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B20 Check

REMOTE · B20CHECK.COM · 2 COMPONENTS · SCANNED AUG 3

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

+4 this week 69 Trust /100
Trust breakdown (6 categories)

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. How we score →

Endpoint Security63
Transport & Reachability100
Schema Quality & AI Usability73
  • 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 Management27
  • Stability observed for 8 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
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
  • Structured output schemas are declared (100% of tools); any adoption earns full credit.Pass
Capabilities100
  • Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
Install

Add this component to your MCP client. Where a client-specific snippet is available, pick your client below and copy it straight into your config; otherwise use the connection detail shown.

remote · b20check.com

# add to Claude Code
claude mcp add --transport http com-b20check-b20check https://b20check.com/mcp
# ~/.codex/config.toml
[mcp_servers.com-b20check-b20check]
url = "https://b20check.com/mcp"
// opencode.json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "com-b20check-b20check": {
      "type": "remote",
      "url": "https://b20check.com/mcp",
      "enabled": true
    }
  }
}
# add to OpenClaw
openclaw mcp add com-b20check-b20check --url https://b20check.com/mcp --transport streamable-http
# ~/.hermes/config.yaml
mcp_servers:
  com-b20check-b20check:
    url: "https://b20check.com/mcp"
// mcp.json
{
  "mcpServers": {
    "com-b20check-b20check": {
      "type": "http",
      "url": "https://b20check.com/mcp"
    }
  }
}

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

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.

  • 3 Aug 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 23 to 27. That category is still filling its 30-day observation window: 7 days of observed history at the previous scan, 8 at this one. The score rises as the window fills, whether or not the server changes.

  • 1 Aug 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 17 to 20. That category is still filling its 30-day observation window: 5 days of observed history at the previous scan, 6 at this one. The score rises as the window fills, whether or not the server changes.

  • 31 Jul 26 0
    • We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
  • 30 Jul 26 +1
    • We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
  • 29 Jul 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 7 to 10. That category is still filling its 30-day observation window: 2 days of observed history at the previous scan, 3 at this one. The score rises as the window fills, whether or not the server changes.

  • 27 Jul 26 +1
    • We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
  • 26 Jul 26 64

    First indexed and scored.

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 3 Aug 2026 · Probed https://b20check.com/mcp

TLS valid

Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .

Subject Issuer Valid from Valid until Key Signature Serial
CN=b20check.com CN=YE1,O=Let's Encrypt,C=US 11 Jul 2026 9 Oct 2026 ECDSA 256 ECDSA-SHA384 5ecc909e7c72b925612122345ebd161fcd8
SANs: b20check.com
CN=YE1,O=Let's Encrypt,C=US (CA) CN=Root YE,O=ISRG,C=US 3 Sept 2025 2 Sept 2028 ECDSA 384 ECDSA-SHA384 5ddd70dd31f801c85c186a7a04b80afe
CN=Root YE,O=ISRG,C=US (CA) CN=ISRG Root X2,O=Internet Security Research Group,C=US 13 May 2026 2 Sept 2032 ECDSA 384 ECDSA-SHA384 872165fc34b6e5fba8add5b3705fb53a
CN=ISRG Root X2,O=Internet Security Research Group,C=US (CA) CN=ISRG Root X1,O=Internet Security Research Group,C=US 13 May 2026 2 Sept 2032 ECDSA 384 SHA256-RSA 6c8f1dc727c7117f7baf853ac980f9cd
DNSSEC insecure

Validation of b20check.com. Not signed

Zone DS Keys Algorithms Outcome
. trust_anchor 20326, 38696 8, 8 Verified
com. present 19718 13 Verified
b20check.com. absent Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation
Authentication No authorisation required

The endpoint answered without asking for a token. Anyone who knows the URL can reach it.

Result No authorisation required
HTTP status 200
Header Value
strict-transport-security max-age=63072000; includeSubDomains
Transports 2 probes
Transport URL Outcome Status Location
streamable-http https://b20check.com/mcp Verified 200
http (plaintext) http://b20check.com/mcp HTTPS enforced 301 https://b20check.com/mcp
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.

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.

NameTypeReqDescription
l30DaysTotalCallsnumber|null
l30DaysUniquePayersnumber|null
lastUpdatedstring
snapshotBlocknumber
sourcestring
tokensIndexednumber

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).
NameTypeReqDescription
addressstringyesThe checked token address (EIP-55).
attestationBlock-pinned EIP-712 attestation; verification recipe at https://b20check.com/v1/schema
creation
dataSourcestringyesData freshness. not_indexed = powers could not be fully checked; never a clean pass.
flagsarrayyesRisk flags. Derivation rules: https://b20check.com/methodology
isB20booleanyesTrue only for a factory-native B20 token.
issuerActivity
issuerPowersmint/burn/pause/freeze/seize/admin powers, latent-inclusive.
networkstring
variant
verdictstringyesRoll-up verdict. not_applicable = out of scope, do NOT read as safe.

No examples provided.