Straight answers · siexchange.lol · updated October 2026
A non-custodial swap engine on 5 chains: Base, Ethereum, Polygon, Solana, and Robinhood Chain. It quotes swaps and produces ready-to-sign transactions. Your wallet keeps the keys and signs; SI Exchange never takes custody.
Quotes are free. Swaps for the launch-set coins (MUSKOX, ARENA, SOLV, AGWC, GITLAWB) are free. Arbitrary token pairs cost $0.02 USDC per swap.
Paid endpoints return HTTP 402 with a signed payment request. The caller pays USDC on Base through the x402 protocol; the facilitator verifies the payment and the trade runs.
No. There are no accounts, no deposits, and no custody. Your wallet extension signs transactions with keys that never leave your browser. See the privacy policy for what the server records.
Any wallet that can sign on the supported chains, including Phantom, MetaMask, and Coinbase Wallet.
Yes. The OpenAPI spec is at /openapi.json, the MCP manifest at /mcp_manifest.json, and machine-readable discovery at /.well-known/mcp.json. Quotes and calldata are callable by agents, with x402 payments for arbitrary pairs.
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