Open Archives API

This documentation describes the Open Archives API.


  • API calls are throttled per IP address to 4 requests per second (Leaky Bucket).
  • All methods are free to use, except methods marked with an asterisk (*) which require an API key, contact Open Archives to apply for one.
  • All output is in UTF-8 and cached (server-side and via max-age header) for a day, unless otherwise specified.


  • Search v1.1 - searches the genealogical data set and returns the found persons (and records)
  • Match v1.0 - searches for records where a person identified by name and birthyear is mentioned
  • Show v1.1 - shows one specific genealogical record
  • Years ago v1.1 - lists people born years ago



  • Weather v1.0 - historical weather measurements
  • Census v1.0 - information about the Dutch population


  • Add (*) v1.0 - adds a comment to a record
  • Delete (*) v1.0 - deletes a comment
  • List v1.0 - lists comments made on records

Open Archives URI

Records presented on Open Archives all have an URI. This URI resolves to content based on content-negotiation.

File exports

Open Archives shares all the data in down­loadable file exports (in CSV, XML and RDF).

Open Search

Open Archives provides search results as defined by the Open Search specification. There's an OpenSearch description docu­ment for each language: NL, EN, DE & FR.

Want to harvest the genealogical data?

Open Archives also provides an OAI-PMH data provider for harvesting.

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