Stablecoin Payment Providers for Machine-to-Machine and AI Agent Payments (2026): Who Supports What
Last updated 2026-09-30.
Eight providers currently document stablecoin support for machine-to-machine or AI agent payments on their own sites: Coinbase, Circle, Stripe, Skyfire, Crossmint, Nevermined, Openfort, and Tempo. Their mechanisms fall into three families: per-request protocol payments (x402, MPP — a server returns a 402/payment challenge, the agent pays, the request completes), agent wallets with a spending-policy layer (Circle, Coinbase, Openfort, Crossmint), and signed identity/payment tokens (Skyfire's KYA-PAY token). Several providers combine more than one.
How we picked
Every provider below had to clear two bars, checked against the vendor's own docs, GitHub repo, or product page — never a third-party blog, directory, or listicle:
- The vendor's own docs name a specific stablecoin (or "stablecoin" generically) and describe a machine-to-machine or agent payment mechanism — not just a roadmap mention.
- A primary-source URL exists for every claim in the table below. Anything we couldn't confirm on the vendor's own page is marked "not documented" — never guessed.
We also checked Payman, whose spend-governance dashboard we've covered elsewhere: its own docs page describes limits in currency-agnostic terms (its worked example uses ₹, Indian rupees) with no mention of USDC, stablecoins, crypto, or blockchain anywhere on the page we checked, so it's excluded from a stablecoin shortlist specifically. That's a scope call, not a knock on the product.
Comparison table
| Provider | Stablecoin(s) + chains (as documented) | M2M mechanism | Who holds keys | Per-agent spending controls | Availability | Source |
|---|---|---|---|---|---|---|
| Coinbase (Agentic Wallet) | USDC on Base, Base Sepolia, Polygon, Solana, Solana Devnet (CLI docs) | x402 per-request payments via an MCP-connected wallet: "An MCP server + wallet app that lets AI agents autonomously pay for x402 services using USDC" (FAQ) | Two Coinbase pages describe custody differently: the MCP FAQ states "Coinbase doesn't have custody of your funds" (embedded wallet, email/OTP); the CLI docs separately state "Key isolation: Private keys stay in Coinbase infrastructure" — they may describe different setups; confirm which one you're integrating | Yes — Max per call and Max per session, set in the wallet UI: "Agents respect these limits but can't change them" (FAQ) | Not documented (no GA/beta label on the pages checked) | docs.cdp.coinbase.com |
| Circle (Agent Wallets) | USDC, EURC, other ERC-20 and native tokens (e.g. ETH, MATIC) on Arbitrum, Arc, Avalanche, Base, Ethereum, Monad, Optimism, Polygon PoS, Unichain (mainnet + testnet) (chains) | Wallet API (Circle CLI) plus Agent Nanopayments: "gasless, sub-cent USDC payments to x402-compatible services" (docs) | MPC — "Built on Circle's user-controlled wallets with 2-of-2 MPC key management, key shares are never exposed to the agent. The user retains custody" | Yes — named "Custom spending policies": "Set transfer limits, recipient allowlists, and contract blocklists per agent wallet"; limits "can be time-bound (for example, daily, or monthly)" | Not documented (no GA/beta label on the pages checked) | developers.circle.com |
| Stripe | USDC on Base (x402) and Solana (MPP); USDC.e on Tempo (MPP) (docs) | x402 and MPP, both per-request: "Your server returns a payment challenge, the agent presents a valid payment credential, and Stripe settles the payment" | Not documented on the page checked (payments settle to the merchant's Stripe balance; agent-side wallet custody isn't described here) | Partial — Shared Payment Tokens (SPTs, the card side of MPP) carry per-token limits: "Each SPT includes usage and expiration limits"; no equivalent per-agent stablecoin cap is documented on this page | Access-gated, not labeled beta: "Stablecoin payments are available to businesses in all US states, except New York"; merchants must enable the payment method and be approved | docs.stripe.com |
| Skyfire | USDC ("a USD-backed stablecoin"); token schema also lists a coin settlement type of usdc (product) (token docs); specific chain not documented |
Signed KYA-PAY token: amount (amt), currency, settlement type, and optional request-count cap (mnr) embedded in a token a seller service verifies before granting access — not a live per-request protocol call like x402 |
