API reference

Every endpoint, runnable

Press Send and watch the real API answer, a company match included. Looking around needs no key: the calls go through a proxy on our server, capped at ten rows.

Base URL https://api.subsido.be/v1 · Bearer auth · full documentation

OpenAPI 3.1 documentNo key needed. Generate a client, or import it into Postman or Insomnia.

Try it

The open routes and the core data routes, through the proxy: at most ten rows and a match body of at most 4 KB. Routes that need a higher plan, such as the change feed, versions and bulk matching, are not in the explorer.

GET/v1/subsidiesDeveloper

List and search measures. Every filter is optional; region includes the national and EU measures that apply everywhere.

q: words, prefix match, any language
region: flanders, brussels, wallonia
topic: comma list of topic ids
company_size: micro, small, medium, large
instrument_type: grant, loan, tax_deduction, ...
status: open, continuous, forthcoming, ...
lang: nl, fr, en
view: compact or full

Runs against the live API, through a proxy on our server. No key needed: lists are capped at ten rows and a match body at 4 KB. With your own key these caps do not apply.

Every operation

Rendered from the API's own OpenAPI document. The descriptions are in English.

Subsido APIv1.0.0 · 32 operations, rendered from /v1/openapi.json.

Service

GET/v1/healthno keyHealth

Database, sources not fresh, and what sign-in the site offers.

200Success

GET/v1/plansno keyPlans and prices

The entitlement table the API enforces, with list prices in euros.

200Success

GET/v1/taxonomyno keyVocabularies

Every closed vocabulary with labels in Dutch, French and English: topics, regions, provinces, instrument types, statuses, sizes, applicant types, cost types, rule fields (with the question asked when one is unknown), operators and event types.

200Success
400invalid_parameter
429rate_limit_exceeded

GET/v1/coverageno keyCoverage

How many measures, by status, source, instrument, level, region and topic.

200Success
400invalid_parameter
429rate_limit_exceeded

GET/v1/keyThe calling key

The key's plan, what it allows, and this month's requests and match evaluations, in the `{data, meta}` envelope. The right first request.

200Success
401unauthorized
429rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

Sources

GET/v1/sourcesno keySources

Every source the API serves measures from, its licence and reuse mode, and how fresh it is. A source that is switched off is not listed.

200Success
400invalid_parameter
429rate_limit_exceeded

GET/v1/sources/{id}no keyOne source

A source with its recent runs.

Parameters of GET /v1/sources/{id}
Parameter	In	Type	Description
id*	path	string	A source id.

200Success
400invalid_parameter
404source_not_found
429rate_limit_exceeded

Subsidies

GET/v1/subsidiesList and search measures

Filter, search and page through every servable measure. Cursor paging; every list is ordered and complete.

Parameters of GET /v1/subsidies
Parameter	In	Type	Description
q	query	string	Words in any language; each must match the start of a word (prefix search, accents ignored).
region	query	string	Measures available to a company in these regions: the region's own plus national and EU measures, which apply everywhere.
topic	query	string	Measures tagged with any of these topics.
company_size	query	micro \| small \| medium \| large	The company's size: measures naming it, and those that do not restrict size.
instrument_type	query	string
status	query	string	Default: every status. `open,continuous,forthcoming` is what can be applied for.
government_level	query	string
scope	query	string
source	query	string	Comma list of source ids (GET /v1/sources).
issuer	query	string	Comma list of issuer ids (`vlaio`, `european-commission`, ...).
nace	query	string	A company's NACE code (62.010): measures with no sector restriction, or one covering it.
programme	query	string	EU programme code: HORIZON, DIGITAL, LIFE, SMP, ...
deadline_before	query	string	RFC 3339, or YYYY-MM-DD meaning the end of that Brussels day.
deadline_after	query	string
updated_since	query	string	Changed on or after this instant.
include_withdrawn	query	boolean	Include measures the source no longer lists.
sort	query	relevance \| deadline \| updated \| title	Default: relevance with `q`, deadline (soonest first, none last) without.
view	query	compact \| full	Default compact.
lang	query	nl \| fr \| en	Language of `title`, `summary` and links. Default en.
limit	query	integer	Page size, up to the plan's maximum (Developer 100, Pro and Business 200, Enterprise 500). Above it is an error, never a silent truncation.
cursor	query	string	From `pagination.next_cursor`. Opaque.

