Read inv.bg invoices, clients, items, payments and banking; create clients, items, invoices. Hosted by usefulapi — connect from Claude, ChatGPT, Cursor, or any MCP client.
Team and Enterprise: an Owner adds the connector for the organization first.
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"
}
}
}No Add custom MCP server option? It depends on your account or workspace settings: see OpenAI's guide.
Run these commands. The second one opens the login page:
Other MCP clients (Windsurf, Cline, Zed and more): add the URL as a remote MCP server (Streamable HTTP). The client then opens the login page in your browser. Do not add an Authorization header: see Before you connect.
The 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.
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.
Turn on the inv.bg connector, then ask in plain words. The AI picks the tools.
| Tool | Type | What it does |
|---|---|---|
invbg_get_account | read | Get account The company (id, name, subdomain) and the user the API token belongs to. GET /account. |
invbg_get_firm | read | Get company The issuing company's details: name, Bulstat, VAT registration and VAT number, address, MOL, contact email, custom properties. GET /firm. |
invbg_list_invoices | read | List invoices List documents (tax invoices, proformas, debit and credit notes) with filters: type, number, issue-date range, amount ranges, payment status, client, draft/annulled, sent status, currency. Each row has number, client, totals, balance_paid, balance_due and dates. GET /invoices. |
invbg_get_invoice | read | Get invoice One document by id: number, type, issuer and recipient, line items, VAT, totals, balance_paid and balance_due, dates, bank accounts, sent/confirmation status. Optionally with its comments. GET /invoices/{id}. |
invbg_list_invoice_types | read | List document types All document types of this company (tax invoice, proforma, debit/credit note and any custom types) with their codes. GET /invoices/types. |
invbg_get_next_invoice_number | read | Get next invoice number The next free document number of the default number set for a document type. Read-only: it does not reserve the number. GET /invoices/free-number. |
invbg_list_number_sets | read | List number sets The company's invoice number sets (separate numbering series) with ids; pass an id as number_set to invbg_create_invoice. GET /invoices/number-sets. |
invbg_list_payment_methods | read | List payment methods The payment method codes a document accepts (cash, bank, card, ...) with their names. GET /invoices/payment-methods. |
invbg_list_vat_exemption_reasons | read | List VAT exemption reasons The legal reasons for issuing a document without VAT (use one as vat_exemption_reason in invbg_create_invoice). GET /invoices/without-vat-reasons. |
invbg_list_clients | read | List clients List or search clients (customers): name, Bulstat, VAT number, address, MOL, whether it is a person. GET /clients. |
invbg_get_client | read | Get client One client by id with all stored details (names in both languages, Bulstat, VAT, address, MOL, code, custom properties). GET /clients/{id}. |
invbg_list_client_contacts | read | List client contacts Contact people of a client (or of all clients) with their names and roles. GET /client-contacts. |
invbg_list_items | read | List items The product/service catalogue: name, price, currency, unit, tags. GET /items. |
invbg_get_item | read | Get item One catalogue item by id. GET /items/{id}. |
invbg_list_item_units | read | List units of measure Units of measure accepted as quantity_unit on items and invoice lines. GET /items/units. |
invbg_list_payments | read | List payments Recorded payments (income and expense) with amount, method, date, counterparty, how much is allocated to invoices (amount_used) and what is left (amount_left). GET /payments. |
invbg_get_payment | read | Get payment One payment by id with its allocations to invoices (invoice_payments). GET /payments/{id}. |
invbg_list_bank_accounts | read | List bank accounts The company's bank accounts (alias, bank, IBAN, BIC, currency). GET /bank/accounts. |
invbg_list_bank_transactions | read | List bank transactions Imported bank transactions with amount, date, counterparty, and whether they are linked to a document. Useful for reconciliation (linked=false = unmatched). GET /bank/transactions. |
invbg_list_cashboxes | read | List cashboxes The company's cash registers (cashboxes) with names and balances. GET /cashboxes. |
invbg_get_exchange_rate | read | Get exchange rate The exchange rate of a currency to BGN on a date (default: today), as inv.bg uses it for documents. GET /currency/rates/{currency}. |
