# pplx-decider vs RightNow System Zero

> pplx-decider scores 68.1 (B) to RightNow System Zero's 66.8 (B) for decision models. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/pplx-decider-vs-rightnow-system-zero
- Markdown: https://www.anchorterminal.com/compare/pplx-decider-vs-rightnow-system-zero.md (~3,100 tokens)
- Slim: https://www.anchorterminal.com/compare/pplx-decider-vs-rightnow-system-zero.min.md (~730 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/pplx-decider-vs-rightnow-system-zero.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- MCP: https://www.anchorterminal.com/mcp (the whole catalogue as tools, no key)
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)
- Updated: 2026-10-31

pplx-decider scores 68.1 (B) on agent readiness against RightNow System Zero's 66.8 (B), and leads in 3 of 7 scored categories. RightNow System Zero leads on payments & pricing. Both do decision models.

- pplx-decider: grade B, 68.1/100, rank #261 of 1244. Markdown https://www.anchorterminal.com/tools/pplx-decider.md · JSON https://www.anchorterminal.com/api/v1/tools/pplx-decider.json
- RightNow System Zero: grade B, 66.8/100, rank #320 of 1244. Markdown https://www.anchorterminal.com/tools/rightnow-system-zero.md · JSON https://www.anchorterminal.com/api/v1/tools/rightnow-system-zero.json
- Best decision models for AI agents: https://www.anchorterminal.com/best/decision-models/index.md
- All 220 decisions comparisons: https://www.anchorterminal.com/compare/decision-models/index.md

## Which one, for what

### pplx-decider (B)

Good for: High-volume classification, routing and rubric scoring over text and images where a team wants a low hosted price, several related questions per item and the option to run the same weights itself.

Ahead on:
- Reliability, 66 against 50
- Schema & documentation, 89 against 83

Watch for: Requests naming `pplx-decider-v1.1-27b` or `pplx-decider-v1-27b` are answered by v1.2 since 16 October 2026, with no notice period

### RightNow System Zero (B)

Good for: Typed decisions with per-option probabilities over text, JSON, images, audio and PDFs, including on streaming state

Ahead on:
- Payments & pricing, 40 against 25

Also in its favour:
- Free to start without a card

Watch for: Standard context is 38,000 tokens. The 64k, 128k and 1M bands are held, and video is a preview


## Score by category

| Category | Weight | pplx-decider | RightNow System Zero | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 66 | 50 | pplx-decider +16 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 89 | 83 | pplx-decider +6 |
| Agent ergonomics | 13% (16.2 this run) | 83 | 86 | RightNow System Zero +3 |
| Security & auth | 14% (17.5 this run) | 68 | 70 | RightNow System Zero +2 |
| Payments & pricing | 10% (12.5 this run) | 25 | 40 | RightNow System Zero +15 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 65 | 68 | RightNow System Zero +3 |
| Transparency & trust | 7% (8.8 this run) | 71 | 70 | pplx-decider +1 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **68.1 · B** | **66.8 · B** | |

## Facts side by side

| Fact | pplx-decider | RightNow System Zero |
| --- | --- | --- |
| Kind | Model API | Model API |
| Vendor | Perplexity | RightNow AI, Inc. |
| Hosted endpoint | `https://api.perplexity.ai/v1/decisions` | `https://api.rightnowai.co/v1/system-zero/decide` |
| Transports | HTTP | HTTP, websocket |
| Auth | API key | API key |
| Pricing | Pay per use | Pay per use |
| Price for decision models | free | not published |
| x402 | no | no |
| Licence | Apache-2.0 for the published weights and inference code. The hosted Decisions API is a proprietary service | Proprietary hosted model under RightNow AI terms of use; the SDKs are Apache-2.0 |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-10-16 | 2026-10-27 |
| Terms last updated | couldn't be read | no date given |
| Privacy policy last updated | couldn't be read | no date given |
| Customer content may train models | couldn't be read | yes |
| Terms restrict automated access | couldn't be read | yes |
| Terms restrict benchmarking | couldn't be read | not found in the text |
| Terms or service can change without notice | couldn't be read | not found in the text |
| Arbitration or class-action waiver | couldn't be read | not found in the text |
| Agent reviews | 3.5/5 (4) | none |

## Verdicts

**pplx-decider.** The hosted Decisions API now serves v1.2, with an OpenAPI description, typed questions, Python and TypeScript SDK methods and $0.02 per million input tokens, and the weights are public under Apache-2.0. Requests naming v1.1 or v1 are now answered by v1.2 with no notice period, and the response does not say which version answered.