200Success
400invalid_parameter, invalid_cursor
401unauthorized
429rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

GET/v1/subsidies/{id}One measure

The full record. `as_of` (Pro and above) returns the version that was current at that instant.

Parameters of GET /v1/subsidies/{id}
Parameter	In	Type	Description
id*	path	string	The measure's id (`vlaio:kmo-portefeuille`, `eu:HORIZON-EIC-2026-ACCELERATOR-01`) or slug.
lang	query	nl \| fr \| en	Language of `title`, `summary` and links. Default en.
as_of	query	string	RFC 3339, or YYYY-MM-DD meaning the end of that Brussels day. Pro and above.

200Success
400invalid_parameter
401unauthorized
403plan_required
404subsidy_not_found, version_not_found
429rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

History

GET/v1/subsidies/{id}/versionsVersions of a measure

Every version, newest first, with the field-level changes that made it. Pro and above.

Parameters of GET /v1/subsidies/{id}/versions
Parameter	In	Type	Description
id*	path	string	The measure's id (`vlaio:kmo-portefeuille`, `eu:HORIZON-EIC-2026-ACCELERATOR-01`) or slug.

200Success
400invalid_parameter
401unauthorized
403plan_required
404subsidy_not_found
429rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

GET/v1/subsidies/{id}/versions/{version}One version

The record as it was in that version. Pro and above.

Parameters of GET /v1/subsidies/{id}/versions/{version}
Parameter	In	Type	Description
id*	path	string	The measure's id (`vlaio:kmo-portefeuille`, `eu:HORIZON-EIC-2026-ACCELERATOR-01`) or slug.
version*	path	integer	The version number.
lang	query	nl \| fr \| en	Language of `title`, `summary` and links. Default en.

200Success
400invalid_parameter
401unauthorized
403plan_required
404subsidy_not_found, version_not_found
429rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

Changes

GET/v1/changesThe change feed

Every new measure, every version (typed by its most significant change, with every category it touched), closing-soon reminders and source freshness events, in order. Page with `cursor` while `has_more` is true. Every page carries `next_cursor`, the last one too: `has_more: false` with a cursor means nothing more for now, so poll again later with that cursor and get only what is new. An empty page returns the cursor it was given (or, on a first call, one at the newest event). Developer and above.

Parameters of GET /v1/changes
Parameter	In	Type	Description
since	query	string	Start here on a first call (at most 400 days back); afterwards use the cursor.
type	query	string
subsidy	query	string	One measure's events.
source	query	string
region	query	string
limit	query	integer	Page size, up to the plan's maximum (Developer 100, Pro and Business 200, Enterprise 500). Above it is an error, never a silent truncation.
cursor	query	string	From `pagination.next_cursor` of any page, the last one included. Opaque.

200Success
400invalid_parameter, invalid_cursor
401unauthorized
403plan_required
429rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

Matching

POST/v1/matchMatch a company and a project

Which measures plausibly fit, why (every rule's pass, fail or unknown with its provenance), what is still unknown (as questions, ranked by how many matches they would settle), and an indicative amount. Statuses: likely_eligible, possibly_eligible, needs_review, not_eligible (only with include_not_eligible). Never "eligible": the competent authority decides. Best first: likely_eligible, then possibly_eligible and needs_review together, then not_eligible; within each by `score`, which weighs topic fit, the match status, rule confidence, whether the measure can be applied for now (open and continuous alike), and how close to the company it is decided (its own region, then national, then EU), less a little per unanswered question; the soonest deadline breaks a tie. `company.nace` takes NACE codes of at least two digits; a section letter is refused. One match evaluation.

Request body object

{
  "company": {
    "postcode": "9000",
    "employees": 12,
    "turnover_eur": 1500000,
    "legal_form": "bv",
    "nace": [
      "62.010"
    ],
    "founded_on": "2019-05-01"
  },
  "project": {
    "topics": [
      "digitalisation",
      "cybersecurity"
    ],
    "budget_eur": 25000,
    "planned_start": "2026-11-01"
  },
  "language": "nl",
  "limit": 10
}

200Success
400invalid_parameter
401unauthorized
422invalid_body
429match_quota_exceeded, rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

POST/v1/match/bulkMatch many companies

Up to 500 companies (Business) or 5,000 (Enterprise) in one request. One evaluation per valid company; an invalid one is answered with its own error. Business and above.

