@one-source/mcp

Unified MCP server for OneSource — 31 tools for blockchain data, live chain queries, and API documentation in a single server.

Combines @one-source/api-mcp (22 tools) and @one-source/docs-mcp (9 tools) so your AI assistant gets full access to OneSource with one MCP connection.

What is MCP? The Model Context Protocol lets AI assistants call tools and access data sources. This server exposes both the OneSource blockchain API and its documentation as tools.

Quick Start

Claude Code

claude mcp add onesource -- npx @one-source/mcp

Claude Desktop / Cursor

Add to your MCP config:

{
  "mcpServers": {
    "onesource": {
      "command": "npx",
      "args": ["-y", "@one-source/mcp"]
    }
  }
}

Any MCP Client (stdio)

npx @one-source/mcp

HTTP Server (self-hosted)

npx @one-source/mcp --http
npx @one-source/mcp --http --port=8080

Then connect your MCP client to http://localhost:3000/.

Health check: GET http://localhost:3000/health

Tools (31)

Blockchain API — Live Chain (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

Blockchain API — Chain Utilities (10 tools)

RPC only.

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

Documentation (9 tools)

Read-only, no API key required.

Tool	Purpose	When to use
search_docs	Keyword search across all documentation	Finding guides, concepts, or API patterns
get_query_reference	Full reference for a root GraphQL query	Building a specific query with correct args/filters
get_type_definition	Schema definition for any type/enum/input	Understanding field shapes and return types
list_examples	Browse or search working GraphQL examples	Finding ready-to-use query patterns
list_supported_chains	All supported blockchain networks + endpoints	First question: "What chains are supported?"
get_filter_reference	Filter fields and operators for a list query	Building filtered queries with correct syntax
get_pagination_guide	Cursor-based pagination pattern with examples	Implementing pagination for list queries
get_schema_overview	High-level summary of the entire schema	Exploring the API surface before diving in
get_authentication_guide	API key format, headers, and endpoints	Setting up authentication for the first time

Networks

All blockchain API tools accept an optional network parameter:

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

Payment (x402)

Blockchain API endpoints are priced in USDC on Base via x402. When the backend has payments enabled, tool calls return a 402 with payment details. Agents using @x402/fetch handle this automatically.

Documentation tools are always free — no API key or authentication needed.

Environment Variables

Variable	Default	Description
ONESOURCE_BASE_URL	https://skills.onesource.io	API base URL
ONESOURCE_ANALYTICS	—	Set to false to disable analytics
ONESOURCE_ANALYTICS_URL	—	Dashboard endpoint for analytics
X402_ANALYTICS_KEY	—	API key for dashboard analytics
X402_PRIVATE_KEY	—	EVM private key (hex, 0x-prefixed) for automatic x402 USDC payments on Base

Troubleshooting

npx hangs with no output That's normal — stdio mode waits for JSON-RPC input on stdin. Use --http if you want an HTTP server you can curl.

Port already in use Specify a different port: npx @one-source/mcp --http --port=8080

Tools return "Data files may be missing" Try reinstalling: npm install @one-source/mcp

"Type not found" even though it exists Type names are case-insensitive but must match the GraphQL name (e.g. Transaction, not transaction_type). The tool will suggest close matches.

License

Apache 2.0 — see LICENSE for details.