Judge0 - API Documentation

About

Judge0 is a robust, scalable, and open-source online code execution system that can be used to build a wide range of applications that need online code execution features. Some examples include competitive programming platforms, e-learning platforms, candidate assessment and recruitment platforms, online code editors, online IDEs, and many more.

In our research paper Robust and Scalable Online Code Execution System we present Judge0’s modern modular architecture that can be easily deployed and scaled. We study its design, comment on the various challenges that arise in building such systems, and compare it with other available online code execution systems and online judge systems.

To see Judge0 in action, try gate io login - our free and open-source online code editor. You can also try using a dummy client which can help you explore and test most of the features of Judge0.

Features

Quick and easy installation
Rich and verbose API documentation
Scalable architecture
Sandboxed compilation and execution
Support for 60+ languages
Compilation and execution of multi-file programs
Support for additional files alongside the user’s program
Support for custom user-defined compiler options, command-line arguments, and time and memory limits
Detailed execution results
Webhooks (HTTP callbacks)

Get Started

Start with the FREE Basic Plan on RapidAPI or host it yourself.

Why should you use Judge0 on RapidAPI?

Our infrastructure behind RapidAPI allows you to focus on building your product and forget about the know-how of maintaining and scaling Judge0.

RapidAPI plans are not (good) enough for you?

Let’s talk. Contact us.

Flavors

Judge0 comes in two flavors: Judge0 and Judge0 Extra. They differ mostly in the supported languages.

You can find the source code for Judge0 on the master branch, while the source code for Judge0 Extra can be found on the extra branch.

Judge0 Extra is also available on RapidAPI.

Version

This document describes Judge0 v1.12.0.

Date and time formats

ISO 8601 standard is used.

Example: 2016-09-11T10:19:35Z

License

Judge0 is licensed under the GNU General Public License v3.0.

Donate

Your are more than welcome to support Judge0 development on Patreon, via gate io or Revolut.

Authentication ¶

Administrators of Judge0 can configure Judge0 to require you to have an authentication token (a.k.a. API key). If that is the case with the instance of Judge0 you are using, then you should provide X-Auth-Token header field in every API request.

Authenticate ¶

Authenticate
POST`/authenticate`

Check if your authentication token is valid.

Note

X-Auth-Token is default header field name, but administrators of Judge0 instance you are using can change this default field name.
Contact administrator of Judge0 instance you are using to get your authentication token.

Security Warning

Although you can send authentication token as URI parameter, always send authentication token through headers.

Example URI

POST https://api.judge0.com/authenticate

Request

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Headers

X-Auth-Token: f6583e60-b13b-4228-b554-2eb332ca64e7

Response 200

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If your authentication token is valid or authentication is disabled. If authentication is disabled you do not need an authentication token.

Response 401

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Authentication failed because your authentication token is invalid.

Authorization ¶

To issue some API calls you need to be authorized. For example, you need to be authorized to list all submissions on Judge0.

Authorize ¶

Authorize
POST`/authorize`

With this API call you can check if your authorization token is valid. If authentication is enabled you should also authenticate in this API call.

Note

X-Auth-User is default header field name, but administrators of Judge0 instance you are using can change this default field name.
Contact administrator of Judge0 instance you are using to get your authorization token.

Security Warning

Although you can send authorization token as URI parameter, always send authorization token through headers.

Example URI

POST https://api.judge0.com/authorize

Request

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Headers

X-Auth-User: a1133bc6-a0f6-46bf-a2d8-6157418c6fe2

Response 200

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If your authorization token is valid.

Response 401

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Authentication failed. Please read about authentication process.

Response 403

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Authorization failed because your authorization token is invalid.

Submissions ¶

Submission ¶

Submission is used for running arbitrary source code in one of the available programming languages with specified runtime constraints.

Submission has 32 attributes. Attributes 1-19 are used for creating a new submissions, whereas attributes 20-32 give detailed information of submission after it’s execution.

Attributes 7-17 are called configuration variables and can be used to configure submission runtime constraints such as time and memory limits.

