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Challonge API v1 Documentation


The Challonge API expands tournament creation and control to the programmatic level. You can create tournaments on the fly and report scores directly from your application. This allows you to define score reporting permissions that fit your user model, and provide a more seamless tournament experience for your users.

The API is accessible over a secure connection at


All interactions with the API require a Challonge account with a verified email address and API key. We support HTTP basic authentication. Username = your Challonge username, Password = your API key. Many clients format these requests as: https://username:[email protected]/v1/... Or, if you prefer, you can just pass your API key as parameter api_key to all method calls.

API methods with GET request types are permitted for any tournament, whether belonging to you or not. All other API methods are scoped to tournaments that you either own or have admin access to.

Response Formats

XML or JSON. The extension in your request indicates your desired response. e.g. or - you may also set your request headers to accept application/json, text/xml or application/xml

Response Codes

The following HTTP response codes are issued by the API. All other codes are the result of a request not reaching the application.

  • 200- OK
  • 401- Unauthorized (Invalid API key or insufficient permissions)
  • 404- Object not found within your account scope
  • 406- Requested format is not supported - request JSON or XML only
  • 422- Validation error(s) for create or update method
  • 500- Something went wrong on our end. If you continually receive this, please contact us.

Validation Errors

Requests that complete but have validation errors or other issues will return an array of error messages and status code 422. e.g.:

  "errors": [
    "Name can't be blank",
    "URL can't be blank"
<?xml version="1.0" encoding="UTF-8"?>
  <error>Name can't be blank</error>
  <error>URL can't be blank</error>

REST API Methods

Please note, two-stage tournaments are not yet supported by our public API. They'll be available in V2 along with 3+ participant per match support.


GET Retrieve a set of tournaments created with your account.
Create POST Create a new tournament.
Show GET Retrieve a single tournament record created with your account.
Update PUT Update a tournament's attributes.
Destroy DELETE Deletes a tournament along with all its associated records. There is no undo, so use with care!
Process Check-ins POST

This should be invoked after a tournament's check-in window closes before the tournament is started.

  1. Marks participants who have not checked in as inactive.
  2. Moves inactive participants to bottom seeds (ordered by original seed).
  3. Transitions the tournament state from 'checking_in' to 'checked_in'
NOTE: Checked in participants on the waiting list will be promoted if slots become available.
Abort Check-in POST

When your tournament is in a 'checking_in' or 'checked_in' state, there's no way to edit the tournament's start time (start_at) or check-in duration (check_in_duration). You must first abort check-in, then you may edit those attributes.

  1. Makes all participants active and clears their checked_in_at times.
  2. Transitions the tournament state from 'checking_in' or 'checked_in' to 'pending'
Start POST Start a tournament, opening up first round matches for score reporting. The tournament must have at least 2 participants.
Finalize POST Finalize a tournament that has had all match scores submitted, rendering its results permanent.
Reset POST Reset a tournament, clearing all of its scores and attachments. You can then add/remove/edit participants before starting the tournament again.
Open for predictions POST Sets the state of the tournament to start accepting predictions. Your tournament's 'prediction_method' attribute must be set to 1 (exponential scoring) or 2 (linear scoring) to use this option. Note: Once open for predictions, match records will be persisted, so participant additions and removals will no longer be permitted.


GET Retrieve a tournament's participant list.
Create POST Add a participant to a tournament (up until it is started).
Bulk Add POST Bulk add participants to a tournament (up until it is started). If an invalid participant is detected, bulk participant creation will halt and any previously added participants (from this API request) will be rolled back.
Show GET Retrieve a single participant record for a tournament.
Update PUT Update the attributes of a tournament participant.
Check in POST Checks a participant in, setting checked_in_at to the current time.
Undo Check In POST Marks a participant as having not checked in, setting checked_in_at to nil.
Destroy DELETE If the tournament has not started, delete a participant, automatically filling in the abandoned seed number. If tournament is underway, mark a participant inactive, automatically forfeiting his/her remaining matches.
Clear DELETE Deletes all participants in a tournament. (Only allowed if tournament hasn't started yet)
Randomize POST Randomize seeds among participants. Only applicable before a tournament has started.


GET Retrieve a tournament's match list.
Show GET Retrieve a single match record for a tournament.
Update PUT Update/submit the score(s) for a match.
Reopen POST Reopens a match that was marked completed, automatically resetting matches that follow it
Mark as underway POST Sets "underway_at" to the current time and highlights the match in the bracket
Unmark as underway POST Clears "underway_at" and unhighlights the match in the bracket

Match Attachments

GET Retrieve a match's attachments.
Create POST Add a file, link, or text attachment to a match. NOTE: The associated tournament's "accept_attachments" attribute must be true for this action to succeed.
Show GET Retrieve a single match attachment record.
Update PUT Update the attributes of a match attachment.
Destroy DELETE Delete a match attachment.

Language Specific Libraries & Examples



A Ruby gem provided by us that greatly eases integration with the Challonge API



PHP wrapper class for the Challonge API that utilizes cURL and SimpleXML (author: Tony Drake)



Python bindings for the Challonge API (author: russ-)



Perl Module for interfacing the Challonge API (author: Alex Kerr)

API Update and Availability Notices

We strongly encourage API users to join the Challonge API Google Group for all API-related notices.

API Changelog