Documentation / published contract
Submit a snapshot.
Pay only after validation.
All 3 processors accept caller-authorized JSON files, enforce the same rights boundary, and cost $0.02 per successfully paid request through x402.
Request and payment flow
- 01Prepare an operation-specific JSON file that satisfies the published request schema.
- 02Submit it once. Invalid input returns an uncharged 4xx response before payment handling.
- 03A valid unpaid request returns HTTP 402 in both the PAYMENT-REQUIRED header and decoded JSON body.
- 04Authorize with an x402 v2 capable client and retry the same URL and file.
- 05Success returns HTTP 200 with PAYMENT-RESPONSE. Payment verification uses an external facilitator, and settlement is public on Base.
Endpoint reference
Choose one processor
The file path below belongs to the caller. Its contents must match the full JSON Schema for that operation. Cannastack publishes no sample inventory.
Uncharged validation responses
400 malformed body, 403 invalid rights attestation, 413 limit exceeded, 415 unsupported content, and 422 schema-invalid input.
Payment service and configuration failures return 502 or 503 without a processing result.
If a 502 reports payment_settlement_indeterminate, inspect PAYMENT-RESPONSE and the public onchain state. Do not submit a new payment authorization until the original is confirmed unsettled.
Discovery and legacy behavior
Legacy retrieval APIs return HTTP 410 without a payment challenge. Active schemas and payment metadata are available through each discovery surface. The x402.json document is a Cannastack service catalog, not an official protocol manifest.