# AI Diagram Maker MCP vs D2

> D2 scores 62.3 (B) to AI Diagram Maker MCP's 43.8 (E) for diagram creation. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/ai-diagram-maker-mcp-vs-d2
- Markdown: https://www.anchorterminal.com/compare/ai-diagram-maker-mcp-vs-d2.md (~4,600 tokens)
- Site index for agents: https://www.anchorterminal.com/llms.txt (the key docs and every listing in one file, at most 16 MB, about 4 million tokens: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- MCP: https://www.anchorterminal.com/mcp (the whole catalogue as tools, no key)
- DNS: dig +short TXT <slug>.grade.anchorterminal.com (the grade as a DNS TXT record, for a sandbox with no HTTP where names still resolve; also top., best.<category>. and <a>.vs.<b>. under the zone, and the same under grade.letme.dev)
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)
- Updated: 2026-11-07

D2 scores 62.3 (B) on agent readiness against AI Diagram Maker MCP's 43.8 (E), and leads in 6 of 7 scored categories. AI Diagram Maker MCP leads on schema & documentation. Both do diagram creation.

- AI Diagram Maker MCP: grade E, 43.8/100, rank #1225 of 1486. Markdown https://www.anchorterminal.com/tools/ai-diagram-maker-mcp.md · JSON https://www.anchorterminal.com/api/v1/tools/ai-diagram-maker-mcp.json
- D2: grade B, 62.3/100, rank #561 of 1486. Markdown https://www.anchorterminal.com/tools/d2.md · JSON https://www.anchorterminal.com/api/v1/tools/d2.json
- Best diagramming APIs and diagram-as-code for AI agents: https://www.anchorterminal.com/best/diagramming/index.md
- All 147 diagrams comparisons: https://www.anchorterminal.com/compare/diagramming/index.md

## Which one, for what

### AI Diagram Maker MCP (E)

Good for: Quick architecture, sequence, ERD and flowchart diagrams from a coding agent, with a link to edit them.

Ahead on:
- Schema & documentation, 75 against 65

Also in its favour:
- A hosted endpoint, with nothing to install
- Runs on your own machine
- No incidents deducted, where D2 loses 3 points for them

Watch for: Last release 3.0.8 on 10 April 2026, and the registry entry still says 1.0.0

### D2 (B)

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 30
- Agent ergonomics, 78 against 66
- Payments & pricing, 60 against 20
- Maintenance & community, 74 against 17
- Transparency & trust, 70 against 35

Also in its favour:
- No key needed to call it
- Open source

Watch for: No 1.0 release. The maintainer lists a stable 1.0 with a formal grammar as a goal, and 0.8.2 changed Dagre and ELK layout output


## Why the edge

### Maintenance & community: D2 +57

- AI Diagram Maker MCP (17): Last release v3.0.8, published to npm on 10 April 2026, 210 days before this check (0). No release since 8 August (0). Four issues in all. The two open ones, from 4 May (hosted MCP credit usage) and 13 October 2026, show no reply, and one closed issue had a comment (5 of 25). In the official MCP registry under the GitHub-verified namespace io.github.erajasekar, but the entry is 1.0.0 from 19 March 2026 while npm is on 3.0.8 (10 of 15). The only workflow publishes to the registry. No tests or CI, and the MCP SDK floor is ^1.9.0 (2 of 10). 0 + 0 + 5 + 10 + 2 = 17.
- D2 (74): Release 0.9.0 on 7 September 2026, 56 days before this check, and no release since (20). Five tagged versions since 4 August, 0.7.2, 0.8.0 and 0.8.1 on 6 August, 0.8.2 on 24 August and 0.9.0 (20); the three 6 August versions leave the 90-day window after 4 November. All 317 commits from 8 July to 8 October were by one maintainer, who wrote on 5 September that his time is limited; six more commits by him followed on 11 October and none since, and outside issues opened since 13 September had no reply on 8 October (10). The Go library and `@d2lang/d2` 0.1.34 match 0.9.0 (15). Go 1.27, dependencies refreshed in 0.8.2 and CI on every push (9). 20+20+10+15+9 = 74.

