x402 vs MPP for AI agent payments
Compare x402 and MPP for AI agent payments and learn how Leash supports both while preserving receipt and identity semantics.
Why it matters
Different paid APIs may speak different payment protocols. Buyers need a consistent way to discover, pay, and verify outcomes.
Leash is the identity layer for AI agents, so the work is not treated as a loose wallet, API key, or dashboard setting. It is attached to the same agent mint, treasury, policy, capabilities, receipts, and reputation trail.
How Leash handles it
Leash probes the paid resource, detects whether it speaks x402 or MPP, settles with a compatible facilitator, and records protocol-aware receipt metadata.
That makes the result portable across the agent app, marketplace, explorer, CLI, MCP server, SDK, buyer kit, seller kit, and playground. The surface can change, but the identity and proof trail stay the same.
Implementation checklist
Pick x402 for HTTP 402 paywalls, MPP where problem+json negotiation is preferred, and keep buyer policy and receipt verification the same across both.
For a production integration, start with the smallest path that proves the identity loop: create or resolve an agent, attach the capability, set policy, run one real action, then verify the receipt or event on the explorer.
Create either kind of payment link
leash pay https://api.example.com/x402-link
leash pay https://api.example.com/mpp-link
# Hosted links can be created with protocol x402 or mpp.FAQ
Should sellers support both x402 and MPP?
Not always. Support the protocol your buyers expect, but keep receipts and identity verification consistent.
Can Leash discover both protocol types?
Yes. Discovery and payment flows can surface protocol metadata so agents know how to call a capability.