Not documented on the pages checked | Yes — "Budgets and Control": "Set spending limits per agent to ensure cost control" | Beta — "Join the Skyfire Beta and start building the future" | skyfire.xyz/product |
| Crossmint (Agent Wallets) | Stablecoins generically named; specific coin/chain list for the wallet product not documented on the page checked | x402 and MPP via the wallet product: "Pay an API per call, or pay another agent → Agent Wallets → x402 and MPP" (docs) | Non-custodial — "Non-custodial stablecoin wallets with scoped agent access, for x402, MPP, and onchain payments" | Yes, named "allowance": "Every allowance is scoped, explicit, and revocable"; enforcement point stated separately for its card product ("Card limits hold at Visa and Mastercard, wallet limits hold onchain") | Not documented on the page checked | docs.crossmint.com |
| Nevermined | Crypto payments named as "USDC" generically: "Payment method - Fiat (cards) or crypto (USDC)"; chain not documented | Per-request 402 gate: "if a caller isn't entitled, they get a 402 before your code even runs"; buyers use a prepaid plan or pay-as-you-go, "no human in the loop" | Not documented on the page checked (crypto payouts "settle directly to your wallet"; the custody model for that wallet isn't stated) | Named as "delegation" elsewhere in Nevermined's own material — see its spend-governance write-up for the specific "$500 between 9 AM and 5 PM EST"-style delegation quote; not repeated on the overview page checked here | Not documented on the page checked | nevermined.ai/docs |
| Openfort (Agent Wallets) | "Stablecoin-based settlement" across "25+ EVM chains"; specific coin(s) not named on the page checked | Wallet API supporting multiple protocols: "the emerging agentic payment standards, including Coinbase's x402 (HTTP-native payments), Google's Agent Payments Protocol (AP2), the Agentic Commerce Protocol (ACP), and the Machine Payments Protocol (MPP)" | Non-custodial — "An agent wallet is a programmable, non-custodial wallet designed specifically for AI agents" | Yes — example shown: "Daily limit $10,000 · Allowlist"; FAQ lists "transaction limits, operation allowlists, anomaly detection, real-time alerts, multi-party approvals, and detailed audit logs" | Self-serve, testnet-first: "No credit card required • Free testnet accounts"; no explicit GA label on this page | openfort.io |
| Tempo (Wallet CLI) | pathUSD, Tempo's own asset, on Tempo Mainnet: "Tempo Wallet CLI uses Tempo Mainnet for balances, funding, transfers, and MPP settlement" (Stripe's own docs separately describe USDC.e moving over the Tempo network via MPP — the two pages use different asset names for the Tempo rail) | CLI-driven MPP settlement plus paid HTTP requests: "gives your agent paid HTTP request capabilities with payment preview (--dry-run) and execution support" |
Not documented on the page checked | Yes — "--max-spend and scoped access keys let you enforce budgets per request and per key" |
Live mainnet, not testnet: "Agents should treat pathUSD in Tempo Wallet as the live mainnet asset, not as a testnet faucet token"; no separate GA/beta label found | tempo.xyz |
How to choose
- Paying per API call to someone else's service. Look at the x402 family: Coinbase's Agentic Wallet MCP, Circle's Agent Nanopayments, or Stripe's x402 integration all document a per-request pay flow. See what is x402? for how the protocol itself works.
- Agent-to-agent payments where the seller is also an agent or an automated service. Nevermined's 402-gate-plus-plan model and Skyfire's KYA-PAY token are both built around a seller service verifying a buyer's credential or entitlement before delivering — useful when you don't control the seller's stack.
- High-frequency, sub-cent payments. Circle names this directly — Agent Nanopayments are for "gasless, sub-cent USDC payments." x402's
uptoscheme (see our x402 vs MPP comparison) is built for the same metered-usage case. - Card-and-stablecoin hybrid, or an agent that might pay by card one day and stablecoin the next. Crossmint and Stripe both document card and stablecoin rails in the same product; Stripe's MPP explicitly spans SPTs (cards) and stablecoin payments in one integration.
