@onlyswaps/mcp-server

OnlySwaps MCP Server

Multi-chain DEX meta-aggregator for AI agents. Queries 15+ DEX aggregators, returns the best price.

MCP (Model Context Protocol) server that enables AI agents to execute token swaps. We query 0x, 1inch, Paraswap, DODO, Uniswap, Li.Fi, and 10+ more sources, returning only the best available quotes.

Why OnlySwaps?

• Meta-Aggregator: Queries 15+ DEX aggregators (0x, 1inch, Paraswap, Li.Fi, etc.) and returns the best available price
• 13 Chains: Ethereum, Base, Arbitrum, Optimism, Polygon, BSC, Avalanche, Solana, and more
• One Integration: Single API call to access all DEX liquidity across all chains
• AI-Native: Built for MCP - works with Claude Desktop, Cursor, and any MCP client

Tools

Tool	Description
get_quote	Get swap quotes from multiple DEX aggregators
build_swap_tx	Build unsigned swap transaction (ready for client-side signing)
execute_swap	Execute swap end-to-end with embedded wallet (Privy)
get_portfolio	Get user token holdings across chains
get_tx_status	Check transaction status
estimate_gas	Estimate gas for a transaction
search_token	Search tokens by name or symbol

Quick Start

Using npx

npx @onlyswaps/mcp-server

Claude Desktop Configuration

Add to ~/.claude/claude_desktop_config.json:

{
  "mcpServers": {
    "onlyswaps": {
      "command": "npx",
      "args": ["-y", "@onlyswaps/mcp-server", "stdio"],
      "env": {
        "ONLYSWAPS_API_URL": "https://api.onlyswaps.fyi"
      }
    }
  }
}

Hosted Server (SSE)

Connect to our hosted MCP server:

https://mcp.onlyswaps.fyi/mcp

Supported Chains

Chain	ID	Native Token
Ethereum	1	ETH
Optimism	10	ETH
BSC	56	BNB
Gnosis	100	xDAI
Polygon	137	MATIC
Fantom	250	FTM
zkSync Era	324	ETH
Base	8453	ETH
Arbitrum	42161	ETH
Avalanche	43114	AVAX
Linea	59144	ETH
Scroll	534352	ETH
Solana	solana	SOL

Tool Examples

get_quote

Get the best swap quote across all aggregators.

{
  "fromToken": "ETH",
  "toToken": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
  "amount": "1000000000000000000",
  "chainId": "base"
}

Returns:

{
  "bestQuote": {
    "provider": "1inch",
    "buyAmount": "3245000000",
    "sellAmount": "1000000000000000000",
    "estimatedGas": "150000",
    "priceImpact": "0.05"
  },
  "allQuotes": [...],
  "meta": { "chain": "Base", "chainId": 8453, "sourcesQueried": 5 }
}

build_swap_tx

Build an unsigned transaction ready for client-side signing.

{
  "fromToken": "ETH",
  "toToken": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
  "amount": "1000000000000000000",
  "chainId": "base",
  "userAddress": "0xYourWalletAddress",
  "slippage": 1
}

Returns transaction data (to, data, value, gas, chainId) ready to sign.

execute_swap

Execute a swap end-to-end using an embedded Privy wallet. Requires Privy configuration.

{
  "fromToken": "ETH",
  "toToken": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
  "amount": "1000000000000000000",
  "chainId": "base",
  "userId": "privy-user-id"
}

get_portfolio

Get user token holdings across all supported chains.

{
  "address": "0xYourWalletAddress",
  "chainIds": ["ethereum", "base", "arbitrum"]
}

get_tx_status

Check the status of a transaction.

{
  "txHash": "0xabc123...",
  "chainId": "base"
}

estimate_gas

Estimate gas for a swap transaction.

{
  "fromToken": "ETH",
  "toToken": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
  "amount": "1000000000000000000",
  "chainId": "base",
  "userAddress": "0xYourWalletAddress"
}

search_token

Search for tokens by name or symbol.

{
  "query": "USDC",
  "chainId": "base"
}

Environment Variables

Variable	Default	Description
MCP_PORT	3001	HTTP server port
MCP_TRANSPORT	http	Transport mode: http or stdio
ONLYSWAPS_API_URL	-	OnlySwaps backend API URL
ONLYSWAPS_API_KEY	-	API key for authenticated access
CORS_ORIGINS	*	Comma-separated CORS origins
PRIVY_APP_ID	-	Privy App ID (for execute_swap)
PRIVY_APP_SECRET	-	Privy App Secret (for execute_swap)
PRIVY_AUTHORIZATION_PRIVATE_KEY	-	Privy auth key (for execute_swap)

Running Locally

# Install dependencies
pnpm install

# Build
pnpm build

# Run HTTP server
pnpm start

# Run stdio mode (for Claude Desktop)
node dist/index.js stdio

Docker

docker build -t onlyswaps-mcp .
docker run -p 3001:3001 \
  -e ONLYSWAPS_API_URL=https://api.onlyswaps.fyi \
  onlyswaps-mcp

API Endpoints

Endpoint	Description
GET /health	Health check
GET /capabilities	Supported chains and tools
GET /mcp	MCP SSE connection endpoint
POST /mcp/messages	MCP message handler

Links

• Website: https://onlyswaps.fyi
• Hosted MCP: https://mcp.onlyswaps.fyi
• GitHub: https://github.com/Delegueinu/onlyswaps

License

MIT