Pay for 1inch APIs by the call with x402

Access 1inch APIs without committing to a monthly subscription. x402 pay-per-call lets verified 1inch Business customers fund a prepaid USDC balance on Base and pay only for the requests they make.

You no longer need a monthly subscription to access 1inch APIs beyond the free tier. x402 pay-per-call access is now available through 1inch Business. Developers can pay for individual API requests in USDC on Base, without managing monthly billing cycles or recurring allowances.

The new payment option runs complementary to the current subscriptions. If the customer has run out of calls, they are not blocked and can continue on a pay-per-call basis. You can choose the model that best fits your usage.

From monthly plans to pay-per-call access

A subscription works well when API usage is consistent and predictable. It can be less practical when demand is occasional, experimental or generated autonomously by software.

x402 pay-per-call provides another option. You deposit USDC into a prepaid channel and authorize individual API requests with signed offchain vouchers. Each request is charged according to usage, while settlement happens onchain in the background.

The prepaid balance does not expire or reset at the end of the month. Unused funds remain available until you spend or withdraw them.

What is x402?

x402 is an open payment protocol, originally developed by Coinbase, built around the HTTP 402 “Payment Required” status code.

HTTP already includes status codes for common interactions, such as successful requests, missing pages and unauthorized access. The 402 status code was reserved for payments but historically had no widely adopted implementation.

x402 turns that status code into a machine-readable payment flow. An API can respond with payment requirements, and a compatible client can authorize the charge before continuing with the request.

The model is particularly relevant for machine-to-machine payments. API clients and autonomous AI agents can identify the price of a request, approve payment and continue without requiring a person to complete a checkout flow.

How x402 pay-per-call works on 1inch Business

Setting up pay-per-call access involves four steps:

1. Complete the 1inch Business onboarding process.
2. Link an application wallet under Applications → Application Details -> x402 wallets.
3. Fund a prepaid channel with USDC on Base. The minimum initial deposit is roughly $2.
4. Make API requests as needed.

Each paid request is authorized through a signed offchain voucher. The API verifies the signature without waiting for an onchain transaction, while batches of payments are settled onchain separately. This structure keeps blockchain settlement away from the request path.

Pay only for the calls you make

x402 pay-per-call does not require a monthly commitment. You do not need to select a recurring plan, manage a billing cycle or use an allowance before it resets. Your costs follow your actual API activity.

The model can suit developers who occasionally exceed the free tier, teams evaluating 1inch APIs and applications with usage that changes significantly from month to month. Existing subscribers can also use pay-per-call access for additional capacity beyond their plan quota.

Built for crypto-native applications and AI agents

x402 handles payment directly at the HTTP layer, using USDC on Base at launch. A machine-readable 402 response allows compatible software to understand that payment is required and determine how to proceed. Autonomous agents can use the same flow to purchase API access programmatically.

The payment model removes the need for an agent to manage invoices, card details or a conventional subscription account for every service it uses. Human-controlled applications can use the same infrastructure. x402 is not limited to AI agents.

Low-latency requests with background settlement

Settling every API call as a separate blockchain transaction would add latency and make small payments expensive.

1inch Business uses a batch-settlement model instead. Each request is checked through a fast offchain signature verification, with no onchain confirmation required before the API responds.

Thousands of vouchers can later be combined into periodic onchain claims. Batch settlement spreads gas costs across many requests, allowing the effective gas overhead per API call to approach zero at scale. The API request remains responsive while settlement runs in the background.

A prepaid balance that does not reset

The USDC deposit remains available until it is used or withdrawn. Monthly subscription allowances often expire or reset at the end of a billing period. An x402 prepaid balance carries over indefinitely, allowing teams to fund access once and use it according to actual demand. Unused funds can be withdrawn rather than lost at the end of a cycle.

Open payment infrastructure

x402 is an open protocol rather than a proprietary payment wall. Developers building x402-compatible applications can connect to a production API endpoint that uses the standard. The open approach also allows payment logic to be integrated into wallets, agents and other API clients without relying on a platform-specific checkout system.

The initial 1inch Business implementation uses the batch-settlement scheme. Generic clients that support only the standard exact-payment scheme require additional integration and cannot use the endpoint out of the box.

Designed to limit relay control

The payment flow uses a three-key trust model. A gas-paying relay can broadcast settlement transactions but cannot independently move customer funds. Payment authorization remains tied to signed vouchers and the rules of the prepaid channel.

The relay therefore handles transaction delivery without receiving unrestricted control over the deposited balance.

Who can benefit from x402 pay-per-call?

x402 pay-per-call access can support several usage patterns:

• Web3 developers who prefer paying for infrastructure in crypto
• Occasional or low-volume customers who need API requests beyond the free tier
• Teams evaluating 1inch APIs before choosing a subscription
• Autonomous AI agents purchasing API access programmatically
• Existing subscribers that need temporary overflow capacity
• Developers building applications around the x402 standard

Monthly subscriptions remain available for teams with sustained and predictable usage.

Launch requirements

x402 pay-per-call access launches with several requirements and limitations:

• The user must complete the 1inch Business verification process.
• Payments and associated onchain activity are subject to monitoring and screening in line with 1inch risk management processes
• Payments are available in USDC on Base.
• An application wallet must be linked through 1inch Business.
• The minimum prepaid deposit is roughly $2.
• Access is enabled per organization behind a feature flag.
• The launch uses the batch-settlement scheme.
• Generic clients supporting only exact-scheme payments require additional integration.
• Browser requests are directed to 1inch Business to link a wallet.
• An in-browser payment widget is not available.

Choose the payment model that fits your usage

x402 pay-per-call expands the ways developers can access 1inch APIs. It does not replace existing subscription plans.

A monthly plan remains suitable for predictable, sustained demand. Pay-per-call access offers more flexibility for occasional, variable or autonomous usage.

Link a wallet and start paying per call.

Disclaimer: This article is for informational purposes only. Features, pricing, and availability are subject to change and to the 1inch Business terms; access requires completion of the 1inch Business verification process and may not be available in all jurisdictions. Nothing in this article constitutes financial, legal, or tax advice.