# Drex 1.5 vs pplx-decider

> Drex 1.5 scores 69.7 (B) to pplx-decider's 62.9 (B) for decision models. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/nace-drex-vs-pplx-decider
- Markdown: https://www.anchorterminal.com/compare/nace-drex-vs-pplx-decider.md (~2,600 tokens)
- Slim: https://www.anchorterminal.com/compare/nace-drex-vs-pplx-decider.min.md (~780 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/nace-drex-vs-pplx-decider.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
- Updated: 2026-10-10

Drex 1.5 scores 69.7 (B) on agent readiness against pplx-decider's 62.9 (B), and leads in 6 of 7 scored categories. Both do decision models.

- Drex 1.5: grade B, 69.7/100, rank #172 of 954. Markdown https://www.anchorterminal.com/tools/nace-drex.md · JSON https://www.anchorterminal.com/api/v1/tools/nace-drex.json
- pplx-decider: grade B, 62.9/100, rank #418 of 954. Markdown https://www.anchorterminal.com/tools/pplx-decider.md · JSON https://www.anchorterminal.com/api/v1/tools/pplx-decider.json
- Best decision models for AI agents: https://www.anchorterminal.com/best/decision-models/index.md
- All 91 decisions comparisons: https://www.anchorterminal.com/compare/decision-models/index.md

## Which one, for what

### Drex 1.5 (B)

Good for: Routing, triage and yes or no gates inside an agent, where the caller supplies the options and acts on the probabilities. Suited to hosted use at a low per-token price, or to open weights where the licence fits.

Ahead on:
- Reliability, 80 against 61
- Agent ergonomics, 85 against 76
- Payments & pricing, 40 against 25
- Transparency & trust, 63 against 52

Watch for: The rank 1 claim comes from Nace's own run on Decision Index 0.3.1, and Drex is not on the public board for 0.3 or 0.2.1.

### pplx-decider (B)

Good 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.

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


## Score by category

| Category | Weight | Drex 1.5 | pplx-decider | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 80 | 61 | Drex 1.5 +19 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 88 | 90 | pplx-decider +2 |
| Agent ergonomics | 13% (16.2 this run) | 85 | 76 | Drex 1.5 +9 |
| Security & auth | 14% (17.5 this run) | 65 | 61 | Drex 1.5 +4 |
| Payments & pricing | 10% (12.5 this run) | 40 | 25 | Drex 1.5 +15 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 65 | 62 | Drex 1.5 +3 |
| Transparency & trust | 7% (8.8 this run) | 63 | 52 | Drex 1.5 +11 |
| Negative events | ≤15 | -2 | 0 | |
| **Total** | | **69.7 · B** | **62.9 · B** | |

## Facts side by side

| Fact | Drex 1.5 | pplx-decider |
| --- | --- | --- |
| Kind | Model API | Model API |
| Vendor | Nace AI, Inc. (Nace.AI) | Perplexity |
| Hosted endpoint | `https://console.nace.ai/v1/systemone` | `https://api.perplexity.ai/v1/decisions` |
| Transports | HTTP | HTTP |
| Auth | API key | API key |
| Pricing | Freemium | Pay per use |
| Price for decision models | not published | free |
| x402 | no | no |
| Licence | Hosted API under the Nace AI Terms of Service, last updated 5 May 2026. Weights under the Nace AI Open RAIL-M licence (modified, version 1.0, October 2026), which is not an open-source licence. Businesses above $1 million in revenue or funding need a separate commercial licence, and competing products are excluded. The bundled code/kev package, derived from Jared Palmer's Kev (https://github.com/jaredpalmer/kev), and the GitHub repository are Apache-2.0, and the agent skill is MIT. | Apache-2.0 for the published weights. The hosted Decisions API is a proprietary service |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-09-28 | 2026-10-05 |
| Terms last updated |  | couldn't be read |
| Privacy policy last updated |  | couldn't be read |
| Customer content may train models |  | couldn't be read |
| Terms restrict automated access |  | couldn't be read |
| Terms restrict benchmarking |  | couldn't be read |
| Terms or service can change without notice |  | couldn't be read |
| Arbitration or class-action waiver |  | couldn't be read |
| Popularity | 318 npm/wk, 156 PyPI/wk | none |

## Verdicts

**Drex 1.5.** The hosted endpoint has a public OpenAPI document, published limits and pinned model versions, at $0.05 per million input tokens with no output charge. The #1 under 10B claim rests on Nace's own run, since Drex is absent from both public boards. Weights carry Open RAIL-M, which requires a commercial licence above $1 million in revenue or funding.

