Documentation

Subsido serves Belgian (federal, Flemish, Walloon and Brussels) and EU measures for citizens and businesses in one normalised record: grants, premiums, loans, guarantees and tax measures. It tells you which of them fit a company and a project, why, and what it still needs to know, and it tells you when any of them changes.

Base URL https://api.subsido.be/v1. JSON over HTTPS, timestamps in RFC 3339 with the Brussels offset, one error shape on every route, and an OpenAPI 3.1 document at /v1/openapi.json that needs no key.

$ curl "https://api.subsido.be/v1/subsidies?region=flanders&status=open,continuous&limit=5&lang=en" \  -H "Authorization: Bearer sb_live_..."

Paste it into an assistant and it will know the endpoints, the auth scheme and the response shape. Read it first

What a match is, and what it is not

A match is an indication based on the published conditions and the facts you provide. Only the competent authority decides who qualifies. Every measure links to the authority's own page, with the time we last checked it.

Start

QuickstartA key, a first search for measures and a first company match, in curl, JavaScript and Python.AuthenticationBearer keys, live and test keys, the routes that answer without one, and checking a key.

The data

Searching measuresListing and searching measures with filters, reading one by id or slug, languages, compact and full views, versions and as_of.The subsidy recordEvery field of a measure, from its window and funding to its eligibility rules and provenance, and every enum.Sources and provenanceWhere measures come from, what the provenance fields mean, and which attribution to show.

Matching

Matching a companyPOST /v1/match: the company and project facts, what is derived from them, the four statuses, the reasons, the missing facts and the estimate.Eligibility rulesThe rule language: nodes, fields, operators and three-valued evaluation.WatchlistsPortfolios of companies that are matched once and re-evaluated whenever a measure changes, with match events.

Staying current

Changes and versionsThe change feed, event types and categories, field-level diffs, closing-soon reminders, versions and history.WebhooksChange and match events pushed to your endpoint, with filters, signature verification in Node and Python, and retries.

Using the API

MCP serverThe same search, matching and change feed as tools for AI agents, over stateless Streamable HTTP, with client configuration.PaginationCursors, page sizes per plan, sort orders, and which lists page and which do not.ErrorsThe error envelope and every error code, with its status, its details and what to do about it.Rate limits and quotasRequests per second, monthly requests and match evaluations per plan, the RateLimit headers and what is counted.

Reference

ChangelogWhat changed in the API, newest first.

Elsewhere

API referenceEvery operation from the OpenAPI document, with a live explorer.PricingThe plans, rendered from the same table the API enforces.SourcesEvery source we read.llms.txtThis documentation in one plain text file, for an AI assistant.