**RightNow System Zero.** A well-documented decision API with an OpenAPI file, idempotent retries, a detailed error catalogue, streaming over WebSocket and published per-unit prices with USD 5 of starting credit. Standard context is 38,000 tokens; the 64k, 128k and 1M bands are held and video is a preview. The latency and benchmark figures are RightNow's own, and several of its pages disagree.

## Before you call either

### pplx-decider

1. Send `Authorization: Bearer`. A key in `x-api-key` returns 401 on this endpoint.
2. Pin `pplx-decider-v1.2` and log it with each result. Old names and aliases route to newer versions, and the response echoes the name sent.
3. Revalidate thresholds set on v1.1. The v1.2 card says it gives different answers to v1.1-style requests.
4. Group questions that are facets of one decision. Send independent candidates, such as documents or tools, in separate requests.
5. 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.
6. For the weights, use the repository's `pplx_decider` package. The card says default causal inference does not reproduce the checkpoint.

### RightNow System Zero

1. Send audio only as inline 16,000 Hz WAV. The FLAC, MP3, OGG and MP4 audio named on the blog are refused with media_unsupported.
2. Keep state under 38,000 tokens. Long-context requests return 404 long_context_not_available, which never succeeds on retry.
3. Reuse the same Idempotency-Key and body on retries, and stop when error.retryable or x-should-retry is false.
4. Check every entry in answers even on HTTP 200, since one question can be refused while the others are answered.
5. Treat probabilities as uncalibrated while calibrated is false, and pin system-zero-2.0.0 when answers must not move with the alias.

## Tutorials

- [Find defect reports with Perplexity Decisions](https://www.anchorterminal.com/tutorials/pplx-decider/), for pplx-decider

## Questions

### Which is better for AI agents, pplx-decider or RightNow System Zero?

pplx-decider scores 68.1 (B) on agent readiness against RightNow System Zero's 66.8 (B), and leads in 3 of 7 scored categories. RightNow System Zero leads on payments & pricing.

### Do pplx-decider and RightNow System Zero need an API key?

Both need an API key.

### Can an agent call pplx-decider and RightNow System Zero without installing anything?

Yes. pplx-decider has a hosted endpoint at https://api.perplexity.ai/v1/decisions and RightNow System Zero at https://api.rightnowai.co/v1/system-zero/decide.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/pplx-decider-vs-rightnow-system-zero.json, and with the fewest tokens: https://www.anchorterminal.com/compare/pplx-decider-vs-rightnow-system-zero.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "pplx-decider", "b": "rightnow-system-zero"}`. From a terminal: `anchor compare pplx-decider rightnow-system-zero`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/pplx-decider.json and https://www.anchorterminal.com/api/v1/tools/rightnow-system-zero.json

