NullClear Arbiter MCP Server

by mithgalalfayez Your server? Claim it

answering

NullClear Arbiter is answering right now. Last checked 14 min ago. 109 installs a week from npm. It exposes 13 tools. Last commit 28 Oct 2026.

Autonomous x402 payment schema-escrow arbiter, spend firewall, failover & ERC-8004 Sybil oracle

Installs per day peak 410 · avg 40 · -79% w/w

a month agotoday

Uptime history 24 days of history

24 days agonow

100.0%

Uptime 24h

91 of 91 checks

Tools

read from the server

193 ms

Response time

average over 24h

109

Installs / week

npm and PyPI

What changed 15

Every tool that appeared, vanished or quietly changed what it asks for. Recorded since 16 October 2026. No other catalogue keeps this.

28 Oct 5 tools appeared decode_calldata_or_failed_tx, inspect_contract_abi_and_proxy, read_url_clean_markdown and 2 more

22 Oct a tool changed version

18 Oct 5 tools appeared nullclear_crypto_market_oracle, nullclear_discover_verified_x402_apis, nullclear_safe_fetch and 2 more

18 Oct a tool description was rewritten nullclear_escrow_x402_call

18 Oct a tool changed version

16 Oct 2 tools changed the parameters they ask for nullclear_check_reputation, nullclear_escrow_x402_call

Nothing serious here today

Today is the operative word: we check NullClear Arbiter every 15 minutes and re-read its code on every release. Watch it and you find out the day that stops being true.

Connect this server

Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 14 min ago.

Claude Code Claude Desktop Codex Cursor VS Code

run in your terminal

claude mcp add nullclear --transport http https://api.nullclear.dev/mcp

Settings → Connectors → Add custom connector, then paste this address

https://api.nullclear.dev/mcp

~/.codex/config.toml

[mcp_servers.nullclear]
url = "https://api.nullclear.dev/mcp"

.cursor/mcp.json

{
  "mcpServers": {
    "nullclear": {
      "url": "https://api.nullclear.dev/mcp"
    }
  }
}

.vscode/mcp.json

{
  "servers": {
    "nullclear": {
      "type": "http",
      "url": "https://api.nullclear.dev/mcp"
    }
  }
}

Available tools 13

Read directly from the server with tools/list, grouped by what they act on. If a tool disappears, we record the date.

nullclear

nullclear_check_reputation

Inspect an AI agent's trust score (0-100), clearing reliability, Sybil wash-trade penalty flags, and corporate KYA backing on Base

nullclear_crypto_market_oracle

Fetch multi-exchange spread-verified crypto spot prices (ETH/USDC, BTC/USDC, SOL/USDC, BASE/USDC) with cryptographic NullClear invariant receipts. Works out-of-the-box with zero configuration (10 free daily calls included).

nullclear_discover_verified_x402_apis

Search the live NullClear Ecosystem Directory for audited, high-uptime x402 & ERC-8004 APIs by topic/keyword, category, minimum uptime, or max latency. Automatically returns the NullClear-protected Zero-Loss Proxy URL ('https://api.nullclear.dev/https://...') for each endpoint.

nullclear_escrow_x402_call

Execute an x402-gated HTTP API call through NullClear deferred schema escrow. Guarantees payment is only settled if upstream returns valid data matching your schema contract. Supports 10 free daily trial calls with zero wallet setup.

nullclear_safe_fetch

Zero-config drop-in URL fetcher with automatic Canonical LLM Refusal Guard, HTTP 5xx crash guard, empty-JSON guard, and cryptographic execution receipt. Protects agents from hallucinated or broken API responses.

nullclear_token_security_audit

Audit any Base ERC-20 token address for honeypot risk, buy/sell taxes, verified bytecode, and x402 compatibility via NullClear Bazaar. Works out-of-the-box with zero configuration (10 free daily calls included).

nullclear_verify_kya_mandate

Verify an agent's Know Your Agent (KYA) corporate liability mandate, active validity, and whether a proposed transaction amount is within corporate limits

nullclear_wallet_risk_score

Check any wallet or agent address on Base for OFAC sanctions, Sybil wash-trading concentration flags, and ERC-8004 counterparty reputation. Works out-of-the-box with zero configuration (10 free daily calls included).

decode

decode_calldata_or_failed_tx

[ZERO API KEY REQUIRED] Universal Calldata, Custom Revert Error & Failed Transaction Post-Mortem Decoder. Accepts raw hex calldata/revert bytes (0x...) OR a 66-char transaction hash (0x...), replays reverted transactions at their exact block, decodes 4-byte signatures & parameters, and flags malicious approvals (approve / permit / setApprovalForAll).

