AI Diagram Maker MCP vs PlantUML

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.

PlantUML 91

Release 1.2026.9 on 17 October 2026, 15 days before the check, and Homebrew carries it (30). Three stable versions since 3 August, 1.2026.7 on 25 August, 1.2026.8 on 5 September and 1.2026.9, plus a rolling snapshot build (20). Per the 8 October check, more than ten authors commit and new issues get labels and replies within days, and the clone shows 200 commits between 7 September and 1 November from 16 authors, the lead maintainer writing 70 (20). Homebrew has 1.2026.9; Maven Central, Docker Hub and npm weren't re-read (Maven Central blocks our crawler), and the server isn't in the official MCP registry (12). Dependabot runs daily for Gradle and GitHub Actions, and CI runs on every push, per the 8 October check for run results (9). 91.

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.

PlantUML 83

Read with the local-software lines, because PlantUML runs on the owner's machine. Release jars on GitHub and Maven Central, Homebrew at 1.2026.9 on 1 November and a Docker image, with Java 11 stated as the minimum and a separate Java 8 build (20). Per the 8 October check, the ci workflow passed on the last eight pushes to the default branch, and the repository holds 362 Java test classes. Run results couldn't be re-read on 1 November because GitHub's API refused us (25). Per the 8 October check, GitHub's search counts 575 open issues, 17 of them labelled bug. Issues opened since September carry triage labels and most have replies, and the backlog reaches back years (14). CHANGES.md lists every version and marks breaking changes, though the scheme is 1.year.count and not semver as the download page says, and 1.2026.7 changed the default sequence diagram engine in a point release (9). Version 1.2026.9, in a 1.x line since 2017 (15). 83.

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.

PlantUML 60

Read with the self-hosted rule. Free software with nothing to buy and no payment protocol (0). No price to publish (20). No card or trial needed (20). An agent can download the jar or run the npm package with no signup (20).

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.

PlantUML 74

GPL-3.0-or-later by default, with the same source under six other open-source licences, and LICENSES.md says generated images belong to the author of the diagram text (30). No privacy policy, and the software runs locally. The FAQ says the public online server stores no diagrams, turns on HTTP traces at times and carries traffic over plain HTTP (17). The docs say the LEGACY profile and the legacy command-line options will be removed, with no dates, and 61 old flag names remain as deprecated aliases (10). Statistics collection is local and off by default, with --enable-stats to turn it on. We found no network call in the statistics code (16).

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.

PlantUML 78

One command with text in and a diagram out, or four compact MCP tools (23). --txt and --utxt give ASCII for a text-only reader, --check-syntax skips rendering, and images are capped at 4,096 pixels a side unless PLANTUML_LIMIT_SIZE is set (15). Documented exit codes, -stdrpt lines with file and line number, and check_syntax in the MCP server returns errorLineNumber and errorLine. The usual message is 'Syntax Error?' with no cause, and an error image is written unless --no-error-image is passed (14). Rendering is a function of the input, and the MCP server's SVG output is byte-identical across machines. The four MCP tools carry no readOnlyHint (14). java -jar plantuml.jar file works with no flags. It needs a Java runtime, and since 1.2026.7 falls back to the built-in Smetana layout when Graphviz is missing. Official surfaces are the Java library and two npm packages (12).

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.

PlantUML 65

Read as a CLI and library. No OpenAPI or formal grammar. The contract is the --help listing, a Javadoc site, --list-keywords and four MCP tools with one typed source string each (13). No llms.txt (HTTP 404). Docs pages are HTML, with a PDF guide (2). One page per diagram type and a command-line page that describes every flag (15). Flags are typed in the help text, with formats listed by name (10). Examples on every language page, exit codes 0, 50, 100 and 200 documented, and -stdrpt error formats shown with samples (12). CHANGES.md and GitHub release notes for every version. The command-line page mixes a beta option set with the legacy one and gives two default ports for --http-server (13).