# Claude Code
claude mcp add onesource-api -- npx onesource-api-mcp

# Claude Desktop / Cursor — add to MCP config:
{
  "mcpServers": {
    "onesource-api": {
      "command": "npx",
      "args": ["-y", "onesource-api-mcp"]
    }
  }
}

Tools (22)

Live Chain Data (12 tools)

Tool	Description
`1s_allowance_live`	ERC20 allowance check
`1s_contract_info_live`	Contract type detection via ERC165
`1s_erc1155_balance_live`	ERC1155 balance via RPC
`1s_erc20_balance_live`	ERC20 balance via balanceOf
`1s_erc20_transfers_live`	ERC20 Transfer logs via eth_getLogs
`1s_erc721_tokens_live`	ERC721 token enumeration
`1s_events_live`	Event logs via eth_getLogs
`1s_multi_balance_live`	ETH + multiple ERC20 balances
`1s_nft_metadata_live`	NFT metadata via tokenURI
`1s_nft_owner_live`	NFT owner via ownerOf
`1s_total_supply_live`	Token total supply
`1s_tx_details_live`	Transaction + receipt via RPC

Chain Utilities (10 tools)

Tool	Description
`1s_contract_code`	Contract bytecode
`1s_ens_resolve`	ENS name/address resolution
`1s_estimate_gas`	Gas estimation
`1s_network_info`	Chain ID, block number, gas price
`1s_nonce`	Transaction count
`1s_pending_block`	Pending block from mempool
`1s_proxy_detect`	Proxy contract detection
`1s_simulate_call`	Simulate eth_call
`1s_storage_read`	Read storage slot
`1s_tx_receipt`	Transaction receipt

Networks

All tools accept an optional network parameter:

Network	Description
`ethereum`	Ethereum mainnet (default)
`sepolia`	Ethereum Sepolia testnet
`avax`	Avalanche C-Chain

Payment (x402)

Endpoints are priced in USDC on Base via x402. When the backend has payments enabled, tool calls return a 402 with payment details.

Automatic payments: Set X402_PRIVATE_KEY to a funded EVM wallet key. The server will automatically sign and settle USDC payments for each tool call.

X402_PRIVATE_KEY=0x... npx onesource-api-mcp

Without this key, 402 responses are returned as tool errors with a descriptive message.

Configuration

Variable	Default	Description
`ONESOURCE_BASE_URL`	`https://skills.onesource.io`	Skills API endpoint
`X402_PRIVATE_KEY`	—	EVM private key (0x-prefixed hex) for automatic x402 USDC payments on Base