invbg_create_client | write | Create client WRITE: add a company client (name, Bulstat, VAT, address, MOL). Check invbg_list_clients first to avoid a duplicate. For an individual (EGN) issue the document with invbg_create_invoice and is_to_person instead. POST /clients. |
invbg_update_client | write | Update client WRITE: change fields of an existing client (only the fields you pass are changed). PATCH /clients/{id}. |
invbg_create_item | write | Create item WRITE: add a product or service to the catalogue (name, price, unit). POST /items. |
invbg_create_invoice | write | Create invoice WRITE: create a document (tax invoice by default; proforma, debit/credit note via type). It is saved as a DRAFT unless draft is false: an issued document takes the next legal number and cannot be undone through this tool. Address it to an existing client_id, or give to_name + to_address (+ to_mol and to_bulstat for a company, to_egn for a person) and inv.bg matches or creates the client from those details (an existing client matched by Bulstat or VAT number is UPDATED with the address, MOL and other details you pass). VAT: set vat_percent on the document, or on every item. POST /invoices. |
invbg_send_invoice_email | write | Email invoice WRITE: email a document to a recipient (as a download link or an attached file). The email goes out immediately and cannot be recalled. POST /invoices/{id}/emails. |
invbg_record_invoice_payment | write | Record invoice payment WRITE: record a payment received for a document and allocate it, which updates the document's balance_paid/balance_due and payment status. Two calls: POST /payments, then POST /payments/{id}/invoices. If the allocation fails the payment stays recorded: the error names its id (see invbg_get_payment). |
invbg_usage_status | Usage status (free-tier meter) Report the caller's current usage: the plan, calls used this month, the limit of the plan (the free monthly cap or the Pro fair use limit), remaining, and whether the limit is reached. Read-only; does not count against the meter. | |
invbg_request_feature | Request a missing feature Tell usefulapi that the user needs something the inv.bg tools cannot do yet (a missing tool, field or filter). Call it only when the user asks for something none of the tools can do, and tell the user that you send the request. Do not call it for errors or for normal requests. Do not include personal data, credentials or customer records. Stored with the product name and the client type (for example Claude or Cursor), without the user's account. At most 5 requests per day. Does not count against the meter. | |
invbg_upgrade | Upgrade to Pro (unlimited*) Get Pro: unlimited tool calls (fair use limit: 10,000 a month) on inv.bg (the free tier caps monthly usage). Plans: "monthly" — $9/month; "yearly" — $90/year (2 months free). Cancel any time: Pro then runs to the end of the paid period, so it also suits a one-time job. *A fair use limit applies. For heavy use (near Pro's limit): "plus" or "plus_yearly" — Pro+, $39/month or $390/year, unlimited tool calls (fair use limit: 100,000 a month); an existing Pro subscription changes to Pro+ in place (needs confirm: true; the price difference for the rest of the period is charged at once). Otherwise returns a short link to open in your browser (it opens Stripe Checkout); after payment the account upgrades automatically. Does not count against the meter. | |
invbg_cancel_subscription | Cancel the Pro subscription Cancel the caller's inv.bg Pro subscription at the end of the paid period (no refund for the current period; Pro continues until then, then the free tier applies). Requires confirm: true. Run invbg_upgrade later to undo the cancel before the period ends. Does not count against the meter. |
| Plan | Price | Limit |
|---|---|---|
| Free | $0 | 50 tool calls / month |
| Proper company | $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 inv.bg server only. Subscribe with invbg_upgrade (it returns a Stripe Checkout link). Cancel any time with invbg_cancel_subscription: Pro continues to the end of the paid period, with no refund for the current period, and running invbg_upgrade before then undoes the cancel. Or write to [email protected].
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 unlimited tool calls (fair use limit: 10,000 tool calls a month), for this inv.bg server only. Cancel any time: Pro 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: it returns a Stripe Checkout link. To cancel, run invbg_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 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.