paidfor.devStress tests
Two deliberate tests on 10 sellers each, with their own small budget, never mixed into the headline rate.
Duplicate: one intent, two back-to-back paid calls
The same purchase intent was sent twice back to back with fresh signatures. 5 of 10 sellers settled both (rate 50.0%, 95% interval [23.7%, 76.3%]). Nothing in the protocol or at these sellers deduplicates by intent; every signature is a payment, so a client retry is a direct double-charge risk.
- https://api.bitrefill.com/x402/checkout/infointent d717441acalls 2settlements 2double-settled yesspent $0.002000
- https://api.vapinetwork.ai/shim/o1/tokensintent 557218a5calls 2settlements 0double-settled nospent $0.004000
- https://api.surplusintelligence.ai/v1/chat/completionsintent e788793acalls 2settlements 0double-settled nospent $0.000000
- https://api.slamai.dev/chain/tokens/trendingintent 3ca5dbaacalls 2settlements 2double-settled yesspent $0.002000
- https://laso.finance/authintent 6f2944d6calls 2settlements 2double-settled yesspent $0.002000
- https://www.ax1.vc/api/dashboard/q-verdict/resourceintent e33d5379calls 2settlements 0double-settled nospent $0.040000
- https://www.api-xpay.com/x402/quoteintent f2e0026ccalls 2settlements 2double-settled yesspent $0.010000
- https://x402.clashofcoins.com/x402/cheap-healthintent 73896b42calls 2settlements 2double-settled yesspent $0.002000
- https://api.nansen.ai/api/v1/profiler/address/current-balanceintent d26a8b15calls 2settlements 0double-settled nospent $0.020000
- https://api.locus.report/api/locus-parcel-lookupintent 508f3511calls 2settlements 0double-settled nospent $0.020000
Timeout: abort after payment, then a naive retry
Sign, send, drop the connection after two seconds, then retry like a naive client. 5 of 10 sellers settled the aborted call anyway, and the retry produced a second settlement at 5 of 10. Settlement precedes validation at many sellers; nothing in the exact scheme ties a payment to an idempotency key.
- https://api.bitrefill.com/x402/checkout/infointent 534b1425call 1 aborted nosettled despite abort nosecond settlement on retry yessettlements 2spent $0.002000
- https://api.vapinetwork.ai/shim/o1/tokensintent b4345dfdcall 1 aborted nosettled despite abort nosecond settlement on retry nosettlements 0spent $0.004000
- https://api.surplusintelligence.ai/v1/chat/completionsintent 085ae8adcall 1 aborted nosettled despite abort nosecond settlement on retry nosettlements 0spent $0.000000
- https://api.slamai.dev/chain/tokens/trendingintent 52a8bcd4call 1 aborted yessettled despite abort yessecond settlement on retry yessettlements 2spent $0.002000
- https://laso.finance/authintent ae7860bdcall 1 aborted nosettled despite abort nosecond settlement on retry yessettlements 2spent $0.002000
- https://www.ax1.vc/api/dashboard/q-verdict/resourceintent 5693407ecall 1 aborted nosettled despite abort nosecond settlement on retry nosettlements 0spent $0.040000
- https://www.api-xpay.com/x402/quoteintent 058583dfcall 1 aborted yessettled despite abort yessecond settlement on retry yessettlements 2spent $0.010000
- https://x402.clashofcoins.com/x402/cheap-healthintent deb8f6decall 1 aborted nosettled despite abort nosecond settlement on retry yessettlements 2spent $0.002000
- https://api.nansen.ai/api/v1/profiler/address/current-balanceintent ef90f48bcall 1 aborted nosettled despite abort nosecond settlement on retry nosettlements 0spent $0.020000
- https://api.locus.report/api/locus-parcel-lookupintent 1de75784call 1 aborted yessettled despite abort nosecond settlement on retry nosettlements 0spent $0.020000
Totals
| metric | value |
|---|---|
| intents (duplicate test) | 10 |
| double-settled intents | 5 |
| intents (timeout test) | 10 |
| settled despite abort | 2 |
| second settlement on retry | 5 |
| total stress spend | $0.204000 |