Read balance, tariffs, SIP and PBX status and call logs; send SMS in Zadarma. Hosted by usefulapi: connect it to Claude, ChatGPT, Cursor or any MCP client.
Turn on the Zadarma connector, then ask in plain words. The AI picks the tools.
For businesses that run their phone lines and SMS on Zadarma.
Read the account balance and the price plan. Then look up the per-minute rate for one destination number.
List the SIP numbers and PBX extensions of the account. Check whether one extension is online before you route a call to it.
Read the call statistics for a period, then get a temporary download link for one recording. Statistics allow 3 calls per minute.
List the virtual phone numbers rented on the account. Then list the SMS templates by category before you write a message.
Send one SMS to up to 10 phone numbers. Each send uses the account balance and is not retried, so check the result first.
Changes dataThe login page asks for your API key (user key) and Secret key.
Find both at my.zadarma.com → API. Your keys are used only to sign calls to Zadarma on your behalf; they are 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": {
"zadarma": {
"url": "https://zadarma.usefulapi.io/mcp"
}
}
} Add to VS Code or add this to .vscode/mcp.json:
{
"servers": {
"zadarma": {
"type": "http",
"url": "https://zadarma.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 API key (user key) and Secret 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 Zadarma server only. Subscribe with zadarma_upgrade (it returns a Stripe Checkout link). Cancel any time with zadarma_cancel_subscription: Pro continues to the end of the paid period, with no refund for the current period, and running zadarma_upgrade before then undoes the cancel. Or write to [email protected].
zadarma_get_balancezadarma_get_tariffzadarma_get_call_pricezadarma_list_sip_numberszadarma_get_sip_statuszadarma_list_pbx_extensionszadarma_get_pbx_extension_statuszadarma_list_virtual_numberszadarma_get_call_statisticszadarma_get_call_recording_linkzadarma_list_sms_templateszadarma_send_smszadarma_usage_statuszadarma_request_featurezadarma_upgradezadarma_cancel_subscriptionCheck the balance and the call rates. See which SIP and PBX extensions are online. Review the calls of a period and fetch a recording. List the virtual numbers and SMS templates. Send an SMS to up to 10 numbers. See what you can do for the details.
No. usefulapi is an independent service. It is not affiliated with or endorsed by Zadarma. The server calls the Zadarma API with your own Zadarma 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 API key (user key) and Secret key. See Before you connect for where to find them.
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 API key (user key) and Secret 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 Zadarma 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 Zadarma.
Yes, if you approve it. 1 of the 12 Zadarma tools can create or change data. The other 11 are marked read-only. Most MCP clients ask you to approve a tool call before it runs.
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 Zadarma server only. Cancel any time: Pro then runs to the end of the paid period. Run zadarma_usage_status to see how many calls you used.
Ask the AI to run zadarma_upgrade: it returns a Stripe Checkout link. To cancel, run zadarma_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 zadarma_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.