josephus
Solve the Josephus problem: find the survivor in a circle of n people eliminating every k-th.
This record as markdown: /tools/io-github-malamutemayhem-unclick-mcp-server/josephus.md
What josephus does on UnClick
AI agents call josephus to retrieve information from UnClick without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
k | number | Yes | Every k-th person is eliminated |
n | number | Yes | Number of people in the circle |
Parameters from the server's own tool schema.
Why josephus is rated Low
Even though josephus only reads data, uncontrolled read access leaks sensitive information and racks up API costs: an agent caught in a retry loop can make thousands of calls a minute without anyone noticing.
Risk signalsBulk/mass operation — affects multiple targets
Attacks that exploit this kind of access
The rule that runs josephus safely
PolicyLayer is an MCP gateway: it sits between your AI agents and UnClick, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For josephus, this is the rule to start with:
josephus is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect UnClick, apply this rule, and every josephus call is checked against it from then on.
Questions about josephus
Solve the Josephus problem: find the survivor in a circle of n people eliminating every k-th. It is categorised as a Read tool in the UnClick MCP Server, which means it retrieves data without modifying state.
josephus accepts 2 parameters: k, n. Required: k, n. The full parameter table on this page comes from the server's own tool schema.
Register the UnClick MCP server in PolicyLayer and add a rule for josephus: 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 UnClick. Nothing to install.
josephus 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 josephus 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 josephus. 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.
josephus is provided by the UnClick MCP server (@unclick/mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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