Best for
- AI agents and IDE users needing real-time multi-chain blockchain data
- Blockchain analysts and developers
- Crypto researchers using Claude, Cursor, ChatGPT, or Codex
B
Blockscout MCP Server
Official
Exposes Blockscout blockchain data via MCP
GitHub source repository ↗
66FMRS · C
An official, full-featured multi-chain blockchain data MCP server from Blockscout, offering a hosted endpoint and self-hosting options; requires a PRO API key and targets read-only blockchain queries and analysis.
Blockscout MCP Server, maintained by Blockscout, wraps Blockscout APIs and exposes blockchain data—balances, tokens, NFTs, transactions, and contract metadata—via the Model Context Protocol to AI agents and IDEs such as Claude and Cursor. It supports multi-chain access via the Blockscout PRO API with Chainscout metadata enrichment, context optimization, smart response slicing, Base64URL cursor pagination, and a versioned REST API. A Blockscout PRO API key (proapi_ prefix) is required, supplied via the Blockscout-MCP-Pro-Api-Key header or the BLOCKSCOUT_PRO_API_KEY environment variable. The official hosted endpoint is https://mcp.blockscout.com/mcp. Community instances collect anonymous telemetry by default, which can be disabled with BLOCKSCOUT_DISABLE_COMMUNITY_TELEMETRY=true. Licensed under the Blockscout Software Licence.
Tools
__unlock_blockchain_analysis__
Initializes a Blockscout MCP session: returns server reference data, the blockscout-analysis skill pointer, and the URI resolution rule. Call once per session before any other tool.
get_chains_list
Returns a list of supported chains, with optional filtering by name, chain ID, native currency, or ecosystem.
get_address_by_ens_name
Converts an ENS domain name to its corresponding Ethereum address.
lookup_token_by_symbol
Searches for token addresses by symbol or name, returning multiple potential matches.
get_contract_abi
Retrieves the ABI (Application Binary Interface) for a smart contract.
inspect_contract_code
Gets the source files of verified contracts.
get_address_info
Gets comprehensive information about an address including balance, ENS association, contract status, token details, and public tags.
get_tokens_by_address
Returns detailed ERC20 token holdings for an address with enriched metadata and market data.
get_block_number
Retrieves the block number and timestamp for a specific date/time or the latest block.
get_transactions_by_address
Gets transactions for an address within a specific time range with optional method filtering.
get_token_transfers_by_address
Returns ERC-20 token transfers for an address within a specific time range.
nft_tokens_by_address
Retrieves NFT tokens owned by an address, grouped by collection.
get_block_info
Returns block information including timestamp, gas used, burnt fees, and transaction count; can optionally include transaction hashes.
get_transaction_info
Gets comprehensive transaction information with decoded input parameters and detailed token transfers.
read_contract
Executes a read-only smart contract function and returns its result. The abi argument is a JSON object describing the function's signature.
direct_api_call
Calls a raw Blockscout API endpoint for advanced or chain-specific data. Supports GET (default) and POST requests with JSON body.
Setup
- Register at the Blockscout Developer Portal (dev.blockscout.com) and generate a PRO API key (free tier requires no credit card). 2. Claude Desktop: download blockscout-mcp.mcpb from GitHub Releases and double-click to install, or configure claude_desktop_config. with docker run sparfenyuk/mcp-proxy. 3. Claude Code: run claude mcp add --transport http blockscout https://mcp.blockscout.com/mcp --header "Blockscout-MCP-Pro-Api-Key: proapi_your_key_here". 4. Cursor: add a config with the Blockscout-MCP-Pro-Api-Key header in .cursor/mcp.. 5. Codex: add a Streamable HTTP server with the key header in settings. 6. Local development: git clone, uv pip install -e ., then run python -m blockscout_mcp_server (stdio) or with --http; Docker image is ghcr.io/blockscout/mcp-server:latest.
claude_desktop_config.json
{"mcpServers":{"blockscout":{"url":"https://mcp.blockscout.com/mcp","headers":{"Blockscout-MCP-Pro-Api-Key":"proapi_your_key_here"}}}}
Fit and risk
Not for
- Users unwilling to register for a Blockscout PRO API key
- Scenarios requiring on-chain writes or signing (all tools are read-only queries)
- Telemetry-sensitive users running community instances without disabling telemetry
Required permissions
- Requires a Blockscout PRO API key (proapi_ prefix) for data access
- Accesses https://mcp.blockscout.com/mcp over HTTP transport
- Self-hosted deployments provide the key via the BLOCKSCOUT_PRO_API_KEY environment variable
Risks and side effects
- PRO API access is metered in credits; tools append advisory notes when the balance drops below a threshold
- Community instances collect anonymous telemetry by default (tool names, parameters, version, SHA-256 hash of the API key); disable with BLOCKSCOUT_DISABLE_COMMUNITY_TELEMETRY=true
- The PRO API key must never be committed to version control or embedded in client-shipped binaries
- Claude Connectors Directory requires a paid Claude plan and may have restrictions due to a shared access key
Troubleshooting
- Verify the PRO API key is supplied via the Blockscout-MCP-Pro-Api-Key header or environment variable
- Malformed keys fail any request needing the PRO API with no fallback; no key at all returns a not-configured error
- In stdio mode, client keys cannot be sent via headers; set BLOCKSCOUT_PRO_API_KEY yourself
- In HTTP mode with Docker, bind --http-host 0.0.0.0 so the server is reachable outside the container
- Ngrok tunnels require BLOCKSCOUT_MCP_ALLOWED_HOSTS and BLOCKSCOUT_MCP_ALLOWED_ORIGINS to bypass DNS rebinding protection
- Codex CLI requires enabling experimental_use_rmcp_client in config.toml
Use cases
Query address balances, token holdings, and NFT collections
Analyze transactions, blocks, and gas fees
Retrieve and inspect ABIs and source code of verified contracts
Execute read-only contract functions via read_contract
Track ERC-20 token transfers within specific time ranges
Supported clients
Claude DesktopFull support
Claude CodeFull support
Claude (Web) Connectors DirectoryFull support
ChatGPT AppsFull support
Codex AppFull support
Codex CLIFull support
CursorFull support