inspect

inspect_contract_abi_and_proxy

[ZERO API KEY REQUIRED] Resolves EIP-1967, EIP-1822, and EIP-1167 proxy implementation addresses via eth_getStorageAt and extracts decoded 4-byte PUSH4 function selectors and dangerous opcodes (SELFDESTRUCT / DELEGATECALL) directly from on-chain bytecode without an Etherscan or Basescan API key.

scan

scan_token_forensics

[ZERO API KEY REQUIRED] Block-pinned on-chain security, EIP-1967/1822 proxy resolution, instruction-boundary opcode disassembly, honeypot, and buy/sell tax audit for Base, Ethereum (ETH), or Solana tokens. Includes cross-chain self-healing auto-detection and <400-token deterministic provenance receipt (100 free calls/day/IP).

simulate

simulate_transaction_preflight

[ZERO API KEY REQUIRED] Pre-flight EVM transaction simulator. Dry-runs eth_call + eth_estimateGas on Base or Ethereum before signing/broadcasting, decodes any custom revert reason, detects unlimited drainer approvals, and outputs recommendedAgentAction ('EXECUTE_SAFE', 'ABORT_WILL_REVERT', or 'ABORT_DRAINER_APPROVAL').

url

read_url_clean_markdown

[ZERO API KEY REQUIRED] Converts any public web URL or documentation page into clean, token-efficient Markdown (<400 tokens) with cryptographic SHA-256 provenance and zero HTML clutter.

Endpoints

URL	Transport	State	Latency	Checked
https://api.nullclear.dev/mcp	streamable-http	answering	118 ms	14 min ago

Alternatives to NullClear Arbiter

same job, measured the same way

HPP x402 MCP Bridge

by hpp-io

MCP bridge for autonomous x402 payments in HPP USDC.e — discover and pay for services per call.

385 installs/wk local only

SpendPreflight

by spendpreflight

Preflight x402 payments. Base ERC-8004 agent #1151628; wallet binding verified Nov 3, 2026.

17 tools answering

Aval

by hstgr-srv1024618-aval

Payment-backed trust scores for AI agents on Base (ERC-8004). $0.01 per check via x402.

2 tools answering

Automan

by i02202

Autonomous AI agent selling pay-per-call skills settled with x402 micropayments (USDC).

12 tools answering

Paysafe

by paysafe-agent

Payment firewall for x402: scans for replay, overpayment, PII/secret leaks, prompt-injection.

65 installs/wk local only

Kokomoji

by kokomoji

Kokomoji NFTs, ERC-8004 agents, jobs, open board and docs. Paid tools return x402 payment terms.

12 tools answering

NostrPulse

by phonguit22

Autonomous payment & Web-of-Trust anti-Sybil layer for AI agents via Nostr & Cashu (NIP-61 NutZaps).

661 installs/wk local only

Agent Token Stripper

by goldminex

Autonomous x402 Token Stripper API settling $0.002 USDC micro-payments on Base L2.

local only

NullClear Arbiter — questions

Answers built from our own checks of this server.

What can NullClear Arbiter do?

It exposes 13 tools, read directly from the server on our last check. Among them: decode_calldata_or_failed_tx, inspect_contract_abi_and_proxy, nullclear_check_reputation, nullclear_crypto_market_oracle, nullclear_discover_verified_x402_apis, nullclear_escrow_x402_call and 7 more. The full list with descriptions is on this page — we take it from the server itself via tools/list, not from a README. How MCP servers expose tools in the first place →

Is NullClear Arbiter working right now?

We send a real MCP handshake every 15 minutes. Over the last 24 hours 91 of 91 checks got a reply (100.0%), average response time 193 ms. The bar chart above shows every period we have measured.

How do I connect NullClear Arbiter?

Copy the ready config from this page. We generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each in the form that client actually reads. It is a remote server, so there is nothing to install — the client connects to the address.

Does NullClear Arbiter need an API key?

No. NullClear Arbiter completed a full MCP handshake with us as an anonymous client and listed its tools without asking for anything. All 13 of them are readable on this page. This is what we observed, not what the docs claim.

How fast is NullClear Arbiter?

It answers our handshake in 193 ms on average, which is faster than 73% of all working MCP servers we measure. The comparison comes from our own checks across the whole registry, every 15 minutes.

How many people use NullClear Arbiter?

The npm package @nullclear/mcp was installed 109 times in the last week. Week over week that is -79%. We show installs rather than GitHub stars on purpose: a star is a bookmark, an install is someone actually running it.

Is NullClear Arbiter open source?

The code is open source: it is published under the MIT licence, written in TypeScript and 1 stars on GitHub. The licence covers the code in the repository, not the hosted service at api.nullclear.dev, which runs on its operator's own terms.