AI agents call get_l2_book to retrieve information from Hyperliquid MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
The L2 order book is market data that reflects the current state of bids and asks on the exchange. Reading this data has no side effects and cannot alter account balances, positions, or exchange state. It is a straightforward data retrieval operation typical of market data APIs. The server description emphasizes 'access to crypto market data' without mentioning trading, execution, or modifications.
From the tool's definition Tool retrieves 'L2 book of a token' (order book data) without modifying any state. Sibling tools include 'get_all_mids' and 'get_candle_snapshot', which are clearly read-only market data queries.
Documented attack patterns abuse exactly the kind of access get_l2_book gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Hyperliquid MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for get_l2_book:
{
"version": "1",
"default": "deny",
"tools": {
"get_l2_book": {}
}
}get_l2_book is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Get the L2 book of a token on Hyperliquid. It is categorised as a Read tool in the Hyperliquid MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Hyperliquid MCP Server MCP server in PolicyLayer and add a rule for get_l2_book: 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 Hyperliquid MCP Server. Nothing to install.
get_l2_book 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 get_l2_book 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 get_l2_book. 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.
get_l2_book is provided by the Hyperliquid MCP Server MCP server (mektigboy/server-hyperliquid). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Hyperliquid 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.
3 Hyperliquid MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.