zap-lookup-invoice

Look up a Lightning invoice status via NWC.

SERVERNostr Bray SOURCEnostr-bray

Low RISK CLASS

Category Read

Parameters 00 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/dev-forgesworn-bray/zap-lookup-invoice.md

WHAT IT DOES

What zap-lookup-invoice does on Nostr Bray

AI agents call zap-lookup-invoice to retrieve information from Nostr Bray without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

RISK

Why zap-lookup-invoice is rated Low

This tool performs a read-only lookup of invoice status via NWC (Nostr Wallet Connect). It retrieves information about an existing invoice but does not create, modify, delete, or finalize payments. The action is non-destructive and has no side effects beyond data retrieval.

From the tool's definition Tool description states 'Look up a Lightning invoice status' — a query operation that retrieves invoice data without modifying state or moving funds.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs zap-lookup-invoice safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Nostr Bray, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For zap-lookup-invoice, this is the rule to start with:

zap-lookup-invoice Allowed

zap-lookup-invoice is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "zap-lookup-invoice": {}
  }
}

ALLOW ONLY THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Nostr Bray, apply this rule, and every zap-lookup-invoice call is checked against it from then on.

FAQ

Questions about zap-lookup-invoice

What does the zap-lookup-invoice tool do? +

Look up a Lightning invoice status via NWC. It is categorised as a Read tool in the Nostr Bray MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on zap-lookup-invoice? +

Register the Nostr Bray MCP server in PolicyLayer and add a rule for zap-lookup-invoice: 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 Nostr Bray. Nothing to install.

What risk level is zap-lookup-invoice? +

zap-lookup-invoice is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit zap-lookup-invoice? +

Yes. Add a rate_limit block to the zap-lookup-invoice 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.

How do I block zap-lookup-invoice completely? +

Set action: deny in the PolicyLayer policy for zap-lookup-invoice. 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.

What MCP server provides zap-lookup-invoice? +

zap-lookup-invoice is provided by the Nostr Bray MCP server (nostr-bray). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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