io.github.89rat/code402-verify-mcp

io.github.89rat/code402-verify-mcp89ratstreamable-httpv0.2.0Scanned 1 hour ago

Verify code402 XDR-1 receipts: keccak digest + secp256k1 signer recovery. Free, stateless.

18 tools: 16 change things and 2 only read.

Reads private data · 0
Reads text others write · 1
Can send data out · 1
1 finding

Tools listed without sign-in. Remote posture

Anlyon alternative

16 of these tools change something. Run those as governed actions.

Declare what an action changes, and Anlyon puts it under a shared limit, binds every approval to the exact request, and grades the outcome. It works on any HTTPS API you can describe as an action.

Anlyon does not run, proxy or govern this MCP server. A tool your own code calls directly is not routed through Anlyon and is not governed by it.

Import an OpenAPI spec →

Tools

Grouped by what each tool does, most consequential first. Open one for its reasons and full description; descriptions are the publisher's own words.

18 tools

Changes things 16Creates or changes something that can be changed back.Claude Code: ask

bundle_verifyPaid ($0.0029–$0.50).No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
Description, as the server wrote it
Paid ($0.0029–$0.50). Multi-gate compliance bundle: run any combination of IBAN validation, sanctions screening, and EVM address validation in a single call. Returns all gate results + XDR-1 signed receipt. Tier auto-detected from field count.
Annotations the server declares
- paid: true
- protocol: x402
- network: base-mainnet
- asset: USDC
chain_balancePaid ($0.0029).No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
Description, as the server wrote it
Paid ($0.0029). Get native ETH balance of any Ethereum address. Returns balance in wei and ETH.
Annotations the server declares
- paid: true
- protocol: x402
- network: base-mainnet
- asset: USDC
chain_block_numberPaid ($0.0029).No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
Description, as the server wrote it
Paid ($0.0029). Get the latest Ethereum mainnet block number. Returns block height and timestamp.
Annotations the server declares
- paid: true
- protocol: x402
- network: base-mainnet
- asset: USDC
chain_codePaid ($0.0029).No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
Description, as the server wrote it
Paid ($0.0029). Get the deployed bytecode at an address. Returns hex bytecode (empty = EOA, non-empty = contract). Useful for distinguishing contracts from wallets.
Annotations the server declares
- paid: true
- protocol: x402
- network: base-mainnet
- asset: USDC
chain_erc20_balancePaid ($0.0029).No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
Description, as the server wrote it
Paid ($0.0029). Get ERC-20 token balance via balanceOf. Returns balance in raw and human-readable form.
Annotations the server declares
- paid: true
- protocol: x402
- network: base-mainnet
- asset: USDC
chain_gas_pricePaid ($0.0029).No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
Description, as the server wrote it
Paid ($0.0029). Get the current Ethereum mainnet gas price. Returns base fee, priority fee, and max fee in wei and gwei. Useful for estimating transaction costs.
Annotations the server declares
- paid: true
- protocol: x402
- network: base-mainnet
- asset: USDC
chain_noncePaid ($0.0029).No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
Description, as the server wrote it
Paid ($0.0029). Get the next transaction nonce for an Ethereum address.
Annotations the server declares
- paid: true
- protocol: x402
- network: base-mainnet
- asset: USDC
chain_txPaid ($0.008).No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
Description, as the server wrote it
Paid ($0.008). Get Ethereum transaction details by hash. Returns from, to, value, gas used, status, block info.
Annotations the server declares
- paid: true
- protocol: x402
- network: base-mainnet
- asset: USDC
chain_tx_receiptPaid ($0.008).No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
Description, as the server wrote it
Paid ($0.008). Get the receipt of a confirmed transaction. Returns status (success/fail), gas used, logs, contract address if deployment.
Annotations the server declares
- paid: true
- protocol: x402
- network: base-mainnet
- asset: USDC
iban_checkPaid ($0.0029).No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
Description, as the server wrote it
Paid ($0.0029). Validate an IBAN: ISO 13616 structure, country registration, length, MOD 97-10 checksum. Returns pass/fail with all checks and issues. Covers 50 countries.
Annotations the server declares
- paid: true
- protocol: x402
- network: base-mainnet
- asset: USDC
lei_checkPaid ($0.0029).No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
Description, as the server wrote it
Paid ($0.0029). Validate a Legal Entity Identifier (LEI, ISO 17442). Checks 20-char alphanumeric format and Mod 97-10 check character. Verified via Rust WASM engine.
Annotations the server declares
- paid: true
- protocol: x402
- network: base-mainnet
- asset: USDC
luhn_checkPaid ($0.0029).No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
Description, as the server wrote it
Paid ($0.0029). Validate a payment card or account number using the Luhn algorithm (ISO/IEC 7812-1). Checks numeric format and Mod-10 checksum. Verified via Rust WASM engine.
Annotations the server declares
- paid: true
- protocol: x402
- network: base-mainnet
- asset: USDC
mod97_checkPaid ($0.0029).No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
Description, as the server wrote it
Paid ($0.0029). Calculate ISO 7064 Mod 97-10 remainder for any alphanumeric string. Returns the remainder (0-96, valid=1). Used for IBAN, LEI, and custom identifier validation. Verified via Rust WASM engine.
Annotations the server declares
- paid: true
- protocol: x402
- network: base-mainnet
- asset: USDC
onchain_address_checkPaid ($0.0029).1 finding
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
Findings
- Warn
  The input schema at properties.address.description contains a 42-character base64 string.
  Matched text
  inputSchema.properties.address.description: "...s to validate (e.g. 0x742d35Cc6634C0532925a3b844Bc9e7595f2bD18)"
  What this check looks for
Description, as the server wrote it
Paid ($0.0029). Validate an EVM address format and EIP-55 mixed-case checksum. Returns valid/invalid with normalization and checksum status.
Annotations the server declares
- paid: true
- protocol: x402
- network: base-mainnet
- asset: USDC
sanctions_checkPaid ($0.0029).No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
Description, as the server wrote it
Paid ($0.0029). Screen Ethereum addresses and entity names against OFAC/UN/EU sanctions lists. Returns clear/hit with matched entries. Supports both EVM addresses and human-readable names.
Annotations the server declares
- paid: true
- protocol: x402
- network: base-mainnet
- asset: USDC
x402_verifyVerify one or more XDR-1 signed receipts offline (free).No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
Description, as the server wrote it
Verify one or more XDR-1 signed receipts offline (free). Returns valid/invalid per receipt with signer recovery, declared signer comparison, and integrity digest. Supply raw_receipt as JSON string or array for batch.
Annotations the server declares
- paid: false

