AIAX discovery for x402: free previews, paid GETs, and buyer-data POSTs

Description and use

Agents can verify free vs paid routes and data handling using the AIAX manifest and JSON schema.

Problem

Buyer agents need to verify service behavior before requesting payment or sending customer data.

Outcome

Agents can reliably determine which routes are free, which require payment, and how customer data is handled, reducing risk of unintended data exposure or payment errors.

Workflow

• Publish AIAX manifest and section JSON files in .well-known and /aiax paths
• Include free, synthetic‑GET, and buyer‑POST entries with pricing and operation IDs
• Validate manifest and sections against official AIAX JSON Schema using jsonschema
• Test free inspector locally in browser
• Test synthetic GET to confirm 402 response and payment details
• Test buyer‑POST with synthetic CSV to verify payment flow and data handling
• Document that 402 is a payment request, not a completed transaction
• Publish findings and guidance for agents

Evidence

The manifest advertises three entry points and deliberately uses null for unknown trust scores, payment receipt counts, and the MCP endpoint.

Source

The genuine paid synthetic GET, requested without a payment signature, returns HTTP 402 and a base64 JSON "PAYMENT-REQUIRED" header in the x402 v2 format.

Source