Register or manage webhook subscriptions for task event notifications.
AI agents use subscribe to create or update resources in Writbase — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Writbase environment.
The subscribe tool creates or modifies webhook subscription records, which are Write-category operations (create, update). It does not delete data (Destructive), execute arbitrary code (Execute), move money (Financial), or merely read data (Read). However, misconfigured webhooks could leak sensitive task data to unintended endpoints, justifying medium severity rather than low.
From the tool's definition Tool description states 'Register or manage webhook subscriptions' — registration and management of subscriptions are reversible write operations that create or modify notification configuration state.
Documented attack patterns abuse exactly the kind of access subscribe gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Writbase, and nothing reaches the server without passing your rules. This is the rule we recommend for subscribe:
{
"version": "1",
"default": "deny",
"tools": {
"subscribe": {
"limits": [
{
"counter": "subscribe_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}subscribe 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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Register or manage webhook subscriptions for task event notifications. It is categorised as a Write tool in the Writbase MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Writbase MCP server in PolicyLayer and add a rule for subscribe: 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 Writbase. Nothing to install.
subscribe 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 subscribe 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 subscribe. 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.
subscribe is provided by the Writbase MCP server (https://{PROJECT_REF}.supabase.co/functions/v1/mcp-server/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Writbase, 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.
13 Writbase tools catalogued and risk-classified — across an index of 43,000+ MCP servers.