Only reads 2Looks things up and changes nothing.Show 2 read-only tools

chain_ens_resolvePaid ($0.008).No findings
Why it is in this group
- The name "chain_ens_resolve" says "resolve": a word for reading.
Description, as the server wrote it
Paid ($0.008). Resolve a .eth ENS name to its Ethereum address via the universal resolver.
Annotations the server declares
- paid: true
- protocol: x402
- network: base-mainnet
- asset: USDC
price_lookupLook up pricing for any code402 tool (free).Reads text others writeCan send data outNo findings
Why it is in this group
- The name "price_lookup" says "lookup": a word for reading.
What it can reach
- untrusted-inputThe input takes a URL (input.url), and the tool reads it: it reads web pages, which anyone can write.
- outboundThe input takes a URL (input.url): a request to a URL can carry data to whoever runs it.
Claude Code: ask, because it is tagged outbound.
Description, as the server wrote it
Look up pricing for any code402 tool (free). Returns current x402 pricing tiers, accepted networks, and tool availability. Use tool_name for named lookups or url for URL-based lookups.
Annotations the server declares
- paid: false

This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.

Exfil surface

Which tools read private data, which read text someone else can write, and which can send data out. One of each is a path a prompt injection can use.

No private-data, untrusted-input, outbound path in this server alone: no tool is tagged private-data.

Reads private data0: Reads files, mail, messages, databases, secrets, calendars or repositories.
Reads text others write1: Brings in text someone else can write: web pages, inbound email, messages, issues and comments.; price_lookup
Can send data out1: Can carry data to people or systems: it sends, posts or publishes, or takes a recipient, channel or URL.; price_lookup

Other servers in the same agent add their own tools to these paths. Audit your whole setup to see them together.

