Register a webhook URL for push notifications on watchlist changes. The secret is only shown once.
Part of the TickerAPI server.
Free to start. No card required.
AI agents use create_webhook to create or modify resources in TickerAPI. 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_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 TickerAPI.
Write tools can modify data. A rate limit prevents runaway bulk operations from AI agents.
{
"version": "1",
"default": "deny",
"tools": {
"create_webhook": {
"limits": [
{
"counter": "create_webhook_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}See the full TickerAPI policy for all 20 tools.
These attack patterns abuse exactly the kind of access create_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 a webhook URL for push notifications on watchlist changes. The secret is only shown once.. It is categorised as a Write tool in the TickerAPI MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the TickerAPI MCP server in PolicyLayer and add a rule for create_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 TickerAPI. Nothing to install.
create_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 create_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 create_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.
create_webhook is provided by the TickerAPI MCP server (tickerapi-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 20 TickerAPI 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.