Likely sale prices from notarial deeds, the latest sales, schools with exam results, door-to-door commute times, noise, flood and zoning: the data behind Osella reports, as JSON for your CRM, listing site or model.
Send your key in the X-API-Key header of every call. Keys are created and revoked in your account; we store only a hash of each, so a lost key is replaced, never recovered.
Base URLhttps://osela.app/api/v1
Every response{ data, meta } data is the answer; meta gives the data dates, the model version and the sources to credit.
Prices are a statistical market analysis of notarial deeds, not a valuation (operat szacunkowy), which only a licensed property valuer may prepare.
Limits
The API is free for everyone signed in to Osella. The limits are per account, across all of its keys.
50 successful calls a day. The day runs on Warsaw time: the calls come back at midnight Europe/Warsaw.
At most one call a second.
Keys are made in your account page, at most 2 at a time. A revoked key stops working at once.
Only an answer with data counts (status 2xx). Refused and failed calls (401, 403, 404, 422, 429, errors) don't count, nor do /usage and /sources; /usage still keeps to one call a second.
Past a limit the API answers 429 with Retry-After: the seconds to midnight in Warsaw when the day's calls are used up, 1 when the call came too soon.
Every successful answer to a call with a key carries X-Quota-Limit (50), X-Quota-Remaining (the calls left today) and X-Quota-Period (day). GET /v1/usage gives the same with the time the day turns.
Places are Warsaw only: an address outside Warsaw's address register, or a point outside the city, answers 404.
Errors
401
No key was sentSend your API key in the X-API-Key header
401
The key is not one of ours, or it was revokedUnknown or revoked API key
401
The key belongs to no accountThis key belongs to no account; make a new key in your account page
401
An old key, made before the limits per accountThis key was made before the API's per-account limits and no longer works; make a new key in your account page
403
The account the key belongs to is blockedThis key's account is blocked, so its API keys do not work
404
No such address in Warsaw (the response suggests close ones)No such address in Warsaw's address register
404
lat and lon point outside WarsawThat point is outside Warsaw
422
A parameter is missing or out of range, or there are no homes at the point
429
The day's calls are used up: Retry-After gives the seconds to midnight in Warsaw, X-Quota-Remaining is 0This account's 50 API calls for today are used up; they come back at midnight Europe/Warsaw
429
Less than a second after the account's last call: Retry-After is 1This account makes at most one API call a second
{
"detail": {
"message": "No such address in Warsaw's address register",
"suggestions": [
"Hoża 88",
"Hoża 86",
"Hoża 76/78"
]
}
}
Sources and attribution
When you show the data, credit the sources listed in meta.attribution. OpenStreetMap-derived data is served only as scores and minutes, never as map features.
Noise, yearly air pollution, flood and airport risks, the local zoning plan, building permits nearby, heritage and city zones, and crime in the district
Parameter
Type
Description
address
string
A Warsaw address, matched against the official address register (PRG)
lat
number
Latitude, instead of an address (with lon)
lon
number
Longitude, instead of an address (with lat)
lang
pl | en | ukdefault pl
Language of the generated texts
Give an address or lat and lon. An address not in the register returns 404 with the closest ones.