Request body object

{
  "companies": [
    {
      "reference": "client-0042",
      "company": {
        "postcode": "9000",
        "employees": 12,
        "turnover_eur": 1500000,
        "legal_form": "bv",
        "nace": [
          "62.010"
        ],
        "founded_on": "2019-05-01"
      },
      "project": {
        "topics": [
          "digitalisation",
          "cybersecurity"
        ],
        "budget_eur": 25000,
        "planned_start": "2026-11-01"
      },
      "language": "nl",
      "limit": 10
    }
  ]
}

200Success
400invalid_parameter
401unauthorized
403plan_required
422invalid_body
429match_quota_exceeded, rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

Export

GET/v1/export/subsidies.ndjsonThe whole catalogue

Every current measure as one full record per line. Business and above.

Parameters of GET /v1/export/subsidies.ndjson
Parameter	In	Type	Description
lang	query	nl \| fr \| en	Language of `title`, `summary` and links. Default en.
include_withdrawn	query	boolean

200Success
400invalid_parameter
401unauthorized
403plan_required
429rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

Watchlists

GET/v1/watchlistsList watchlists

Business and above.

200Success
400invalid_parameter
401unauthorized
403plan_required
429rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

POST/v1/watchlistsCreate a watchlist

A portfolio of companies re-evaluated whenever a measure changes; each difference is a match.* webhook event. Business and above.

Request body object

{
  "name": "Manufacturing clients",
  "language": "nl"
}

201Success
401unauthorized
403plan_required
409conflict
422invalid_body
429rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

GET/v1/watchlists/{id}One watchlist

Parameters of GET /v1/watchlists/{id}
Parameter	In	Type	Description
id*	path	string	A `wl_` id.

200Success
401unauthorized
403plan_required
404watchlist_not_found
429rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

PATCH/v1/watchlists/{id}Rename or change options

Parameters of PATCH /v1/watchlists/{id}
Parameter	In	Type	Description
id*	path	string	A `wl_` id.

Request body object

{
  "name": "Renamed"
}

200Success
401unauthorized
403plan_required
404watchlist_not_found
422invalid_body
429rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

DELETE/v1/watchlists/{id}Delete a watchlist

Parameters of DELETE /v1/watchlists/{id}
Parameter	In	Type	Description
id*	path	string	A `wl_` id.

200Success
401unauthorized
403plan_required
404watchlist_not_found
429rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

GET/v1/watchlists/{id}/companiesCompanies on a watchlist

Parameters of GET /v1/watchlists/{id}/companies
Parameter	In	Type	Description
id*	path	string	A `wl_` id.
limit	query	integer	Page size, up to the plan's maximum (Developer 100, Pro and Business 200, Enterprise 500). Above it is an error, never a silent truncation.
cursor	query	string	From `pagination.next_cursor`. Opaque.

200Success
400invalid_parameter
401unauthorized
403plan_required
404watchlist_not_found
429rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

POST/v1/watchlists/{id}/companiesAdd or replace companies

Up to 1,000 per request, by your own reference. Each is evaluated at once and counts one match evaluation; invalid ones are listed in `rejected` and not stored.

Parameters of POST /v1/watchlists/{id}/companies
Parameter	In	Type	Description
id*	path	string	A `wl_` id.

Request body object

{
  "companies": [
    {
      "reference": "client-0042",
      "company": {
        "postcode": "9000",
        "employees": 12,
        "turnover_eur": 1500000,
        "legal_form": "bv",
        "nace": [
          "62.010"
        ],
        "founded_on": "2019-05-01"
      },
      "project": {
        "topics": [
          "digitalisation",
          "cybersecurity"
        ],
        "budget_eur": 25000,
        "planned_start": "2026-11-01"
      }
    }
  ]
}

200Success
401unauthorized
403plan_required
404watchlist_not_found
422invalid_body
429match_quota_exceeded, rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

DELETE/v1/watchlists/{id}/companies/{reference}Remove a company

Parameters of DELETE /v1/watchlists/{id}/companies/{reference}
Parameter	In	Type	Description
id*	path	string	A `wl_` id.
reference*	path	string	Your reference.

200Success
401unauthorized
403plan_required
404watchlist_not_found, not_found
429rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

GET/v1/watchlists/{id}/matchesCurrent matches

Every company's current matches, best first.

Parameters of GET /v1/watchlists/{id}/matches
Parameter	In	Type	Description
id*	path	string	A `wl_` id.
company	query	string	One company's reference.
include_not_eligible	query	boolean
limit	query	integer	Up to 5,000.