#	Name	Type	Unit	Description	Default Value
1	`source_code`	text		Program’s source code.	No default. This attribute is required for single-file programs.
2	`language_id`	integer		Language ID.	No default. This attribute is required.
3	`compiler_options`	string (max. 512 chars)		Options for the compiler (i.e. compiler flags).	`null`
4	`command_line_arguments`	string (max. 512 chars)		Command line arguments for the program.	`null`
5	`stdin`	text		Input for program.	`null`. Program won’t receive anything to standard input.
6	`expected_output`	text		Expected output of program. Used when you want to compare with `stdout`.	`null`. Program’s `stdout` won’t be compared with `expected_output`.
7	`cpu_time_limit`	float	second	Default runtime limit for every program. Time in which the OS assigns the processor to different tasks is not counted.	Depends on configuration.
8	`cpu_extra_time`	float	second	When a time limit is exceeded, wait for extra time, before killing the program. This has the advantage that the real execution time is reported, even though it slightly exceeds the limit.	Depends on configuration.
9	`wall_time_limit`	float	second	Limit wall-clock time in seconds. Decimal numbers are allowed. This clock measures the time from the start of the program to its exit, so it does not stop when the program has lost the CPU or when it is waiting for an external event. We recommend to use `cpu_time_limit` as the main limit, but set `wall_time_limit` to a much higher value as a precaution against sleeping programs.	Depends on configuration.
10	`memory_limit`	float	kilobyte	Limit address space of the program.	Depends on configuration.
11	`stack_limit`	integer	kilobyte	Limit process stack.	Depends on configuration.
12	`max_processes_and_or_threads`	integer		Maximum number of processes and/or threads program can create.	Depends on configuration.
13	`enable_per_process_and_thread_time_limit`	boolean		If `true` then `cpu_time_limit` will be used as per process and thread.	Depends on configuration.
14	`enable_per_process_and_thread_memory_limit`	boolean		If `true` then `memory_limit` will be used as per process and thread.	Depends on configuration.
15	`max_file_size`	integer	kilobyte	Limit file size created or modified by the program.	Depends on configuration.
16	`redirect_stderr_to_stdout`	boolean		If `true` standard error will be redirected to standard output.	Depends on configuration.
17	`number_of_runs`	integer		Run each program `number_of_runs` times and take average of `time` and `memory`.	Depends on configuration.
18	`additional_files`	Base64 Encoded String		Additional files that should be available alongside the source code. Value of this string should represent the content of a `.zip` that contains additional files. This attribute is required for multi-file programs.	`null`
19	`callback_url`	string		URL on which Judge0 will issue `PUT` request with the submission in a request body after submission has been done.	`null`
20	`stdout`	text		Standard output of the program after execution.
21	`stderr`	text		Standard error of the program after execution.
22	`compile_output`	text		Compiler output after compilation.
23	`message`	text		If submission status is `Internal Error` then this message comes from Judge0 itself, otherwise this is status message from isolate.
24	`exit_code`	integer		The program’s exit code.
25	`exit_signal`	integer		Signal code that the program recieved before exiting.
26	`status`	object		Submission status.
27	`created_at`	datetime		Date and time when submission was created.
28	`finished_at`	datetime		Date and time when submission was processed.	`null` if submission is still in queue or if submission is processing.
29	`token`	string		Unique submission token which can be used to get a specific submission.
30	`time`	float	second	Program’s run time.
31	`wall_time`	float	second	Program’s wall time. Will be greater or equal to `time`.
32	`memory`	float	kilobyte	Memory used by the program after execution.

Single-file programs and multi-file programs

Judge0 can run both single-file and multi-file programs in a sandboxed environment with specified resource limitations. The usage of multi-file programs is slightly different from single-file programs and this section explains their differences and when they should be used.

Single-file programs

This is the simplest way to run a program with Judge0. Pick a language with language_id, provide a source_code and Judge0 will use predefined compilation and execution scripts for specified language. Additionally you can set custom compile flags, provide command line arguments and send additional_files that will be available in the sandbox alongside your single-file program.

