Read invoices, offers, payment status and the product catalog in Solo. Hosted by usefulapi: connect it to Claude, ChatGPT, Cursor or any MCP client.
Turn on the Solo connector, then ask in plain words. The AI picks the tools.
For Croatian businesses and freelancers who issue invoices and offers in Solo.
List the latest invoices of the account. Check the payment status of each one and see which ones have no payment date.
Open one invoice to read the buyer, the line items, the taxes, the totals and the PDF link. Use it to answer a question from a client.
List the offers of the account and read the status of each one. Open an offer to see the buyer, the items and the total before you call the client.
List the products and services with the code, unit, price, discount and tax rate. Use the list to check the prices before you write a new offer.
The login page asks for your Solo API token.
Find it in Solo after you sign in: Postavke (Settings) → API token. Your token is used only to call the Solo API on your behalf and to derive a private account id.
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": {
"solo": {
"url": "https://solo.usefulapi.io/mcp"
}
}
} Add to VS Code or add this to .vscode/mcp.json:
{
"servers": {
"solo": {
"type": "http",
"url": "https://solo.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 Solo API token. 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 | 10,000 tool calls / month |
| Pro+per user | $39/mo · $390/yr | 100,000 tool calls / month |
Each paid plan covers this Solo server only. Ask your AI to run solo_upgrade and choose Pro or Pro+, billed monthly or yearly (it returns a Stripe Checkout link). If you already have Pro, ask to change it to Pro+. The change requires your confirmation, keeps your billing interval and charges the price difference for the rest of the period immediately. Cancel any time with solo_cancel_subscription: your paid plan continues to the end of the paid period, with no refund for the current period, and asking to resume the same plan with solo_upgrade before then undoes the cancel. Or write to [email protected].
solo_list_invoicessolo_get_invoicesolo_get_invoice_statussolo_list_offerssolo_get_offersolo_get_offer_statussolo_list_catalogsolo_usage_statussolo_request_featuresolo_upgradesolo_cancel_subscriptionFind the invoices that are not paid yet. Check the line items and VAT of an invoice. Follow up on open offers. Review the products and prices in the catalog. See what you can do for the details.
No. usefulapi is an independent service. It is not affiliated with or endorsed by Solo. The server calls the Solo API with your own Solo 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 Solo API token. 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 Solo API token. 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 Solo 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 Solo.
All 7 Solo tools are marked read-only.
The Free plan gives 50 tool calls / month. Pro costs $9/mo or $90/yr, with 10,000 tool calls / month. Pro+ costs $39/mo or $390/yr, with 100,000 tool calls / month. Each subscription covers this Solo server only. Cancel any time: your paid plan then runs to the end of the paid period. Run solo_usage_status to see how many calls you used.
Ask the AI to run solo_upgrade and choose Pro or Pro+, billed monthly or yearly: it returns a Stripe Checkout link. If you already have Pro, ask to change it to Pro+. After you confirm, your existing subscription changes in place, keeps its billing interval and charges the price difference for the rest of the period immediately. To cancel, run solo_cancel_subscription. Your paid plan continues to the end of the paid period.
Tell the AI what you wanted to do. It can send the request with solo_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.