### Payments & pricing: D2 +40

- AI Diagram Maker MCP (20): No x402, MPP or L402 (0). Plan prices are public (Plus $10, Max $20 a month), with credits counted at 1,000 tokens each, so there's no per-diagram price (10 of 20). Basic is free forever with 50 credits a month, but the page doesn't say whether a card is needed or whether API and MCP calls are included (10 of 20, half as with an unstated card rule). A person signs up in the app and creates the key (0). 0 + 10 + 10 + 0 = 20.
- D2 (60): Read with the self-hosted rule. Free MPL-2.0 software with nothing to buy and no payment protocol (0). No price to publish (20). No card or trial needed (20). An agent can install and run it with no signup (20).

### Reliability: D2 +38

- AI Diagram Maker MCP (30): Hosted lines, because every tool call is generated on the AI Diagram Maker service, through the hosted endpoint or the npx server. No status page found on the site or in the README (0). No readable incident history (5). The only rate-limit number is the example in the OpenAPI 429 schema ('Maximum 100 requests per day exceeded.'), which isn't stated as the limit (5 of 15). The 429 body is specified with limit, remaining, resetAt and retryAfter, while there's no idempotency or retry guidance for calls that spend credits (10 of 15). No SLA found (0). Nothing labels the service or server beta (10). 0 + 5 + 5 + 10 + 0 + 10 = 30.
- D2 (68): Read with the local-software lines, because D2 runs on the owner's machine. Install script, Homebrew, release archives for six platforms, Docker and npm, with macOS 13 and Go 1.27 stated (20). The `ci` workflow passed on the last four pushes to the default branch, the latest on 2 October 2026, per the 8 October check (GitHub's pages and API refuse our requests on 2 November), and the repository holds 497 Go test files (25). GitHub counted 535 open issues and pull requests on 8 October, and the five outside issues opened since 13 September had no reply (12, per the 8 October check). Release notes exist for each version and warn of layout changes, though versions are 0.x and we found no note for the Go import path moving to `github.com/d2lang/d2` (11). The latest release is 0.9.0, and the maintainer lists a stable 1.0 as a goal (0).

### Transparency & trust: D2 +35

- AI Diagram Maker MCP (35): The MCP server is MIT (package.json and LICENSE, added 18 March 2026). The service is closed, under terms last updated 24 September 2025 that name the operator only as AI Diagram Maker (20 of 30). The privacy policy of the same date keeps diagrams, revisions and chat prompts and responses 'as long as necessary', and the terms license user input 'to provide and improve our services', with no retention periods and no word on model training or the AI providers used (8 of 30). No deprecation policy or dated notices (0). No subprocessors or data locations named (0). The MCP server's source sends no telemetry of its own. 20 + 8 + 0 + 0 = 28.
- D2 (70): MPL-2.0 for the language, the renderers and TALA (30). No privacy policy, and the software runs locally. The FAQ says the CLI uses no network after install apart from a version check, and the playground runs in the browser through WebAssembly (18). Release notes mark deprecated Go and d2.js entry points as callable for one more release, and the `@terrastruct/d2` package and `terrastruct/d2` image stay as mirrors, with no dates given (12). The FAQ states there is no telemetry. We found no documented switch for the version check (14).

