Connector for Claude and ChatGPT

Ask Claude or ChatGPT about your company's invoices

Connect InvoiceHub once and ask in plain language: how much a supplier invoiced, which documents are duplicates, what was deleted. The assistant sees only your company's documents and cannot change anything.

Connect in 2 minutes Tools

Server URLhttps://web.invoicehub.work/mcp

What the assistant can do

Searches documents

By period, supplier, type and amount range, page by page.

Opens a document

Every extracted field: number, dates, amounts and VAT, issuer, recipient, IBAN and the description of services.

Finds duplicates

Likely duplicate documents, and suppliers stored under different names.

Shows the history

Which documents were deleted as duplicates, and what changed on the issuers.

Tracks cash register reports

Which locations have uploaded their monthly cash register report and which are still missing.

Read-only. The connector has no tools for uploading, changing or deleting documents — those actions stay in the browser.

Connect your assistant

Every client uses the same URL. You need the company's API key: an administrator generates it under Administration → API key. The key is shown only once — keep it in a password manager.

OAuth · recommended

Claude (claude.ai and Claude Desktop)

Open Settings → Connectors and choose Add custom connector.
Enter the name InvoiceHub and the URL https://web.invoicehub.work/mcp. Leave the OAuth Client ID and Secret fields empty.
Click Connect and paste the API key on the InvoiceHub approval page.

OAuth · developer mode

ChatGPT

Turn on Developer mode in ChatGPT's settings.
Create a new connector with the URL https://web.invoicehub.work/mcp and OAuth authentication.
Approve access on the InvoiceHub page with the API key.

API key in a header

Claude Code and developer tools

Send the key as a bearer token:

claude mcp add --transport http invoicehub https://web.invoicehub.work/mcp \
  --header "Authorization: Bearer $INVOICEHUB_API_KEY"

Cursor, VS Code and the MCP SDKs take the same configuration:

{
  "mcpServers": {
    "invoicehub": {
      "type": "http",
      "url": "https://web.invoicehub.work/mcp",
      "headers": { "Authorization": "Bearer sk-…" }
    }
  }
}

Menu names in Claude and ChatGPT change, and connector availability depends on your plan and workspace policies.

Approve once, revoke any time

When you connect, InvoiceHub opens an approval page that names the client and the address it will return to.
The connector never sees your API key — it gets its own token, bound to your company.
The token gives read-only access to the company's documents and lasts up to a year; then you approve again.
Deactivate the key under Administration → API key and every connection stops at once. Generating a new key also ends the existing connections.

The key sees all of the company's documents. Personal visibility restrictions in the browser do not apply to it, so give it only to people with full access to the accounting.

In practice

Ask in natural language

The assistant picks the tool and the filters on its own, then summarizes, compares and calculates on what it finds.

“How much did we pay BILLA in May?”
“Show the invoices over €1,000 for the third quarter.”
“Are there duplicate invoices, and which one should I keep?”
“Which suppliers are stored under different names?”
“What was deleted as a duplicate this month?”
“Which locations have not uploaded their cash register report for September yet?”

Sample conversation

How much did we pay BILLA in May?

I called search_invoices for BILLA and 1–31 May. I found 6 invoices totalling €64.82 including VAT; the largest is from 26 May, for €15.49.

How a request works

The client sends a request with a bearer token. InvoiceHub derives the company from the token itself, runs the tool on its documents and returns the result. The company identifier never comes from the conversation text.

Tools

The seven tools the MCP server advertises. All are marked read-only, so Claude can run them without asking for confirmation on every call.
Tool	Parameters	Result
`search_invoices`	`date_from`, `date_to` (ISO date), `type`, `issuer`, `amount_min`, `amount_max`, `page` (default 1), `per_page` (default 20, maximum 100)	Document list and `pagination` with `page`, `per_page`, `total`, `total_pages`
`get_invoice`	`invoice_id`	One company document, or a message that it was not found
`duplicate_invoices`	no parameters	Groups of likely duplicates with each document's rows and the one recommended to keep (`keep_id`) — the suggestions from the “Duplicate documents” page
`issuer_names`	no parameters	Issuers recorded under different names, with document counts and the recommended name, UIC and VAT number, plus the set standards — the suggestions and rules from the “Issuers — standard names” page
`invoice_audit_log`	`limit` (default 50, maximum 200)	The history of deleted duplicates: the kept document, the deleted documents as they were saved, and the objects removed from storage — the “History” table on the “Duplicate documents” page
`issuer_audit_log`	`limit` (default 50, maximum 200)	The history of merges, renames, removals and restores: the standard, the changed documents with before and after values, the added and removed rules, and whether the record can still be restored — the “History” table on the “Issuers — standard names” page
`cash_register_reports`	`month` (`YYYY-MM`, default: the month that has just ended)	Each location with an uploaded or missing report. Each report has `total_amount` (the VAT-inclusive total of the device report), `vat_amount` (the VAT inside it at the standard rate, or “0.00” when the company has no VAT number) and `currency` (EUR), its files (name, type, size), when and by whom it was uploaded, and the Google Drive delivery – the month from the “Cash register reports” page. Amounts are null for reports uploaded before they were recorded. The images themselves are not returned.

Each document is returned with its number, type, issuer (name, UIC, VAT number), recipient, amount excluding and including tax, currency, original currency and amounts, issue date, payment method, description of services, IBAN and the date it entered the system.

Frequently asked questions

Can the assistant change or delete documents?

No. All seven tools only read. Uploading, review, deleting duplicates, merging issuers and uploading or deleting cash register reports stay browser actions.

Which documents does the assistant see?

All documents of the company whose key you used — and none from any other company, even if asked. The company comes from the token, not from the conversation.

I have several companies. How do I connect them?

Each key and each connection serves one company. To connect another company, use that company's API key.

What does the assistant receive from my data?

Only the results of the tools it calls during the conversation, which the assistant's provider processes under its own terms. InvoiceHub does not receive the conversation — it sees only the tool requests.

How do I disconnect?

Remove the connector in your assistant's settings. To stop every connection at once, deactivate the key under Administration → API key.

OAuth technical details

Clients discover the server through /.well-known/oauth-protected-resource and /.well-known/oauth-authorization-server, register themselves at /register, get a code at /authorize and a token at /token. PKCE S256 is required; authorization codes are stored as hashes, are valid for five minutes and can be used only once. A token is revoked at /oauth2/revoke.