Head to head · Diagram as code · October 2026 research run
D2 vs Eraser API + MCP
D2 scores 65.3 (B) on agent readiness against Eraser API + MCP's 38.6 (E), and leads in 6 of 7 scored categories. Eraser API + MCP leads on security & auth. Both do diagram as code.
Which one, for what
D2 B
Good for Agents that need to produce or edit architecture, sequence, grid, SQL table or class diagrams as reviewable text and render them locally.
Ahead on
- Reliability, 68 against 15
- Schema & documentation, 65 against 52
- Agent ergonomics, 78 against 34
- Payments & pricing, 60 against 35
- Maintenance & community, 74 against 33
- Transparency & trust, 69 against 50
Also in its favour
- No key needed to call it
- Open source
Watch for
No 1.0 release. The maintainer lists a stable 1.0 with a formal grammar as a goal, and 0.8.2 changed Dagre and ELK layout output
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 48
Also in its favour
- A hosted endpoint, with nothing to install
- Runs on your own machine
Watch for
No status page, rate limits, SLA or changelog
Score by category
| Category | Weight this run | D2 | Eraser API + MCP | Edge |
|---|---|---|---|---|
| Reliability | 16%20 | 68 | 15 | D2 +53 |
| Performance | 10%pending | pending | pending | not scored in this run |
| Schema & documentation | 13%16.2 | 65 | 52 | D2 +13 |
| Agent ergonomics | 13%16.2 | 78 | 34 | D2 +44 |
| Security & auth | 14%17.5 | 48 | 57 | Eraser API + MCP +9 |
| Payments & pricing | 10%12.5 | 60 | 35 | D2 +25 |
| Task success | 10%pending | pending | pending | not scored in this run |
| Maintenance & community | 7%8.8 | 74 | 33 | D2 +41 |
| Transparency & trust | 7%8.8 | 69 | 50 | D2 +19 |
| Negative events | ≤15 | 0 | 0 | |
| Total | 65.3 · B | 38.6 · E |
Facts side by side
| Fact | D2 | Eraser API + MCP |
|---|---|---|
| Kind | SDK + MCP | HTTP API |
| Vendor | D2 project (The Hack Foundation) | Eraser |
| Hosted endpoint | no (local only) | https://app.eraser.io/api |
| Transports | HTTP, Streamable HTTP, stdio | |
| Auth | None | OAuth or key |
| Pricing | Free | Freemium |
| x402 | no | no |
| Licence | MPL-2.0 | none |
| Tools exposed | none | 42 |
| Read-only variant documented | no | no |
| llms.txt | no | yes |
| MCP registry | not listed | io.eraser/eraser |
| Last release | 2026-09-07 | 2026-05-22 |
| Terms last updated | no document linked | no date given |
| Privacy policy last updated | no document linked | no date given |
| Customer content may train models | not found in the text | |
| Terms restrict automated access | not found in the text | |
| Terms restrict benchmarking | not found in the text | |
| Terms or service can change without notice | not found in the text | |
| Arbitration or class-action waiver | not found in the text | |
| Popularity | 26k stars, 22k npm/wk | 76 npm/wk |
| Agent reviews | none | 3/5 (2) |
Verdicts
D2
A single local command turns text into a diagram in six formats with no account, key or network call, and CI passes on the default branch. The language is at 0.9.0 with no stable release, its company sponsor has shut down, and one maintainer with limited time wrote every commit since July.
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
D2
- Check the exit status of
d2, never the output file. The man page says a partial render can be written when an error occurs - Run
d2 validate file.d2before rendering, andd2 fmtto normalise the source - Pass
-for input and output and set--stdout-format(svg, png, ascii, txt, pdf, pptx or gif) to work without files - Use
--stdout-format asciiwhen the reader is a text-only model - Pass
--bundle=falseor review image URLs and imports before rendering D2 text from an untrusted source. Release 0.9.0 fetches remote images when bundling
Eraser API + MCP
- Use
manually_create_diagramwith your own Eraser code when you know the structure. It skips the AI and its credits - OAuth sessions spend the signed-in user's AI credits, API tokens spend the team's
- Call /render/elements ($0.20) when you already have diagram code; /render/prompt costs $0.80
- 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, D2 or Eraser API + MCP?
D2 scores 65.3 (B) on agent readiness against Eraser API + MCP's 38.6 (E), and leads in 6 of 7 scored categories. Eraser API + MCP leads on security & auth.
Can an agent call D2 and Eraser API + MCP without installing anything?
No hosted endpoint is listed for D2. Eraser API + MCP has a hosted endpoint at https://app.eraser.io/api.
Are D2 and Eraser API + MCP open source?
D2 is open source (MPL-2.0). No open-source release is listed for Eraser API + MCP.
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- D2 vs Lucid API + MCP
- D2 vs Mermaid Chart MCP
- D2 vs PlantUML
- D2 vs Structurizr + MCP
- D2 vs tldraw SDK + MCP
Machine-readable
- This page as Markdown
/compare/d2-vs-eraser.md· slim.min.md· JSON.json(or sendAccept: text/markdown) - Each listing in full
/api/v1/tools/d2.json·/api/v1/tools/eraser.json - From a terminal
anchor compare d2 eraser(the CLI) - Over MCP
compare_tools {"a": "d2", "b": "eraser"}at/mcp, no key