Creates a new alias for the deployment with the given deployment ID
AI agents use assign_alias to create or update resources in Vercel MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Vercel MCP Server environment.
This tool performs a reversible write operation by creating a new alias record for an existing deployment. While it modifies infrastructure state, it does not irreversibly delete data (not Destructive), execute arbitrary code (not Execute), move money (not Financial), or merely read data (not Read). Creating an alias is a standard configuration write.
From the tool's definition Tool description states it 'Creates a new alias for the deployment' — a create operation that modifies deployment routing configuration.
Documented attack patterns abuse exactly the kind of access assign_alias gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Vercel MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for assign_alias:
{
"version": "1",
"default": "deny",
"tools": {
"assign_alias": {
"limits": [
{
"counter": "assign_alias_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}assign_alias 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 new alias for the deployment with the given deployment ID. It is categorised as a Write tool in the Vercel MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Vercel MCP Server MCP server in PolicyLayer and add a rule for assign_alias: 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 Vercel MCP Server. Nothing to install.
assign_alias 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 assign_alias 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 assign_alias. 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.
assign_alias is provided by the Vercel MCP Server MCP server (quegenx/vercel-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 154 Vercel MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
154 Vercel MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.