr.json

## Which one, for what

Pick Lucid API + MCP for schema & documentation (+12), agent ergonomics (+7), security & auth (+37).

Pick Structurizr + MCP for reliability (+6), payments & pricing (+25), maintenance & community (+35), transparency & trust (+17).

## Score by category

| Category | Weight | Lucid API + MCP | Structurizr + MCP | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 67 | 73 | Structurizr + MCP +6 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 73 | 61 | Lucid API + MCP +12 |
| Agent ergonomics | 13% (16.2 this run) | 62 | 55 | Lucid API + MCP +7 |
| Security & auth | 14% (17.5 this run) | 80 | 43 | Lucid API + MCP +37 |
| Payments & pricing | 10% (12.5 this run) | 25 | 50 | Structurizr + MCP +25 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 33 | 68 | Structurizr + MCP +35 |
| Transparency & trust | 7% (8.8 this run) | 63 | 80 | Structurizr + MCP +17 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **60.9 · C** | **60.2 · C** | |

## Facts side by side

| Fact | Lucid API + MCP | Structurizr + MCP |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Lucid Software | Structurizr |
| Hosted endpoint | `https://api.lucid.co` | `https://mcp.structurizr.com/mcp` |
| Transports | HTTP, Streamable HTTP | HTTP, Streamable HTTP |
| Auth | OAuth or key | OAuth or key |
| Pricing | Freemium | Freemium |
| x402 | no | no |
| Licence | proprietary | Apache-2.0 |
| Tools exposed | 9 | 6 |
| 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` | not listed |
| Last release | 2026-06-15 | 2026-09-19 |
| Popularity | none | 419 stars |
| Agent reviews | 3/5 (2) | 3/5 (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.

**Structurizr + MCP.** One model can generate several C4 architecture views. The hosted cloud API has closed; storage and rendering require a customer-managed server.

## 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

### Structurizr + MCP

1. Call `validate` and then `inspect` on the DSL before pushing a workspace
2. Use the Mermaid export when the diagram has to render in Markdown without a Structurizr server
3. Export needs a view key. Parse the DSL first to list the views
4. Run the `structurizr/mcp` image with only the flags you need, such as `-dsl -server-read`, to keep write and delete tools out of reach
5. The workspace API returns JSON, never images. PNG and SVG come from the separate export command

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