SVM Mechanisms

This directory contains payment mechanism implementations for SVM (Solana Virtual Machine) networks.

What This Exports

This package provides scheme implementations for Solana-based blockchains that can be used by clients, servers, and facilitators.

Exact Payment Scheme

The exact scheme implementation enables fixed-amount payments using Solana token transfers for USDC SPL tokens.

Export Paths

The exact scheme is organized by role:

For Clients

Import Path:

github.com/coinbase/x402/go/mechanisms/svm/exact/client

Exports:

• NewExactSvmScheme(signer) - Creates client-side SVM exact payment mechanism
• Used for creating payment payloads with partial transaction signatures

For Servers

Import Path:

github.com/coinbase/x402/go/mechanisms/svm/exact/server

Exports:

• NewExactSvmScheme() - Creates server-side SVM exact payment mechanism
• Used for building payment requirements and parsing prices
• Supports custom money parsers via RegisterMoneyParser()

For Facilitators

Import Path:

github.com/coinbase/x402/go/mechanisms/svm/exact/facilitator

Exports:

• NewExactSvmScheme(signer) - Creates facilitator-side SVM exact payment mechanism
• Used for verifying transaction signatures and settling payments on-chain
• Requires facilitator signer with Solana RPC integration

Supported Networks

All Solana networks using CAIP-2 network identifiers:

• Solana Mainnet: solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp
• Solana Devnet: solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1
• Solana Testnet: solana:4uhcVJyU9pJkvQyS88uRDiswHXSCkY3z

Use solana:* wildcard to support all Solana networks.

Scheme Implementation

The exact scheme implements fixed-amount payments:

• Method: Solana token transfers
• Token: USDC SPL token
• Signing: Partial transaction signing (client + facilitator)
• Fees: Rent and transaction fees paid by facilitator
• Confirmation: On-chain settlement with transaction signature

Future Schemes

This directory currently contains only the exact scheme implementation. As new payment schemes are developed for Solana networks, they will be added here alongside the exact implementation:

svm/
├── exact/          - Fixed amount payments (current)
├── upto/           - Variable amount up to a limit (planned)
├── subscription/   - Recurring payments (planned)
└── batch/          - Batched payments (planned)

Each new scheme will follow the same three-role structure (client, server, facilitator).

Contributing New Schemes

We welcome contributions of new payment scheme implementations for Solana networks!

To contribute a new scheme:

1. Create directory structure: svm/{scheme_name}/client/, svm/{scheme_name}/server/, svm/{scheme_name}/facilitator/
2. Implement the required interfaces for each role
3. Add comprehensive tests
4. Document the scheme specification
5. Provide usage examples

See CONTRIBUTING.md for more details.

Related Documentation

• Mechanisms Overview - About mechanisms in general
• EVM Mechanisms - Ethereum implementations
• Exact Scheme Specification - Exact scheme specifications