Bnbchain MCP skill

BNB Chain MCP Skill

How to connect to the BNB Chain MCP server and use its tools: blocks, transactions, contracts, tokens, NFTs, wallet, ERC-8004 agents, and Greenfield. Use this skill when working with BNB Chain / opBNB / EVM or Greenfield via MCP.

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Connection and credentials

• Run the server: npx @bnb-chain/mcp@latest (fetches from npm at runtime). Source: github.com/bnb-chain/bnbchain-mcp.
• RPC: Default chains use built-in RPC; no config unless self-hosting or custom RPC.
• PRIVATE_KEY: Omit or leave empty for read-only (blocks, balances, contract reads). Set in the MCP server env for state-changing tools (transfers, write_contract, approve_token_spending, ERC-8004 register/set_uri, Greenfield writes). Never log or expose private keys.
• Read-only vs state-changing: Block/balance/contract-read tools work without a key; transfers and writes require PRIVATE_KEY in the server environment.

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1. MCP server config

Add the bnbchain-mcp server to the MCP client config (e.g. Cursor MCP settings, Claude Desktop claude_desktop_config.json).

Default (stdio):

{
  "mcpServers": {
    "bnbchain-mcp": {
      "command": "npx",
      "args": ["-y", "@bnb-chain/mcp@latest"],
      "env": {
        "PRIVATE_KEY": ""
      }
    }
  }
}

SSE mode: "args": ["-y", "@bnb-chain/mcp@latest", "--sse"] (and client SSE URL if required). Local dev server (e.g. bun dev:sse in bnbchain-mcp): "url": "http://localhost:3001/sse" with the same env.

Restart or reload the MCP client after changing config so the server starts.

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2. Credentials and environment

• RPC: Built-in for default chains.
• PRIVATE_KEY: Set in the server’s env when state-changing tools are needed; leave empty for read-only. Do not commit or echo keys.

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3. Agent registration (ERC-8004)

1. Register the agent on-chain with the MCP tool register_erc8004_agent (see references/erc8004-tools-reference.md).
2. Owners can then check registration on 8004scan (mainnet) or 8004scan (testnet).

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4. Quick reference — tools and prompts

Network parameter

• Read-only tools (blocks, balances, contract reads, get_chain_info, etc.): network is optional; default is bsc. Use get_supported_networks to list options.
• Write operations (transfer_native_token, transfer_erc20, transfer_nft, transfer_erc1155, approve_token_spending, write_contract, register_erc8004_agent, set_erc8004_agent_uri, Greenfield writes): network is REQUIRED. There is no default for writes. If the user does not specify the network, you MUST ask before calling the tool. Do not assume or default to mainnet (bsc); accidental mainnet execution causes irreversible financial loss.

Tool categories

Category	Examples	Needs PRIVATE_KEY?
Blocks	get_latest_block, get_block_by_number, get_block_by_hash	No
Transactions	get_transaction, get_transaction_receipt, estimate_gas	No (estimate only)
Network	get_chain_info, get_supported_networks	No
Wallet / balance	get_native_balance, get_erc20_balance, get_address_from_private_key	Balance: optional address or privateKey
Transfers / writes	transfer_native_token, transfer_erc20, transfer_nft, transfer_erc1155, approve_token_spending, write_contract	Yes
Contracts	read_contract, is_contract	No for read
Tokens / NFT	get_erc20_token_info, get_nft_info, get_erc1155_token_metadata, check_nft_ownership, get_nft_balance, get_erc1155_balance	No for read
ERC-8004	register_erc8004_agent, set_erc8004_agent_uri, get_erc8004_agent, get_erc8004_agent_wallet	Register/set_uri: Yes
Greenfield	gnfd_* bucket/object/payment tools	Writes: Yes

Prompts (MCP prompts)

Use the MCP prompt names when the user wants analysis or guidance:

• analyze_block — Analyze a block and its contents
• analyze_transaction — Analyze a specific transaction
• analyze_address — Analyze an EVM address
• interact_with_contract — Guidance on interacting with a smart contract
• explain_evm_concept — Explain an EVM concept
• compare_networks — Compare EVM-compatible networks
• analyze_token — Analyze an ERC20 or NFT token
• how_to_register_mcp_as_erc8004_agent — Guidance on registering MCP as ERC-8004 agent

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5. Reference files (per-tool usage)

For parameter names, examples, and detailed usage of each tool, use:

Reference	Content
references/evm-tools-reference.md	Blocks, transactions, network, wallet, contracts, tokens, NFT — all EVM tools
references/erc8004-tools-reference.md	register_erc8004_agent, set_erc8004_agent_uri, get_erc8004_agent, get_erc8004_agent_wallet
references/greenfield-tools-reference.md	Buckets, objects, folders, payment accounts — all Greenfield tools
references/prompts-reference.md	All MCP prompts and when to use them

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6. Safety and best practices

1. Confirm before sending transactions: For transfer_*, write_contract, or approve_token_spending, confirm recipient, amount, and network before calling the tool.
2. Network required for writes: For any write (transfers, write_contract, approve_token_spending, ERC-8004 register/set_uri), you MUST have an explicit network from the user. If not specified, ask — do not default to mainnet. Do not use advisory language like "prefer testnet" as a substitute; the constraint is: no network specified → do not call the write tool until the user confirms.
3. Private keys: Only in MCP server env; never in chat or logs.
4. ERC-8004 agentURI: JSON metadata per the Agent Metadata Profile (name, description, image, services e.g. MCP endpoint).

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Documentation links

• BNB Chain MCP repo: https://github.com/bnb-chain/bnbchain-mcp
• npm: npx @bnb-chain/mcp@latest
• ERC-8004 (Identity Registry); Agent Metadata Profile for agentURI format.