200Success
400invalid_parameter
401unauthorized
403plan_required
404watchlist_not_found
429rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

Webhooks

GET/v1/webhooksList webhooks

Pro and above.

Parameters of GET /v1/webhooks
Parameter	In	Type	Description
limit	query	integer	Page size, up to the plan's maximum (Developer 100, Pro and Business 200, Enterprise 500). Above it is an error, never a silent truncation.
cursor	query	string	From `pagination.next_cursor`. Opaque.

200Success
400invalid_parameter
401unauthorized
403plan_required
429rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

POST/v1/webhooksCreate a webhook

Deliveries are signed (Subsido-Signature: t=,v1=), retried at 1, 5, 30, 120 and 720 minutes, and the endpoint is switched off after 20 failures in a row (POST /v1/webhooks/{id}/enable turns it back on). The plan sets how many endpoints an account may have (`webhook_endpoints` in GET /v1/plans). Filters: event_types, sources, regions, topics, subsidy_ids, watchlists. Pro and above.

Request body object

{
  "url": "https://hooks.example.com/subsidies",
  "filters": {
    "event_types": [
      "subsidy.deadline_changed",
      "subsidy.status_changed"
    ],
    "regions": [
      "flanders"
    ]
  }
}

201Success
400invalid_parameter
401unauthorized
403plan_required
404source_not_found, watchlist_not_found
429rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

DELETE/v1/webhooks/{id}Delete a webhook

Parameters of DELETE /v1/webhooks/{id}
Parameter	In	Type	Description
id*	path	string	A `wh_` id.

200Success
400invalid_parameter
401unauthorized
403plan_required
404webhook_not_found
429rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

POST/v1/webhooks/{id}/enableSwitch a webhook back on

After 20 failed deliveries in a row an endpoint is switched off (`active: false`). This switches it on again with its failure count at zero, and answers the endpoint. Deliveries given up on while it was off are not resent; read them from the change feed.

Parameters of POST /v1/webhooks/{id}/enable
Parameter	In	Type	Description
id*	path	string	A `wh_` id.

200Success
400invalid_parameter
401unauthorized
403plan_required
404webhook_not_found
429rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

POST/v1/webhooks/{id}/rotateRotate the signing secret

The old secret stops verifying at once.

Parameters of POST /v1/webhooks/{id}/rotate
Parameter	In	Type	Description
id*	path	string	A `wh_` id.

200Success
400invalid_parameter
401unauthorized
403plan_required
404webhook_not_found
429rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

POST/v1/webhooks/{id}/testSend a test delivery

Queues a signed ping.

Parameters of POST /v1/webhooks/{id}/test
Parameter	In	Type	Description
id*	path	string	A `wh_` id.

200Success
400invalid_parameter
401unauthorized
403plan_required
404webhook_not_found
429rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

GET/v1/webhooks/{id}/deliveriesRecent deliveries

The last 50, newest first.

Parameters of GET /v1/webhooks/{id}/deliveries
Parameter	In	Type	Description
id*	path	string	A `wh_` id.

200Success
400invalid_parameter
401unauthorized
403plan_required
404webhook_not_found
429rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

MCP

POST/mcpModel Context Protocol server

Streamable HTTP, stateless: POST one JSON-RPC message (or a batch). Tools: search_subsidies, get_subsidy, match_company, explain_eligibility, list_changes, list_sources. Same key, limits and answers as the REST API.

Request body object

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/list"
}

200Success
401unauthorized
429rate_limit_exceeded, quota_exceeded
500internal_error
504timeout

The contract

What is true of every endpoint, so you only have to learn it once.

One envelope

Lists return { data, pagination, meta } and one resource { data, meta }; the match routes and a few service routes return their own documented objects. Errors always return { error: { code, message, request_id, details } }. Branch on code; it will not change.

Cursor pagination

limit and cursor, keyed on the sort value plus a tiebreaker id, so page 2,000 costs what page 1 costs. A limit above your plan is an error, never a silent truncation.

Every field present

A value that does not apply is null, never omitted, so a row has the same keys on every page.

Strict parameters

An unknown or repeated parameter, or a value outside its vocabulary, is a 400 that names it. A typo never silently widens a result.

Provenance

Every measure carries its source, when it was last checked, and a link to the authority's own page.

Capabilities, not plan names

A refused call names the capability and the cheapest plan that would have answered it. RateLimit headers show your monthly quota before you reach it.