How to Connect Falco to ChatGPT via MCP

💡 No install? Use cloud.anythingmcp.com directly. Sign in, click Connectors → Falco, paste your credentials, mint an MCP API key and you're done. No Docker, no git clone, no local server.

Falco + ChatGPT

Falco, Belgian accounting and Peppol e-invoicing: purchase and sale documents with their files, invoices received over Peppol, Peppol participant lookups, and the customers, articles and invoices of the Falco invoicing module. Mostly read-only; setting a purchase payment status and sending Peppol invoice responses are installed switched off.

Prerequisites

See the full setup instructions baked into the connector (visible in the in-app store when you select the connector). The required environment variables for this connector are:

FALCO_APP_SECRET, FALCO_API_KEY

Step 1 — Get credentials

The connector needs two keys, and both are required: an application secret from the integrator and an API key from the Falco customer.

1. The integrator creates an application on the Falco developer portal (dev.falco-app.be), requests the scopes it needs, for example documents:purchases:read, documents:sales:read, peppol:inbound:read, peppol:participants:read, customers:read, articles:read and invoices:read, and makes it Public. Its production Application Secret (as_live_...) goes into FALCO_APP_SECRET.
2. The Falco customer, an administrator of the organisation on the Expert Essential or Expert Premium plan, opens API access under their initials in the Falco desktop application, picks that application by its id (app_...) and generates an API key (sk_live_...) for their organisation. It goes into FALCO_API_KEY.
3. Install the connector and run falco_get_organization to check both keys. The connector calls the production API, https://api.falco-app.be/v1; sandbox keys (as_test_, sk_test_) only work on the sandbox host and are refused here.

What it reads: the organisation behind the key (name, VAT number, Peppol identifier, address, IBANs, plan); purchase documents (supplier invoices and credit notes) with payment and Peppol status, event history and attached files; sale documents, including those imported as PDF or UBL; documents received over Peppol with sender, amounts, due date, payment reference and bank account; and the customers, articles and invoices of the Falco invoicing module, with invoice lines, VAT subtotals and Peppol status. It also downloads files: the main file, the UBL XML or an attachment of a purchase document, the UBL of a document received over Peppol, and the PDF of an invoice from the invoicing module.

How the AI works with it: for supplier invoices it starts with falco_list_peppol_inbound (what arrived over Peppol) and falco_list_purchase_documents (all purchase documents with their files); for sales with falco_list_sale_documents or, for documents made in the invoicing module, falco_list_invoices. To see whether a company can receive e-invoices it uses falco_find_peppol_participant with the VAT number, or falco_check_peppol_participant with a participant id such as 0208:0123456789.

Switched off at install: falco_set_purchase_payment_status and falco_send_invoice_response. The first replaces the payment status of a purchase document with not_paid, partially_paid or paid, for example after paying a supplier. The second sends an invoice response for a received document to its sender over Peppol (acknowledged, in_process, under_query, conditionally_accepted, rejected, accepted or paid); the supplier receives it at once and it cannot be withdrawn. An administrator turns them on deliberately. Even then the AI shows you the document and the new status or the response and waits for your yes.

Dates and amounts: filters take YYYY-MM-DD. Amounts are strings in the document currency, usually EUR. Lists are paged with page (from 0) and page_size (20 to 200, invoices up to 100), and the AI asks for the next page while a page comes back full.

Limits: 60 requests per minute per application secret. Above that Falco answers 429, and the AI waits and retries.

Common errors: errors follow RFC 9457 with title, detail and code. 401 means a wrong application secret or API key, or a sandbox key on production. 403 means the key lacks the scope for that area; the customer grants scopes when creating the key. 404 on a participant lookup means the company is not reachable on Peppol.

Step 2 — Install the adapter

curl -fsSL https://raw.githubusercontent.com/HelpCode-ai/anythingmcp/main/docker-compose.quickstart.yml -o docker-compose.yml
printf 'JWT_SECRET=%s\nENCRYPTION_KEY=%s\n' "$(openssl rand -hex 32)" "$(openssl rand -hex 32)" > .env
docker compose up -d

Step 3 — Add the connector in ChatGPT

Your server URL: in AnythingMCP, open MCP Servers → the server this connector is on, and copy its URL (https://cloud.anythingmcp.com/mcp/…). Use it wherever this guide shows YOUR_SERVER_ID.

ChatGPT adds MCP servers as plugins on its Plugins page, on the web and on paid plans. Developer mode is no longer needed. In a Business workspace only admins and owners can add one; in Enterprise and Edu an admin can grant the Create plugins with MCPs permission.

1. Go to chatgpt.com/plugins, click Add, then Add custom MCP server.
2. Enter a name, e.g. Name: Falco.
3. Under Connection, enter the Server URL https://cloud.anythingmcp.com/mcp/YOUR_SERVER_ID and keep Authentication on OAuth.
4. Select I understand and want to continue, then Create as a plugin. When ChatGPT asks, sign in to AnythingMCP and allow access.
5. Install the new plugin from your personal plugins, then type @ in a chat and pick it.

Available tools

Example prompts

• "Which supplier invoices received over Peppol this month are still unpaid, and when are they due?"
• "Show me the purchase documents from the last 30 days with supplier, amount and payment status."
• "Can the company with VAT number BE0123456789 receive e-invoices over Peppol?"
• "List the invoices from the invoicing module that were sent but not paid yet, with their amounts including VAT."
• "Download the PDF of invoice 2026-0142 from the invoicing module."

FAQ

Does the free ChatGPT plan work with custom MCP servers? OpenAI documents custom MCP servers for paid plans only; the Free plan is not on its list.

Next steps

• Connector landing page
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