[Requires authentication] This tool needs OAuth. If it returns an authentication error, prompt the user to connect/authenticate this MCP server (OAuth), then retry. Swap tokens via 1inch. Supports classic (on-chain), Fusion (intent/gasless), and cross-chain swaps. Omit preferredType and the tool picks a type for you; set preferredType (classic, fusion, crosschain) to choose explicitly.
When quoteOnly returns a `recommended` type and that type is available, present **only** that type to the user. Do not mention, compare, or suggest other swap types unless the user explicitly asks to compare alternatives.
ERC-20 source tokens may require a one-time approval transaction before the swap can proceed; the approval costs native gas on the source chain even for gasless Fusion/cross-chain swaps. When a response includes an `approval` block, tell the user upfront (approval.estimatedCost holds the estimated cost in native units).
Usage modes:
1. **Quote** (quoteOnly=true): Returns only one swap type and its quote. If you pass `preferredType` explicitly (classic, fusion, or crosschain), the response returns that exact type (when a quote for it is available). If `preferredType` is omitted, the tool compares classic, Fusion, and cross-chain internally and picks the best one. The chosen type is echoed as `recommended`.
2. **Execute** (default): Returns data to sign. Response type depends on swap mode:
- Classic → {type:"classic", step:"approve"|"swap", tx:{to,data,value}} → sign with eth_sendTransaction, wait for receipt. If step="approve", sign the approve tx first, then call swap again for the actual swap tx.
- Fusion → {type:"fusion", orderHash, typedData} → sign typedData with eth_signTypedData_v4, then call this tool again with signedOrder=<signature> and orderHash.
- Cross-chain → {type:"crosschain", orderHash, typedData, srcChain, dstChain} → same as Fusion: sign typedData, then submit with signedOrder.
3. **Submit** (signedOrder=<sig>): Submit a previously signed Fusion/cross-chain order. Returns {status:"submitted", orderHash}.
Flows:
- **Full flow**: quote first (quoteOnly=true), then execute with chosen preferredType, then sign + submit.
- **Shortcut**: skip the quote — call directly without quoteOnly. Omit preferredType to let the tool pick a type, or set preferredType explicitly. Set dstChain for cross-chain.
Responses that require on-chain transactions link to a guide. Use the product_api tool with path="/web3/{chainId}" to broadcast (see linked guide for body format).
With an active WalletConnect session (`walletconnect` action=connect), swap execution is automatic by default: classic approve/swap txs, Fusion/cross-chain sign-and-submit, and native escrow sends are prompted in the user’s wallet — no manual broadcast or separate submit step. Set `execute=false` to receive unsigned payloads instead. Set `execute=true` to require WalletConnect (fails if not connected).