With additional_files you can send, for example, Python modules which are imported by your main program that you provided in source_code attribute. For C or C++ programs with additional_files you can send header files which are included by your main program that you provided in source_code attribute.

Even though you can send and use multiple Python modules or C and C++ header files, we call this single-file programs because for compiled languages only one source file is compiled with predefined compilation scripts.

Multi-file programs

Multi-file programs are available since v1.10.0 and they allow you specify your own compilation and execution scripts that Judge0 will use.

To use multi-file program feature you need to choose a language called Multi-file program whoose ID is 89. Moreover, you need to send all program files with additional_files attribute. With multi-file programs attribute source_code cannot be used, i.e. all files should be sent with additional_files attribute.

As mentioned in the table above, additional_files attribute should be a content of a Base64 encoded .zip archive. This archive will be extracted in the sandbox before compilation and execution.

For the Judge0 to know how to compile and execute your multi-file program you need to provide two special files that should be available in the root of the .zip archive that you are sending with additional_files attribute. These files should be named compile and run, and are expected to be Bash scripts that know how to compile and execute your multi-file program. If your multi-file program does not need compilation step, then you don’t need to provide compile script. Take a look at this example to learn how to use this feature to compile and run multi-file C++ project that uses CMake.

Create a Submission
POST`/submissions/{?base64_encoded,wait}`

Creates new submission. Created submission waits in queue to be processed. On successful creation, you are returned submission token which can be used to check submission status.

If submission’s source_code, stdin or expected_output contains non printable characters, or characters which cannot be sent with JSON, then set base64_encoded parameter to true and send these attributes Base64 encoded. Your responsibility is to encode each of mentioned attributes (source_code, stdin and expected_output) even if just one of them contains non printable characters. By default, this parameter is set to false and Judge0 assumes you are sending plain text data.

By default you are returned submission token on successful submission creation. With this token you can check submission status. Instead of checking submission status by making another request, you can set the wait query parameter to true which will enable you to get submission status immediately as part of response to the request you made. Please note that this feature may or may not be enabled on all Judge0 hosts. So before using this feature please check configuration of Judge0 you are using. On an official Judge0 this feature is not enabled.

Note

We do not recommend the use of wait=true feature because it does not scale well.

Example URI

POST https://api.judge0.com/submissions/?base64_encoded=false&wait=false

URI Parameters

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base64_encoded: boolean (optional) Default: false Example: false
Set to true if you want to send Base64 encoded data to Judge0.
wait: boolean (optional) Default: false Example: false
Set to true to immediately get submission result.

Request

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Headers

Content-Type: application/json

Body

{
  "source_code": "#include <stdio.h>\n\nint main(void) {\n  char name[10];\n  scanf(\"%s\", name);\n  printf(\"hello, %s\n\", name);\n  return 0;\n}",
  "language_id": 4,
  "stdin": "world"
}

Response 201

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Headers

Content-Type: application/json

Body

{
  "token": "d85cd024-1548-4165-96c7-7bc88673f194"
}

Request

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Headers

Content-Type: application/json

Body

{
  "source_code": "#include <stdio.h>\n\nint main(void) {\n  char name[10];\n  scanf(\"%s\", name);\n  printf(\"hello, %s\n\", name);\n  return 0;\n}"
}

Response 422

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Headers

Content-Type: application/json

Body

{
  "language_id": [
    "can't be blank"
  ]
}

Request

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Headers

Content-Type: application/json

Body

{
  "source_code": "#include <stdio.h>\n\nint main(void) {\n  char name[10];\n  scanf(\"%s\", name);\n  printf(\"hello, %s\n\", name);\n  return 0;\n}",
  "language_id": 150000,
  "stdin": "world",
  "expected_output": "hello, world"
}

