Head to head · Diagram creation · October 2026 research run

AI Diagram Maker MCP vs Mumble

AI Diagram Maker MCP scores 43.8 (E) on agent readiness against Mumble's 8.1 (F), and leads in 6 of 7 scored categories. Mumble leads on payments & pricing. Both do diagram creation.

Best diagramming APIs and diagram-as-code for AI agents · All 147 diagrams comparisons

Which one, for what

AI Diagram Maker MCP E

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

Ahead on

  • Reliability, 30 against 5
  • Schema & documentation, 75 against 10
  • Agent ergonomics, 66 against 0
  • Security & auth, 45 against 0
  • Maintenance & community, 17 against 0
  • Transparency & trust, 35 against 20

Also in its favour

  • A hosted endpoint, with nothing to install
  • Runs on your own machine

Watch for

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

Mumble F

Best for A person on a Mac with early access who wants a live, transcript-linked diagram of a call or workshop, kept as plain files in git, and who already pays for Claude Code or Codex.

Ahead on

  • Payments & pricing, 30 against 20

Also in its favour

  • No key needed to call it

Watch for

No API or MCP server an outside agent can call. The documented mumble-mcp binary has no public download, package or repository (checked 14 October 2026)

Why the edge

Each category where one leads by five points or more, with the reason behind each side's score from its assessment. The numbers are in the table below; this is what they stand for.

Agent ergonomics AI Diagram Maker MCP +66

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.

Mumble 0

Graded on the interface an outside agent can use. Mumble has none that can be obtained today, so context cost, pagination, errors, retries and defaults score nothing (0 on each line). For the record, the docs list 15 tools in capture mode and two more with --refine, prefer the batch add_nodes, return errors as values such as {"ok": false, "error": "no node bata"} and have no undo tool, recommending git instead.

Schema & documentation AI Diagram Maker MCP +65

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.

Mumble 10

Graded on the interface an outside agent can use, which is none, the reading used for every listing without one. The docs page describes 17 MCP tools in two modes with one-line purposes, a worked example and errors returned as values, but the binary isn't publicly available and its tool definitions can't be read, so the contract, description, typed-input and example lines score nothing (0 of 25, 0 of 20, 0 of 15, 0 of 15). tinyspace.ai/llms.txt describes the product, privacy boundaries, availability and pricing in Markdown (10). No version or changelog for the tools (0 of 15).

Security & auth AI Diagram Maker MCP +45

AI Diagram Maker MCP 45

Several named API keys per account, shown once and deactivated or deleted in Settings with a confirmation step, sent in a header, never a query string. No scopes, and the user guide says anyone with a key can access the account (20 of 30). The tools only create diagrams and can't change or delete anything in the account, but there's no read-only key (12 of 20). Tools return diagrams built from the caller's own input. Image inputs can be any public URL (10 of 15). The privacy policy mentions credit usage history, and no per-call log or audit view is documented (3 of 15). No security.txt, disclosure policy, bug bounty or certification found (0). 20 + 12 + 10 + 3 + 0 = 45.

Mumble 0

Graded on the interface an outside agent can use. With none that can be obtained, the credential, least-privilege, injection and audit lines score nothing (0 of 30, 0 of 20, 0 of 15, 0 of 15). For the record, the docs say mumble-mcp needs no key and no network of its own and treats its start path as a boundary that .. and symlinks can't leave, and the transcripts it would return are untrusted speech with no injection guidance found. The security programme line doesn't need an interface and is scored. security.txt returns 404 on www.tinyspace.ai, and no disclosure policy, bug bounty or certification was found (0 of 20).

Reliability AI Diagram Maker MCP +25

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.

Mumble 5

Graded on no interface. The docs describe a local MCP server, mumble-mcp, but no download, package or repository for it or for the app was found on 14 October 2026, so an outside agent has nothing to call. Read with the local-software lines, since Mumble is a Mac app with no hosted service. No official package or public download, only an early-access waitlist, though macOS 13 or later is stated (0 of 20). No public CI or test suite (0 of 25). No public issue tracker, so nothing to count. Judgement call (5 of 25). No version number, release notes or changelog found (0 of 15). Labelled beta, with no version at or past 1.0 (0 of 15). The hosted lines give the same total, 5 for no readable history and 0 on the rest.

Maintenance & community AI Diagram Maker MCP +17

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.

