Create a new Unphurl account. Returns an API key (shown once, store it securely). After signup, the user must check their email and click the verification link. The API key won't work for URL checks until the email is verified. Verification link expires after 24 hours. If the link expires, use th...
Part of the Unphurl server.
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AI agents use signup to create or modify resources in Unphurl. 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 signup 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 Unphurl.
Write tools can modify data. A rate limit prevents runaway bulk operations from AI agents.
{
"version": "1",
"default": "deny",
"tools": {
"signup": {
"limits": [
{
"counter": "signup_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}See the full Unphurl policy for all 16 tools.
These attack patterns abuse exactly the kind of access signup 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.
Create a new Unphurl account. Returns an API key (shown once, store it securely). After signup, the user must check their email and click the verification link. The API key won't work for URL checks until the email is verified. Verification link expires after 24 hours. If the link expires, use the "resend_verification" tool to request a new one. The account starts with 20 free pipeline check credits so the user can test with real URLs. Known domain lookups (google.com, github.com, etc.) and cached domain lookups are always free. To check more unknown domains through the full analysis pipeline, the user can purchase credits via the "purchase" tool. Once the user has their API key, they need to add it to their MCP server configuration as UNPHURL_API_KEY. This tool does not require an API key.. It is categorised as a Write tool in the Unphurl MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Unphurl MCP server in PolicyLayer and add a rule for signup: 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 Unphurl. Nothing to install.
signup 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 signup 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 signup. 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.
signup is provided by the Unphurl MCP server (123Ergo/unphurl-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 16 Unphurl tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
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