x402 API

DGrid x402 API is DGrid's pay-per-inference access mode for api payments. Instead of creating an account, pre-funding a balance, or managing separate billing flows, developers and autonomous agents can pay LLM inference costs directly through the x402 payment protocol as part of the API request lifecycle.

This makes x402 especially useful for:

• Agents and autonomous workflows that need to call an LLM and settle payment immediately
• Server-side tools and scripts that should avoid account provisioning and manual top-ups
• On-demand integrations where the simplest path is "request inference, authorize payment, receive the result"

Why x402 API Matters

Traditional AI billing usually requires:

• Creating an account with the provider
• Funding a prepaid balance or attaching a billing method
• Managing API keys, quotas, and billing dashboards

With x402 on DGrid, the flow becomes much more direct:

Request inference → receive payment requirements → sign once → submit payment and inference together

For agentic systems, this is a major simplification. The same runtime that decides to use a model can also authorize and settle the cost of that inference call, without switching into a separate account-management workflow.

Primary Use Case: Agents Paying for Inference

x402 is designed for the case where an agent needs to:

1. Choose a model
2. Call the model API
3. Pay the inference fee
4. Continue execution with the result

This is valuable for:

• AI agents operating in backend workflows
• Web3 agents or protocols that want payment-aware inference
• Multi-step automations that should treat inference as a directly payable resource

How the Flow Works

x402 on DGrid uses a two-step request flow:

1. Initial request without x-payment The server returns 402 Payment Required plus signable payment requirements.
2. Client signs and retries The client generates the x-payment payload and sends the same inference request again with the payment header.

This pattern keeps payment authorization explicit while still letting the inference call remain simple and automatable.

Supported Payment Asset

The current x402 endpoint uses:

• Protocol: x402
• Network: eip155:56 (BSC)
• Payment token: USD1
• Asset contract: 0x8d0D000Ee44948FC98c9B98A4FA4921476f08B0d

Operational Notes

After successful settlement, the service records payment logs into the x402_payment_logs table on the backend.

When to Use x402 vs AI Gateway

Use AI Gateway when you want:

• classic API-key access
• unified account-based model routing
• long-running product integrations with standard billing workflows

Use x402 when you want:

• direct per-request payment
• no pre-funded account balance
• agent-friendly inference plus payment in one flow