Crate r402_stellar 

Stellar chain support for the x402 payment protocol.

This crate implements the x402 "exact" scheme for Stellar: the buyer signs Soroban authorization entries for one SEP-41 transfer, and the facilitator is the transaction source / fee sponsor.

Features

• CAIP-2 Addressing: stellar:pubnet and stellar:testnet
• SEP-41 Payments: exact transfer of a Soroban token (USDC by default)
• Auth-entry signing: the client never spends a sequence number
• In-process facilitator: RPC verify, rebuild, submit, and confirm

Feature Flags

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

Re-exports

pub use chain::StellarJsonRpc;client or facilitator

pub use chain::StellarChainProvider;facilitator

pub use chain::StellarFacilitatorError;facilitator

pub use chain::StellarRpc;client or facilitator

pub use chain::StellarRpcError;client or facilitator

pub use chain::StellarSigner;client or facilitator

pub use exact::StellarExact;

pub use exact::client::StellarExactClient;client

Modules

chain

Stellar chain support for x402 payments.

exact

Stellar "exact" payment scheme implementation.

Structs

USDC

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

Constants

BASE_FEE_STROOPS

Inclusion buffer in stroops (BASE_FEE in the official Stellar SDK).

DEFAULT_ESTIMATED_LEDGER_SECONDS

Fallback ledger close time when Horizon is unavailable.

DEFAULT_MAX_TRANSACTION_FEE_STROOPS

Safety ceiling for simulation-derived settlement fees (stroops).

DEFAULT_TIMEOUT_SECONDS

Default maxTimeoutSeconds when the requirement omits it.

DEFAULT_TOKEN_DECIMALS

Default USDC decimal precision on Stellar (SEP-41).

HORIZON_LEDGERS_SAMPLE_SIZE

Number of recent Horizon ledgers sampled for close-time estimation.

NULL_ACCOUNT

Dummy source used by the client so only auth entries are signed.

SIGNATURE_EXPIRATION_LEDGER_TOLERANCE

Ledger-skew tolerance applied to auth-entry expiration.

TRANSFER_FUNCTION

SEP-41 transfer method name.

USDC_PUBNET_ADDRESS

USDC contract on Stellar pubnet.

USDC_TESTNET_ADDRESS

USDC contract on Stellar testnet.

Statics

STELLAR_NETWORKS

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

Functions

network_idclient or facilitator

SHA-256 of the network passphrase (Stellar network id).

timeout_ledgers

ledgerTimeout = ceil(maxTimeoutSeconds / estimatedLedgerSeconds).

usdc_stellar_deployment

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

usdc_stellar_deployments

Returns all known USDC deployments on Stellar chains.