How Avalon works

Avalon meters media the way the cloud meters compute. Video bills per second, books bill per page, and you only pay for the moments you actually consume, down to sub-cent amounts in USDC on Arc testnet.

The hard part is not metering, it is paying. A wallet prompt for every metered tick is unusable, which is why most pay-per-use media never ships. Avalon's answer is to approve a rate, not a transaction: one signature authorizes a spending allowance, then the meter draws against it as off-chain accounting and settles in batches.

Per-second billing and per-transaction signing are incompatible. Signing fatigue, one wallet popup per tick, is the reason streaming nanopayments have stayed a demo. Avalon removes the per-draw signature entirely. The single human action is the up-front authorization; nothing is signed per second or per page after that.

One approval reserves a cap; every tick draws against it; folded draws settle on-chain in batches.

approve once  ->  reserve cap against Gateway pool   (available -> reserved)
   every tick ->  Ember decides (continue | throttle | stop)
              ->  atomic draw against allowance       (off-chain accounting)
   threshold  ->  claim batch -> sign -> Gateway settle -> finalize
              ->  one ledger row + tx ref             (reserved -> spent)
 session end  ->  release the unused reservation       (reserved -> available)

Creators receive 85% and the platform 15%, split per settled batch. Each batch writes exactly one ledger row, so the history reconciles against the per-tick draws behind it.

Circle Gateway / Nanopayments

One-time deposit, then batched settlement of folded draws on Arc testnet.

Circle developer-controlled Wallets

An EOA buyer wallet signs EIP-3009 authorizations programmatically, no per-draw popup.

x402 batching

The facilitator that verifies and settles the signed authorizations.

USDC on Arc testnet

The unit of account, down to integer atomic amounts (6 decimals).

viem

On-chain Gateway balance + wallet USDC reads, and the deposit contract calls.

Arcscan (Blockscout)

Verify-on-chain links for settled batches and wallet addresses.

DeepSeek

The model behind Ember's in-loop budget-allocation decision.

EIP-712 domain is GatewayWalletBatched v1, chainId 5042002 (Arc testnet), with the GatewayWallet as the verifying contract (not the USDC token). Amounts are decimal-string atomic USDC.

When you open a title, the approval gate asks for a per-session cap. Pick a preset ($0.06, $0.25, $1, or $5) or type a custom amount, then approve once. That cap is reserved against your Gateway balance and the meter draws against it. You are not asked again unless it runs out, in which case you can extend.

Video bills per second through socket heartbeats while the tab is focused and playing; pausing or leaving stops the meter. Books read as a continuous scroll and bill per page as you reach it; a page you already paid for is free on revisit. Every draw is an atomic deduction in integer USDC units, so concurrent draws can never overspend the cap.

Ember decides how fast to spend. Cheap deterministic guards run first every tick (exhausted, would-exceed, or above your rate cap). On a genuine judgment call, low remaining budget with more content queued, Ember consults its model to continue, throttle to stretch the budget, or stop and conserve.

The decision is shown on screen with its source: Ember when the model reasoned it, rule for a deterministic guard, model offline for the safe fallback. Ember never blocks billing, a model timeout or error falls back to approve-within-policy and keeps drawing.

In circle mode there is no local balance to top up. The Top up page shows the buyer wallet's USDC balance and its address, deposits test USDC into Gateway from the browser (approve, then deposit), and reflects the new on-chain balance. To add funds, send Arc testnet USDC to the shown address, then deposit it into Gateway.

The Dashboard shows your settled spend, sessions, and creator payouts. The Transactions page lists every settled batch with its Gateway ref and the signed payer to recipient authorization behind it.