Enables AI agents to perform secure HTTP 402 transactions using deferred non-custodial escrow and on-chain reputation scoring.
Also known as Nullclear-Protocol/nullclear, nullclear, @nullclear/mcp
- Stars
- 1
- Tools
- 3
- Downloads, 30 days
- —
- Latest version
- 1.1.1
- Last commit
- Oct 28, 2026
- License
- MIT
What is NullClear Arbiter MCP?
NullClear Arbiter enables AI agents to perform secure HTTP 402 transactions using deferred non-custodial escrow and on-chain reputation scoring. It exposes 3 tools, such as nullclear_check_reputation, nullclear_escrow_x402_call, nullclear_verify_kya_mandate.
Summary generated from the project's README
About NullClear Arbiter MCP server
NullClear Arbiter provides a specialized interface for autonomous AI agents to manage financial transactions via HTTP 402. It allows clients like Claude Desktop, Cursor, Gemini, and OpenAI Agents to interact with a deferred non-custodial escrow system. This setup ensures that funds are only committed when a transaction is successful, protecting the agent from malformed data or counterparty failure.
Developers integrate this server by adding it to their MCP client configuration using a node command. The setup requires an ARBITER_URL and a BUYER_PRIVATE_KEY to function. The server provides specific tools to manage risk, including checking on-chain reputation scores and verifying legal corporate liability through the kya mandate. It specifically addresses Sybil wash-trade penalties and clearing reliability to maintain a secure environment for agent-to-agent commerce.
What you can do with it
- 1Verify agent reliabilityAn AI agent can check the on-chain trust score and reliability of another agent before initiating a transaction.
- 2Execute protected transactionsPerform an HTTP 402 call that uses escrow to ensure no money is spent if the response is invalid.
- 3Validate legal liabilityConfirm that an agent has the necessary corporate backing and transaction limits in place.
Written from the project's README. Every use case is checked against a quote from it.
How to install NullClear Arbiter MCP
Formats verified 10 Nov 2026Add to CursorAdd to GooseInstall NullClear Arbiter MCP in Claude Code
$ claude mcp add nullclear -- npx -y @nullclear/mcpInstall NullClear Arbiter MCP in Cursor
~/.cursor/mcp.json
{
"mcpServers": {
"nullclear": {
"command": "npx",
"args": [
"-y",
"@nullclear/mcp"
]
}
}
}Install NullClear Arbiter MCP in VS Code
.vscode/mcp.json
{
"servers": {
"nullclear": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"@nullclear/mcp"
]
}
}
}Install NullClear Arbiter MCP in VS Code CLI
$ code --add-mcp '{"name":"nullclear","type":"stdio","command":"npx","args":["-y","@nullclear/mcp"]}'Install NullClear Arbiter MCP in Claude Desktop
claude_desktop_config.json
{
"mcpServers": {
"nullclear": {
"command": "npx",
"args": [
"-y",
"@nullclear/mcp"
]
}
}
}Install NullClear Arbiter MCP in Codex
$ codex mcp add nullclear -- npx -y @nullclear/mcpInstall NullClear Arbiter MCP in Codex config.toml
~/.codex/config.toml
[mcp_servers.nullclear] command = "npx" args = ["-y", "@nullclear/mcp"]
Install NullClear Arbiter MCP in Gemini CLI
$ gemini mcp add -s user nullclear npx -- -y @nullclear/mcpInstall NullClear Arbiter MCP in Gemini settings.json
~/.gemini/settings.json
{
"mcpServers": {
"nullclear": {
"command": "npx",
"args": [
"-y",
"@nullclear/mcp"
]
}
}
}NullClear Arbiter MCP tools 3
Detected from the READMEnullclear_check_reputationnullclear_escrow_x402_callnullclear_verify_kya_mandate
| nullclear_check_reputation | — | |
| nullclear_escrow_x402_call | — | |
| nullclear_verify_kya_mandate | — |
Configuration
ARBITER_URLBUYER_PRIVATE_KEY
| Name | Description | |
|---|---|---|
| ARBITER_URL | — | |
| BUYER_PRIVATE_KEY | — |
Automated checks
Ran Nov 13, 2026Full report →Passed our automated checks. That is not a security audit: read the code and give the server the narrowest access it needs. How checks work
- Source repository linked and reachablenullclear-protocol/nullclear is public and reachablegithub.com/nullclear-protocol/nullclear ↗Pass
- Package names this repository as its source@nullclear/mcp names nullclear-protocol/nullclear as sourcenpmjs.com/package/@nullclear/mcp ↗Pass
- Build provenance (Sigstore attestation)No build attestation published for this releaseNot checked
- Open source license (OSI)MITspdx.org/licenses/MIT.html ↗Pass
- Commit or release in the last yearLast commit or release 2026-10-28github.com/nullclear-protocol/nullclear ↗Pass
- OpenSSF ScorecardNot checked
- Package name not close to a popular packageNo popular package one edit away from @nullclear/mcpPass
- No critical advisory in the package or its dependencies114 resolved dependencies checked; no critical advisoryosv.dev ↗Pass
- No hidden instructions to the model3 tool descriptions and the README read; no override phrases, credential paths or hidden charactersPass
- Destructive tools are labelledNo tool named like delete, drop or execPass
- Remote endpoint answers the MCP handshakeinitialize answered with protocol 2024-11-05 in 181 msPass
README
View on GitHub@nullclear/mcp
Model Context Protocol (MCP) server enabling autonomous AI agents (Claude Desktop, Cursor, Gemini, OpenAI Agents) to safely transact over HTTP 402 with NullClear deferred escrow and reputation scoring.
Exposed Tools
nullclear_check_reputation: Query an agent's on-chain trust score, clearing reliability, and Sybil wash-trade penalty flags.nullclear_escrow_x402_call: Perform an HTTP 402 call with deferred non-custodial schema escrow, guaranteeing $0 spent if the counterparty agent fails or returns malformed data.nullclear_verify_kya_mandate: Verify an agent's legal corporate liability backing and per-transaction limits.
Configuration
Add to your MCP client config (e.g., claude_desktop_config.json):
{
"mcpServers": {
"nullclear": {
"command": "node",
"args": ["/path/to/nullclear/packages/mcp-server/dist/index.js"],
"env": {
"ARBITER_URL": "https://arbiter.nullclear.dev",
"BUYER_PRIVATE_KEY": "0x..."
}
}
}
}
NullClear Arbiter MCP questions
How do I add NullClear Arbiter MCP to Claude Code?
Run claude mcp add nullclear -- npx -y @nullclear/mcp in your terminal. Add --scope user to make it available in every project.
How do I add NullClear Arbiter MCP to Cursor?
Open ~/.cursor/mcp.json and add the server under mcpServers, using the Cursor config shown in the install section above.
What tools does NullClear Arbiter MCP provide?
It exposes 3 tools, including nullclear_check_reputation, nullclear_escrow_x402_call, nullclear_verify_kya_mandate.
What does the escrow service guarantee?
It guarantees that zero funds are spent if the counterparty agent fails to perform or provides malformed data.
How can I check an agent's reliability?
You can use the reputation tool to query an agent's on-chain trust score, clearing reliability, and Sybil wash-trade penalty flags.
Can I verify an agent's legal backing?
Yes, the server provides a tool to verify an agent's legal corporate liability backing and per-transaction limits.