{
  "markdown": "# b20check-mcp\n\nAn MCP (Model Context Protocol) server for [B20 Check](https://b20check.com). It lets Claude,\nChatGPT, or any MCP client verify a B20 token on Base before you touch it: you ask, in plain\nlanguage, whether a token is safe, and your assistant runs the check and reads you the signed\nverdict.\n\n## What it exposes\n\n- `verify_b20_token(address)` — is this address a legitimate B20 token on Base, and what powers\n  does its issuer hold? Returns a verdict (ok / caution / danger), risk flags (mint, freeze,\n  seize, pause, admin, impostor, and more), data freshness (indexed / live / not_indexed), and an\n  EIP-712 signed attestation you can verify independently. A token that cannot be fully checked is\n  never signed as a clean pass.\n- `b20_stats()` — how many B20 tokens B20 Check has indexed.\n\nThe tool description instructs the assistant to run the check before helping move value into a B20\ntoken it has not already verified.\n\n## Add to Claude Desktop\n\nIn `claude_desktop_config.json`:\n\n```json\n{\n  \"mcpServers\": {\n    \"b20-check\": {\n      \"command\": \"npx\",\n      \"args\": [\"-y\", \"b20check-mcp\"]\n    }\n  }\n}\n```\n\nNo-code alternative (no install): B20 Check also runs a remote MCP connector. Paste\n`https://b20check.com/mcp` into Claude (Settings, Connectors) or add it in ChatGPT as a custom MCP\nconnector.\n\n## Free vs paid\n\nBy default this server calls the free, rate-limited demo route (20 checks/minute, no wallet, no\nkeys). For unmetered access, set `B20_AGENT_KEY` to a Base private key that holds USDC; the server\nthen pays $0.01 per call via x402 through the paid `/v1/verify` endpoint.\n\n| Env | Default | Meaning |\n|-----|---------|---------|\n| `B20_BASE_URL` | `https://b20check.com` | B20 Check API base URL |\n| `B20_AGENT_KEY` | (unset) | 0x Base key holding USDC; enables paid, unmetered access via x402 |\n\nVerify-don't-trust: the attestation is EIP-712 signed. Recover the signer\n(`0x1388d1e3751512955A53C7c2795Eaf8a3B029e6A`) from the signature yourself rather than trusting the\n`verdict` field alone.\n\nMIT licensed.",
  "bytes": 2044,
  "sha": "5cf2506624bc96a22296b40526b742357da40b9f936ce3db331a0e2bc9de6080",
  "repo_slug": "",
  "fonte": "npm",
  "truncated": false,
  "api": "https://agentalog.com/api/listings/mcp_com_b20check_b20check_049b9747/readme"
}