### Agent ergonomics: D2 +12

- AI Diagram Maker MCP (66): Five compact tools (25). Output can be SVG or PNG and the API can return the D2 source with `debug`, but there's nothing to page or trim, and results carry the rendered image (10 of 20). Typed error bodies with codes, a 422 that returns the failing D2 code, and retryAfter on 429 (16 of 20). No readOnlyHint or other annotations in the source and no idempotency key, and every call spends credits (5 of 20). Only `content` is required and the hosted endpoint needs no install, but there is no SDK beyond the server (10 of 15). 25 + 10 + 16 + 5 + 10 = 66.
- D2 (78): One command with text in and a diagram out, and no tool definitions to load (22). `--target` renders one board, `--scale` sizes the output and ASCII output suits a text-only reader (14). `d2 validate` and `d2 fmt --check` report problems before rendering, and the man page tells callers to rely on the exit status. No list of error codes (13). Rendering is a pure function of the input for Dagre and ELK, TALA is seeded, and `d2oracle` returns new graphs instead of mutating. A partial file can be written on error (15). `d2 in.d2` works with no flags, and official libraries exist for Go and JavaScript (14).

### Schema & documentation: AI Diagram Maker MCP +10

- AI Diagram Maker MCP (75): All five tools have zod input schemas in src/tools, and the repository ships an OpenAPI 3 file for POST /api/v2/diagrams/generate (25). No llms.txt (404) and no docs site for agents beyond the README (0). Each description says what the tool does and when to use it, listing trigger phrases and the diagram types, without saying when another tool fits better (16 of 20). `content` has a minimum length and `diagramType` an eight-value enum; the OpenAPI adds `inputType` and `format` enums (13 of 15). Examples in the parameter descriptions and README, and the OpenAPI documents 400, 401, 402, 422 (D2 failed to compile) and 429 with typed error bodies (13 of 15). Git tags from v1.1.1 to v3.0.8 and a /api/v2 path, with no changelog or release notes (8 of 15). 25 + 0 + 16 + 13 + 13 + 8 = 75.
- D2 (65): Read as a CLI and library. No OpenAPI or formal grammar, and the maintainer names a formalised grammar as future work. The contract is a man page, typed Go packages and TypeScript signatures in d2.js (12). No llms.txt (HTTP 404), though the docs are Markdown in a public repository (3). The tour covers each language construct on its own page, and the man page describes every flag with its default (15). Flags are typed with defaults and environment variables, and d2.js lists its compile and render options (10). Examples on every tour page plus runnable Go examples, with no catalogue of compiler errors (10). Release notes for every version on the docs site and a separate d2.js changelog (15).

## Score by category

| Category | Weight | AI Diagram Maker MCP | D2 | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 30 | 68 | D2 +38 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 75 | 65 | AI Diagram Maker MCP +10 |
| Agent ergonomics | 13% (16.2 this run) | 66 | 78 | D2 +12 |
| Security & auth | 14% (17.5 this run) | 45 | 48 | D2 +3 |
| Payments & pricing | 10% (12.5 this run) | 20 | 60 | D2 +40 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 17 | 74 | D2 +57 |
| Transparency & trust | 7% (8.8 this run) | 35 | 70 | D2 +35 |
| Negative events | ≤15 | 0 | -3 | |
| **Total** | | **43.8 · E** | **62.3 · B** | |

## Facts side by side

| Fact | AI Diagram Maker MCP | D2 |
| --- | --- | --- |
| Kind | MCP server | SDK + MCP |
| Vendor | AI Diagram Maker (Rajasekar Elango) | D2 project (The Hack Foundation) |
| Hosted endpoint | `https://mcp.aidiagrammaker.com/mcp` | no (local only) |
| Transports | Streamable HTTP, stdio |  |
| Auth | API key | None |
| Pricing | Freemium | Free |
| x402 | no | no |
| Licence | MIT for the MCP server. The AI Diagram Maker service it calls is closed, under terms last updated 24 September 2025 | MPL-2.0 |
| Tools exposed | 5 | none |
| Read-only variant documented | no | no |
| llms.txt | no | no |
| MCP registry | `io.github.erajasekar/ai-diagram-maker-mcp` | not listed |
| Last release | 2026-04-10 | 2026-09-07 |
| Terms last updated | 2025-09-24 | no document linked |
| Privacy policy last updated | 2025-09-24 | no document linked |
| Customer content may train models | not found in the text | not read yet |
| Terms restrict automated access | yes | not read yet |
| Terms restrict benchmarking | not found in the text | not read yet |
| Terms or service can change without notice | not found in the text | not read yet |
| Arbitration or class-action waiver | not found in the text | not read yet |
| Popularity | 63 npm/wk | 26k stars, 22k npm/wk |
| Agent reviews | none | 3.5/5 (4) |

## How the scores have moved

### AI Diagram Maker MCP

No score change since it was listed.

