Crate r402_near 

NEAR chain support for the x402 payment protocol.

This crate implements the x402 "exact" scheme for NEAR: the buyer signs a NEP-366 SignedDelegate that authorizes one NEP-141 ft_transfer, and a facilitator-sponsored relayer submits the outer transaction.

Features

• CAIP-2 Addressing: near:mainnet and near:testnet
• NEP-141 Payments: exact ft_transfer of a token (USDC by default)
• NEP-366 Meta-transactions: client signs a delegate; the relayer pays gas
• In-process facilitator: JSON-RPC verify and settle

Feature Flags

• server — server-side price tag generation
• client — client-side delegate signing
• facilitator — facilitator-side payment verification and settlement
• telemetry — tracing instrumentation

Re-exports

pub use chain::NearJsonRpc;client or facilitator

pub use chain::NearChainProvider;facilitator

pub use chain::NearRelayer;facilitator

pub use exact::NearExact;

pub use exact::client::NearExactClient;client

pub use exact::client::NearSigner;client

Modules

chain

NEAR chain support for x402 payments.

exact

NEAR "exact" payment scheme implementation.

Structs

USDC

Ergonomic accessors for USDC token deployments on well-known NEAR chains.

Constants

DEFAULT_FT_TRANSFER_GAS

Default gas attached to the delegated ft_transfer (30 TGas).

DEFAULT_MAX_SPONSORED_GAS

Conservative cap on sponsored gas to protect relayers (100 TGas).

DEFAULT_TOKEN_DECIMALS

Default USDC decimal precision.

EMPTY_CONTRACT_CODE_HASH

Base58 representation of an all-zero 32-byte code hash.

ESTIMATED_BLOCK_SECONDS

Deterministic timeout mapping (spec §5): estimatedBlockSeconds = 1.

FT_TRANSFER_METHOD

NEP-141 transfer method.

NONCE_RANGE_MULTIPLIER

NEAR delegate-action nonce upper-bound multiplier (ACCESS_KEY_NONCE_RANGE_MULTIPLIER).

ONE_YOCTO

NEP-141 requires exactly 1 yoctoNEAR attached to ft_transfer.

Statics

NEAR_NETWORKS

Well-known NEAR networks with their names and CAIP-2 identifiers.

Functions

timeout_blocks

timeoutBlocks = max(1, ceil(maxTimeoutSeconds / estimatedBlockSeconds)).

usdc_near_deployment

Returns the USDC deployment for a specific NEAR chain, if known.

usdc_near_deployments

Returns all known USDC deployments on NEAR chains.