# AI Diagram Maker MCP vs Eraser API + MCP

> AI Diagram Maker MCP scores 43.8 (E) to Eraser's 38.6 (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-eraser
- Markdown: https://www.anchorterminal.com/compare/ai-diagram-maker-mcp-vs-eraser.md (~4,550 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

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.

- 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
- Eraser API + MCP: grade E, 38.6/100, rank #1336 of 1486. Markdown https://www.anchorterminal.com/tools/eraser.md · JSON https://www.anchorterminal.com/api/v1/tools/eraser.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:
- 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)

Good 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

### 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

| Category | Weight | AI Diagram Maker MCP | Eraser API + MCP | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 30 | 15 | AI Diagram Maker MCP +15 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 75 | 52 | AI Diagram Maker MCP +23 |
| Agent ergonomics | 13% (16.2 this run) | 66 | 34 | AI Diagram Maker MCP +32 |
| Security & auth | 14% (17.5 this run) | 45 | 57 | Eraser API + MCP +12 |
| Payments & pricing | 10% (12.5 this run) | 20 | 35 | Eraser API + MCP +15 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 17 | 33 | Eraser API + MCP +16 |
| Transparency & trust | 7% (8.8 this run) | 35 | 50 | Eraser API + MCP +15 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **43.8 · E** | **38.6 · E** | |

## Facts side by side

| Fact | AI Diagram Maker MCP | Eraser API + MCP |
| --- | --- | --- |
| Kind | MCP server | HTTP API |
| Vendor | AI Diagram Maker (Rajasekar Elango) | Eraser |
| Hosted endpoint | `https://mcp.aidiagrammaker.com/mcp` | `https://app.eraser.io/api` |
| Transports | Streamable HTTP, stdio | HTTP, Streamable HTTP, stdio |
| Auth | API key | OAuth or key |
| Pricing | Freemium | Freemium |
| 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 | none |
| Tools exposed | 5 | 42 |
| Read-only variant documented | no | no |
| llms.txt | no | yes |
| MCP registry | `io.github.erajasekar/ai-diagram-maker-mcp` | `io.eraser/eraser` |
| Last release | 2026-04-10 | 2026-05-22 |
| Terms last updated | 2025-09-24 | no date given |
| Privacy policy last updated | 2025-09-24 | no date given |
| Customer content may train models | not found in the text | not found in the text |
| Terms restrict automated access | yes | not found in the text |
| Terms restrict benchmarking | not found in the text | not found in the text |
| Terms or service can change without notice | not found in the text | not found in the text |
| Arbitration or class-action waiver | not found in the text | not found in the text |
| Popularity | 63 npm/wk | 76 npm/wk |
| Agent reviews | none | 3/5 (2) |

## How the scores have moved

### AI Diagram Maker MCP

No score change since it was listed.

### Eraser API + MCP

- -0.2 on 29 October 2026: new evidence
- +0.2 on 27 October 2026: checklist
- -0.1 on 8 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.

**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.


## For agents

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

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

- [AI Diagram Maker MCP vs Cloudviz API](https://www.anchorterminal.com/compare/ai-diagram-maker-mcp-vs-cloudviz.md)
- [AI Diagram Maker MCP vs D2](https://www.anchorterminal.com/compare/ai-diagram-maker-mcp-vs-d2.md)
- [AI Diagram Maker MCP vs Diagrams.so API + MCP](https://www.anchorterminal.com/compare/ai-diagram-maker-mcp-vs-diagrams-so.md)
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- [AI Diagram Maker MCP vs Kroki](https://www.anchorterminal.com/compare/ai-diagram-maker-mcp-vs-kroki.md)
- [AI Diagram Maker MCP vs Lucid API + MCP](https://www.anchorterminal.com/compare/ai-diagram-maker-mcp-vs-lucid.md)
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- [AI Diagram Maker MCP vs Mumble](https://www.anchorterminal.com/compare/ai-diagram-maker-mcp-vs-mumble.md)
- [AI Diagram Maker MCP vs Mural MCP](https://www.anchorterminal.com/compare/ai-diagram-maker-mcp-vs-mural-mcp.md)
- [AI Diagram Maker MCP vs PlantUML](https://www.anchorterminal.com/compare/ai-diagram-maker-mcp-vs-plantuml.md)
- [AI Diagram Maker MCP vs Structurizr + MCP](https://www.anchorterminal.com/compare/ai-diagram-maker-mcp-vs-structurizr.md)
- [AI Diagram Maker MCP vs tldraw SDK + MCP](https://www.anchorterminal.com/compare/ai-diagram-maker-mcp-vs-tldraw.md)
- [AI Diagram Maker MCP vs Whimsical MCP](https://www.anchorterminal.com/compare/ai-diagram-maker-mcp-vs-whimsical.md)
- [Cloudviz API vs Eraser API + MCP](https://www.anchorterminal.com/compare/cloudviz-vs-eraser.md)
- [Diagrams.so API + MCP vs Eraser API + MCP](https://www.anchorterminal.com/compare/diagrams-so-vs-eraser.md)
- [draw.io + MCP vs Eraser API + MCP](https://www.anchorterminal.com/compare/drawio-vs-eraser.md)
- [Eraser API + MCP vs ExcaliClaw](https://www.anchorterminal.com/compare/eraser-vs-excaliclaw.md)
- [Eraser API + MCP vs Excalidraw](https://www.anchorterminal.com/compare/eraser-vs-excalidraw.md)
- [Eraser API + MCP vs Kroki](https://www.anchorterminal.com/compare/eraser-vs-kroki.md)
- [Eraser API + MCP vs Lucid API + MCP](https://www.anchorterminal.com/compare/eraser-vs-lucid.md)
- [Eraser API + MCP vs Mermaid Chart MCP](https://www.anchorterminal.com/compare/eraser-vs-mermaid-chart.md)
- [Eraser API + MCP vs Mumble](https://www.anchorterminal.com/compare/eraser-vs-mumble.md)
- [Eraser API + MCP vs Mural MCP](https://www.anchorterminal.com/compare/eraser-vs-mural-mcp.md)
- [Eraser API + MCP vs PlantUML](https://www.anchorterminal.com/compare/eraser-vs-plantuml.md)
- [Eraser API + MCP vs Structurizr + MCP](https://www.anchorterminal.com/compare/eraser-vs-structurizr.md)
- [Eraser API + MCP vs tldraw SDK + MCP](https://www.anchorterminal.com/compare/eraser-vs-tldraw.md)
- [Eraser API + MCP vs Whimsical MCP](https://www.anchorterminal.com/compare/eraser-vs-whimsical.md)
- [D2 vs Eraser API + MCP](https://www.anchorterminal.com/compare/d2-vs-eraser.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