GET /api/activeUsers
AI agents call get_active_users to retrieve information from REI Crypto MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This is a data retrieval operation that queries active user metrics from crypto data APIs (DefiLlama Pro, CoinGecko Pro, or Arkham Intelligence). It has no side effects, cannot modify data, execute code, or commit financial transactions. The blast radius of misuse is minimal—at worst, an agent could retrieve unwanted data about active users, which is a low-severity information disclosure risk.
From the tool's definition Tool name 'get_active_users' and description 'GET /api/activeUsers' indicate a read-only API endpoint that retrieves user activity data without modifying state or executing external operations.
Attacks that exploit this kind of access
GET /api/activeUsers. It is categorised as a Read tool in the REI Crypto MCP Server MCP Server, which means it retrieves data without modifying state.
Register the REI Crypto MCP Server MCP server in PolicyLayer and add a rule for get_active_users: 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 REI Crypto MCP Server. Nothing to install.
get_active_users 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_active_users 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_active_users. 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_active_users is provided by the REI Crypto MCP Server MCP server (0xreisearch/crypto-mcp-beta). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
get_active_users is one line of REI Crypto MCP Server'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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