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Tenjin: x402 Redelivery Signature Security Analysis
x402
Tenjin: x402 Redelivery Signature Security Analysis is a paid API for AI agents from tenjin.blog, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-13).
Retrieves a technical article explaining why recovering the payment signature does not secure x402 redelivery attacks in EVM/EIP-3009 transferWithAuthorization schemes
Price / call$0.01
Success—
StatusUnknown
How this service works
Why recovering the payment signature does not secure x402 "redelivery". As of 2026-08-10. Applies to x402 with the exact/EVM scheme over EIP-3009 transferWithAuthorization (USDC-style tokens). The protocol property below is stable; the SDK symbol names may drift. You build an x402-paid API. A buyer's client sometimes dies right after paying, before it reads the response, so you add "redelivery": let them re-present their payment and collect the result they already bought. The obvious implementation: This is insecure. Step 2 proves nothing. When an exact/EVM x402 pay
Output
The full text of a technical blog article analyzing the x402 protocol redelivery vulnerability, covering why signature recovery in the exact/EVM scheme over EIP-3009 transferWithAuthorization (USDC-style tokens) does not prevent redelivery attacks, including protocol details stable as of 2026-08-10
Example use cases
Auditing x402 API redelivery implementation
“I'm building an x402-paid API and I want to add a redelivery feature so clients can re-present their payment — can you fetch me the Tenjin article explaining why signature recovery alone is insecure for this use case?”
Researching EIP-3009 payment attack vectors
“I'm doing a security review of EIP-3009 transferWithAuthorization flows — fetch me the Tenjin piece on how the x402 redelivery attack works so I can understand what the protocol-level flaw is.”
Learning x402 protocol security tradeoffs
“I'm trying to understand the security model of x402 micropayment APIs — get me the Tenjin article dated around August 2026 that covers why signature recovery doesn't protect redelivery in the exact/EVM scheme.”
Technical details
Endpoint
GEThttps://tenjin.blog/api/read/0xe4c16d163d80fd972e6e1e9b94bc71c5fbe5a9c5/why-recovering-the-payment-signature-does-not-secure-x402-redeliveryWhen to prefer
Use this endpoint when you need to read this specific Tenjin article about x402 redelivery security; prefer it over generic web search when you want the original, paid-access technical content with guaranteed authenticity via the x402 payment trail
Side effects
- Article not found if slug or wallet address is incorrect (404)
- Payment required if x402 payment header is missing or invalid (402)
- Network timeout if Tenjin platform is unavailable
- Invalid wallet address format returns an error
- Using handle 'latest' as a payable path may fail per schema constraints
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Tags
x402
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