The Zion Facilitator

Zion operates as a Managed Facilitator Cloud, acting as the trusted intermediary that verifies payments between AI Agents and your API.

Architecture

1. Request: The AI Agent makes a request to your API.
2. Challenge (402): Your API (via Zion SDK) sees no payment proof and responds with 402 Payment Required. The response includes the Payment-Required header with payment details (amount, developer wallet, asset, network in CAIP-2 format).
3. Payment: The Agent signs a Solana transaction transferring 100% of the payment to the developer (no platform fee).
4. Verification: The Agent sends the transaction proof to the Zion Facilitator via the X-Payment header.
5. Settlement: The Facilitator verifies the transaction on-chain and records the settlement (usage is tracked for subscription tiers).
6. Access: The Agent's request is authorized and the Zion SDK grants access to your API endpoint.

[!NOTE] x402 Protocol v2 Zion uses the x402 Protocol v2 standard with CAIP-2 network identifiers and the Payment-Required/X-Payment header pair for standardized micropayments.

Why a Facilitator?

• Speed: We handle the heavy lifting of RPC calls and transaction verification, so your API doesn't have to wait for block confirmations.
• Security: We ensure that payments are valid, confirmed on-chain, and haven't been double-spent.
• Simplicity: You don't need to run a Solana node or manage complex wallet infrastructure.
• Usage Tracking: We track transaction counts for subscription tier management and overage billing.