# Can AI agents buy from ZeroGPU? Yes. An AI agent can buy ZeroGPU's inference API from its agent storefront with no human step and no ZeroGPU account: it registers a free agent credential, buys Credits over x402 or MPP from $0.01 or by card from $0.50, and calls the API against that credit. An agent that does not register can buy a small anonymous credit with a wallet and call with its receipt, and [the buyer skill](https://agents.zerogpu.ai/zcj/sqyi4h0io5ac/SKILL.md) is where either path starts. ## At a glance - **Endpoints:** `POST https://agents.zerogpu.ai/zcj/sqyi4h0io5ac/zeroclick/v1/chat/completions` and `POST https://agents.zerogpu.ai/zcj/sqyi4h0io5ac/zeroclick/v1/responses`. Both are OpenAI-compatible and route each request by `model`. - **Identity:** a bearer credential, which is the agent identity the storefront issues. Registering is free and needs no email. - **Buy:** `POST https://agents.zerogpu.ai/zcj/sqyi4h0io5ac/plans/{planId}/purchase` for the Credits plan, with `amountUsd`. The plan's `purchase.url` is in `https://agents.zerogpu.ai/zcj/sqyi4h0io5ac/manifest.json`. - **Minimums:** $0.01 per purchase on a wallet rail, $0.50 by card. - **Payment:** you can pay over x402 (Base USDC) or MPP (Tempo USDC), which are the wallet rails. You can also pay by card through a hosted checkout or a shared payment token. - **Price example:** for `LFM2.5-1.2B-Instruct`, input is $0.02 per million tokens and output is $0.05 per million tokens. - **Response:** an OpenAI Chat Completions object, with the reply in `choices[0].message.content` and token counts in `usage`. - **Full purchase flow:** [the buyer skill](https://agents.zerogpu.ai/zcj/sqyi4h0io5ac/SKILL.md) ## Buy Credits and call the inference API Register a free agent credential with `POST https://agents.zerogpu.ai/zcj/sqyi4h0io5ac/agent/identity`, or reuse a ZeroClick credential you already hold, which works at every ZeroClick storefront. Trade it for an access token, then send `POST https://agents.zerogpu.ai/zcj/sqyi4h0io5ac/plans/{planId}/purchase` with the bearer and `{"amountUsd": ""}`. The storefront answers with a 402, the price quote: pay it on a wallet rail or by card and retry, and the purchase returns `purchased: true`. [The buyer skill](https://agents.zerogpu.ai/zcj/sqyi4h0io5ac/SKILL.md) has each step. Then call a model against the credit: ```http POST https://agents.zerogpu.ai/zcj/sqyi4h0io5ac/zeroclick/v1/chat/completions Authorization: Bearer Content-Type: application/json {"model": "LFM2.5-1.2B-Instruct", "messages": [{"role": "user", "content": "Summarize this support ticket in one sentence: ..."}]} ``` The response is `200` with a chat completion, and the tokens the call used are drawn from your Credits. ## Pay with a wallet, without registering 1. **Find the amount.** The Credits plan's `purchase.anonymousCredit` in the manifest gives the amount to buy, in `amountUsd`. 2. **Buy the credit.** Send `POST https://agents.zerogpu.ai/zcj/sqyi4h0io5ac/plans/{planId}/purchase` with no credential and the body `{"amountUsd": ""}`. Pay the wallet challenge over x402 or MPP. 3. **Save the receipt.** Store the response's `receiptId` privately. 4. **Call with the receipt.** Send `Authorization: Receipt ` on each call. Each receipt has these limits: - It spends only its own balance. - It cannot be topped up. - Losing it loses the remaining credit. - A call that needs more than the receipt holds needs Credits bought with a credential. ## What is charged, and when - **The purchase:** nothing is charged until you pay the purchase 402. Paying it completes the purchase and accepts the terms of service of both ZeroGPU and the platform. - **Calls:** each call draws its metered tokens from your credit. Credit you do not use stays on your balance. Each response that draws on credit carries a `zc-billing` header with `chargedUsd` and `remainingCreditUsd`. - **Unclaimed credentials:** an anonymous credential that is not claimed expires after a few days, and Credits bought with it expire too. Claiming the credential to a person's verified email keeps it. - **Exploring:** reading the storefront's documents and catalog needs no credential or payment. ## Frequently asked questions ### Does an agent need a ZeroGPU account or API key? No. The storefront issues the agent credential and handles payment. Calls go to the storefront's `/zeroclick/v1/` endpoints with that credential or an anonymous receipt. No ZeroGPU account or upstream key is involved. ### Is each API call paid separately? No. Calls draw on prepaid credit, and the only 402 is the Credits purchase, which you settle once. A call without a credential returns `401 bearer_required`. A call with a credential that holds no Credits returns `403 plan_required`, and the body lists the plans that cover the call. ### What happens when the credit runs out? A call returns `usage_exhausted`. Send `POST https://agents.zerogpu.ai/zcj/sqyi4h0io5ac/extend` with `amountUsd` and the same bearer, and pay the one 402 it returns. An anonymous receipt cannot be extended, so buy a new receipt instead. ### Can an agent pay by card? Yes, with a bearer credential and at least $0.50. Add `"checkout": true` to the purchase for an unpaid hosted checkout URL that a browser agent or a person can open. Alternatively, answer the 402's card challenge with a shared payment token over MPP. Poll the returned `statusUrl` until it reports complete before you spend the credit. ### Where should an agent start? Start with [the buyer skill](https://agents.zerogpu.ai/zcj/sqyi4h0io5ac/SKILL.md), which covers registration, purchase and recovery. ## Keep reading - [The buyer skill](https://agents.zerogpu.ai/zcj/sqyi4h0io5ac/SKILL.md): the full purchase and recovery flow - [How to pay](https://agents.zerogpu.ai/zcj/sqyi4h0io5ac/payment.md): x402, MPP and card step by step - [Agent identity](https://agents.zerogpu.ai/zcj/sqyi4h0io5ac/auth.md): register, exchange and claim a credential - [Error reference](https://agents.zerogpu.ai/zcj/sqyi4h0io5ac/errors.md): every code and how to react - [Catalog](https://agents.zerogpu.ai/zcj/sqyi4h0io5ac/manifest.json): live services, plans and prices --- Updated 2026-10-14. All ZeroGPU guides: https://agents.zerogpu.ai/guides.md. Storefront: https://agents.zerogpu.ai/zcj/sqyi4h0io5ac/llms.txt.