Register an HTTPS endpoint to receive signed push notifications for compel lifecycle events (compel.ready when renderable, compel.completed, compel.failed). Returns webhook_id and the HMAC-SHA256 signing secret exactly once - store the secret immediately, it is never returned again. Deliveries ar...
Risk signalsAccepts URL/endpoint input (url) · Bulk/mass operation — affects multiple targets
Part of the Compeller server.
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AI agents use register_webhook to create or modify resources in Compeller. 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 register_webhook 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 Compeller.
Write tools can modify data. A rate limit prevents runaway bulk operations from AI agents.
{
"version": "1",
"default": "deny",
"tools": {
"register_webhook": {
"limits": [
{
"counter": "register_webhook_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}See the full Compeller policy for all 30 tools.
These attack patterns abuse exactly the kind of access register_webhook 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.
Register an HTTPS endpoint to receive signed push notifications for compel lifecycle events (compel.ready when renderable, compel.completed, compel.failed). Returns webhook_id and the HMAC-SHA256 signing secret exactly once - store the secret immediately, it is never returned again. Deliveries are signed via X-Compeller-Signature: sha256=<hex> over the raw body. Delivery is at-least-once: a failed delivery is retried with backoff (up to 6 attempts) and every retry carries the same X-Compeller-Event-Id, so dedupe on it.. It is categorised as a Write tool in the Compeller MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Compeller MCP server in PolicyLayer and add a rule for register_webhook: 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 Compeller. Nothing to install.
register_webhook 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 register_webhook 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 register_webhook. 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.
register_webhook is provided by the Compeller MCP server (https://compeller.ai/api/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 30 Compeller tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
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