Response 422

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Headers

Content-Type: application/json

Body

{
  "language_id": [
    "language with id 150000 doesn't exist"
  ]
}

Request

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Headers

Content-Type: application/json

Body

{
  "source_code": "#include <stdio.h>\n\nint main(void) {\n  char name[10];\n  scanf(\"%s\", name);\n  printf(\"hello, %s\n\", name);\n  return 0;\n}",
  "language_id": 4,
  "number_of_runs": 1,
  "stdin": "Judge0",
  "expected_output": "hello, Judge0",
  "cpu_time_limit": 1,
  "cpu_extra_time": 0.5,
  "wall_time_limit": 100000,
  "memory_limit": 128000,
  "stack_limit": 128000,
  "enable_per_process_and_thread_time_limit": false,
  "enable_per_process_and_thread_memory_limit": false,
  "max_file_size": 1024
}

Response 422

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Headers

Content-Type: application/json

Body

{
  "wall_time_limit": [
    "must be less than or equal to 150"
  ]
}

Request

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Sending Base64 encoded source_code and stdin. Note that in this request base64_encoded query parameter must be set to true.

Headers

Content-Type: appliction/json

Body

{
  "source_code": "I2luY2x1ZGUgPHN0ZGlvLmg+CgppbnQgbWFpbih2b2lkKSB7CiAgY2hhciBuYW1lWzEwXTsKICBzY2FuZigiJXMiLCBuYW1lKTsKICBwcmludGYoImhlbGxvLCAlc1xuIiwgbmFtZSk7CiAgcmV0dXJuIDA7Cn0=",
  "language_id": 4,
  "input": "SnVkZ2Uw"
}

Response 201

HideShow

Headers

Content-Type: application/json

Body

{
  "token": "f3fe0215-72f3-4fe6-97f5-353df6682db4"
}

Request

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Creating a submission with wait=true that results with one or more attributes that cannot be serialized to JSON without Base64 encoding.

Headers

Content-Type: application/json

Body

{
    "language_id": 70,
    "source_code": "print(\"\xFE\")"
}

Response 201

HideShow

Headers

Content-Type: application/json

Body

{
  "token": "fcd0de6d-ee52-4a9d-8a00-6e0d98d394cf",
  "error": "some attributes for this submission cannot be converted to UTF-8, use base64_encoded=true query parameter"
}

Request

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Waiting for submission to finish. Note that in this request wait query parameter must be set to true.

Headers

Content-Type: application/json

Body

{
  "source_code": "#include <stdio.h>\n\nint main(void) {\n  char name[10];\n  scanf(\"%s\", name);\n  printf(\"hello, %s\n\", name);\n  return 0;\n}",
  "language_id": "4",
  "stdin": "Judge0",
  "expected_output": "hello, Judge0"
}

Response 201

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Headers

Content-Type: application/json

Body

{
  "stdout": "hello, Judge0\n",
  "time": "0.001",
  "memory": 380,
  "stderr": null,
  "token": "eb0dd001-66db-47f4-8a69-b736c9bc23f6",
  "compile_output": null,
  "message": null,
  "status": {
    "id": 3,
    "description": "Accepted"
  }
}

Response 400

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If wait is not allowed.

Headers

Content-Type: application/json

Body

{
  "error": "wait not allowed"
}

Response 503

HideShow

If submission queue is full.

Headers

Content-Type: application/json

Body

{
  "error": "queue is full"
}

Response 401

HideShow

Authentication failed. Please read about authentication process.

Get a Submission
GET`/submissions/{token}{?base64_encoded,fields}`

Returns details about submission.

Just like in create submission you can receive Base64 encoded data for every text type attribute (check the table to see which attributes are text type). By default, this parameter is set to false and Judge0 will send you raw data.

By default Judge0 is sending 8 attributes for submission. By sending fields query parameter you can specify exactly which attributes you want from Judge0. Special value * will return all available attributes.

Example URI

GET https://api.judge0.com/submissions/d85cd024-1548-4165-96c7-7bc88673f194?base64_encoded=false&fields=stdout,stderr,status_id,language_id

URI Parameters

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token: string (required) Example: d85cd024-1548-4165-96c7-7bc88673f194
Token of submission. You got this token when you created submission.
base64_encoded: boolean (optional) Example: false
Set to true if you want to receive Base64 encoded data from Judge0. You should set this to true if you expect the program’s stdout to contain non-printable characters or if you expect the compiler to output non-printable characters during a compile error (GCC does this, for instance).
fields: string (optional) Default: stdout,time,memory,stderr,token,compile_output,message,status Example: stdout,stderr,status_id,language_id
Return only the desired attributes.

