Create a new mixin type. Check existing mixins first with get_mixins_and_relation_groups to avoid duplicates. Mixins are reusable property sets applicable to any node.
Part of the CoreModels server.
Free to start. No card required.
AI agents use create_mixin_type to create or modify resources in CoreModels. 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 create_mixin_type 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 CoreModels.
Write tools can modify data. A rate limit prevents runaway bulk operations from AI agents.
{
"version": "1",
"default": "deny",
"tools": {
"create_mixin_type": {
"limits": [
{
"counter": "create_mixin_type_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}See the full CoreModels policy for all 19 tools.
These attack patterns abuse exactly the kind of access create_mixin_type 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 new mixin type. Check existing mixins first with get_mixins_and_relation_groups to avoid duplicates. Mixins are reusable property sets applicable to any node.. It is categorised as a Write tool in the CoreModels MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the CoreModels MCP server in PolicyLayer and add a rule for create_mixin_type: 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 CoreModels. Nothing to install.
create_mixin_type 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_mixin_type 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_mixin_type. 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_mixin_type is provided by the CoreModels MCP server (https://go.coremodels.io/mcp-admin). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 19 CoreModels tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
4,600+ MCP servers and 31,000+ tools scanned and risk-classified.