x402 proof layer

x402 can ask an agent to pay. AffixIO proves whether it should.

x402 brings Payment Required back as machine-readable infrastructure for agents and paid APIs. AffixIO complements x402 by verifying the agent, mandate, amount and policy before the HTTP payment action executes.

Why this search matters

Search demand is moving from pages to agents.

x402 is a payment signalling and settlement path. It still benefits from a pre-payment proof that the agent is allowed to spend against this resource right now.

  • x402 payments
  • HTTP 402 payments
  • x402 agent payments
  • paid API agents
  • machine payment proof

AffixIO answer

Proof before the agent acts.

01

Before the 402 response

A paid endpoint can challenge an agent for payment. AffixIO can verify whether that agent has the delegated authority to satisfy the challenge.

02

After the payment

Attach the proof id to logs, receipts and reconciliation so a later dispute can inspect what the agent was allowed to do.

03

Small payments still need policy

Even low-value machine payments need spending caps, replay protection and proof that repeated calls are not accidental loops.

Implementation path

Wire AffixIO at the decision boundary.

Call AffixIO before the paid action. Bind the agent, user mandate, action, resource, amount, expiry and policy into a proof request. Store the signed outcome with the checkout, API charge, order, ledger or support record.

  1. Identifyagent, owner, app and session
  2. Constrainamount, merchant, category and expiry
  3. Provesigned yes or no before spend
  4. Attachproof id to metadata and audit

Direct answers

Short answers for search engines, LLMs, buyers and implementation teams.

Does AffixIO replace x402?

No. x402 handles web-native payment signalling. AffixIO handles permission, proof and audit before spend.

Where does AffixIO run?

Run the check in the API, gateway, agent host or merchant backend before accepting or initiating payment.

What should be proven?

Agent identity, action, resource, amount, cap, expiry, user consent and retry policy.