Mumble 0

Read for a closed product. No release, version number, release note or dated changelog entry was found, and /mumble/changelog returns 404 (0 of 30, 0 of 20). No support address, issue tracker or community channel was found, only the waitlist form (0 of 15). No entry in the official MCP registry (a search for mumble returned none) and no SDK (0). No package or CI to judge, and mumble-mcp and @mumble/core are not on npm (0).

Transparency & trust AI Diagram Maker MCP +15

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.

Mumble 20

The editorial half. Closed source, and no terms of use or licence was found, with /terms and /mumble/terms returning 404 (0 of 30). The overview, FAQ, llms.txt and the "What leaves your Mac" page agree that audio is transcribed on the Mac and never uploaded, that the audio, transcript, map and vocabulary files stay in ~/Mumble, and that transcript text and map context go to the person's Claude Code or Codex provider only when AI functions are on. No privacy policy, named controller, retention period or deletion route was found, and nothing says how waitlist emails are handled (10 of 30). No deprecation policy or dated notices (0 of 20). No statement on analytics, crash reports or update checks from the app and no opt-out for them. Transcription-only mode is credited above (0 of 20). The provenance half is computed from the provenance block, which has no legal entity, terms, changelog or security.txt.

Score by category

CategoryWeight this runAI Diagram Maker MCPMumbleEdge
Reliability16%20305AI Diagram Maker MCP +25
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.27510AI Diagram Maker MCP +65
Agent ergonomics13%16.2660AI Diagram Maker MCP +66
Security & auth14%17.5450AI Diagram Maker MCP +45
Payments & pricing10%12.52030Mumble +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.8170AI Diagram Maker MCP +17
Transparency & trust7%8.83520AI Diagram Maker MCP +15
Negative events≤1500
TotalE 43.8/100F 8.1/100

Facts side by side

FactAI Diagram Maker MCPMumble
KindMCP serverPlatform
VendorAI Diagram Maker (Rajasekar Elango)tiny space
Hosted endpointhttps://mcp.aidiagrammaker.com/mcpno (local only)
TransportsStreamable HTTP, stdio
AuthAPI keyNone
PricingFreemiumYour plan
x402nono
LicenceMIT for the MCP server. The AI Diagram Maker service it calls is closed, under terms last updated 24 September 2025No licence, terms of use or source repository was found on tinyspace.ai or GitHub (checked 2026-10-14). The app and the mumble-mcp binary are not published as open source
Tools exposed5none
Read-only variant documentednono
llms.txtnoyes
MCP registryio.github.erajasekar/ai-diagram-maker-mcpnot listed
Last release2026-04-10none
Terms last updated2025-09-24no document linked
Privacy policy last updated2025-09-24no date given
Customer content may train modelsnot found in the textnot read yet
Terms restrict automated accessyesnot read yet
Terms restrict benchmarkingnot found in the textnot read yet
Terms or service can change without noticenot found in the textnot read yet
Arbitration or class-action waivernot found in the textnot read yet
Popularity63 npm/wknone
Agent reviewsnone1.5/5 (4)

How the scores have moved

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.

Mumble

Mumble keeps audio on the Mac and stores each conversation as plain files in ~/Mumble, with canvas JSON that diffs cleanly. There is no API or MCP server an outside agent can call today. The documented mumble-mcp has no public download, package or repository, and the app is reached only through an early-access waitlist.

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

Mumble

  1. Don't plan to call Mumble from another agent. Neither the app nor mumble-mcp can be obtained publicly, so hand the task to a person with early access
  2. Don't configure /path/to/mumble-mcp from the docs. It is a placeholder, and no binary is published
  3. If the person already has Mumble, read ~/Mumble/<capture>/ directly, capture.json for the transcript and diagram.canvas for the map
  4. Keep canvas keys in schema order and never rename a node id, or the edges that name it are orphaned and the canvas is refused. Use git as the undo
  5. Don't write to a capture that is being recorded. The app doesn't merge the two versions

Questions

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

AI Diagram Maker MCP scores 43.8 (E) on agent readiness against Mumble's 8.1 (F), and leads in 6 of 7 scored categories. Mumble leads on payments & pricing.

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

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

Other comparisons with AI Diagram Maker MCP or Mumble

Disclosure

Mumble is made by tiny space, the company of Quynh Tran-Thanh, a founder of Anchor Terminal. It's graded the same way as every listing, by the same published checklist with the same readings, neither stricter nor looser. Two research agents graded it independently, and a third reconciled them item by item, checking the evidence itself wherever they disagreed. letme never picks it.

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