Module payment 

Payment verification system for ant-node.

This module implements the payment verification strategy:

1. Check LRU cache for already-verified data
2. Require and verify EVM/Arbitrum payment for new data

Default Policy

Production nodes require payment by default.

• EVM verification is always on — there is no way to disable it
• For unit tests, pre-populate the cache via PaymentVerifier::cache_insert()

Architecture

PUT request received
       │
       ▼
┌─────────────────────┐
│ Check LRU cache     │
└─────────┬───────────┘
          │
   ┌──────┴──────┐
   │             │
  HIT          MISS
   │             │
   ▼             ▼
Store (paid)   Require EVM payment

Payment Flow

All new data requires EVM payment:

1. Client requests a quote from the node
2. Node generates PaymentQuote with ML-DSA-65 signature
3. Client pays on Arbitrum via PaymentVault.payForQuotes()
4. Client sends PUT with ProofOfPayment
5. Node verifies on-chain payment and stores data

Re-exports

pub use metrics::QuotingMetricsTracker;

pub use pricing::calculate_price;

pub use quote::wire_ml_dsa_signer;

pub use quote::QuoteGenerator;

pub use quote::XorName;

pub use wallet::is_valid_address;

pub use wallet::parse_rewards_address;

pub use wallet::WalletConfig;

Modules

metrics

Quoting metrics tracking for ant-node.

pricing

Quadratic pricing with a baseline floor for ant-node (Phase 1 recalibration).

proof

Payment proof re-exports from ant_protocol.

quote

Payment quote generation for ant-node.

single_node

SingleNode payment re-exports from ant_protocol.

wallet

EVM wallet management for receiving payments.

Structs

CacheStats

Cache statistics for monitoring.

EvmVerifierConfig

Configuration for EVM payment verification.

PaymentProof

A payment proof that includes both the quote-based proof and on-chain tx hashes.

PaymentVerifier

Main payment verifier for ant-node.

PaymentVerifierConfig

Configuration for the payment verifier.

SingleNodePayment

Single node payment structure for a chunk.

VerifiedCache

LRU cache for verified XorName values.

Enums

PaymentStatus

Status returned by payment verification.

ProofType

The detected type of a payment proof.

Constants

MAX_PAYMENT_PROOF_SIZE_BYTES

Maximum allowed size for a payment proof in bytes (256 KB).

MIN_PAYMENT_PROOF_SIZE_BYTES

Minimum allowed size for a payment proof in bytes.

Functions

deserialize_merkle_proof

Deserialize proof bytes as a MerklePaymentProof.

deserialize_proof

Deserialize proof bytes from the PaymentProof format (single-node).

detect_proof_type

Detect the proof type from the first byte (version tag).

serialize_merkle_proof

Serialize a MerklePaymentProof with the version tag prefix.

serialize_single_node_proof

Serialize a PaymentProof (single-node) with the version tag prefix.

verify_merkle_candidate_signature

Verify a MerklePaymentCandidateNode’s ML-DSA-65 signature.

verify_quote_content

Verify that a payment quote’s content address matches the expected address.

verify_quote_signature

Verify a payment quote’s ML-DSA-65 signature.