Create a mock HTTP expectation on MockServer. Define request matching criteria and the response to return.
Risk signalsAccepts file system path (httpRequest.path) · Accepts raw HTML/template content (httpRequest.body) · High parameter count (24 properties)
Part of the Mockserver server.
Free to start. No card required.
AI agents use mockserver_create_expectation to create or modify resources in Mockserver. Write operations carry medium risk because an autonomous agent could trigger bulk unintended modifications. Rate limits prevent a single agent session from making hundreds of changes in rapid succession. Argument validation ensures the agent passes expected values.
Without a policy, an AI agent could call mockserver_create_expectation repeatedly, creating or modifying resources faster than any human could review. PolicyLayer's rate limiting ensures write operations happen at a controlled pace, and argument validation catches malformed or unexpected inputs before they reach Mockserver.
Write tools can modify data. A rate limit prevents runaway bulk operations from AI agents.
{
"version": "1",
"default": "deny",
"tools": {
"mockserver_create_expectation": {
"limits": [
{
"counter": "mockserver_create_expectation_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}See the full Mockserver policy for all 6 tools.
These attack patterns abuse exactly the kind of access mockserver_create_expectation gives an agent. Each links to the full case and the policy that stops it:
Other write tools across the catalogue. The same approach applies to each: rate-limit and validate the arguments.
Create a mock HTTP expectation on MockServer. Define request matching criteria and the response to return.. It is categorised as a Write tool in the Mockserver MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Mockserver MCP server in PolicyLayer and add a rule for mockserver_create_expectation: 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 Mockserver. Nothing to install.
mockserver_create_expectation 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 mockserver_create_expectation 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 mockserver_create_expectation. 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.
mockserver_create_expectation is provided by the Mockserver MCP server (mockserver-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 6 Mockserver tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
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