Add an address to a TIP-403 policy whitelist.
AI agents use add_to_whitelist to create or update resources in Tempo — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Tempo environment.
This tool performs a create/modify operation on a policy whitelist rather than retrieving data (Read), executing arbitrary code (Execute), irreversibly deleting data (Destructive), or moving money (Financial).
From the tool's definition The tool 'add_to_whitelist' modifies a TIP-403 policy whitelist by adding an address, which is a data modification action. The description states 'Add an address to' the whitelist, indicating a reversible write operation (addresses can be removed).
Documented attack patterns abuse exactly the kind of access add_to_whitelist gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Tempo, and nothing reaches the server without passing your rules. This is the rule we recommend for add_to_whitelist:
{
"version": "1",
"default": "deny",
"tools": {
"add_to_whitelist": {
"limits": [
{
"counter": "add_to_whitelist_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}add_to_whitelist 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.
Free to start. No card required.
Add an address to a TIP-403 policy whitelist. It is categorised as a Write tool in the Tempo MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Tempo MCP server in PolicyLayer and add a rule for add_to_whitelist: 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 Tempo. Nothing to install.
add_to_whitelist 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 add_to_whitelist 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 add_to_whitelist. 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.
add_to_whitelist is provided by the Tempo MCP server (arome3/tempo-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Tempo, 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.
61 Tempo tools catalogued and risk-classified — across an index of 43,000+ MCP servers.