Connect NBB to Claude via MCP

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

NBB Central Balance Sheet Office + Claude

Belgian annual accounts from the Central Balance Sheet Office of the National Bank of Belgium (authentic data web service): list every annual account a company filed by enterprise number, read a filing's reference data, and fetch its accounting data as JSON-XBRL or XBRL or the published PDF. Read-only.

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:

NBB_CBSO_SUBSCRIPTION_KEY

Step 1 — Get credentials

Setting up takes a few minutes once the NBB has approved your subscriptions. You need a subscription to the NBB CBSO web services and an account on the CBSO developer portal with an approved subscription to the NBB CBSO Web Services - Authentic Data product.

1. Subscribe to the CBSO web services with the subscription form on nbb.be (Central Balance Sheet Office, products). The NBB sends you a CLIENT_ID for your technical user; the connector itself only needs the subscription key from the next steps.
2. Sign up on the developer portal developer.cbso.nbb.be, open Products and subscribe to NBB CBSO Web Services - Authentic Data. The NBB approves the request.
3. Open your Profile on the portal and copy the primary key of the Authentic Data subscription into NBB_CBSO_SUBSCRIPTION_KEY (the secondary key works too; letters and digits only). The connector sends it in the NBB-CBSO-Subscription-Key header.
4. Install the connector and check the connection with nbb_cbso_list_annual_accounts for the enterprise number 0203201340, the NBB itself.

Cloud and self-hosted work the same way: the connector only needs the subscription key; there is nothing else to configure.

Enterprise and reference numbers: the enterprise number is the 10-digit number in the Crossroads Bank for Enterprises (KBO/BCE), without dots or the BE prefix: 0203201340 for BE 0203.201.340. Each filing (deposit) has its own reference number, such as 2023-00123456, in the ReferenceNumber field of the list. year is the year in which the exercise ends and cannot be later than the current year.

Corrections replace the initial filing: an exercise can have an initial filing and a correction (DepositType). Use the latest filing of an exercise, and check which exercise dates the figures cover.

Figures only for standardised accounts: nbb_cbso_get_annual_account_data returns JSON-XBRL by default, or XBRL, coded with the rubric codes of the Belgian schema: for example 10/15 equity, 70 turnover, 9904 profit or loss of the period and 9087 average number of FTE workers. Accounts that are not standardised exist only as PDF; nbb_cbso_get_annual_account_pdf works for both.

Attached files: JSON-XBRL and XBRL can arrive as an attached file instead of inline text; the PDF always does. Large filings can exceed the 10 MB attachment limit.

Request ids: every call carries an X-Request-Id, a version 4 UUID for tracing. The tools fill one in; pass your own request_id to trace a call.

Common errors: the NBB answers with problem JSON (title, status, violations). 400 means a malformed enterprise or reference number or a year in the future, 401 a missing or wrong subscription key, 403 a key whose subscription does not cover the Authentic Data product or is not approved yet, 404 that nothing was found and 429 too many calls.

Not included: the NBB's archive, extracts (daily batches as zip) and improved-data products need separate subscriptions and are not exposed here. Companies exempt from publication have no public documents.

What it reads: the annual accounts that Belgian companies and associations filed with the Central Balance Sheet Office and that the NBB accepted. For each filing: deposit date, exercise start and end dates, model type (full, abridged, micro or an association model), deposit type, language and currency, and the company's name, address, legal form, legal situation, activity code and general assembly date. Then the accounting data itself (balance sheet, income statement, notes and social balance) as JSON-XBRL or XBRL, and the published annual account as a PDF.

Read-only: all four tools only read. Nothing is filed, corrected or changed at the NBB.

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 Claude

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.

Recommended path: works on claude.ai web without editing any config file.

1. In Claude, open Customize → Connectors.
2. Click +, then Add custom connector.
3. Enter a name, e.g. NBB Central Balance Sheet Office, and the remote MCP server URL https://cloud.anythingmcp.com/mcp/YOUR_SERVER_ID, then click Add.
4. Click Connect and sign in to AnythingMCP (OAuth) to allow access.

All tools below appear in your chat: start typing prompts.

Available tools

Example prompts

• "List every annual account that enterprise 0203.201.340 filed, with the exercise dates, deposit date and model type."
• "What were equity, turnover and the profit or loss of the period in the latest annual account of enterprise 0203201340, and which exercise do they cover?"
• "Which legal form, address and activity code does the latest filing show, and when was the general assembly?"
• "How did the average number of FTE workers change over the last three annual accounts this company filed?"
• "Get me the published PDF of the company's most recent annual account."

FAQ

Does it work with Claude Code as well as Claude Desktop? Yes, point both at https://cloud.anythingmcp.com/mcp/YOUR_SERVER_ID.

Next steps

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