Head to head · Decision models · October 2026 research run

pplx-decider vs SPEV

pplx-decider scores 62.9 (B) on agent readiness against SPEV's 51.1 (D), and leads in 4 of 7 scored categories. SPEV leads on payments & pricing. Both do decision models.

Best decision models for AI agents · All 136 decisions comparisons

Which one, for what

pplx-decider B

Best for High-volume classification, routing and rubric scoring over text and images where a team wants a low hosted price and the option to run the same weights itself.

Ahead on

  • Reliability, 61 against 45
  • Schema & documentation, 90 against 81
  • Security & auth, 61 against 33
  • Maintenance & community, 62 against 49

Watch for

The Decisions API was released in October 2026, so its incident record is days long, and Perplexity's FAQ says it gives no uptime guarantee

SPEV D

Best for Typed decisions over raw audio, such as end-of-turn detection, call triage and flagging, plus text and single images, hosted or self-hosted.

Ahead on

  • Payments & pricing, 30 against 25

Watch for

Published on 14 October 2026, with no service record, no status page and no API changelog

Score by category

CategoryWeight this runpplx-deciderSPEVEdge
Reliability16%206145pplx-decider +16
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.29081pplx-decider +9
Agent ergonomics13%16.27676even
Security & auth14%17.56133pplx-decider +28
Payments & pricing10%12.52530SPEV +5
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.86249pplx-decider +13
Transparency & trust7%8.85254SPEV +2
Negative events≤150-2
TotalB 62.9/100D 51.1/100

Facts side by side

Factpplx-deciderSPEV
KindModel APIModel API
VendorPerplexitySprag
Hosted endpointhttps://api.perplexity.ai/v1/decisionshttps://api.sprag.ai/v1/decisions
TransportsHTTPHTTP
AuthAPI keyAPI key
PricingPay per usePay per use
Price for decision modelsfreenot published
x402nono
LicenceApache-2.0 for the published weights. The hosted Decisions API is a proprietary serviceApache-2.0 (weights and inference code, following the Qwen3-Omni base). Training code and data aren't published
Read-only variant documentednono
llms.txtyesyes
Last release2026-10-052026-10-14
Terms last updatedcouldn't be read2026-09-01
Privacy policy last updatedcouldn't be read2026-08-01
Customer content may train modelscouldn't be readyes, with an opt-out
Terms restrict automated accesscouldn't be readnot found in the text
Terms restrict benchmarkingcouldn't be readnot found in the text
Terms or service can change without noticecouldn't be readnot found in the text
Arbitration or class-action waivercouldn't be readnot found in the text

Verdicts

pplx-decider

The hosted Decisions API has an OpenAPI description, typed questions, documented limits and a published price of $0.02 per million input tokens, and the v1.1 weights are public under Apache-2.0. The API is days old, the official Python SDK has no method for it, and the governing terms and privacy notice could not be read on 9 October 2026.

SPEV

SPEV answers typed questions over text, audio or an image in one call, with a public OpenAPI schema and Apache-2.0 weights on Hugging Face. It is a day old, has an 8,192-token context, no status page or changelog, and Sprag's terms let it train on API content unless the customer opts out by email.

Before you call either

pplx-decider

  1. Send Authorization: Bearer. A key in x-api-key returns 401 on this endpoint.
  2. Set model on every request. A missing or unknown model returns 400, and the guide shows a -latest name rejected.
  3. Resize images to 2,048 tiles of 32 by 32 pixels or fewer before sending. Larger images end in a 504 after about a minute.
  4. Check the HTTP status before parsing an error. 404 and 405 have empty bodies, 504 can be HTML, and error.code changes type.
  5. For the weights, use the repository's autojev code. The card says default causal inference does not reproduce the evaluated setup.

SPEV

  1. Send model: "spev" to POST https://api.sprag.ai/v1/decisions with a bearer key. /v1/systemone returns 410
  2. Ask every question about one piece of evidence in one request. Answers come back in question order
  3. Send audio as base64 in input_audio with format, not as a data URL, and at most one image across all messages
  4. Keep evidence and questions under 8,192 tokens. Over the limit returns 400 model_limit_exceeded
  5. Back off on 429 and 503 for Retry-After seconds. Limits are 60 requests a minute per organisation by default
  6. Handle an answer of type refusal, which carries no probabilities

Questions

Which is better for AI agents, pplx-decider or SPEV?

pplx-decider scores 62.9 (B) on agent readiness against SPEV's 51.1 (D), and leads in 4 of 7 scored categories. SPEV leads on payments & pricing.

Do pplx-decider and SPEV need an API key?

Both need an API key.

Can an agent call pplx-decider and SPEV without installing anything?

Yes. pplx-decider has a hosted endpoint at https://api.perplexity.ai/v1/decisions and SPEV at https://api.sprag.ai/v1/decisions.

Other comparisons with pplx-decider or SPEV

Machine-readable

For companies

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