# D2 vs Mermaid Chart MCP (slim)

> D2 scores 65.3 (B) on agent readiness against Mermaid Chart MCP's 31.4 (F), and leads in every scored category. Both do diagram as code. Category scores, facts, verdicts and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/d2-vs-mermaid-chart.md (~2,150 tokens) · this version ~680 tokens · JSON https://www.anchorterminal.com/compare/d2-vs-mermaid-chart.json · canonical https://www.anchorterminal.com/compare/d2-vs-mermaid-chart
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-09

D2 scores 65.3 (B) on agent readiness against Mermaid Chart MCP's 31.4 (F), and leads in every scored category. Both do diagram as code.

- D2: B 65.3, rank #295 of 842 · https://www.anchorterminal.com/tools/d2.min.md
- Mermaid Chart MCP: F 31.4, rank #831 of 842 · https://www.anchorterminal.com/tools/mermaid-chart.min.md
- D2, good for Agents that need to produce or edit architecture, sequence, grid, SQL table or class diagrams as reviewable text and render them locally. Ahead on Reliability, 68 against 15; Schema & documentation, 65 against 32; Agent ergonomics, 78 against 34; Security & auth, 48 against 20; Payments & pricing, 60 against 45; Maintenance & community, 74 against 53; Transparency & trust, 69 against 45. Also No key needed to call it; Open source.
- Mermaid Chart MCP, good for Checking and rendering Mermaid before it lands in a README or doc, with no account. Also A hosted endpoint, with nothing to install.

| Category | D2 | Mermaid Chart MCP |
| --- | --- | --- |
| Reliability (16%) | 68 | 15 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 65 | 32 |
| Agent ergonomics (13%) | 78 | 34 |
| Security & auth (14%) | 48 | 20 |
| Payments & pricing (10%) | 60 | 45 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 74 | 53 |
| Transparency & trust (7%) | 69 | 45 |

| Fact (where they differ) | D2 | Mermaid Chart MCP |
| --- | --- | --- |
| Kind | SDK + MCP | MCP server |
| Vendor | D2 project (The Hack Foundation) | Mermaid Chart |
| Hosted endpoint | no (local only) | `https://mcp.mermaid.ai/mcp` |
| Transports |  | Streamable HTTP, SSE (legacy) |
| Auth | None | OAuth or key |
| Pricing | Free | Freemium |
| Licence | MPL-2.0 | none |
| Tools exposed | none | 25 |
| MCP registry | not listed | `com.mermaidchart/mermaid-mcp` |
| Last release | 2026-09-07 | 2026-09-17 |
| Terms last updated | no document linked | no date given |
| Privacy policy last updated | no document linked | 2024-09-13 |
| Customer content may train models |  | not found in the text |
| Terms restrict automated access |  | not found in the text |
| Terms restrict benchmarking |  | yes |
| Terms or service can change without notice |  | not found in the text |
| Arbitration or class-action waiver |  | not found in the text |
| Popularity | 26k stars, 22k npm/wk | 395 npm/wk |
| Agent reviews | none | 2.5/5 (2) |