COVERNOTE: the silver folded C on midnight-blue paper, the sealed cover envelope

Cover note · USDC thresholds on Arc

Prove the backing. Keep the balance.

Create a budget page, confirm control of one funding account, and share a verifiable receipt that a USDC balance met the public threshold at a snapshot block.

Blank slip 1

Snapshot only. Funds are not reserved.

The sealed lantern: the folded C and keyhole in silver leading

The clerk's desk

SimulationScripted and wallet-free. Fixture data only.

COVERNOTE clerk{{ clerkStatus }}{{ clerkCaret }}

State the budget you want to prove. Each step is filed as a numbered slip: 1 Budget, 2 Funding account, 3 Snapshot, 4 Certificate.

{{ it.n }}{{ it.title }}Simulation

· Arc testnet ·

explorer ↗

4Certificate · not filedSimulation

Snapshot only. Funds are not reserved.

Verify certificatereceipt {{ it.rid }} · nullifier {{ it.nulShort }} · root {{ it.rootShort }}

How it works

Three hands on one note

a.Team creates budget.
b.Attestor records balance at a final block.
c.Circuit proves threshold membership.
d.Receipt shows four separate statuses.

Four entries on Arc

Every step shows its transaction hash and explorer link.

1Create budget

createBudget is recorded on Arc testnet.

2Funding account

The EOA signs a one-time challenge in its own wallet.

3Snapshot

The attestor registers a root at a final block.

4Certificate

Your browser builds the proof, and a relayer submits it so the funding account never appears.

Simulation

Example receipt

The example below is a fixture, not a live snapshot.

Snapshot only. Funds are not reserved.

Verify certificate

{{ chainName }}, as read

The chain these notes are filed on. Mainnet figures below are real reads from the snapshot file, not Simulation. Snapshot read at block {{ snapBlock }} · {{ snapAt }} · loaded from {{ chainFrom }}.

Live head: read at block {{ liveBlockTxt }} · https://rpc.mainnet.arc.io eth_blockNumber

Top pools{{ totPools }}api.geckoterminal.com/api/v2/networks/arc/pools · block {{ snapBlock }}

Top pools volume 24h{{ totVol }}api.geckoterminal.com/api/v2/networks/arc/pools · {{ snapAt }}

New pools{{ totNew }}api.geckoterminal.com/api/v2/networks/arc/new_pools · {{ snapAt }}

Logos shipped{{ totLogos }}logos: CoinGecko (tokens) · DexScreener (DEXes, chain)

Top pools · first {{ shownTop }} of the list

{{ p.dex.mono }} {{ p.dexName }} · {{ p.addrShort }}

Price{{ p.price }} Volume 24h{{ p.vol }} Reserve{{ p.reserve }} Trades 24h{{ p.trades }}

Source: https://api.geckoterminal.com/api/v2/networks/arc/pools · read {{ snapAt }} · block {{ snapBlock }} · logos: CoinGecko (tokens) · DexScreener (DEXes, chain)

New pools · first {{ shownNew }} of the list

{{ p.dex.mono }} {{ p.dexName }} · {{ p.addrShort }}

Opened{{ p.opened }} Volume 24h{{ p.vol }} Reserve{{ p.reserve }} Trades 24h{{ p.trades }}

Source: https://api.geckoterminal.com/api/v2/networks/arc/new_pools · read {{ snapAt }} · block {{ snapBlock }} · logos: CoinGecko (tokens) · DexScreener (DEXes, chain)

Slip 1 · Budget. Fill the numbered blanks; the controller wallet signs createBudget.

Budget

Simulation

1 · Purpose 2 · Threshold in USDCUSDCTyped as {{ nbMicro }} 3 · Public controllerThe controller is public. It must not be the funding account.

createBudget
·
· Arc testnet ·
{{ nbSt }}{{ nbCaret }}
explorer ↗

Receipt read. Numeral 1 filed. Open budget {{ nbNewId }} → · Continue to slip 2 →

Live mode is unavailable: Arc testnet (chainId 5042002) addresses are not yet deployed, so this slip runs as Simulation and no wallet is asked to sign. Numeral 1 fills only after the line reads Landed at block.

No budget is filed under this id. Open B-0417

Envelope {{ bv.id }}

Budget slip · version {{ bv.version }}Simulation

Threshold{{ bv.threshold }} USDC

Purpose{{ bv.purpose }}

Snapshot time{{ bv.snap }}

Data age{{ bv.age }} · {{ bv.fresh }}

Data sourceAttested snapshot

Public controller{{ bv.controllerShort }}

registerRoot· Arc testnet · Landed at block {{ bv.block }}explorer ↗

Latest receipt{{ bv.rid }}

No receipt yet. Continue with slips 2–4.