- Enterprise treasury controls — caps, allowlists, audit trails. Circle's per-wallet spending policies (time-bound limits, recipient allowlists, contract blocklists) and Openfort's allowlist-plus-multi-party-approval-plus-audit-log combination document the most controls among the providers on this list, on the pages we checked; see our fuller spend-governance comparison for card-network options too.
- A wallet you don't want the provider able to touch. Circle (MPC, "Circle cannot unilaterally move funds") and Openfort/Crossmint (self-described "non-custodial") are the three providers here that make an explicit custody claim in the vendor's own words; Coinbase's MCP FAQ and CLI docs word custody differently (see "What's still missing").
What's still missing
Custody wording can differ between pages from the same vendor. Coinbase's MCP FAQ says "Coinbase doesn't have custody of your funds," while its CLI docs state "Private keys stay in Coinbase infrastructure." The two pages may describe different setups, and neither page explains how they relate; if the custody model is a compliance requirement for you, confirm with the vendor which setup you'd actually be integrating.
Refunds on stablecoin rails are barely documented. Stripe states that fiat-side machine payments get its standard Refunds API, but the same page doesn't describe a refund path for the stablecoin/x402 leg specifically. None of the other seven providers in this table document a refund or dispute process for a stablecoin M2M payment on the pages we checked — once a wallet signs and a chain settles, "refund" isn't a term any of them define here.
Per-agent policy, where it exists, mostly lives inside the wallet or token, not as a portable, protocol-level object. Circle's spending policies are Circle-wallet-scoped; Openfort's allowlists are Openfort-wallet-scoped; Skyfire's cap lives inside a signed token a seller has to choose to honor. None of the eight document a spending policy that travels with the agent across providers — switch wallets and you rebuild the rules.
Half the providers (Stripe, Skyfire, Nevermined, Tempo) don't state a key-custody model at all on the pages we checked for this table — not "custodial" or "non-custodial," just silent. Treat that as an open question for your own vendor call, not evidence either way.
Pink Agentic AI Payment (early access) enforces per-agent spending caps, allowlists and approval thresholds at the MCP layer, before a payment executes.
FAQ
Which providers support machine-to-machine payments with stablecoins? Eight vendors document this on their own sites as of 2026-09-30: Coinbase, Circle, Stripe, Skyfire, Crossmint, Nevermined, Openfort, and Tempo. See the comparison table above for the specific stablecoin, chain, and mechanism each one documents.
What's the difference between x402 and MPP for stablecoin payments? Both are per-request payment protocols a server can use to charge an agent before serving a request, but they come from different origins and cover different rails — see our dedicated x402 vs MPP comparison for the field-level differences. In this shortlist, Coinbase and Circle document x402 specifically; Stripe and Tempo document MPP; Crossmint and Openfort document both.
Do any of these providers let an agent hold a stablecoin wallet without the provider being able to move the funds? Circle, Openfort, and Crossmint each make an explicit non-custodial or MPC claim in their own docs — Circle names 2-of-2 MPC key management with the user retaining custody, and Openfort and Crossmint both describe their agent wallets as "non-custodial." Coinbase's MCP FAQ and CLI docs word custody differently (see "What's still missing" above). Stripe, Skyfire, Nevermined, and Tempo don't state a custody model on the pages we checked.
Which of these is a protocol and which is a company? x402 and MPP are protocols, not companies. Coinbase created x402, which describes itself as "an open standard for internet native payments"; its governance now sits with the x402 Foundation under the Linux Foundation (see who sets the standards for AI agent payments). Stripe documents MPP as a protocol it and other companies implement. Circle, Stripe, Skyfire, Crossmint, Nevermined, Openfort, and Tempo are companies that implement one or both protocols, or run their own token/delegation mechanism, on top of a stablecoin rail. See x402 vs AP2 vs ACP for how these protocols relate to each other.
This page is published by PinkWallet, which is building Pink Agentic AI Payment (early access). We are not neutral in this space, which is why every factual claim links to a primary source.
