# B20 Check

> Verify B20 tokens on Base: issuer powers, imposter detection, signed EIP-712 verdicts.

- name: com.b20check/b20check
- version: 0.1.1
- connection class: unknown (unknown)
- trust: 48/100 flags: no-repository
- quality: 82/100 (good)
- owner: not claimed
- descriptor: https://api.protogrid.dev/v1/servers/com.b20check%2Fb20check
- tools: https://api.protogrid.dev/v1/servers/com.b20check%2Fb20check/tools

**Not classified yet.** The remote endpoints have not been probed successfully, or the listing has nothing to connect to.

## Connection (mcpServers)

```json
{
  "mcpServers": {
    "b20check": {
      "type": "http",
      "url": "https://b20check.com/mcp"
    }
  }
}
```


## Trust

- hygiene: 80
- liveness: 9
- freshness: 65
- provenance: 55
- drivers: +dns-namespace +website -unreachable(3 failures) ~updated-100d-ago -no-repository
- Derived from observable signals (official registry feed and our own credential-free probes); no code audit performed.

## Quality 82/100 (good)

### protocol: 75 (weight 25)

- warn `protocol.modern`: newest supported version is 2025-11-25; 2026-07-28 not supported, older versions are deprecated until 2027-07-28
- n/a `protocol.stateless`: only applies to 2026-07-28 servers
- pass `protocol.transport`: streamable HTTP
- n/a `protocol.list_ttl`: only applies to 2026-07-28 servers

### authorization: n/a (weight 15)

- n/a `auth.prm`, `auth.as_metadata`, `auth.cimd`: no remote uses OAuth
- n/a `auth.secret_in_url`: no templated URL

### tool hygiene: 86 (weight 30)

- pass `tools.descriptions`: every tool has a description
- pass `tools.description_length`: descriptions are concise
- pass `tools.schemas`: every tool has an object input schema
- pass `tools.annotations`: 2 of 2 tools declare readOnlyHint or destructiveHint
- fail `tools.directory_hints`: no tool declares all four of readOnlyHint, destructiveHint, idempotentHint and openWorldHint; missing: verify_b20_token (destructiveHint); b20_stats (destructiveHint)
- pass `tools.token_cost`: about 425 tokens to load every tool
- pass `tools.api_dump`: tools are not a one-to-one API dump

### stability: 100 (weight 15)

- pass `stability.changes`: no tool changes in 30 days
- pass `stability.rug_pull`: no tool changed its meaning under the same name

### dependencies: 67 (weight 15)

- pass `deps.known_vulns`: no known advisory in 114 resolved packages
- fail `deps.mcp_sdk_version`: @modelcontextprotocol/sdk 1.30.1 has 1 known advisory (GHSA-6qxp-vccf-f47h); update @modelcontextprotocol/sdk to 1.31.0 or later
- pass `deps.resolvable`: b20check-mcp@0.1.1 resolved: 114 packages

- tools: 2, about 425 tokens to load them all
- tool set hash: 47d874adad7e09c1dfa52a7ec5853955
- badge: [![protogrid quality](https://protogrid.dev/badge/com.b20check/b20check.svg)](https://protogrid.dev/servers/com.b20check/b20check)
- Checks run on what our credential-free, read-only probes observe; tools are never called and no code audit is performed.

### Tool changes

_No tool definition changes recorded._

## Dependencies

- npm b20check-mcp@0.1.1: resolved, 113 dependencies, MCP SDK @modelcontextprotocol/sdk 1.30.1
  - GHSA-6qxp-vccf-f47h (high) in `` @modelcontextprotocol/sdk@1.30.1 ``, direct, fixed in `` 1.31.0 ``, advisory summary: "MCP TypeScript SDK: OAuth client could send credentials to an authorization server chosen by the MCP server" https://osv.dev/vulnerability/GHSA-6qxp-vccf-f47h

Dependency graphs from deps.dev; advisories from OSV.dev, including the GitHub Advisory Database and the PyPI Advisory Database; all CC BY 4.0.

## Remotes

- https://b20check.com/mcp (streamable-http, auth none, reachable false, uptime30d 0.9724771)

## Packages

- npm b20check-mcp@0.1.1

## Tools (2)

- `b20_stats`: Report B20 Check's own live usage: how many B20 tokens are indexed and how many paid calls and unique payers it has served in the last 30 days (from the public Coinbase discovery API).
- `verify_b20_token`: Check whether a token address on Base is a legitimate B20 token and what powers its issuer holds. Call this BEFORE helping the user buy, swap, approve, or move value into any B20 token you have not already verified in this conversation (B20 addresses usually start with 0xb20). Returns a signed verdict: isB20, a verdict of ok/caution/danger/not_applicable, risk flags (mint, freeze, seize, pause, admin, impostor, and more), and the data freshness (indexed/live/not_indexed). not_applicable means the address is not a B20 and not a recognized canonical asset: do NOT read it as safe, there is simply nothing B20-specific to vouch for. Never treat a not_indexed or error result as safe either: a token that cannot be fully checked is never a clean pass. The result carries an EIP-712 signature the user can verify independently; do not overstate it as a guarantee of safety, report what the flags and verdict actually say.