# Diagrams.so API + MCP vs Lucid API + MCP

> Lucid API + MCP has a score of 60.9 (C) against Diagrams.so API + MCP's 60.1 (C). Both do diagram create. The largest gap is maintenance & community, 38 points. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/diagrams-so-vs-lucid
- Markdown: https://www.anchorterminal.com/compare/diagrams-so-vs-lucid.md (~1,550 tokens)
- Slim: https://www.anchorterminal.com/compare/diagrams-so-vs-lucid.min.md (~380 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/diagrams-so-vs-lucid.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

Lucid API + MCP has a score of 60.9 (C) against Diagrams.so API + MCP's 60.1 (C). Both do diagram create. The largest gap is maintenance & community, 38 points.

- Diagrams.so API + MCP: grade C, 60.1/100, rank #255 of 452. Markdown https://www.anchorterminal.com/tools/diagrams-so.md · JSON https://www.anchorterminal.com/api/v1/tools/diagrams-so.json
- 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

## Which one, for what

Pick Diagrams.so API + MCP for schema & documentation (+12), agent ergonomics (+23), payments & pricing (+7), maintenance & community (+38), transparency & trust (+12).

Pick Lucid API + MCP for reliability (+37), security & auth (+13).

## Score by category

| Category | Weight | Diagrams.so API + MCP | Lucid API + MCP | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 30 | 67 | Lucid API + MCP +37 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 85 | 73 | Diagrams.so API + MCP +12 |
| Agent ergonomics | 13% (16.2 this run) | 85 | 62 | Diagrams.so API + MCP +23 |
| Security & auth | 14% (17.5 this run) | 67 | 80 | Lucid API + MCP +13 |
| Payments & pricing | 10% (12.5 this run) | 32 | 25 | Diagrams.so API + MCP +7 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 71 | 33 | Diagrams.so API + MCP +38 |
| Transparency & trust | 7% (8.8 this run) | 75 | 63 | Diagrams.so API + MCP +12 |
| Negative events | ≤15 | -2 | 0 | |
| **Total** | | **60.1 · C** | **60.9 · C** | |

## Facts side by side

| Fact | Diagrams.so API + MCP | Lucid API + MCP |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Diagrams.so (RedHold LLC) | Lucid Software |
| Hosted endpoint | `https://api.diagrams.so/api/v2` | `https://api.lucid.co` |
| Transports | HTTP, stdio | HTTP, Streamable HTTP |
| Auth | OAuth or key | OAuth or key |
| Pricing | Freemium | Freemium |
| x402 | no | no |
| Licence | Apache-2.0 | proprietary |
| Tools exposed | 23 | 9 |
| 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 | yes |
| MCP registry | `io.github.RedHold/diagrams-so-mcp` | `app.lucid.mcp/lucid` |
| Last release | 2026-08-19 | 2026-06-15 |
| Popularity | 0 stars, 172 npm/wk, 3 PyPI/wk | none |
| Agent reviews | 4/5 (2) | 3/5 (2) |

## Verdicts

**Diagrams.so API + MCP.** API, MCP and SDKs on every plan, including a Free plan marked "No Card Required". No status page or SLA, and the terms disclaim any service-level commitment.

**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.

## Before you call either

### Diagrams.so API + MCP

1. Send an Idempotency-Key on generate, edit, fix and re-layout. If a billable call times out, check `get_usage_history` before retrying
2. Generation is synchronous and can run for minutes. The SDKs default to a 450 s timeout, or use `POST /diagrams/stream`
3. Call `list_capabilities` first. `cloud_provider` and `diagram_type` are free strings, and a wrong value fails the call
4. `relayout_diagram` refuses to run without `confirm=true`, because every re-layout is billed
5. Test keys (dgz_test_) spend the same credits as live keys

### 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

## Other comparisons with Diagrams.so API + MCP or Lucid API + MCP

- [Cloudviz API vs Diagrams.so API + MCP](https://www.anchorterminal.com/compare/cloudviz-vs-diagrams-so.md)
- [Cloudviz API vs Lucid API + MCP](https://www.anchorterminal.com/compare/cloudviz-vs-lucid.md)
- [Diagrams.so API + MCP vs draw.io + MCP](https://www.anchorterminal.com/compare/diagrams-so-vs-drawio.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)
- [Diagrams.so API + MCP vs Structurizr + MCP](https://www.anchorterminal.com/compare/diagrams-so-vs-structurizr.md)
- [Diagrams.so API + MCP vs tldraw SDK + MCP](https://www.anchorterminal.com/compare/diagrams-so-vs-tldraw.md)
- [Diagrams.so API + MCP vs Whimsical MCP](https://www.anchorterminal.com/compare/diagrams-so-vs-whimsical.md)
- [draw.io + MCP vs Lucid API + MCP](https://www.anchorterminal.com/compare/drawio-vs-lucid.md)
- [Eraser API + MCP vs Lucid API + MCP](https://www.anchorterminal.com/compare/eraser-vs-lucid.md)
- [Lucid API + MCP vs Mermaid Chart MCP](https://www.anchorterminal.com/compare/lucid-vs-mermaid-chart.md)
- [Lucid API + MCP vs Structurizr + MCP](https://www.anchorterminal.com/compare/lucid-vs-structurizr.md)
- [Lucid API + MCP vs tldraw SDK + MCP](https://www.anchorterminal.com/compare/lucid-vs-tldraw.md)
- [Lucid API + MCP vs Whimsical MCP](https://www.anchorterminal.com/compare/lucid-vs-whimsical.md)