Validate phone numbers, line types and TCPA litigator risk in Trestle. Hosted by usefulapi: connect it to Claude, ChatGPT, Cursor or any MCP client.
Turn on the Trestle connector, then ask in plain words. The AI picks the tools.
For sales and support teams that check lead phone numbers before they call or text them.
Validate a phone number and read whether it is valid, its country, carrier, line type and prepaid flag. Use the result to confirm the lead gave a real number.
Validate each number in a lead list one by one. Keep the numbers with an activity score of 30 or below for review before you call.
Check a US number for TCPA litigator risk before you call or text it. The check works only when the add-on is enabled on your Trestle key.
Read the line type of a caller's number, such as mobile, landline or VOIP. Use the line type to decide how the call is routed.
The login page asks for your Trestle API key.
Copy the key in the Trestle portal (portal.trestleiq.com). Use the results only for identity or lead verification and caller routing, never for credit, insurance, employment, housing or benefits decisions. Your key is used only to call the Trestle API on your behalf and is never shown to anyone.
Team and Enterprise: an Owner adds the connector for the organization first.
No Add custom MCP server option? It depends on your account or workspace settings: see OpenAI's guide.
Run this command, then run /mcp in Claude Code to log in:
Add to Cursor or add this to ~/.cursor/mcp.json:
{
"mcpServers": {
"trestle": {
"url": "https://trestle.usefulapi.io/mcp"
}
}
} Add to VS Code or add this to .vscode/mcp.json:
{
"servers": {
"trestle": {
"type": "http",
"url": "https://trestle.usefulapi.io/mcp"
}
}
} Run these commands. The second one opens the login page:
Windsurf, Cline, Zed and other MCP clients: add this URL as a remote MCP server (Streamable HTTP). The client then opens the login page in your browser.
Add only the URL. Do not add an Authorization header or an API key to the client config. The server signs you in with OAuth: the login page asks for your Trestle API key. If the config has such a header, remove it: some clients then send that header instead of the login token, and every call fails with 401.
| Plan | Price | Limit |
|---|---|---|
| Free | $0 | 50 tool calls / month |
| Proper user | $9/mo · $90/yr | Unlimited* |
*Pro fair use limit: 10,000 tool calls a month on this server. For more, write to [email protected].
Pro covers this Trestle server only. Subscribe with trestle_upgrade (it returns a Stripe Checkout link). Cancel any time with trestle_cancel_subscription: Pro continues to the end of the paid period, with no refund for the current period, and running trestle_upgrade before then undoes the cancel. Or write to [email protected].
trestle_validate_phonetrestle_check_tcpa_litigatortrestle_usage_statustrestle_request_featuretrestle_upgradetrestle_cancel_subscriptionConfirm a lead's phone number is valid. Review a lead list by activity score. Screen US numbers for TCPA litigator risk. Route inbound calls by line type. See what you can do for the details.
No. usefulapi is an independent service. It is not affiliated with or endorsed by Trestle. The server calls the Trestle API with your own Trestle access, so it sees only the data that your account can see.
Yes. In Claude, add this server's URL as a custom connector. In ChatGPT, add it as a custom MCP server in Plugins. Then log in once. Cursor, VS Code, Claude Code and Codex work too. See the setup steps.
The login page asks for your Trestle API key. See Before you connect for where to find it.
No. Add only the URL. Do not add an Authorization header or an API key to the client config. The server signs you in with OAuth: the login page asks for your Trestle API key. If the config has such a header, remove it: some clients then send that header instead of the login token, and every call fails with 401.
The login stores them encrypted in the authorization grant of your connection. The server uses them to call the Trestle API for you and to derive a private account id for usage metering. usefulapi does not show them on any page or in any reply. To stop all access, remove the connector and change or delete these credentials in Trestle.
All 2 Trestle tools are marked read-only.
The Free plan gives 50 tool calls / month. Pro costs $9/mo or $90/yr, with unlimited tool calls (fair use limit: 10,000 tool calls a month), for this Trestle server only. Cancel any time: Pro then runs to the end of the paid period. Run trestle_usage_status to see how many calls you used.
Ask the AI to run trestle_upgrade: it returns a Stripe Checkout link. To cancel, run trestle_cancel_subscription. Pro continues to the end of the paid period.
Tell the AI what you wanted to do. It can send the request with trestle_request_feature. We store the text with the server name, the type of AI client and the tool you tried, not with your account, and read every request when we plan new tools. You can send up to 5 requests per day.
Any client that supports remote MCP servers (Streamable HTTP) with OAuth login: Claude (web and desktop), Claude Code, ChatGPT, Codex, Cursor, VS Code, Windsurf and others.
This is a Model Context Protocol endpoint — meant to be connected from an AI client, not opened in a browser. An invalid_token response at the URL is the auth gate working as designed; clients authenticate automatically.
Need a tool this server does not have, or a connection to another system? We build custom integrations and MCP servers.