- name
- etherscan-mcp-skill
- description
- Use Etherscan MCP through UXC for address balance checks, token holder analysis, transaction inspection, and contract lookup tasks. Use when tasks need Etherscan MCP tools for onchain investigation with help-first schema inspection, bearer-key auth, and tier-aware read-first handling.
Etherscan MCP Skill
Use this skill to run Etherscan MCP operations through uxc.
Reuse the uxc skill for shared protocol discovery, output parsing, and generic auth/binding flows.
Prerequisites
uxcis installed and available inPATH.- Network access to
https://mcp.etherscan.io/mcp. - An Etherscan API key is available for authenticated calls.
Core Workflow
- Confirm endpoint and protocol with help-first probing:
- uxc https://mcp.etherscan.io/mcp -h - expected unauthenticated behavior today: 401 Unauthorized
- Configure credential/binding for repeatable auth:
- uxc auth credential set etherscan-mcp --auth-type bearer --secret-env ETHERSCAN_API_KEY - uxc auth credential set etherscan-mcp --auth-type bearer --secret-op op://Engineering/etherscan/api-key - uxc auth binding add --id etherscan-mcp --host mcp.etherscan.io --path-prefix /mcp --scheme https --credential etherscan-mcp --priority 100
- Use fixed link command by default:
- command -v etherscan-mcp-cli - If missing, create it: uxc link etherscan-mcp-cli https://mcp.etherscan.io/mcp - etherscan-mcp-cli -h
- Inspect operation schema before execution:
- etherscan-mcp-cli balance -h - etherscan-mcp-cli tokenTopHolders -h - etherscan-mcp-cli getContractAbi -h - etherscan-mcp-cli transaction -h
- Prefer read operations first, then any workflow that could trigger heavy data pulls or follow-up automation.
Capability Map
- Address investigation:
- balance - tokenHoldings - fundedBy - getAddressMetadata
- Token holder analysis:
- balanceERC20 - balanceERC20Historical - tokenTopHolders - getTokenInfo
- Transaction investigation:
- txList - internalTxsByAddress - erc20Transfers - erc721Transfers - erc1155Transfers - transaction - checkTransaction
- Contract research:
- getContractAbi - getContractSourceCode - getContractCreation
- Verification:
- verifySourceCode - checkVerifyStatus
Inspect etherscan-mcp-cli -h after auth setup for the current full tool list. Etherscan can expand MCP tools independently of this wrapper skill.
Recommended Usage Pattern
- Start from a read-only investigation goal:
- balance or holdings for an address - holder concentration for a token - transaction inspection for a hash - source/metadata lookup for a contract
- Run
-hon the specific tool before the first real call. - Prefer one chain/address/token at a time before broadening the scope.
- Parse the JSON envelope first, then inspect
data.
Guardrails
- Keep automation on JSON output envelope; do not rely on
--text. - Parse stable fields first:
ok,kind,protocol,data,error. - Use
etherscan-mcp-clias default command path. etherscan-mcp-cli <operation> ...is equivalent touxc https://mcp.etherscan.io/mcp <operation> ....- If unauthenticated probe or runtime call returns
401 Unauthorized:
- confirm auth binding matches endpoint with uxc auth binding match https://mcp.etherscan.io/mcp - confirm credential shape with uxc auth credential info etherscan-mcp - reset credential as bearer if needed: uxc auth credential set etherscan-mcp --auth-type bearer --secret-env ETHERSCAN_API_KEY
- Use
key=valueonly for simple scalar inputs. - Prefer positional JSON when an operation accepts nested objects, arrays, or optional flags that may evolve.
- Do not assume tool argument names from memory; inspect
<operation> -hfirst because Etherscan may revise MCP schemas independently of this skill. - Some MCP tools are tier-gated by Etherscan plan. Today
getTokenInfocan returnNOTOKwith an API Pro upgrade message on non-Pro keys. - Treat
verifySourceCodeas a write-like action requiring explicit user confirmation.
References
- Invocation patterns:
- references/usage-patterns.md