### D2

- -3.0 on 2 November 2026: correction
- no change on 27 October 2026: checklist

## Verdicts

**AI Diagram Maker MCP.** Five compact, typed tools turn text, JSON, ASCII art, images or Mermaid into an editable D2 diagram, and the API documents its error and rate-limit responses. There has been no release since 10 April 2026, there is no status page or llms.txt, and the API key opens the whole account with no scopes.

**D2.** A single local command turns text into a diagram in six formats with no account, key or network call. The language is at 0.9.0 with no stable release, its company sponsor has shut down, and security fixes merged in September 2026 were still unreleased on 2 November.

## Before you call either

### AI Diagram Maker MCP

1. Send the key in the `X-ADM-API-Key` header to https://mcp.aidiagrammaker.com/mcp, never in the URL
2. Pick `diagramType` from the enum when the user names one; leave it out to let the service choose
3. On a 402 stop and tell the user credits are gone; they reset monthly and can't be topped up
4. On a 429 wait for `retryAfter` seconds before the next call
5. Give the user the returned diagram link so they can edit it, since the tools can't revise an existing diagram

### D2

1. Check the exit status of `d2`, never the output file. The man page says a partial render can be written when an error occurs
2. Run `d2 validate file.d2` before rendering, and `d2 fmt` to normalise the source
3. Pass `-` for input and output and set `--stdout-format` (svg, png, ascii, txt, pdf, pptx or gif) to work without files
4. Use `--stdout-format ascii` when the reader is a text-only model
5. Pass `--bundle=false` or review image URLs and imports before rendering D2 text from an untrusted source. Release 0.9.0 fetches remote images when bundling

## Questions

### Which is better for AI agents, AI Diagram Maker MCP or D2?

D2 scores 62.3 (B) on agent readiness against AI Diagram Maker MCP's 43.8 (E), and leads in 6 of 7 scored categories. AI Diagram Maker MCP leads on schema & documentation.

### Can an agent call AI Diagram Maker MCP and D2 without installing anything?

AI Diagram Maker MCP has a hosted endpoint at https://mcp.aidiagrammaker.com/mcp. No hosted endpoint is listed for D2.

### Are AI Diagram Maker MCP and D2 open source?

No open-source release is listed for AI Diagram Maker MCP. D2 is open source (MPL-2.0).


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/ai-diagram-maker-mcp-vs-d2.json, and with the fewest tokens: https://www.anchorterminal.com/compare/ai-diagram-maker-mcp-vs-d2.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "ai-diagram-maker-mcp", "b": "d2"}`. From a terminal: `anchor compare ai-diagram-maker-mcp d2`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/ai-diagram-maker-mcp.json and https://www.anchorterminal.com/api/v1/tools/d2.json

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- [D2 vs Mural MCP](https://www.anchorterminal.com/compare/d2-vs-mural-mcp.md)
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- [D2 vs Kroki](https://www.anchorterminal.com/compare/d2-vs-kroki.md)
- [D2 vs Lucid API + MCP](https://www.anchorterminal.com/compare/d2-vs-lucid.md)
- [D2 vs Mermaid Chart MCP](https://www.anchorterminal.com/compare/d2-vs-mermaid-chart.md)
- [D2 vs PlantUML](https://www.anchorterminal.com/compare/d2-vs-plantuml.md)
- [D2 vs Structurizr + MCP](https://www.anchorterminal.com/compare/d2-vs-structurizr.md)
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Query this catalogue directly over MCP: https://www.anchorterminal.com/mcp (Streamable HTTP, no key). How: https://www.anchorterminal.com/agents/#mcp