**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.

## Before you call either

### Drex 1.5

1. Call https://console.nace.ai/v1/systemone with Authorization: Bearer nace_sk_..., and pin model drex-v1.5 rather than drex-latest in production.
2. Stop on 402 insufficient_credit or 402 payment_required until credit is topped up or the unpaid invoice is paid.
3. Retry 429 and 529 after retry-after-ms. On a 422 for an unknown model, use one of the ids the error message lists.
4. Keep state below 131,072 tokens and the body below 1,048,576 bytes, and send at most 512 questions per request.
5. Keep the key on a server. A key in browser code is exposed, and the /v1 routes send no Access-Control-Allow-Origin header.
6. Check usage.input_tokens and the usage CSV after retries, since /v1/systemone documents no idempotency key.

### 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.

## Questions

### Which is better for AI agents, Drex 1.5 or pplx-decider?

Drex 1.5 scores 69.7 (B) on agent readiness against pplx-decider's 62.9 (B), and leads in 6 of 7 scored categories.

### Do Drex 1.5 and pplx-decider need an API key?

Both need an API key.

### Can an agent call Drex 1.5 and pplx-decider without installing anything?

Yes. Drex 1.5 has a hosted endpoint at https://console.nace.ai/v1/systemone and pplx-decider at https://api.perplexity.ai/v1/decisions.


## For agents

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

## Other comparisons with Drex 1.5 or pplx-decider

- [Celeris-1 Decision vs Drex 1.5](https://www.anchorterminal.com/compare/celeris-1-decision-vs-nace-drex.md)
- [Celeris-1 Decision vs pplx-decider](https://www.anchorterminal.com/compare/celeris-1-decision-vs-pplx-decider.md)
- [Clef vs Drex 1.5](https://www.anchorterminal.com/compare/cloudflare-clef-vs-nace-drex.md)
- [Clef vs pplx-decider](https://www.anchorterminal.com/compare/cloudflare-clef-vs-pplx-decider.md)
- [Laya vs Drex 1.5](https://www.anchorterminal.com/compare/convai-laya-vs-nace-drex.md)
- [Laya vs pplx-decider](https://www.anchorterminal.com/compare/convai-laya-vs-pplx-decider.md)
- [Decider vs Drex 1.5](https://www.anchorterminal.com/compare/decider-vs-nace-drex.md)
- [Decider vs pplx-decider](https://www.anchorterminal.com/compare/decider-vs-pplx-decider.md)
- [GLiClass vs Drex 1.5](https://www.anchorterminal.com/compare/gliclass-vs-nace-drex.md)
- [GLiClass vs pplx-decider](https://www.anchorterminal.com/compare/gliclass-vs-pplx-decider.md)
- [Kev vs Drex 1.5](https://www.anchorterminal.com/compare/jaredpalmer-kev-vs-nace-drex.md)
- [Kev vs pplx-decider](https://www.anchorterminal.com/compare/jaredpalmer-kev-vs-pplx-decider.md)
- [Liquid d1 vs Drex 1.5](https://www.anchorterminal.com/compare/liquid-d1-vs-nace-drex.md)
- [Liquid d1 vs pplx-decider](https://www.anchorterminal.com/compare/liquid-d1-vs-pplx-decider.md)
- [Microsoft-Decision-1 vs Drex 1.5](https://www.anchorterminal.com/compare/microsoft-decision-1-vs-nace-drex.md)
- [Microsoft-Decision-1 vs pplx-decider](https://www.anchorterminal.com/compare/microsoft-decision-1-vs-pplx-decider.md)
- [Drex 1.5 vs OpenAI Decisions API](https://www.anchorterminal.com/compare/nace-drex-vs-openai-decisions-api.md)
- [Drex 1.5 vs Strands Decider 2B](https://www.anchorterminal.com/compare/nace-drex-vs-strands-decider.md)
- [Drex 1.5 vs Jev](https://www.anchorterminal.com/compare/nace-drex-vs-typesafe-jev.md)
- [Drex 1.5 vs Vela 2.0](https://www.anchorterminal.com/compare/nace-drex-vs-vela.md)
- [OpenAI Decisions API vs pplx-decider](https://www.anchorterminal.com/compare/openai-decisions-api-vs-pplx-decider.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)