Find x402 pay-per-call APIs by keyword (name, description, tags). Returns endpoints an agent can pay in USDC to call, with price and network. Use this to discover a paid capability, e.g.
AI agents call search_x402_services to retrieve information from X402hub without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This is a search/discovery tool that queries a directory and returns matching results. It has no side effects on data or systems. While the discovered services themselves may have financial implications (they are 'pay-per-call APIs'), this tool does not execute them or move money—it only retrieves and presents information about them. Classification as Read is appropriate.
From the tool's definition Tool description states it 'Find[s] x402 pay-per-call APIs by keyword' and 'Returns endpoints'. The verb 'find' and 'returns' indicate data retrieval only.
Attacks that exploit this kind of access
Find x402 pay-per-call APIs by keyword (name, description, tags). Returns endpoints an agent can pay in USDC to call, with price and network. Use this to discover a paid capability, e.g. It is categorised as a Read tool in the X402hub MCP Server, which means it retrieves data without modifying state.
Register the X402hub MCP server in PolicyLayer and add a rule for search_x402_services: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches X402hub. Nothing to install.
search_x402_services is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the search_x402_services rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for search_x402_services. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
search_x402_services is provided by the X402hub MCP server (zacharytroberts03-ctrl/x402hub). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
search_x402_services is one line of X402hub's registry record.
The record carries the whole server: verified identity, auth posture, risk grade, every tool classified, recommended policy — re-checked continuously.
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