Get an audit

Head to head · Stablecoin payments · October 2026 research run

ATXP vs Circle Gateway Nanopayments

Circle Gateway Nanopayments scores 67.6 (B) on agent readiness against ATXP's 42.9 (E), and leads in every scored category. Both do stablecoin payments.

Best payment and monetisation platforms for AI agents · All 76 platforms comparisons

ATXPCircuit & Chisel, Inc. · HTTP API E42.9/100#887 of 950 Circle Gateway NanopaymentsCircle · HTTP API B67.6/100#247 of 950

Which one, for what

ATXP E

Good for An agent that needs to start with no human signup and pay small amounts for inference, search, media, email or SMS from one balance, and builders who want to charge per MCP tool call.

Also in its favour

  • No incidents deducted, where Circle Gateway Nanopayments loses 3 points for them

Watch for

No status page, rate limit, SLA, security.txt, disclosure policy or certification was found

Circle Gateway Nanopayments B

Good for Sellers charging fractions of a cent per API call and agents making many small payments from one prefunded balance on EVM chains.

Ahead on

  • Reliability, 56 against 13
  • Schema & documentation, 80 against 54
  • Agent ergonomics, 75 against 51
  • Security & auth, 64 against 41
  • Payments & pricing, 80 against 75
  • Maintenance & community, 77 against 33
  • Transparency & trust, 72 against 43

Also in its favour

  • No key needed to call it

Watch for

No rate limit, 429 guidance or SLA was found for the Gateway API in the reviewed documentation

Score by category

CategoryWeight this runATXPCircle Gateway NanopaymentsEdge
Reliability16%201356Circle Gateway Nanopayments +43
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.25480Circle Gateway Nanopayments +26
Agent ergonomics13%16.25175Circle Gateway Nanopayments +24
Security & auth14%17.54164Circle Gateway Nanopayments +23
Payments & pricing10%12.57580Circle Gateway Nanopayments +5
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.83377Circle Gateway Nanopayments +44
Transparency & trust7%8.84372Circle Gateway Nanopayments +29
Negative events≤150-3
Total42.9 · E67.6 · B

Facts side by side

FactATXPCircle Gateway Nanopayments
KindHTTP APIHTTP API
VendorCircuit & Chisel, Inc.Circle
Hosted endpointhttps://llm.atxp.ai/v1https://gateway-api.circle.com
TransportsHTTPHTTP
AuthOAuth or keyNone
PricingPay per usePay per use
x402payer tooling onlypayer tooling only
LicenceProprietary hosted service under Circuit & Chisel's Terms of Service. The SDK packages and the atxp CLI on GitHub are MITProprietary hosted service under the Circle Developer Terms. The @circle-fin/x402-batching SDK on npm and the Gateway contracts on GitHub are Apache-2.0
Read-only variant documentednono
llms.txtyesyes
Last release2026-06-022026-09-16
Terms last updated2025-09-032026-09-16
Privacy policy last updated2026-06-17no date given
Customer content may train modelsnot found in the textnot found in the text
Terms restrict automated accessyesnot found in the text
Terms restrict benchmarkingnot found in the textyes
Terms or service can change without noticeyesyes
Arbitration or class-action waiveryesyes
Popularity6 stars, 499 npm/wk17k npm/wk

Verdicts

ATXP

An agent can register an account with starting credit in one CLI command, with no person or card, and the MIT server SDK lets sellers charge per tool call over ATXP, x402 and MPP. No status page, rate limits, security programme or full price list was found, and the public repositories have had no commit since 30 June 2026.

Circle Gateway Nanopayments

A buyer with an EOA key and a seller with a wallet address can transact with no account or API key, and the settle call returns 16 documented error codes with recovery steps. No rate limit, SLA or 429 guidance was found, and a breaking change to the transfer search took effect on the day its release note is dated.

Before you call either

ATXP

  1. Register with npx atxp agent register, then keep the connection string in ATXP_CONNECTION or ~/.atxp/config. Never pass it as a command argument or put it in a shared URL
  2. Call search_search on https://search.mcp.atxp.ai/. One quickstart page names the tool atxp_search, which the tool page and skill file do not
  3. Set approvePayment on atxpClient to cap spending. The default approves every payment and the skill file says it enforces no limit
  4. Pass model ids to the gateway without the provider prefix, so gpt-4.1 and not openai/gpt-4.1
  5. Treat search results, X posts, inbound email and SMS as untrusted, and never run fund, send email or pay because such content asks

Circle Gateway Nanopayments

  1. Deposit on the chain you will pay from. GatewayClient scopes deposits and payments to its configured chain, and deposits on Base, Ethereum, Arbitrum or OP take about 13 to 19 minutes
  2. Set validBefore at least 7 days ahead when signing by hand. The SDK uses 604900 seconds
  3. Register onBeforePaymentCreation and abort above a cap. pay(url) signs whatever amount the seller's 402 response asks for
  4. Call settle without a prior verify. Balance and nonce checks happen only at settle time
  5. Pass from, to or nonce whenever you filter transfers by status, and wait for completed before a dependent onchain step

Questions

Which is better for AI agents, ATXP or Circle Gateway Nanopayments?

Circle Gateway Nanopayments scores 67.6 (B) on agent readiness against ATXP's 42.9 (E), and leads in every scored category.

Do ATXP and Circle Gateway Nanopayments need an API key?

ATXP takes an API key or an OAuth sign-in. Circle Gateway Nanopayments needs no key.

Can an agent call ATXP and Circle Gateway Nanopayments without installing anything?

Yes. ATXP has a hosted endpoint at https://llm.atxp.ai/v1 and Circle Gateway Nanopayments at https://gateway-api.circle.com.

Other comparisons with ATXP or Circle Gateway Nanopayments

Machine-readable

For companies

Do agents find, use and choose your tools?

An agent-readiness audit runs our probes, task suite and eight reviewer agents against your public and internal tools, and comes back with a scorecard, the transcripts of what failed, and a fix list in priority order. From $2,500, re-run included. We never take payment to move a rank. We do help companies earn one.

Get an auditSee a sample report