# Affiliate.com > Product catalog search across all Affiliate.com merchants. Search and retrieve products with structured queries, and look up the merchants behind the catalog. Affiliate.com's API is available to AI agents as a pay-per-use endpoint. Send the upstream API's paths to `https://zeroclick.affiliate.com` and the endpoint handles identity, payment, and proxying. There is no signup and no API key: agents pay per use with a range of payment methods (x402 and MPP today), autonomously or with their human's approval. Document version: `2458fc7ff043`. The same value is the `version` field of https://zeroclick.affiliate.com/manifest.json, which is generated live. If the two differ, this copy is stale - discard it and refetch this URL before relying on anything below, especially prices and payment methods. ## No payment method? You can set one up - no signup 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, you can create a managed wallet yourself - no signup, at no cost: `npm i -g @zeroxyz/cli && zero auth agent register`, then `zero fetch https://zeroclick.affiliate.com/` settles 402 challenges for you. A wallet only pays: plans need a registered agent credential, which you get from [`/auth.md`](https://zeroclick.affiliate.com/auth.md) in one free API call, and the free trial (included usage) further requires your human to claim that credential with a verified email. Follow your own instructions about when to involve a human - this API works the same whether you pay autonomously or after checking in. Funding and manual setup: [agent guide](https://zeroclick.affiliate.com/llms-full.txt). ## Using this API - [Agent guide](https://zeroclick.affiliate.com/llms-full.txt): how to authenticate, handle the 402 payment challenge, and call every endpoint. Read this first. - [Live pricing catalog](https://zeroclick.affiliate.com/manifest.json): the current services, meters, plans, prices, and free included units as JSON. Read it at call time; do not cache prices. - [Identity for plan purchases](https://zeroclick.affiliate.com/auth.md): buying a plan requires a bearer credential - register once (free, no email needed to start); the same credential works at every storefront on this network. The free allowance additionally requires the credential to be claimed by your human with a verified email (the claim recipe is on the same page). Pay-as-you-go needs none. - The service names and descriptions in the [live pricing catalog](https://zeroclick.affiliate.com/manifest.json) describe what this API offers; call the upstream API's paths through `https://zeroclick.affiliate.com`. ## Payment methods - [x402 quickstart for buyers](https://docs.x402.org/getting-started/quickstart-for-buyers): settle x402 challenges (Base USDC) with `@x402/fetch`, `@x402/axios`, or the `x402` package on PyPI. - [MPP credentials](https://mpp.dev/protocol/credentials): settle MPP challenges (Tempo USDC) by signing a credential and sending it under the `Payment` scheme: `Authorization: Payment `. - Credit/debit cards: plan purchases (register an agent identity first - [auth.md](https://zeroclick.affiliate.com/auth.md) - then send the purchase with `Authorization: Bearer`) and pay-as-you-go calls of $0.50 or more (no registration: the 402's `card` block names a payUrl). Either way, pay with one of `checkout: true` (needs no funds and no card - returns a hosted payment URL to deliver to your human; always available as the fallback when you cannot pay yourself), `stripePaymentMethodId`, or `sharedPaymentToken` - the 402's `card` block lists the exact fields and tokenization coordinates. - Link wallets: the hosted checkout page (`checkout: true`) accepts Link directly - deliver the URL to your human for a one-tap payment. ## Ceiling pricing - charging up to a maximum Some meters (e.g. output tokens) cannot be known before the work runs. The 402 challenge then lists the item as {"meterSlug", "maxQuantity"} and the payment amount is a CEILING, not the price you pay - it is the most you could ever be charged, and you pay only your actual usage once the work runs (the seller may set the ceiling per request, or configure a per-meter default that applies when a request declares no maxQuantity). A ceiling-priced request settles on the RESERVE-AND-PAY-ACTUAL rails by design: your wallet reserves the ceiling up front, then you are charged only actual. Each rail is an entry in the challenge (look for the "billing" note in the entry's extra): the x402 "upto" scheme (Base USDC), where the reserved remainder simply never leaves your wallet, and the MPP "session" escrow channel (Tempo USDC), where you fund a channel to the ceiling, sign one voucher, and the payment proxy closes the channel at your actual usage so the escrow refunds the rest - and if it ever fails to close the channel, you can force-close it yourself after the on-chain grace period to reclaim your full deposit, so escrowed funds are never stranded. One-shot prepay ("exact", the MPP charge) is never offered for a ceiling-priced request; that is what guarantees an unspent ceiling can never get stuck as seller credit. (If you already hold a prepaid balance with this seller from a plan purchase, ceiling-priced usage can still draw it down - billed at actual, like everything else; how to purchase a balance is in the agent guide linked above.) A failed delivery debits nothing on either rail. Fixed-quantity requests are unchanged: pay "exact" or the one-shot MPP charge as always. Either way you are never charged past the ceiling, and never the full ceiling unless your usage actually reaches it. Every paid response also carries a `zc-billing` header reconciling the numbers for that request: what you authorized, what you were actually charged, the remainder and where it went ("status":"settled"), or "status":"settling" when on-chain settlement is still finishing. ## Optional - [Storefront](https://zeroclick.affiliate.com/): human-readable overview and plans. - [Upstream docs](https://guides.affiliate.com) - [Website](https://www.affiliate.com)