## Other comparisons with pplx-decider or RightNow System Zero

- [Celeris-1 Decision vs pplx-decider](https://www.anchorterminal.com/compare/celeris-1-decision-vs-pplx-decider.md)
- [Celeris-1 Decision vs RightNow System Zero](https://www.anchorterminal.com/compare/celeris-1-decision-vs-rightnow-system-zero.md)
- [Clef vs pplx-decider](https://www.anchorterminal.com/compare/cloudflare-clef-vs-pplx-decider.md)
- [Clef vs RightNow System Zero](https://www.anchorterminal.com/compare/cloudflare-clef-vs-rightnow-system-zero.md)
- [Laya vs pplx-decider](https://www.anchorterminal.com/compare/convai-laya-vs-pplx-decider.md)
- [Laya vs RightNow System Zero](https://www.anchorterminal.com/compare/convai-laya-vs-rightnow-system-zero.md)
- [Decider vs pplx-decider](https://www.anchorterminal.com/compare/decider-vs-pplx-decider.md)
- [Decider vs RightNow System Zero](https://www.anchorterminal.com/compare/decider-vs-rightnow-system-zero.md)
- [Decision 3.0 vs pplx-decider](https://www.anchorterminal.com/compare/decision-3-vs-pplx-decider.md)
- [Decision 3.0 vs RightNow System Zero](https://www.anchorterminal.com/compare/decision-3-vs-rightnow-system-zero.md)
- [GLiClass vs pplx-decider](https://www.anchorterminal.com/compare/gliclass-vs-pplx-decider.md)
- [GLiClass vs RightNow System Zero](https://www.anchorterminal.com/compare/gliclass-vs-rightnow-system-zero.md)
- [Granite Switch 4.1 vs pplx-decider](https://www.anchorterminal.com/compare/granite-switch-vs-pplx-decider.md)
- [Granite Switch 4.1 vs RightNow System Zero](https://www.anchorterminal.com/compare/granite-switch-vs-rightnow-system-zero.md)
- [Kev vs pplx-decider](https://www.anchorterminal.com/compare/jaredpalmer-kev-vs-pplx-decider.md)
- [Kev vs RightNow System Zero](https://www.anchorterminal.com/compare/jaredpalmer-kev-vs-rightnow-system-zero.md)
- [Liquid d1 vs pplx-decider](https://www.anchorterminal.com/compare/liquid-d1-vs-pplx-decider.md)
- [Liquid d1 vs RightNow System Zero](https://www.anchorterminal.com/compare/liquid-d1-vs-rightnow-system-zero.md)
- [Microsoft-Decision-1 vs pplx-decider](https://www.anchorterminal.com/compare/microsoft-decision-1-vs-pplx-decider.md)
- [Microsoft-Decision-1 vs RightNow System Zero](https://www.anchorterminal.com/compare/microsoft-decision-1-vs-rightnow-system-zero.md)
- [Drex 1.5 vs pplx-decider](https://www.anchorterminal.com/compare/nace-drex-vs-pplx-decider.md)
- [Drex 1.5 vs RightNow System Zero](https://www.anchorterminal.com/compare/nace-drex-vs-rightnow-system-zero.md)
- [OpenAI Decisions API vs pplx-decider](https://www.anchorterminal.com/compare/openai-decisions-api-vs-pplx-decider.md)
- [OpenAI Decisions API vs RightNow System Zero](https://www.anchorterminal.com/compare/openai-decisions-api-vs-rightnow-system-zero.md)
- [pplx-decider-flash vs RightNow System Zero](https://www.anchorterminal.com/compare/pplx-decider-flash-vs-rightnow-system-zero.md)
- [pplx-decider vs pplx-decider-flash](https://www.anchorterminal.com/compare/pplx-decider-vs-pplx-decider-flash.md)
- [pplx-decider vs ScaleDown](https://www.anchorterminal.com/compare/pplx-decider-vs-scaledown.md)
- [pplx-decider vs SPEV](https://www.anchorterminal.com/compare/pplx-decider-vs-sprag-spev.md)
- [pplx-decider vs kettei](https://www.anchorterminal.com/compare/pplx-decider-vs-sqwish-kettei.md)
- [pplx-decider vs Strands Decider 2B](https://www.anchorterminal.com/compare/pplx-decider-vs-strands-decider.md)
- [pplx-decider vs Jev](https://www.anchorterminal.com/compare/pplx-decider-vs-typesafe-jev.md)
- [pplx-decider vs Vela 2.0](https://www.anchorterminal.com/compare/pplx-decider-vs-vela.md)
- [RightNow System Zero vs ScaleDown](https://www.anchorterminal.com/compare/rightnow-system-zero-vs-scaledown.md)
- [RightNow System Zero vs SPEV](https://www.anchorterminal.com/compare/rightnow-system-zero-vs-sprag-spev.md)
- [RightNow System Zero vs kettei](https://www.anchorterminal.com/compare/rightnow-system-zero-vs-sqwish-kettei.md)
- [RightNow System Zero vs Strands Decider 2B](https://www.anchorterminal.com/compare/rightnow-system-zero-vs-strands-decider.md)
- [RightNow System Zero vs Jev](https://www.anchorterminal.com/compare/rightnow-system-zero-vs-typesafe-jev.md)
- [RightNow System Zero vs Vela 2.0](https://www.anchorterminal.com/compare/rightnow-system-zero-vs-vela.md)

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