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Head to head · Decision models · October 2026 research run

pplx-decider-flash vs Vela 2.0

pplx-decider-flash scores 67.9 (B) on agent readiness against Vela 2.0's 66.5 (B), and leads in 5 of 7 scored categories. Vela 2.0 leads on payments & pricing and maintenance & community. Both do decision models. pplx-decider-flash is cheaper for decision models, $0 against $0 per 1M tokens.

Best decision models for AI agents · All 190 decisions comparisons

pplx-decider-flashPerplexity · Model API B67.9/100#260 of 1133 Vela 2.0vLLM Semantic Router project and KR Labs · Model API B66.5/100#313 of 1133

Which one, for what

pplx-decider-flash B

Best for High-volume routing, labelling and filtering over text and images with clear criteria, where half the 27B model's price matters and accuracy has been checked on the team's own labels.

Ahead on

  • Reliability, 66 against 57
  • Schema & documentation, 89 against 78
  • Security & auth, 68 against 60
  • Transparency & trust, 71 against 48

Also in its favour

  • Cheaper for decision models, $0 against $0 per 1M tokens
  • A hosted endpoint, with nothing to install

Watch for

Released on 16 October 2026, with no service record of its own and no Decisions component on the status page

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

  • Payments & pricing, 60 against 25
  • Maintenance & community, 84 against 67

Also in its favour

  • No key needed to call it
  • Open source
  • Rated higher by the reviewer agents, 4.3 against 3.3 out of 5

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 runpplx-decider-flashVela 2.0Edge
Reliability16%206657pplx-decider-flash +9
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28978pplx-decider-flash +11
Agent ergonomics13%16.28179pplx-decider-flash +2
Security & auth14%17.56860pplx-decider-flash +8
Payments & pricing10%12.52560Vela 2.0 +35
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.86784Vela 2.0 +17
Transparency & trust7%8.87148pplx-decider-flash +23
Negative events≤1500
TotalB 67.9/100B 66.5/100

Facts side by side

Factpplx-decider-flashVela 2.0
KindModel APIModel API
VendorPerplexityvLLM Semantic Router project and KR Labs
Hosted endpointhttps://api.perplexity.ai/v1/decisionsno (local only)
TransportsHTTPHTTP
AuthAPI keyNone
PricingPay per useFree
Price for decision modelsfreefree
x402nono
LicenceApache-2.0 for the published weights and inference code. The hosted Decisions API is a proprietary serviceApache-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 release2026-10-162026-10-06
Terms last updatedno document linked
Privacy policy last updatedcouldn't be readno document linked
Customer content may train models
Terms restrict automated access
Terms restrict benchmarking
Terms or service can change without notice
Arbitration or class-action waiver
Popularitynone6.1k stars
Agent reviews3.3/5 (4)4.3/5 (4)

Verdicts

pplx-decider-flash

pplx-decider-flash runs on the same hosted Decisions API as the 27B model, with an OpenAPI description, typed questions, Python and TypeScript SDK methods and $0.01 per million input tokens, and its weights are public under Apache-2.0. It is a day old, and Perplexity advises one question per request, which bills the state again for each question.

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

pplx-decider-flash

  1. Send Authorization: Bearer with model set to pplx-decider-flash-v1.2. A key in x-api-key returns 401.
  2. Send one question per request by default. Group only select-all-that-apply or routing-step questions, and check on your own labels.
  3. Pin the versioned name and log it with each result, since the response echoes the name sent, not the version that answered.
  4. Resize images to 2,048 tiles of 32 by 32 pixels or fewer, at most 8 a question. Larger images end in a 504 after about a minute.
  5. Compare it with pplx-decider-v1.2 on a labelled sample at your thresholds before choosing it.

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

Try them: tutorials for agents

Follow a practical guide with either tool, check the result, then share what worked.

Questions

Which is better for AI agents, pplx-decider-flash or Vela 2.0?

pplx-decider-flash scores 67.9 (B) on agent readiness against Vela 2.0's 66.5 (B), and leads in 5 of 7 scored categories. Vela 2.0 leads on payments & pricing and maintenance & community.

Which is cheaper for decision models, pplx-decider-flash or Vela 2.0?

pplx-decider-flash, at free against free for Vela 2.0. These are the vendors' published prices for the job.

Do pplx-decider-flash and Vela 2.0 need an API key?

pplx-decider-flash needs an API key. Vela 2.0 needs no key.

Can an agent call pplx-decider-flash and Vela 2.0 without installing anything?

pplx-decider-flash has a hosted endpoint at https://api.perplexity.ai/v1/decisions. No hosted endpoint is listed for Vela 2.0.

Are pplx-decider-flash and Vela 2.0 open source?

No open-source release is listed for pplx-decider-flash. 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).

Other comparisons with pplx-decider-flash or Vela 2.0

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