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B20 Check

NPM · B20CHECK-MCP · 2 COMPONENTS · SCANNED SEP 22

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

Available components

remote · b20check.com 81 npm · b20check-mcp 79
0 this week 79 Trust /100
Trust breakdown (7 categories)

How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, and we only credit what we can confirm. How we score → Why this is hard to score →

Supply Chain Security99
  • No malware found by supply-chain analysis.Pass
  • No known CVEs affecting this package version or its production dependencies.Pass
  • No install/post-install scripts declared.Pass
  • 31 of 114 dependencies flagged as unhealthy. View diagnostics → Partial
Provenance & Transparency19
Schema Quality & AI Usability74
  • AI-judged instruction clarity (excellent).Pass
  • Context-footprint check failed: tool/resource definitions use about 350 tokens (~175/item across 2 items; 2 tools + 0 resources), over budget; trim descriptions and params. See how to fix → Fail
  • Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management100
  • No destabilizing schema changes in the last 30 days.Pass
Tool Coverage100
  • 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
  • 100% of tool parameters carry a description.Pass
Tool Safety100
  • No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
  • We read all 2 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
  • An AI judge read all 3 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
  • Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
Install

How do I install the B20 Check MCP server?

B20 Check runs locally as an npm package, launched with npx -y b20check-mcp. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

npm · b20check-mcp

# add to Claude Code
claude mcp add com-b20check-b20check -- npx -y b20check-mcp
// .cursor/mcp.json
{
  "mcpServers": {
    "com-b20check-b20check": {
      "command": "npx",
      "args": [
        "-y",
        "b20check-mcp"
      ]
    }
  }
}
// .vscode/mcp.json
{
  "servers": {
    "com-b20check-b20check": {
      "command": "npx",
      "args": [
        "-y",
        "b20check-mcp"
      ]
    }
  }
}
# add to Codex CLI
codex mcp add com-b20check-b20check -- npx -y b20check-mcp
// opencode.json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "com-b20check-b20check": {
      "type": "local",
      "command": [
        "npx",
        "-y",
        "b20check-mcp"
      ],
      "enabled": true
    }
  }
}
# add to OpenClaw
openclaw mcp add com-b20check-b20check --command npx --arg -y --arg b20check-mcp
# ~/.hermes/config.yaml
mcp_servers:
  com-b20check-b20check:
    command: "npx"
    args: ["-y", "b20check-mcp"]
// ~/.netclaw/config/netclaw.json
{
  "McpServers": {
    "com-b20check-b20check": {
      "Transport": "stdio",
      "Command": "npx",
      "Arguments": [
        "-y",
        "b20check-mcp"
      ]
    }
  }
}
# add to Vellum
assistant mcp add com-b20check-b20check -t stdio -c npx -a -y b20check-mcp
// mcp.json
{
  "mcpServers": {
    "com-b20check-b20check": {
      "command": "npx",
      "args": [
        "-y",
        "b20check-mcp"
      ]
    }
  }
}
Changelog

Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.

  • 22 Sept 26 +1
    • Stability: 0.97 → pass security
  • 20 Sept 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 90 to 93. That category is still filling its 30-day observation window: 27 days of observed history at the previous scan, 28 at this one. The score rises as the window fills, whether or not the server changes.

  • 18 Sept 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 83 to 87. That category is still filling its 30-day observation window: 25 days of observed history at the previous scan, 26 at this one. The score rises as the window fills, whether or not the server changes.

  • 16 Sept 26 −3
    • Stability: pass → 0.80 functional
  • 15 Sept 26 +1
    • Stability: 0.97 → pass security
  • 13 Sept 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 90 to 93. That category is still filling its 30-day observation window: 27 days of observed history at the previous scan, 28 at this one. The score rises as the window fills, whether or not the server changes.

  • 11 Sept 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 83 to 87. That category is still filling its 30-day observation window: 25 days of observed history at the previous scan, 26 at this one. The score rises as the window fills, whether or not the server changes.

  • 10 Sept 26 −3
    • Stability: pass → 0.83 functional
Diagnostics

Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.

Captured 22 Sept 2026 · Analysed npm/b20check-mcp@0.1.1

Provenance No attestation

The registry publishes no build provenance for this version, so there is nothing to verify.

Result No attestation
Ecosystem npm

Background: How many MCP packages publish verified provenance →

Dependencies 114 packages
Packages resolved 114
Stale 31
Tree resolution Complete

Background: SBOMs and build attestations, explained →

MCP tools · 2 exposed · ~296 tokens

The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →

Tool Tokens
b20_stats ~51

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).

Input schema present but exposes no named parameters.

No output schema declared.

No examples provided.

verify_b20_token ~245

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.

NameTypeReqDescription
addressstringyesThe token contract address on Base to check (B20 addresses usually start with 0xb20).

No output schema declared.

No examples provided.

Common questions

What is the B20 Check MCP server?

B20 Check is an MCP server listed in the public MCP registry as com.b20check/b20check. Verify B20 tokens on Base: issuer powers, imposter detection, signed EIP-712 verdicts. This page covers its npm package (b20check-mcp).

Is the B20 Check MCP server safe to use?

B20 Check scores 79 out of 100 on VerifyMCP. We found no known CVEs affecting it as of 22 September 2026. It declares no install or post-install scripts. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

What tools does the B20 Check MCP server expose?

B20 Check exposes 2 tools: verify_b20_token, b20_stats. Their descriptions and schemas cost roughly 296 tokens of context every time the server is loaded.

Is the B20 Check MCP server still maintained?

B20 Check is still listed as active in the MCP registry. We last reached this channel on 22 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

What licence is the B20 Check MCP server under?

B20 Check declares the MIT licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.