Creates a custom conversion for tracking specific actions. Args: - ad_account_id (string): Ad account ID - name (string): Conversion name - pixel_id (string): Pixel ID to associate with - custom_event_type (string): Event type — CONTENT_VIEW, SEARCH, ADD_TO_CART, ADD_TO_WISHLIST, INITIATED_CHECKO...
AI agents use meta_create_custom_conversion to create or update resources in Meta MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Meta MCP Server environment.
This tool creates and stores new conversion tracking configurations in Meta Ads Manager. This is a Write operation because it creates new data structures (custom conversions) that can be modified or deleted later. While it affects ad tracking and analytics, it does not execute arbitrary code, delete data irreversibly, or move money.
From the tool's definition Creates a custom conversion for tracking specific actions. The tool creates a new conversion tracking configuration in Meta's ad system, which modifies data through arguments like ad_account_id, name, pixel_id, custom_event_type, and rule.
Documented attack patterns abuse exactly the kind of access meta_create_custom_conversion gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Meta MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for meta_create_custom_conversion:
{
"version": "1",
"default": "deny",
"tools": {
"meta_create_custom_conversion": {
"limits": [
{
"counter": "meta_create_custom_conversion_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}meta_create_custom_conversion stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
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Creates a custom conversion for tracking specific actions. Args: - ad_account_id (string): Ad account ID - name (string): Conversion name - pixel_id (string): Pixel ID to associate with - custom_event_type (string): Event type — CONTENT_VIEW, SEARCH, ADD_TO_CART, ADD_TO_WISHLIST, INITIATED_CHECKOUT, ADD_PAYMENT_INFO, PURCHASE, LEAD, COMPLETE_REGISTRATION, OTHER - rule (string): URL rule as JSON (e.g., {. It is categorised as a Write tool in the Meta MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Meta MCP Server MCP server in PolicyLayer and add a rule for meta_create_custom_conversion: 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 Meta MCP Server. Nothing to install.
meta_create_custom_conversion 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 meta_create_custom_conversion 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 meta_create_custom_conversion. 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.
meta_create_custom_conversion is provided by the Meta MCP Server MCP server (oliverames/meta-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Meta MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
200 Meta MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.