API Authentication

Your application needs to identify itself every time it sends a request to the Crowdin API by an API Key with each request. Each Crowdin project has its own API Key.

Acquiring and using an API key

To find your project API key you have to login to your Crowdin account. Find the project, open Project Settings page and activate API tab.

API Settings Page

Please note that almost all API calls require the Project Identifier (ID). You can find your project identifier right above the API key.

Making requests

For every API request you make, you'll need to present the API access key as the main URI parameter to be authenticated. Keep the API key in secret! It should be guarded just as your regular account password.

Here's an example and principle of API request URI forming.


Typical API call URL looks like this: https://api.crowdin.com/api/project/. First placeholder (keyword in brackets) holds project identifier and action needed (download as shown in the example). API access key is specified as a URI parameter.

Error codes

0: Unknown internal error
1: Requested project does not exist or API key is not valid
2: Unknown API action
3: API key is not valid
4: No files specified in request
5: File with such name is already uploaded
6: File was uploaded with error
7: Invalid file extension
8: File was not found
9: No language specified in request
10: Language was not found
11: Account does not exist
12: Account key is invalid
13: Unknown error occurred
14: No type specified in request
15: Invalid file type
16: No file scheme specified in request
17: Specified directory was not found
18: No user id specified in request
19: User with such id already exists
20: User was not found
21: Specified value for "files" parameter is invalid. Array expected
22: Specified value for "titles" parameter is invalid. Array expected
23: Specified value for "export_patterns" parameter is invalid. Array expected
24: Specified value for "languages" parameter is invalid. Array expected
25: An error occurred while uploading glossary
26: Directory or path does not exist
27: One or several parameters are invalid
28: Invalid file scheme specified in request
29: Parameter "engine" was not found
30: Specified machine translation engine is not supported
31: Microsoft Translator API keys were not found
32: Google Translate API key was not found
33: Reference was not found
34: Specified value for "reference" parameter is invalid. String expected
35: Parameter "tm" was not found
36: Translation memory was not found
37: No user login specified in request
38: Specified values are invalid for some parameters
39: Yandex Translate API key was not found
40: OAuth authorization failed
41: This action is forbidden for you
42: Uploaded file is too large
43: The request cannot be submitted since this project is suspended
44: No user id or login specified in request
45: Maximum number of uploaded files should not exceed 20
46: Versions are not available for your current subscription plan
47: Specified value for "new_names" parameter is invalid. Array expected
48: This feature is not available on your current subscription plan
49: Not allowed to remove the project owner

The Crowdin API gives you access to almost all of the features available in your account, letting you automate a lot of common operations. If you need help working with the API please do not hesitate to contact us.