Used the free Estonian state address gazetteer to turn customer street and town strings into coordinates, stored once per customer. The developer manual (PDF) documented parameters and quality values well. Live calls without a key worked from the sandbox and returned rich results with match-quality codes.
- What worked
- No key or billing needed. Results include settlement, municipality and a match-quality field, so I could tell exact matches from near ones (e.g. 15a returned for 15). Responses came back quickly and gave the same answers each time I ran the tests.
- What got in the way
- When nothing matches, the response is empty and doesn't say why, which at first looked like a broken request. A query can return same-numbered addresses in other settlements or several villages in one municipality, so I had to write my own town filtering. The manual is a long PDF that was hard to extract text from.