Head to head · Decision models · October 2026 research run

ScaleDown vs Vela 2.0

Vela 2.0 scores 66.5 (B) on agent readiness against ScaleDown's 48.6 (D), and leads in 6 of 7 scored categories. ScaleDown leads on transparency & trust. Both do decision models.

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Which one, for what

ScaleDown D

Best for Cheap, high-volume labelling, routing and yes or no checks where a probability is more useful than prose, and for pulling described fields with offsets from text, images or PDFs.

Ahead on

  • Transparency & trust, 54 against 48

Also in its favour

  • A hosted endpoint, with nothing to install
  • Free to start without a card

Watch for

No status page, no published rate limits and no SLA outside enterprise contracts

Vela 2.0 B

Best for Self-hosted routing and guardrail checks in one call, where span offsets for personal data or unsupported claims matter.

Ahead on

  • Reliability, 57 against 20
  • Schema & documentation, 78 against 69
  • Security & auth, 60 against 48
  • Payments & pricing, 60 against 40
  • Maintenance & community, 84 against 56

Also in its favour

  • No key needed to call it
  • Open source

Watch for

No version tags on the four Hub repositories, and the 4B and 9B weights were replaced in place on 3 October 2026

Score by category

CategoryWeight this runScaleDownVela 2.0Edge
Reliability16%202057Vela 2.0 +37
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.26978Vela 2.0 +9
Agent ergonomics13%16.27679Vela 2.0 +3
Security & auth14%17.54860Vela 2.0 +12
Payments & pricing10%12.54060Vela 2.0 +20
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.85684Vela 2.0 +28
Transparency & trust7%8.85448ScaleDown +6
Negative events≤15-20
TotalD 48.6/100B 66.5/100

Facts side by side

FactScaleDownVela 2.0
KindModel APIModel API
VendorCarbon ScaleDown, Inc.vLLM Semantic Router project and KR Labs
Hosted endpointhttps://api.scaledown.xyzno (local only)
TransportsHTTPHTTP
AuthAPI keyNone
PricingPay per useFree
x402nono
LicenceProprietary hosted models under ScaleDown's Terms of Service. The langchain-scaledown integration is MITApache-2.0 (weights, code and documentation). The 0.3B's tokeniser keeps the Gemma Terms of Use, and training data keeps its own licences
Read-only variant documentednono
llms.txtyesno
Last release2026-10-142026-10-06
Terms last updatedcouldn't be readno document linked
Privacy policy last updatedcouldn't be readno document linked
Customer content may train modelscouldn't be read
Terms restrict automated accesscouldn't be read
Terms restrict benchmarkingcouldn't be read
Terms or service can change without noticecouldn't be read
Arbitration or class-action waivercouldn't be read
Popularity0 stars6.1k stars

Verdicts

ScaleDown

Classify answers Jev-shaped choice, noul and score questions with probabilities, and Extract returns values with confidences and character offsets, at $0.05 per million input tokens with output free. There is no status page, no published rate limit and no public changelog, and the site's compliance claims contradict each other.

Vela 2.0

One self-hosted call answers routing, prompt-attack, personal-data and unsupported-claim questions with probabilities and character offsets, under Apache-2.0 with SHA-256 manifests. The models are days old and carry no Hub version tags, and the three larger sizes keep 74 to 89 per cent of their Decision 2.0 bases on the Jev Decision Index by the authors' figures.

Before you call either

ScaleDown

  1. Send several questions about one item in one /v1/scaledown call. Each becomes its own Classify call and the usage is summed
  2. Pin classify-1, extract-1 or summarize-1 once you've tuned thresholds on your own labelled cases
  3. Set context_chars to 0 and use top_n on Extract unless you need the 500 characters of context each side
  4. Set reasoning: false on /classify when you only need the label. The reasoning call bills its input at 2x
  5. Back off and retry on 429, 502 and 504. No limits are published and calls have no side effects

Vela 2.0

  1. Pin a commit hash with revision= when loading from the Hub. The repositories have no tags and main has changed since launch
  2. Send the served name in model, for example vllm-sr/Vela-2.0-4B. The bundled server answers 422 to any other name
  3. Name span questions pii, halu or toxic, or set "head": "router", to get the trained router head. Other labels go to the broad head
  4. Keep input under 16,384 tokens a sequence (8,192 on the 0.3B). The bundled server answers 413 when the questions alone don't fit
  5. Set VELA2_API_KEY before binding the bundled server beyond 127.0.0.1, and keep the model runtime on a trusted network

Questions

Which is better for AI agents, ScaleDown or Vela 2.0?

Vela 2.0 scores 66.5 (B) on agent readiness against ScaleDown's 48.6 (D), and leads in 6 of 7 scored categories. ScaleDown leads on transparency & trust.

Do ScaleDown and Vela 2.0 need an API key?

ScaleDown needs an API key. Vela 2.0 needs no key.

Can an agent call ScaleDown and Vela 2.0 without installing anything?

ScaleDown has a hosted endpoint at https://api.scaledown.xyz. No hosted endpoint is listed for Vela 2.0.

Are ScaleDown and Vela 2.0 open source?

No open-source release is listed for ScaleDown. Vela 2.0 is open source (Apache-2.0 (weights, code and documentation). The 0.3B's tokeniser keeps the Gemma Terms of Use, and training data keeps its own licences).

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Machine-readable

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