Challenge another player
AI agents use create_challenge to create or update resources in Lichess Integration — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Lichess Integration environment.
| Parameter | Type | Required | Description |
|---|---|---|---|
fen | string | — | Custom initial position in FEN format |
days | number | — | Days per turn for correspondence games |
clock | object | — | Clock settings |
color | string | — | Color to play |
rated | boolean | — | Whether the game is rated |
variant | string | — | Game variant |
username | string | — | Username of the player to challenge |
Parameters from the server's own tool schema.
This tool creates a new chess challenge, which is a reversible write operation. It generates a new game invitation/state in the Lichess platform without permanently destroying data or executing arbitrary code. The impact is limited to the game context and can be undone by canceling the challenge. No financial transactions or destructive operations are involved.
From the tool's definition Tool creates a new challenge (creates data), described as 'Challenge another player'. The sibling tools like 'accept_challenge', 'cancel_challenge', and 'claim_victory' confirm this server manages game state changes.
Attacks that exploit this kind of access
Challenge another player. It is categorised as a Write tool in the Lichess Integration MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
create_challenge accepts 7 parameters: fen, days, clock, color, rated, variant, username. The full parameter table on this page comes from the server's own tool schema.
Register the Lichess Integration MCP server in PolicyLayer and add a rule for create_challenge: 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 Lichess Integration. Nothing to install.
create_challenge is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the create_challenge 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 create_challenge. 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.
create_challenge is provided by the Lichess Integration MCP server (karayaman/lichess-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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