Read inv.bg invoices, clients, items, payments and banking; create clients, items, invoices. Hosted by usefulapi: connect it to Claude, ChatGPT, Cursor or any MCP client.
Turn on the inv.bg connector, then ask in plain words. The AI picks the tools.
For Bulgarian businesses who issue invoices with inv.bg.
The AI lists documents by payment status, client and issue date, with totals and balance due, and puts the oldest first.
The AI finds a client and lists the documents issued to them in a date range, and adds up the totals.
The AI lists imported bank transactions and picks the ones that are not linked to a document, which helps with reconciliation.
The AI creates an invoice, proforma or credit note saved as a draft, using your items, number set and VAT reasons.
Changes dataThe AI adds a company client with Bulstat, VAT and address, or updates one, and adds a product or service to the catalogue.
Changes dataThe AI emails a document to a recipient, which cannot be recalled, or records a payment received and allocates it to a document.
Changes dataThe login page asks for your inv.bg API token.
Create it in inv.bg under Settings → About the Company → API access (a long-term token). Do not use your inv.bg password. The token is used only to call the inv.bg API on your behalf and is never shown to anyone; you can delete it in the same place at any time.
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": {
"inv-bg": {
"url": "https://inv-bg.usefulapi.io/mcp"
}
}
} Add to VS Code or add this to .vscode/mcp.json:
{
"servers": {
"inv-bg": {
"type": "http",
"url": "https://inv-bg.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 inv.bg 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 company | $9/mo · $90/yr | 10,000 tool calls / month |
| Pro+per company | $39/mo · $390/yr | 100,000 tool calls / month |
Each paid plan covers this inv.bg server only. Ask your AI to run invbg_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 invbg_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 invbg_upgrade before then undoes the cancel. Or write to [email protected].
invbg_get_accountinvbg_get_firminvbg_list_invoicesinvbg_get_invoiceinvbg_list_invoice_typesinvbg_get_next_invoice_numberinvbg_list_number_setsinvbg_list_payment_methodsinvbg_list_vat_exemption_reasonsinvbg_list_clientsinvbg_get_clientinvbg_list_client_contactsinvbg_list_itemsinvbg_get_iteminvbg_list_item_unitsinvbg_list_paymentsinvbg_get_paymentinvbg_list_bank_accountsinvbg_list_bank_transactionsinvbg_list_cashboxesinvbg_get_exchange_rateinvbg_create_clientinvbg_update_clientinvbg_create_iteminvbg_create_invoiceinvbg_send_invoice_emailinvbg_record_invoice_paymentinvbg_usage_statusinvbg_request_featureinvbg_upgradeinvbg_cancel_subscriptionFind unpaid invoices, oldest first. See everything invoiced to a client. Find bank transactions not linked to an invoice. Create a draft invoice for a client. Add or update a client, or add an item. Email an invoice or record a payment. See what you can do for the details.
No. usefulapi is an independent service. It is not affiliated with or endorsed by inv.bg. The server calls the inv.bg API with your own inv.bg 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 inv.bg 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 inv.bg 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 inv.bg 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 inv.bg.
Yes, if you approve it. 6 of the 27 inv.bg tools can create or change data. The other 21 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 10,000 tool calls / month. Pro+ costs $39/mo or $390/yr, with 100,000 tool calls / month. Each subscription covers this inv.bg server only. Cancel any time: your paid plan then runs to the end of the paid period. Run invbg_usage_status to see how many calls you used.
Ask the AI to run invbg_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 invbg_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 invbg_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.