AI Diagram Maker MCP vs Structurizr + MCP

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.

Structurizr + MCP 88

Application release 2026.10.26 and library v6.2.4 on 26 October 2026, 9 days before this check (30). Four releases since 6 August (library v6.2.3 on 17 September, application 2026.09.19, application 2026.10.26 and library v6.2.4), each fixing a named issue (20). Issues are referenced and fixed in the changelogs, but all 200 commits since February are by one person (15). Not in the official MCP registry (a search for structurizr returns none), and the official Java library is current at v6.2.4 (15). CI on every push and Docker base images bumped on 26 October (8). 30+20+15+15+8 = 88.

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.

Structurizr + MCP 76

Apache 2.0, and the prebuilt binaries add a EULA (28). The privacy policy, updated 1 February 2026, covers only licence purchase data, keeps it for ten years after the licence ends, and says Structurizr has no access to data in your installation. The hosted MCP isn't covered (20). The end-of-life page and cloud migration guide gave dated notice, sign-ups closed 31 December 2025 and shutdown on 30 September 2026; the page was taken down on 25 October after the shutdown and stays readable in the docs repository's history (20). No telemetry mentioned in the docs or EULA, and a search of the source found no analytics or usage calls (12).

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.

Structurizr + MCP 70

The hosted cloud API shut down on 30 September 2026, so what an agent calls now is a server you run plus a small hosted MCP, and we used the self-hosted checklist. Prebuilt binaries and Docker images with Java 21 stated (20). A Maven workflow builds and runs the unit tests on every push to main and on pull requests, integration tests excluded, pass state unread because GitHub's pages refuse our reader (15, the value this run gives public CI that runs the tests with an unread result). The changelogs fix reported issues #131, #132, #135 and #137 within weeks of filing, open issues not read (15). Date-stamped application releases and a semver library (v6.2.4), each with a changelog (12). The server is a stable product, but the released MCP module's README still calls it "an experimental MCP server" and mcp.structurizr.com has no status page or published limits (8). 20+15+15+12+8 = 70.

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.

Structurizr + MCP 50

Apache 2.0 code with a paid option, the licence for prebuilt binaries. No payment protocol (0). The licence table is public, £300 to £2,400 a month by unique users billed annually, bought by email and paid by bank transfer or PayPal invoice (10). Building from source is free, and a 14-day trial licence comes from trial.structurizr.com with no payment (20). The hosted MCP needs no key and the local tools need no signup (20).

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.

Structurizr + MCP 61

OpenAPI 3.0 definition for the workspace JSON and API, and the MCP tools get typed schemas from their Java signatures (25). No llms.txt found (0). Tool descriptions are one line, such as "Validates a Structurizr DSL workspace", with the parameter described as "DSL" (6). Required flags and a numeric workspace ID, no enums (8). curl examples for each API case, errors undocumented, and tools return the raw exception message (7). Dated changelogs for the application and the library (15).

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.

Structurizr + MCP 55

Six compact tools on the hosted MCP, and the self-hosted image enables tool groups by flag (-dsl, -server-read, -server-update and so on) (25). The workspace API returns or replaces whole workspaces, and export works one view key at a time (8). Errors come back as exception text, and API errors aren't documented (8). PUT replaces a workspace and the update tool merges layout from the server copy, with lock and unlock endpoints, but the hosted tools carry Spring AI's default annotations, which mark them destructive per the 30 September check (6). Official Java client library, no second language (8).