Snapshot only. Funds are not reserved.

Verify certificate

3 Snapshot · refreshed · Simulation{{ bp1 }}{{ bp2 }}{{ bp3 }}

Earlier versions · carbon copies

Each copy keeps its own receipt. An old receipt never carries over to a new threshold.

Carbon copy · version {{ c.v }}{{ c.threshold }} USDC{{ c.fresh }}

Pinned receipt {{ c.rid }} · version {{ c.v }} only
Snapshot {{ c.snap }}
Reason: {{ c.revoked }}

Prove · slips 2–4

Budget B-0417 · version 3 · 10,000.000000 USDC · SIMULATION

2Funding account

Request text to be signed

COVERNOTE one-time challenge
budget: B-0417 · version 3
network: Arc testnet (chainId 5042002)
nonce: 7f3a91c2
purpose: confirm control of the funding account
This signature moves no funds and expires in 10 minutes.

Funding address

Not shown — kept private

3Snapshot

Waiting for slip 2

{{ pvB }}· registryTxHash {{ pvRegShort }} · Arc testnetexplorer ↗

The attestor reads the funding account's USDC balance at a final block and registers a root on Arc testnet.

4Certificate · prove threshold

Waiting for slip 3

The proof is built in this browser. The funding account and balance never leave the device.

Warning slip · blocking

Local prover · {{ pvC }}{{ pvCaretC }}

submitCertificate · tx {{ pvSubShort }} · Arc testnet · {{ pvD }}explorer ↗

Snapshot only. Funds are not reserved.

Verify certificate {{ pvRid }}

A relayer submits the certificate, so the funding account never signs or appears onchain.

Receipt {{ vrId }}

No wallet needed.

{{ vr0 }}{{ vr1 }}{{ vr2 }}
Arc mainnet head: read at block {{ liveBlockTxt }} · https://rpc.mainnet.arc.io eth_blockNumber

Verify the sample receipt R-0417-3 instead

Data source revoked · {{ vv.revoked }}

Alter one byteSimulation

A tampered card shows a different seal. Toggle to redraw the rosette with {{ vv.byteNote }}.

explorer ↗

Share card · 1200 × 675

No funding address and no exact balance appear on the card.

Reverse of the cover note

Conditions of this cover note

Trust model: the circuit checks the arithmetic, the attestor supplies the data, and Arc records both.

1The statement. A receipt states that one funding account held at least the public USDC threshold at one snapshot block on Arc. It states nothing else.
2Attested data. The balance comes from an attestor's snapshot. A viewer relies on that attestor for the figure; the circuit only checks it against the threshold.
3The attestor sees the account. The attestor can see the funding address and its balance. Viewers of the receipt cannot.
4Freshness is data age. Freshness reports how old the snapshot is. It does not hold, freeze or set aside funds. Snapshot only. Funds are not reserved.
5No payout promise, no liabilities. A receipt is not a promise to pay, not an escrow, and not a liability of COVERNOTE or of the team.
6One public threshold per version. Each budget version carries one threshold. Changing it files a new version; earlier receipts stay pinned to the version they were issued for.
7Arc privacy is roadmap. Today the proof and relayer keep the funding account out of the receipt. Network-level privacy on Arc is planned, not shipped.

CNOTE is a proposed ticker only. It is not needed to use COVERNOTE, and there is no token contract, supply plan or launch date.

How it works

One envelope, four entries

A team publishes a public USDC threshold on Arc testnet. An attestor records the funding account's balance at a final block. The browser proves the balance met the threshold, and a relayer files the certificate. Anyone can check the receipt without a wallet.

Run the simulation Read the conditions

The six panes of a receipt

A six-pane lancet window: budget version numeral, key, tree, stacked blocks, chain and hourglass, with the sealed envelope at the apex

Numeral · budget version

contextMatched: the receipt belongs to this version only.

Key · proof

mathValid: the Groth16 proof checks out.

Tree · root

rootAccepted: the attestor's root is registered and not revoked.

Blocks · block

The final block the snapshot was taken at.

Chain · network

Arc testnet, chainId 5042002.

Hourglass · freshness

freshnessStatus: data age in words. Snapshot only. Funds are not reserved.

No slip filed here

This page is not part of the cover note.

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