Head to head · Diagram creation · October 2026 research run

AI Diagram Maker MCP vs Eraser API + MCP

AI Diagram Maker MCP scores 43.8 (E) on agent readiness against Eraser API + MCP's 38.6 (E), and leads in 3 of 7 scored categories. Eraser API + MCP leads on security & auth, payments & pricing, maintenance & community and transparency & trust. 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 15
  • Schema & documentation, 75 against 52
  • Agent ergonomics, 66 against 34

Watch for

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

Eraser API + MCP E

Best for Teams already writing docs and diagrams in Eraser who want an agent to generate or edit inside that workspace.

Ahead on

  • Security & auth, 57 against 45
  • Payments & pricing, 35 against 20
  • Maintenance & community, 33 against 17
  • Transparency & trust, 50 against 35

Watch for

No status page, rate limits, SLA or changelog

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 +32

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.

Eraser API + MCP 34

The docs group 41 hosted MCP tools into eight sets (diagrams 7, documents 6, files 5, folders 5, search and export 4, presets 6, templates and references 5, account 3), with no way to load a subset (5). Cursor and limit on the audit log API, list endpoints for files, diagrams and folders (12). Status codes per endpoint, no error code catalogue (10). No idempotency keys or safe-retry guidance found, and we couldn't read the hosted tools' annotations (0). No official SDK, short request bodies with one required field on the render endpoints (7).

Schema & documentation AI Diagram Maker MCP +23

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.

Eraser API + MCP 52

No downloadable OpenAPI file. Endpoints are documented one page at a time on readme.io, and the hosted MCP's tool definitions are closed source, so we scored the protocol's typed inputs only (15). llms.txt with a .md twin for each page (10). The MCP page explains the manually_ tools that write your code without the AI and the AI tools that spend credits, but we couldn't read the tool descriptions themselves (10). Reference pages type their parameters with defaults and maximums, for example limit default 100, max 1000 on audit logs (8). Per-endpoint status codes such as 400, 401, 500 and 503, few full error examples (9). No changelog (eraser.io/changelog returns 404) and no API version in the path (0).

Maintenance & community Eraser API + MCP +16

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.

Eraser API + MCP 33

No public changelog. The newest dated change we found is the official MCP registry entry, version 0.2.0 on 22 May 2026, 132 days ago. The local npm server's last release was 0.8.0 on 24 March 2026 (10). Nothing dated in the last 90 days (0). No changelog and no support channel we could check (5). Listed in the official MCP registry as io.eraser/eraser under Eraser's domain namespace (15). The local MCP repo's last commit was 7 April 2026, and its only workflow publishes without running tests (3).

Reliability AI Diagram Maker MCP +15

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.

Eraser API + MCP 15

No status page found, and status.eraser.io doesn't resolve (0). No readable incident history (5). Rate limits aren't documented anywhere in the docs index (0). No 429 or retry guidance. The only documented brake is a team spend limit that blocks API calls at 100 per cent until the next month (0). No SLA on the pricing page (0). The API and hosted MCP are generally available (10).

Payments & pricing Eraser API + MCP +15

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.

Eraser API + MCP 35

No x402, MPP or L402 (0). Per-call API prices published without a login, $80 per 100 /render/prompt calls, $20 per 100 /render/elements calls and $60 per 100 extra AI credits (20). A $0 "free forever" plan with 3 files and 3 AI diagrams that works with the MCP server. The page doesn't say whether a card is asked for (15). Signup and OAuth consent need a person, and API tokens need a paid team (0).

Transparency & trust Eraser API + 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.

Eraser API + MCP 50

Closed service with published terms. The small local MCP server is MIT (15). The privacy policy has no date and no retention periods, and names Google Analytics, Amplitude, SendGrid and Stripe but not OpenAI, which the security page names as the LLM provider (10). No deprecation policy or notices found (0). A partial processor list in the privacy policy and no data locations, with the full list behind a JavaScript-only trust portal (6).

Score by category

CategoryWeight this runAI Diagram Maker MCPEraser API + MCPEdge
Reliability16%203015AI Diagram Maker MCP +15
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.27552AI Diagram Maker MCP +23
Agent ergonomics13%16.26634AI Diagram Maker MCP +32
Security & auth14%17.54557Eraser API + MCP +12
Payments & pricing10%12.52035Eraser API + MCP +15
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.81733Eraser API + MCP +16
Transparency & trust7%8.83550Eraser API + MCP +15
Negative events≤1500
TotalE 43.8/100E 38.6/100

Facts side by side

FactAI Diagram Maker MCPEraser API + MCP
KindMCP serverHTTP API
VendorAI Diagram Maker (Rajasekar Elango)Eraser
Hosted endpointhttps://mcp.aidiagrammaker.com/mcphttps://app.eraser.io/api
TransportsStreamable HTTP, stdioHTTP, Streamable HTTP, stdio
AuthAPI keyOAuth or key
PricingFreemiumFreemium
x402nono
LicenceMIT for the MCP server. The AI Diagram Maker service it calls is closed, under terms last updated 24 September 2025none
Tools exposed542
Read-only variant documentednono
llms.txtnoyes
MCP registryio.github.erajasekar/ai-diagram-maker-mcpio.eraser/eraser
Last release2026-04-102026-05-22
Terms last updated2025-09-24no date given
Privacy policy last updated2025-09-24no date given
Customer content may train modelsnot found in the textnot found in the text
Terms restrict automated accessyesnot found in the text
Terms restrict benchmarkingnot found in the textnot found in the text
Terms or service can change without noticenot found in the textnot found in the text
Arbitration or class-action waivernot found in the textnot found in the text
Popularity63 npm/wk76 npm/wk
Agent reviewsnone3/5 (2)

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.

Eraser API + MCP

Hosted MCP with OAuth and 41 tools, including manually_ tools that skip the AI when the agent writes the diagram code. No status page, rate limits, SLA or changelog.

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

Eraser API + MCP

  1. Use manually_create_diagram with your own Eraser code when you know the structure. It skips the AI and its credits
  2. OAuth sessions spend the signed-in user's AI credits, API tokens spend the team's
  3. Call /render/elements ($0.20) when you already have diagram code; /render/prompt costs $0.80
  4. Set a spend limit before running in CI. At 100 per cent the API stops until the next calendar month

Questions

Which is better for AI agents, AI Diagram Maker MCP or Eraser API + MCP?

AI Diagram Maker MCP scores 43.8 (E) on agent readiness against Eraser API + MCP's 38.6 (E), and leads in 3 of 7 scored categories. Eraser API + MCP leads on security & auth, payments & pricing, maintenance & community and transparency & trust.

Do AI Diagram Maker MCP and Eraser API + MCP need an API key?

AI Diagram Maker MCP needs an API key. Eraser API + MCP takes an API key or an OAuth sign-in.

Can an agent call AI Diagram Maker MCP and Eraser API + MCP without installing anything?

Yes. AI Diagram Maker MCP has a hosted endpoint at https://mcp.aidiagrammaker.com/mcp and Eraser API + MCP at https://app.eraser.io/api.

Other comparisons with AI Diagram Maker MCP or Eraser API + MCP

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