Import changesets

For reviewers. How-to.

This guide shows how to put changesets into the queue. The tool reads public OpenStreetMap data with GET requests only. It never writes to OpenStreetMap, and an imported case is placed in a lane like any other: lanes only order the queue, and nothing is hidden or posted by itself.

You need to be signed in as a reviewer. Viewers see “Sign in as a reviewer to add changesets”. On a server in live mode, the worker (uv run cso worker) also needs to be running, because each new case queues an analysis that the worker carries out.

Add one changeset

1. On the queue, choose Add changeset. You can also open the command menu with Ctrl and K and choose Add changeset.
2. Enter a changeset number, or a link such as https://www.openstreetmap.org/changeset/123. The link is read for its number only. It is never opened.
3. Choose Add to queue.

The tool says “Added changeset” followed by the number, and that its analysis is queued. Choose Open case to go to it. If the changeset is already in the queue, the tool says so and does not add it twice.

In replay mode the tool serves only the saved demo changesets and does not call OpenStreetMap. A number that is not in the demo set is still added to the queue, but its analysis fails with the code osm_not_found and is not retried.

Import from a MapRoulette challenge

A MapRoulette challenge is a list of tasks, and each task can point to a changeset. The import reads that list, and it works in live mode only.

1. On the queue, choose Import from MapRoulette, or choose it from the command menu.
2. Enter the Challenge id, which is the challenge’s number on MapRoulette.
3. Enter How many to import, from 1 to 100.
4. Choose Import.

The tool reports “Imported N new and found M already in the queue”. Each id is handled once, so running the same import again does not make duplicates.

What can go wrong

• “Enter a changeset number, or a link such as …”. The text was not a number or an openstreetmap.org changeset link.
• “The daily analysis limit has been reached. Try again after midnight UTC.” The server caps how many analyses it queues each day. Wait until the next UTC day.
• “Importing from a challenge is only available in live mode.” The server is in replay mode. See replay and live.
• “MapRoulette could not be reached. Try again later.” The tool could not read the challenge list. Nothing was queued from it.
• “Enter a challenge number and a count between 1 and 100.” One of the two fields is empty or out of range.

For scripts

The same actions are available from the API. POST /api/v1/cases takes a changeset_id. POST /api/v1/cases/import takes a source of maproulette or osmcha, and either a list of ids or a challenge_id, with a limit of up to 100. Both need a reviewer session. The interface offers only the MapRoulette import.

With the osmcha source, send ids only. A challenge_id with that source is refused as an invalid parameter. The source value is recorded with each case, and the interface does not offer it.

Check that it worked

The new cases appear in the queue, and the lane counts in the side bar change as their analyses finish. A case that is still being analyzed shows the status Queued or Analyzing. Open one and you see the step the analysis is on, such as “fetching evidence” or “reading the evidence with the model”.

Next, read a new case with read the evidence.