Provides a list of all Rune assets held by the specified address. It returns both total and available balances, allowing for token inventory management and portfolio tracking.
AI agents call runes_by_address to retrieve information from Maestro MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool performs a read-only lookup of token holdings at a given address on the Bitcoin blockchain. It returns data for portfolio tracking and inventory management but does not execute code, modify state, delete data, or move funds. The blast radius of misuse is minimal—an attacker could only gather information about what assets an address holds, which is already public blockchain data.
From the tool's definition Tool provides 'a list of all Rune assets held by the specified address' with 'total and available balances' — retrieves and queries blockchain data without modification, deletion, or execution.
Documented attack patterns abuse exactly the kind of access runes_by_address gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Maestro MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for runes_by_address:
{
"version": "1",
"default": "deny",
"tools": {
"runes_by_address": {}
}
} runes_by_address is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Provides a list of all Rune assets held by the specified address. It returns both total and available balances, allowing for token inventory management and portfolio tracking. It is categorised as a Read tool in the Maestro MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Maestro MCP Server MCP server in PolicyLayer and add a rule for runes_by_address: 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 Maestro MCP Server. Nothing to install.
runes_by_address 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 runes_by_address 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 runes_by_address. 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.
runes_by_address is provided by the Maestro MCP Server MCP server (maestro-org/maestro-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Maestro MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
117 Maestro MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.