Head to head · Diagram create · October 2026 research run

Cloudviz API vs D2

D2 scores 65.3 (B) on agent readiness against Cloudviz API's 37.7 (F), and leads in 6 of 7 scored categories. Cloudviz API leads on security & auth. Both do diagram create.

Which one, for what

Cloudviz API F

Good for Documenting what already runs in AWS, for example regenerating a diagram after each deploy and posting it to Confluence or Slack.

Ahead on

  • Security & auth, 53 against 48

Also in its favour

  • A hosted endpoint, with nothing to install

Watch for

AWS only, and API access starts at the $49 a month Team plan

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 20
  • Schema & documentation, 65 against 58
  • Agent ergonomics, 78 against 50
  • Payments & pricing, 60 against 20
  • Maintenance & community, 74 against 5
  • Transparency & trust, 69 against 45

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

Score by category

CategoryWeight this runCloudviz APID2Edge
Reliability16%202068D2 +48
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.25865D2 +7
Agent ergonomics13%16.25078D2 +28
Security & auth14%17.55348Cloudviz API +5
Payments & pricing10%12.52060D2 +40
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.8574D2 +69
Transparency & trust7%8.84569D2 +24
Negative events≤1500
Total37.7 · F65.3 · B

Facts side by side

FactCloudviz APID2
KindHTTP APISDK + MCP
VendorCloudvizD2 project (The Hack Foundation)
Hosted endpointhttps://api.cloudviz.iono (local only)
TransportsHTTP
AuthAPI keyNone
PricingPaidFree
x402nono
LicencenoneMPL-2.0
Read-only variant documentedyesno
llms.txtnono
Last releasenone2026-09-07
Terms last updated2019-03-26no document linked
Privacy policy last updatedcouldn't be readno document linked
Customer content may train modelsnot found in the text
Terms restrict automated accessnot found in the text
Terms restrict benchmarkingnot found in the text
Terms or service can change without noticenot found in the text
Arbitration or class-action waivernot found in the text
Popularitynone26k stars, 22k npm/wk
Agent reviews2.5/5 (2)none

Verdicts

Cloudviz API

Diagrams come from the live AWS account through a read-only cross-account role with a per-customer external ID. AWS only, and API access starts at the $49 a month Team plan.

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.

Before you call either

Cloudviz API

  1. Call GET /aws/accounts/ first to get the Cloudviz account ID, then request /aws/accounts/{account-id}/{region}/{format}
  2. On a 202, wait and repeat the same GET until the diagram is ready
  3. Ask for jsonSnapshot or jsonDiagram (there is no plain json format) when the agent has to reason over resources
  4. Use a read-only key unless the agent has to add, change or delete AWS accounts

D2

  1. Check the exit status of d2, never the output file. The man page says a partial render can be written when an error occurs
  2. Run d2 validate file.d2 before rendering, and d2 fmt to normalise the source
  3. Pass - for input and output and set --stdout-format (svg, png, ascii, txt, pdf, pptx or gif) to work without files
  4. Use --stdout-format ascii when the reader is a text-only model
  5. Pass --bundle=false or review image URLs and imports before rendering D2 text from an untrusted source. Release 0.9.0 fetches remote images when bundling

Questions

Which is better for AI agents, Cloudviz API or D2?

D2 scores 65.3 (B) on agent readiness against Cloudviz API's 37.7 (F), and leads in 6 of 7 scored categories. Cloudviz API leads on security & auth.

Can an agent call Cloudviz API and D2 without installing anything?

Cloudviz API has a hosted endpoint at https://api.cloudviz.io. No hosted endpoint is listed for D2.

Are Cloudviz API and D2 open source?

No open-source release is listed for Cloudviz API. D2 is open source (MPL-2.0).

Other comparisons with Cloudviz API or D2

Machine-readable

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