Mobile app API inventory

[tschuy]

General

https://www.duolingo.com/api/1/version_info
https://www.duolingo.com/api/1/users/show?id=?????
https://www.duolingo.com/api/1/store/get_items

Skills:

1. main skill page https://api.duolingo.com/api/1/skills/show?id=?????
2. lessons https://api.duolingo.com/api/1/sessions?device=mobile&select_capable=true&offline=true&lesson_number=???&type=lesson&skill_id=????&speak_capable=true

Sentence: http://d2.duolingo.com/words/hints/de/en?sentence=plus+separated+words.&format=new It appears this API can take arbitrary sentences.

Other The cloudflare URL should be replaced with static.duolingo.com, which is the value returned by https://www.duolingo.com/api/1/version_info for the TTS CDN url.

[tschuy]

Fresh Login

There's a cookie, duo_ab, with some unknown value. it's included in the GET of the first request. My guess is some kind of device ID.

1. https://www.duolingo.com/api/1/version_info

I log in.

1. POST https://www.duolingo.com/login.
   • password: (password)
   • login: (username)

This request sets a cookie auth_tkt.

Response body: {'response': 'OK', 'username': (username), 'user_id': (user id)}

1. GET https://www.duolingo.com/api/1/users/show?id={user_id}
2. GET https://www.duolingo.com/api/1/version_info. The response body appears to be the same.
3. GET https://www.duolingo.com/api/1/store/get_items.

After that, it starts getting the next available skills, including every lesson and their sentence audio.

[tschuy]

Switching Languages

1. POST /api/1/me/switch_language

• from_language: en
  • learning_language=fr

response body: an object with

• languages (incl. ones not being learned, with current_learning set to True or False)
  • language_data
• fr (or chosen language)
  • various info about the language, incl. skills. It's the same as the language_data returned by the users/show?id={user_id} endpoint.

[tschuy]

Looks like the mobile API is a much better base for writing the duolingo API than the web api, since it doesn't allow the developers to do things like embed their TTS url in the webpage.

[tschuy]

I've been writing some documentation here: http://tschuy.com/duolingo/duolingo.html

[samwest88]

@tschuy

http://tschuy.com/duolingo/duolingo.html

Is a broken link - are the docs up yet?

[tylerwhipple]

@samwest88 FYI http://tschuy.com/duolingo/ doesnt look recent

[tschuy]

@tylerwhipple @samwest88 it's on github: https://github.com/tschuy/duolingo/blob/master/docs/source/api/endpoints.rst I broke the Github Pages hosting for now, I'll get around to it eventually :P

[tschuy]

https://github.com/tschuy/duolingo/blob/master/docs/source/api/data.rst <-- explains a bit more about the data they return.

[CJDennis]

Regarding the value of the cookie duo_ab: It refers to Duolingo's A/B tests and is two fields concatenated together. The first is a 40-byte hex-encoded (160 bits in binary) hash (probably SHA-1) of the second field. The second field is Base64-encoded JSON containing the following fields (as of this post):

• schools_new_signup_test
• web_branded_mobile_buttons_test
• signup_modal_buttons_experiment
• login_modal_experiment

Each field can be true or false independently.