Resolve a formatted legal citation string (e.g., "410 U.S. 113", "93 S. Ct. 705") to a cluster ID and case metadata. Enables workflows that start from a known citation rather than a search query. Supports standard US reporter formats. Requires authentication — uses the CourtListener /citation-loo...
Part of the Courtlistener Mcp Server server.
Free to start. No card required.
AI agents call courtlistener_lookup_citation to retrieve information from Courtlistener Mcp Server without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.
Even though courtlistener_lookup_citation only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.
Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.
{
"version": "1",
"default": "deny",
"tools": {
"courtlistener_lookup_citation": {}
}
}See the full Courtlistener Mcp Server policy for all 13 tools.
These attack patterns abuse exactly the kind of access courtlistener_lookup_citation gives an agent. Each links to the full case and the policy that stops it:
Other read tools across the catalogue. The same approach applies to each: allow, with a rate cap to control cost.
Resolve a formatted legal citation string (e.g., "410 U.S. 113", "93 S. Ct. 705") to a cluster ID and case metadata. Enables workflows that start from a known citation rather than a search query. Supports standard US reporter formats. Requires authentication — uses the CourtListener /citation-lookup/ endpoint.. It is categorised as a Read tool in the Courtlistener Mcp Server MCP Server, which means it retrieves data without modifying state.
Register the Courtlistener Mcp Server MCP server in PolicyLayer and add a rule for courtlistener_lookup_citation: 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 Courtlistener Mcp Server. Nothing to install.
courtlistener_lookup_citation 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 courtlistener_lookup_citation 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 courtlistener_lookup_citation. 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.
courtlistener_lookup_citation is provided by the Courtlistener Mcp Server MCP server (@cyanheads/courtlistener-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 13 Courtlistener Mcp Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
4,600+ MCP servers and 31,000+ tools scanned and risk-classified.