Remote posture

What anyone on the internet sees at the remote endpoint: an anonymous initialize and tools/list, and the public OAuth metadata.

Tools listed without sign-in

Looked at Oct 24, 2026, 16:18 UTC, unchanged since Oct 24, 2026. No credentials were sent and no tool was called. What is looked at.

Reachable: yes
HTTP status of an anonymous initialize: 200
tools/list served without credentials: yes
Tools that change things, listed without credentials: 16
Protocol version: 2025-06-18
WWW-Authenticate on 401: not observed
resource_metadata in WWW-Authenticate: not observed
RFC 9728 protected resource metadata: not observed
Authorization servers: not observed
Legacy HTTP+SSE transport: no
Dynamic client registration: not observed
Client ID metadata documents: not observed

WarnThe whole server
The endpoint served tools/list without credentials, and the list has 16 tools that change things (16 write). Whether a call also works without credentials was not tested: tools are never called.
Matched text
https://verify.code402.dev/mcp: tools/list returned 18 tools to an anonymous client, including x402_verify (write), iban_check (write), sanctions_check (write), onchain_address_check (write), lei_check (write) and 11 more
What this check looks for

Findings

Matches of fixed checks, with the text they matched.

1 warn

Warnonchain_address_check
The input schema at properties.address.description contains a 42-character base64 string.
Matched text
inputSchema.properties.address.description: "...s to validate (e.g. 0x742d35Cc6634C0532925a3b844Bc9e7595f2bD18)"
What this check looks for

History

Changes to its tool definitions and to its remote endpoint, newest first.

No change seen yet. Its tools are rescanned every day, and a remote endpoint is looked at once a week.

All changes to this server

Install

Pinned to version 0.2.0. Values in angle brackets are yours to fill in.

claude mcp add --transport http code402-verify https://verify.code402.dev/mcp

claude mcp add --transport http code402-verify https://verify.code402.dev/mcp

Run in a terminal.

Claude Code permissions

Allow the reads, ask before a change or a way out, deny the deletes. Paste into .claude/settings.json.

.claude/settings.json

{
  "permissions": {
    "allow": [
      "mcp__code402-verify__chain_ens_resolve"
    ],
    "ask": [
      "mcp__code402-verify__x402_verify",
      "mcp__code402-verify__price_lookup",
      "mcp__code402-verify__iban_check",
      "mcp__code402-verify__sanctions_check",
      "mcp__code402-verify__onchain_address_check",
      "mcp__code402-verify__lei_check",
      "mcp__code402-verify__luhn_check",
      "mcp__code402-verify__mod97_check",
      "mcp__code402-verify__bundle_verify",
      "mcp__code402-verify__chain_block_number",
      "mcp__code402-verify__chain_balance",
      "mcp__code402-verify__chain_erc20_balance",
      "mcp__code402-verify__chain_nonce",
      "mcp__code402-verify__chain_tx",
      "mcp__code402-verify__chain_gas_price",
      "mcp__code402-verify__chain_tx_receipt",
      "mcp__code402-verify__chain_code"
    ],
    "deny": []
  }
}

Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. A read that can send data out (it takes a URL, say) asks first too. It assumes the server is installed as code402-verify. Review it before you use it.

Capability tags behind 1 rule

mcp__code402-verify__price_lookup untrusted-input, outbound

Keep the decision: fail CI when the tools change, follow every change, or show a badge.

Pin in CI

Fail a build when the tools you reviewed are not the tools the server serves today.

curl -s "https://anlyon.dev/api/v1/servers/io.github.89rat/code402-verify-mcp/verify?hash=bec1cce355069f999b04ffdf3a5cd97522ac016ccc59838c018af4eab05aba53" | jq -e '.changed == false'

Pinned hash bec1cce35506, from Oct 24, 2026, 15:18 UTC.

Watch

Get told when its tools change: a new tool, a new description, a new class.

https://anlyon.dev/servers/io.github.89rat/code402-verify-mcp/changes.xml

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Badge

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Source: MCP Registry. Synced Oct 24, 2026, 15:17 UTC.