Onchain Infra · Markets & Payments · 22 / 22
Machine Payments
Software that pays
AI agents and APIs paying each other per request, in stablecoins, with budgets set by the humans behind them.
Where it connects
How It Works
- 01RequestAn agent calls a paid endpoint.
- 02QuoteThe server answers HTTP 402 with a price.
- 03Pay and retryThe agent pays within its budget and gets the result.
Designs
01
Pay per request
One onchain payment per call.
02
Sessions and channels
Deposit once, pay off-chain per call.
03
Agent checkout
Agents buy from merchants on a user's behalf.
Who Builds It
Across ecosystems, not one chain.
x4x402CoinbaseHTTP 402 payments in stablecoins
MPMPPTempoMachine payments: charge, sessions, streams
APAP2GoogleAgent payments protocol
ACACPOpenAI · StripeAgentic commerce protocol
SkSkyfireNetworkPayments and identity for agents
What to Compare
01
Cost per call
02
Budget and scope controls
03
Discovery of paid services
On Tempo
On Tempo · In the protocol
MPP prices any endpoint per call, per session or per streamed token, with scoped keys to bound spend.
HTTP 402
Native flow
−72%
Channel gas
$0.001
Per word, streamed
Charge
HTTP 402 AgentAPI
→ GET /v1/forecast
← 402 · WWW-Authenticate: Payment
→ Authorization: Payment · $0.01
← 200 OK · Payment-Receipt
Session · streamed
$0.001 / wordChannel open$0.000
0 off-chain vouchers · 1 settlement
Spend controls
Access key · $5 / day Scoped to api.weather.dev --max-spend 0.10 --dry-run Revocable
MPP charge
Fixed price per request, settled onchain
Sessions
Open a channel once, pay per call off-chain
Streams
Per-token billing over SSE
Mercator
Discover, quote, pay, and run paid tools
Spend controls
Budgets, scopes, --max-spend, dry runs
RedotPay