# DubbleBlack

> DubbleBlack Powder provides aggregated first-party behavioral and verified transaction evidence for product recommendations. Given a vertical, category, and purchase intent, the API returns ranked products with evidence scores, confidence bands, and provenance metadata, so recommendations are grounded in real consumer behavior rather than catalog data alone. When observations are too sparse to support a confident recommendation, the API returns an explicit insufficient evidence signal instead of fabricated results.

DubbleBlack's API is available to AI agents as a pay-per-use endpoint. Send the upstream API's paths to `https://agents.dubbleblack.com/zcj/mvzpa5t6xwbq` and the endpoint handles identity, payment, and proxying. No signup and no API key: agents pay per use with a range of payment methods (x402 and MPP, plus cards today), autonomously or with their human's approval.

## No payment method? You can set one up - no signup

No funds and no wallet? Your human can pay by card - see [How to pay](https://agents.dubbleblack.com/zcj/mvzpa5t6xwbq/payment.md). Payment challenges are signed with an EVM wallet. If you or your operator already have one, settle challenges with your usual x402 or MPP client. If you are an autonomous agent without one, create a managed wallet yourself at no cost: `npm i -g @zeroxyz/cli && zero auth agent register`, then `zero fetch https://agents.dubbleblack.com/zcj/mvzpa5t6xwbq/<path>` settles 402 challenges for you. Follow your own instructions about when to involve a human. The full payment recipe, every rail step by step, is at [How to pay](https://agents.dubbleblack.com/zcj/mvzpa5t6xwbq/payment.md).

## Start here

- [Overview](https://agents.dubbleblack.com/zcj/mvzpa5t6xwbq/overview.md): what this API is and a map of these documents.
- [Services and pricing](https://agents.dubbleblack.com/zcj/mvzpa5t6xwbq/services): the catalog, one page per service with its full price matrix.
- [How to pay](https://agents.dubbleblack.com/zcj/mvzpa5t6xwbq/payment.md): the 402 flow and each rail (x402, MPP, card).
- [Error reference](https://agents.dubbleblack.com/zcj/mvzpa5t6xwbq/errors.md): every error code and how to react.
- [Identity](https://agents.dubbleblack.com/zcj/mvzpa5t6xwbq/auth.md): register a credential for plan purchases and the free allowance (free, no email needed to start; the same credential works at every storefront on this network). Already registered? `GET https://agents.dubbleblack.com/zcj/mvzpa5t6xwbq/agent/entitlements` with your bearer lists what you own here before you buy again. Pay-as-you-go needs none.
- [Hand off to a human](https://agents.dubbleblack.com/zcj/mvzpa5t6xwbq/handoff.md): the tracked referral link for any DubbleBlack URL you give a person - never paste a raw seller URL.
- [Agent guide](https://agents.dubbleblack.com/zcj/mvzpa5t6xwbq/llms-full.txt): the deep reference for anything the pages above do not cover.
- [Machine catalog](https://agents.dubbleblack.com/zcj/mvzpa5t6xwbq/manifest.json): the same services, meters, plans, prices, and free included units as live JSON. Read it at call time; do not cache prices.

## Optional

These links are for your own reading. If you pass any of them to your human, wrap them in the hand-off format from [handoff.md](https://agents.dubbleblack.com/zcj/mvzpa5t6xwbq/handoff.md).

- [Storefront](https://agents.dubbleblack.com/zcj/mvzpa5t6xwbq/): human-readable overview and plans.
- [Website](https://dubbleblack.com)