FAQ
Frequently asked questions about the AMP protocol.
How is AMP different from x402?
x402 requires one on-chain transaction per API call. The client sends a request, gets a 402 rejection, signs a payment on Base (EVM), and retries with a receipt. Every call costs gas.
AMP opens a channel once and makes unlimited calls with zero per-request transactions. Settlement happens periodically, netting all usage into a single transaction. For 1,000 calls, x402 costs ~$1.00 in gas; AMP costs ~$0.00075.
How is AMP different from MPP?
MPP is a payment-method-agnostic framework that works across multiple rails (Tempo, Stripe, cards, Lightning). AMP is Solana-native — channels are on-chain PDAs, composable with DeFi.
MPP sessions use off-chain vouchers on Tempo; AMP uses off-chain metering with on-chain net settlement on Solana. AMP additionally supports delegation (budget forwarding to sub-agents), channel chaining (agent supply chains), and on-chain reputation scoring.
They serve different needs: MPP for multi-method flexibility, AMP for Solana-native composability.
Is AMP compatible with MPP or x402?
AMP uses HTTP 402 for initial discovery (same status code), but the channel lifecycle is different. AMP is a separate protocol optimized for Solana-native persistent channels. You could run AMP and x402 on different routes of the same server.
What payment methods does AMP support?
USDC on Solana (SPL token). AMP is intentionally Solana-only for maximum on-chain composability. Any SPL token can be used — the server specifies the accepted mint in its pricing manifest.
Do I need a Solana wallet?
Yes. Both the agent (client) and service (server) need Solana keypairs. The agent's keypair signs channel operations and request credentials. The server's keypair signs metering proofs for settlement.
How much does it cost?
The protocol is free and open source. Transaction costs are Solana fees: ~$0.00025 per transaction. A typical channel lifecycle (open + settle + close) costs ~$0.00075 in gas, regardless of how many API calls were made.
What are channels?
A channel is a persistent financial state object between two parties, stored as a PDA on Solana. The agent deposits funds, consumes services freely, and the service settles periodically. Unlike per-request payments, the channel maintains state across interactions.
What is delegation?
An agent can assign a portion of its channel budget to a sub-agent. The sub-agent consumes services against the original channel up to a specified limit. This enables multi-agent workflows without each agent needing its own capital.
What is channel chaining?
When Service B needs to call Service C to fulfill a request, Service B can create a downstream channel funded from the upstream channel. Value flows through the chain automatically. No separate capital required.
Is it safe?
Channel funds are held in a PDA-owned vault on Solana. Only the AMP program can move funds — via settlement (to recipient) or close (refund to funder). Replay attacks are prevented by monotonic sequence numbers. The client can close the channel at any time to recover unspent funds.
Is AMP deployed?
Yes, to both Solana mainnet and devnet. Mainnet program ID: 2d1B2PmumwYWuR82AbXAARTL1nrn8N7Vu9bLXTXUDmVA. Devnet program ID: 2KQCaQ9j8YtewZ4QjmDfnsVANZXLBcPSYFhAj2eUNaPP.
Who is building AMP?
AMP is built by Valeo. The protocol is open source under the MIT license.