x402 Multi-Chain Blockchain API

Pay-per-call blockchain data API for NEAR Protocol, Solana, and Base (Ethereum L2) — powered by x402 USDC micropayments.

Live: ironflip.duckdns.org

Features

- 24 REST endpoints across 3 chains (NEAR, Solana, Base)
- x402 micropayments — $0.001–$0.005 USDC per call on Solana or Base
- No API keys, no signup — just attach an X-PAYMENT header
- Agent-discoverable — OpenAPI 3.1, A2A agent card, ChatGPT plugin manifest, llms.txt
- Analytics dashboard with payment tracking
- MCP Registry listed as io.github.trevorflipper/near-solana-blockchain-api

Endpoints

NEAR Protocol (8)

| Endpoint | Price | Description | |----------|-------|-------------| | GET /api/near/account/{id}/balance | $0.001 | NEAR balance (total, staked, available) | | GET /api/near/account/{id}/keys | $0.001 | Access keys (full + function-call) | | GET /api/near/tx/{hash}?sender_id={id} | $0.001 | Transaction with receipts and actions | | GET /api/near/validators | $0.002 | Active validator set | | GET /api/near/validators/{id} | $0.001 | Single validator details | | GET /api/near/account/{id}/staking | $0.002 | Staking delegations across pools | | GET /api/near/nft/{contract}/tokens | $0.002 | NFT tokens with metadata | | GET /api/near/defi/pools | $0.005 | Ref Finance liquidity pools |

Solana (9)

| Endpoint | Price | Description | |----------|-------|-------------| | GET /api/solana/account/{id}/balance | $0.001 | SOL balance | | GET /api/solana/account/{id}/info | $0.001 | Account metadata | | GET /api/solana/account/{id}/tokens | $0.002 | SPL token holdings | | GET /api/solana/account/{id}/stakes | $0.002 | Stake accounts | | GET /api/solana/account/{id}/transactions | $0.002 | Recent transaction signatures | | GET /api/solana/tx/{signature} | $0.001 | Parsed transaction details | | GET /api/solana/validators | $0.002 | Top vote accounts by stake | | GET /api/solana/tokens/prices | $0.002 | SOL, USDC, JUP, JTO, BONK prices | | GET /api/solana/network/stats | $0.002 | Epoch, TPS, supply |

Base / Ethereum L2 (7)

| Endpoint | Price | Description | |----------|-------|-------------| | GET /api/base/account/{id}/balance | $0.001 | ETH balance on Base | | GET /api/base/account/{id}/info | $0.001 | EOA vs contract detection | | GET /api/base/account/{id}/tokens | $0.002 | ERC-20 balances (USDC, DAI, WETH, etc.) | | GET /api/base/tx/{hash} | $0.001 | Transaction details | | GET /api/base/block/latest | $0.002 | Latest block info | | GET /api/base/gas | $0.001 | Current gas price | | GET /api/base/network/stats | $0.002 | Network stats |

Payment

Payments use the x402 protocol. Include an X-PAYMENT header with a USDC transaction proof:

- Solana mainnet — solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp
- Base (EIP-155:8453) — eip155:8453

The facilitator (AutoIncentive) is free — no API key needed.

Discovery

| Standard | URL |
|----------|-----|
| OpenAPI 3.1 | /openapi.json |
| A2A Agent Card | /.well-known/agent-card.json |
| ChatGPT Plugin | /.well-known/ai-plugin.json |
| LLMs.txt | /llms.txt |
| Dashboard | /dashboard |

Self-hosting

git clone https://github.com/trevorflipper/x402-multichain-gateway.git
cd x402-multichain-gateway
npm install
npm run build
Required env vars for paid mode:
export X402_PAY_TO="<your-solana-usdc-address>"
export X402_BASE_PAY_TO="<your-base-usdc-address>"
npm start

Without X402_PAY_TO, the gateway runs in free/demo mode (no payment required).

Tech Stack

- TypeScript + Express
- @x402/express middleware
- near-api-js v5
- Raw JSON-RPC for Solana and Base (no SDK dependencies)
- better-sqlite3 for analytics

License

MIT