Payments and USDC checkout

#Choose a rail

Across checkout, wallet purchases and x402, one account (a root and all its children) receives at most $2,000 of paid credit in any 24 hours: 402 paid_daily_cap_exceeded past it. GET /v1/payment-methods reports what is enabled.

#Hosted USDC checkout

POST/v1/credits/checkout

Body {"amount_usd": 20}, whole cents, $5 to $1,000. Returns 201 {"session_id", "url"}. Open url and pay; email is optional, because credits belong to the key. The page also offers Pay from another chain: USDC from an EVM chain Circle CCTP V2 supports, minted on Solana and forwarded to the treasury. Such a payment is credited net of the relayer's refuel fee, which GET /v1/payment-methods reports as credits.zoneless.cross_chain_fee_micros, capped at cross_chain_fee_max_bps of the amount.

• The credit posts once the payment is final. POST /v1/credits/reconcile asks for any paid checkouts of the key and posts them, if a credit seems late (30 per hour).
• Each key may open 10 checkouts an hour and hold 5 unpaid at once (429 too_many_open_checkouts).

#Refusals

#Pay with any coin (NEAR Intents)

When the operator enables it (NEAR_INTENTS=on; GET /v1/payment-methods reports credits.near_intents.enabled with min_micros, max_micros, fee_micros and deadline_minutes), a key can pay in an asset and chain that NEAR Intents 1Click, a third party, swaps into USDC on Solana. Dagon's minimum is $5; 1Click's per-chain minimums also apply. The gateway never holds the origin coin. Otherwise these routes answer 404 near_intents_disabled. Not for lease keys (400 not_topup_key).

1. GET /v1/credits/near-intents/assets lists asset_id, symbol, blockchain, decimals, price_usd and contract_address.

2. POST/v1/credits/near-intents

   with {"amount_usd": 20, "origin_asset": "<asset_id>", "refund_address": "<your address on the origin chain>"}. The answer (201) is the deposit: deposit_address, deposit_memo, amount_in and amount_in_formatted (what to send, including 1Click's fees and slippage buffer), min_amount_in, amount_micros (the immutable USDC quote), fee_snapshot_micros (the immutable Dagon rail fee), deadline and a qr_svg of the address.
3. Send amount_in of the origin asset to deposit_address, with deposit_memo when set, before deadline.
4. A poller follows every deposit, including terminal deposits on a six-hour backfill; POST /v1/credits/near-intents/:deposit_address/check asks 1Click at once (120 an hour). GET /v1/credits/near-intents lists the key's newest 20, GET /v1/credits/near-intents/:deposit_address reads one.

• Credit posts only after the gateway checks every Solana destination transaction 1Click reports. A receipt must contain exactly one parsed USDC transfer whose amount equals the treasury account's complete transaction delta. Batched, unparsed, reused or otherwise ambiguous transfers are held and never credited as a whole transaction. Each unambiguous finalized transfer posts exactly once, including late and additional receipts. The current Dagon rail fee is 0%; settlement uses fee_snapshot_micros from the quote, never a later setting. The response keeps amount_micros as the quote and exposes aggregate received_micros, fee_micros and credited_micros.
• For a deposit below min_amount_in, one after the deadline, or a failed swap, NEAR Intents may return the origin asset to refund_address through its own mechanism, less its network fee. Dagon neither performs nor guarantees that return. Make sure the address is yours and can receive the asset.
• Dagon's minimum is $5. 1Click's larger chain minimums apply and are returned as 400 quote_rejected with 1Click's message.
• The return address is screened against the OFAC SDN list at quote time and before credit. For USDC on Solana, the visible origin token-account owner and transfer authority are also screened; an exchange withdrawal exposes the exchange hot wallet, not its customer. Destination source evidence is screened too. A list or RPC outage, missing finality, or unresolved visible source fails closed until evidence is available. Other origin chains do not expose a reliable sender through 1Click.
• Each account may hold 3 unpaid deposits (429 too_many_open_deposits) and open 10 an hour. Open deposits count toward the daily cap.
• Other answers: 400 invalid_asset, invalid_refund_address, invalid_amount, amount_out_of_range, 502 near_intents_unavailable, 404 deposit_not_found.

#Credits

• Credits are not money and have no cash value. They move only between keys under the same account.
• Credits are non-refundable except where the law requires otherwise; see the terms of service.
• From 2026-11-27, credits still unused 365 days after the top-up that bought them may expire, except where the law requires otherwise.