Economics

Payments

Tollex pays and gets paid with x402 v2, in USDG on Robinhood Chain.

The exchange

x402 v2 over HTTP

→ POST /tools/chain_get_block           (no payment)
← 402  PAYMENT-REQUIRED: <terms>          scheme, amount, asset, payTo, network, extensions

→ POST /tools/chain_get_block
  PAYMENT-SIGNATURE: <signed payload>
← 200  PAYMENT-RESPONSE: <settlement>     transaction, network, payer, signed receipt

The live 402 terms are authoritative. Catalogue and plan prices tell you what to expect; the client checks the live terms against your policy before signing.

Schemes

Scheme	The payer signs	Needs first	Use for
`exact`	EIP-3009 transferWithAuthorization for the price	Nothing. The facilitator submits; the payer pays no gas.	Fixed-price calls
`exact` via Permit2	A Permit2 transfer for the price	A Permit2 allowance (gas-sponsored where the facilitator offers EIP-2612)	Assets without EIP-3009
`upto`	A Permit2 ceiling; the merchant settles the metered amount	A Permit2 allowance	Metered work
`batch-settlement`	A channel deposit once, then a voucher per call	An open channel	Very frequent, very small charges

Each resource offers the schemes it chooses. When a plan selects a route with a precondition, it says so in route.preconditions rather than failing halfway through a payment.

Networks and assets

Network	CAIP-2	Status
Robinhood Chain testnet	`eip155:46630`	Live. Verified end to end with real testnet USDG.
Robinhood Chain mainnet	`eip155:4663`	Read only. Payments are disabled until the mainnet gates are cleared.

USDG has six decimals. All amounts on the wire are integer strings of atomic units: "2000" is 0.002 USDG.

Settlement assurance

Robinhood Chain is an Arbitrum Nitro L2. Tollex distinguishes broadcast, l2_included, l2_confirmed, parent_safe and parent_finalized, and merchants can hold a result until a level is reached. The default policy asks more of larger payments:

Charge	Result released at
Under 100 USDG	`l2_included`
100 USDG and above	`l2_confirmed`, 20 blocks deep
10,000 USDG and above	`parent_finalized`

Facilitators

Verification and settlement go through x402 facilitators. Tollex routes between them by capability and health, and never fails over blindly: for an ambiguous exact settlement it reads the chain first to see whether the authorization was already used. Metered routes are bound to the facilitator chosen before signing, because the upto contract only accepts that facilitator.

The Tollex facilitator adds no fee. The amount in the payment terms is the amount that settles.