llms.txt

# x402.review

> Reviews of x402 services, prices, and the agents that use them. Every price on this site is read from the service's live 402 handshake, never copied from a price list.

## Method

- An unpaid HTTP request to a paid endpoint returns 402 with a payment challenge. The challenge is decoded and recorded; that amount is the price this site publishes.
- A catalogue figure, a price list or an about page is used to check a number, never to supply one.
- Metered (`upto`) ceilings are published against the `max_tokens` that produced them, because the ceiling moves with the output allowance.
- Behaviour is tested on the endpoint where one exists. Where no endpoint exists, the piece is a preview: it states what is specified and what is not, and no price is published.

## Start here

- [The services reviewed](https://x402.review/the-services-reviewed/) — all seven services with state and measured price.
- [DeepSeek, Qwen and HyperFusion compared](https://x402.review/2026/10/31/inference-endpoints-compared/) — the same call, three products, and a decision rule by constraint.

## Service reviews

- [DeepSeek](https://x402.review/2026/10/31/deepseek-review/) — chat completions, `deepseek-v4-flash` / `-pro`, $0.00700 exact on Base.
- [Qwen](https://x402.review/2026/10/31/qwen-review/) — `qwen3.8-flash` $0.00875 and `qwen3.8-max` $0.256125 on Base, a 29x gap.
- [HyperFusion](https://x402.review/2026/10/31/hyperfusion-review/) — DeepSeek, Qwen and MiniMax on UAE-domiciled GPUs, same price as the model elsewhere, no streaming.
- [SpiralStake](https://x402.review/2026/10/31/spiralstake-review/) — unsigned leverage transactions, $0.006125 a build; the agent assembles, the wallet signs.
- [Wolfram Alpha](https://x402.review/2026/10/31/wolfram-alpha-review/) — pending review: deterministic computation, exact evaluation, charts, each with a citation.
- [ElevenLabs](https://x402.review/2026/10/31/elevenlabs-review/) — pending review: speech synthesis priced by the call.
- [Mage](https://x402.review/2026/10/31/mage-review/) — pending review: image and video generation, priced by the attempt.

## Jobs — how the work is done

- [Jobs index](https://x402.review/jobs/) — six families, the roles beneath them, and the measured month for each.

Fifty-six cluster articles sit beneath the six pillars: eight on audit, twelve on finance, ten on commercial operations, six on property, fourteen on content and knowledge, six on the front office. Each carries a table or checklist, a worked example and a stated limitation. Links to them are on the index page.
Six families of work, each written as a method rather than a product: the evidence the job needs, the ways it fails, what a month costs at measured prices, and what a human still signs.

- [Quality and compliance](https://x402.review/2026/10/31/quality-and-compliance/) — ISO 9001 internal audit: the programme, the evidence, the finding, and the certificate an agent cannot issue.
- [Finance and markets](https://x402.review/2026/10/31/finance-and-markets/) — three engines, four jobs, one price; why the desk costs more per call and less per question.
- [Commercial operations](https://x402.review/2026/10/31/commercial-operations/) — one record read from both ends: quote, comparison, approval, order, match.
- [Property](https://x402.review/2026/10/31/property/) — the six documents a deal turns on, and the valuation no agent may sign.
- [Content and knowledge](https://x402.review/2026/10/31/content-and-knowledge/) — research, draft, edit and distribute as one chain; the citation chain, and a measured month at $1.85.
- [Front office](https://x402.review/2026/10/31/front-office/) — the reply that cites its source, the escalation rule, the daily brief, and what neither role may send.

## Foundations

- [What x402 is](https://x402.review/2026/10/31/what-is-x402/) — the two-round handshake, `accepts`, the schemes, the facilitator, and the five ways settlement goes wrong.

## Agents

- [Assembled, not prompted](https://x402.review/2026/10/31/custom-agentic-ai/) — what a custom agent is: parts, connections, wallet, ceilings, record.
- [How an agent pays](https://x402.review/2026/10/31/how-an-agent-pays/) — the float, the three ceilings, the record, chain choice, metered calls and failure handling.

## Where to buy

- [x402.press services](https://x402.press/services/) — the marketplace: one page per service, nothing in review priced.
- [x402.press studio](https://studio.x402.press/) — custom agents assembled from parts.

## Disclosure

x402.review is published alongside x402.press, which sells the services reviewed here. The commercial relationship is disclosed in each piece; the method above is what keeps the reviews checkable.

## Contact

admin@x402.review — https://x402.review/contact/