# 0x402 MCP server

Agent View of the PolicyLayer registry record for 0x402: identity, probed posture, risk grade, and all 7 tools classified. HTML page: https://policylayer.com/tools/0x402-mcp

## Facts

- Server id: `@0x402/mcp`
- Install: `npx -y @0x402/mcp`
- Homepage: https://www.npmjs.com/package/@0x402/mcp
- Registry record: grade D, identity unverified
- Lifecycle: active
- Rate-limited: no
- Tools: 7 (6 with introspected schema)
- Tool categories present: Execute, Read
- Context-window cost: 1222 tokens per request — https://policylayer.com/token-cost/0x402-mcp
- Tags: 0x402 mcp, automation
- Record last modified: 2026-09-21T14:09:33.797Z

## Tools (7)

| Tool | Category | Risk | Record |
| --- | --- | --- | --- |
| `underwrite` | Execute | High | https://policylayer.com/tools/0x402-mcp/underwrite.md |
| `agent_status` | Read | Low | https://policylayer.com/tools/0x402-mcp/agent-status.md |
| `describe_auditor` | Read | Low | https://policylayer.com/tools/0x402-mcp/describe-auditor.md |
| `get_listing` | Read | Low | https://policylayer.com/tools/0x402-mcp/get-listing.md |
| `hire_audit` | Read | Low | https://policylayer.com/tools/0x402-mcp/hire-audit.md |
| `quote_audit` | Read | Low | https://policylayer.com/tools/0x402-mcp/quote-audit.md |
| `verify_seal` | Read | Low | https://policylayer.com/tools/0x402-mcp/verify-seal.md |

## Tool descriptions

- `underwrite` — Run the full underwriting: read the token, pay and verify an auditor's seal B, compose and sign seal A around it, publish the body to 0G Storage, and list it on the CollateralRegistry. Refuses with a named code at whichever step fails. W…
- `agent_status` — Report whether this agent can underwrite right now: key, USDC balance on the payment chain, whether the auditor is answering, what the budget has left, and the single next step to take. Call this first, and whenever a paid tool refuses.
- `describe_auditor` — Fetch an auditor's agent card (GET /agent on its origin): who it claims to be, what it charges, and on which network. Free, unauthenticated, and never trusted — the seal it returns later is what gets verified.
- `get_listing` — Look up a token's listing on the CollateralRegistry, fetch the seal body its sealHash points at from 0G Storage, and verify that seal locally. Answers what the chain says, what the seal says, and whether the two agree.
- `hire_audit` — Pay the auditor over x402 and verify the seal B it returns against the six checks (signature, live agentId, subject, request, expiry, attestation). Returns the verified seal, or a refusal naming the check that failed. Without a key this …
- `quote_audit` — Price a code audit for an ERC-20 on 0G testnet: reads the token's bytecode over RPC (free), asks the auditor for a 402 quote, and runs it past the budget gate. Never pays and never signs — use hire_audit or underwrite to act on the quote.
- `verify_seal` — Verify a seal A or seal B locally, in this process — signature, live agentId, subject and request bindings, expiry, and TEE attestation. Never asks a server whether a seal is valid. An invalid seal is a normal answer: { valid: false, fai…

## Related servers

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- Apibase (1384 tools) — https://policylayer.com/tools/io-github-whiteknightonhorse-apibase.md
- Delx Mcp A2a (1068 tools) — https://policylayer.com/tools/io-github-davidmosiah-delx-mcp-a2a.md
- MCP Framework Personal (912 tools) — https://policylayer.com/tools/inggerman-mcps.md
- Hermoso (896 tools) — https://policylayer.com/tools/hermoso.md
- Nodebench (824 tools) — https://policylayer.com/tools/io-github-homenshum-nodebench.md
- Altium-MCP-Suite (817 tools) — https://policylayer.com/tools/altium-mcp-suite.md
- Eda Agent (777 tools) — https://policylayer.com/tools/eda-agent.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

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Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=0x402-mcp · API: https://policylayer.com/registry/api · Recommended policies for every tool: https://policylayer.com/policies/0x402-mcp