Learn how to interact with the o!rdr API in this documentation.
If you plan on using this API, consider getting a key to bypass the rate limit of 1 render request per 5 minutes, and getting a BOT badge on the render list page.
DM "masterioo" on Discord to get one.
When tesing your code against the API and Websocket, please use the dev mode, to not flood o!rdr with useless render requests. It simulates what would happen if you sent a real render request. Check the "Developer mode" section to learn more about it.

The o!rdr Websocket can be accessed at https://apis.issou.best/ordr/ws.
It is powered by socket.io! Make sure to use a library that is compatible with socket.io websockets.
Note: most socket.io libraries require you to set the path of the URL (/ordr/ws) in a separate parameter. So the websocket URL is https://apis.issou.best, the path is /ordr/ws.

It sends 4 events:

• render_added_json: { renderID: number }
• render_progress_json: { renderID: number, username: string, progress: string, renderer: string, description: string }
• render_done_json: { renderID: number, videoUrl: string }
• render_failed_json: { renderID: number, errorCode: number, errorMessage: string }

Check this example in NodeJS to communicate with the Websocket.

Since rev12, error codes are sent after every POST request to send a render, and with the render_fail event on the Websocket.

• 0 = no error

Error codes that can be sent to the render_fail event on the Websocket:

• 1 = emergency stop (triggered manually)
• 2 = replay download error (bad upload from the sender)
• 3 = replay download error (bad download from the server), can happen because of invalid characters
• 4 = all beatmap mirrors are unavailable
• 15 = beatmap not found on all the beatmap mirrors
• 18 = unknown error from the renderer
• 19 = the renderer cannot download the map
• 20 = beatmap version on the mirror is not the same as the replay
• 21 = the replay is corrupted (danser cannot process it)
• 22 = server-side problem while finalizing the generated video
• 27 = something with the renderer went wrong: it probably has an unstable internet connection (multiple renders at the same time)
• 28 = the renderer cannot download the replay

Error codes that can be used before the request has been sent (http code 400/500)

• 2 = replay parsing error (bad upload from the sender)
• 5 = replay file corrupted
• 6 = invalid osu! gamemode (not 0 = std)
• 7 = the replay has no input data
• 8 = beatmap does not exist on osu! (probably because of custom difficulty or non-submitted map)
• 9 = audio for the map is unavailable (because of copyright claim)
• 10 = cannot connect to osu! api
• 11 = the replay has the autoplay mod
• 12 = the replay username has invalid characters
• 13 = the beatmap is longer than 15 minutes
• 14 = this player is banned from o!rdr
• 16 = this IP is banned from o!rdr
• 17 = this username is banned from o!rdr
• 23 = server-side problem while preparing the render
• 24 = the beatmap has no name
• 25 = the replay is missing input data
• 26 = the replay has incompatible mods
• 29 = the replay is already rendering or in queue
• 30 = the star rating is greater than 20
• 31 = the mapper is blacklisted
• 32 = the beatmapset is blacklisted
• 33 = the replay has already errored less than an hour ago
• 34 = invalid replay URL or can't download the replay (if replayURL is provided)
• 35 = a required field is missing (the missing field is shown in the message)
• 36 = your last replays have a too high error rate (cannot be triggered when you're a verified bot)
• 37 = the replay username is inappropriate
• 38 = this skin does not exist
• 39 = this custom skin does not exist or has been deleted
• 40 = o!rdr is not ready to take render jobs at the moment
• 41 = o!rdr is not ready to take render jobs from unauthenticated users at the moment (verified bots are not authenticated users)
• 42 = replay accuracy is too bad and you're not authenticated
• 43 = this score does not exist
• 44 = the replay for this score isn't available
• 45 = invalid osu! ruleset score ID

This mode is used when testing your code against the API and Websocket to avoid flooding o!rdr with useless render requests.
It simulates what would happen if you sent a real render request. The renderIDs of simulated renders are random and between 1 and 20000.
The websocket used by this mode is the same as the websocket used by o!rdr globally.
To use the dev mode, add a verificationKey key in your form data API request if you do not already have it, and as value you can use:

• devmode_success: simulates a request that will successfully render a video. Listen to the websocket to get the state of this fake render (render_added, render_progress and render_done are emitted).
• devmode_fail: simulates a request that will fail on the API level. No websocket events are emitted.
• devmode_wsfail: simulates a request that will fail on the Websocket level (render_failed event is emitted).