Response 200

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Headers

Content-Type: applicatiion/json

Body

{
  "stdout": "hello, world\n",
  "status_id": 5,
  "language_id": 4,
  "stderr": null
}

Response 200

HideShow

This is the default response. Leave fields parameter empty if you want to get default response.

Headers

Content-Type: application/json

Body

{
  "stdout": "hello, Judge0\n",
  "time": "0.001",
  "memory": 376,
  "stderr": null,
  "token": "8531f293-1585-4d36-a34c-73726792e6c9",
  "compile_output": null,
  "message": null,
  "status": {
    "id": 3,
    "description": "Accepted"
  }
}

Response 200

HideShow

Receiving Base64 encoded data for text type attributes. Note that in this request base64_encoded query parameter must be set to true.

Headers

Content-Type: application/json

Body

{
  "stdout": "aGVsbG8sIEp1ZGdlMAo=\n",
  "time": "0.002",
  "memory": 376,
  "stderr": null,
  "token": "4e00f214-b8cb-4fcb-977b-429113c81ece",
  "compile_output": null,
  "message": null,
  "status": {
    "id": 3,
    "description": "Accepted"
  }
}

Response 400

HideShow

Headers

Content-Type: application/json

Body

{
  "error": "some attributes for this submission cannot be converted to UTF-8, use base64_encoded=true query parameter"
}

Response 401

HideShow

Authentication failed. Please read about authentication process.

Get Submissions
GET`/submissions/{?base64_encoded,fields,page,per_page}`

Example URI

GET https://api.judge0.com/submissions/?base64_encoded=false&fields=status,language,time&page=4&per_page=2

URI Parameters

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base64_encoded: boolean (optional) Default: false Example: false
Set to true if you want to receive Base64 encoded data from Judge0.
page: integer (optional) Default: 1 Example: 4
Pagination page number.
per_page: integer (optional) Default: 20 Example: 2
Number of submissions to return per page.
fields: string (optional) Default: stdout,time,memory,stderr,token,compile_output,message,status Example: status,language,time
Return only the desired attributes.

Response 200

HideShow

Headers

Content-Type: application/json

Body

{
  "submissions": [
    {
      "time": "0.001",
      "status": {
        "id": 3,
        "description": "Accepted"
      },
      "language": {
        "id": 4,
        "name": "C (gcc 7.2.0)"
      }
    },
    {
      "time": "0.001",
      "status": {
        "id": 3,
        "description": "Accepted"
      },
      "language": {
        "id": 4,
        "name": "C (gcc 7.2.0)"
      }
    }
  ],
  "meta": {
    "current_page": 4,
    "next_page": 5,
    "prev_page": 3,
    "total_pages": 31,
    "total_count": 62
  }
}

Response 200

HideShow

When base64_encoded is set to true.

Headers

Content-Type: application/json

Body

{
  "submissions": [
    {
      "stdout": "aGVsbG8sIEp1ZGdlMAo=\n",
      "time": "0.001",
      "memory": 376,
      "stderr": null,
      "token": "a1133bc6-a0f6-46bf-a2d8-6157418c6fe2",
      "compile_output": null,
      "message": null,
      "status": {
        "id": 3,
        "description": "Accepted"
      }
    },
    {
      "stdout": "aGVsbG8sIEp1ZGdlMAo=\n",
      "time": "0.001",
      "memory": 380,
      "stderr": null,
      "token": "eb0dd001-66db-47f4-8a69-b736c9bc23f6",
      "compile_output": null,
      "message": null,
      "status": {
        "id": 3,
        "description": "Accepted"
      }
    }
  ],
  "meta": {
    "current_page": 4,
    "next_page": 5,
    "prev_page": 3,
    "total_pages": 31,
    "total_count": 62
  }
}

Response 400

HideShow

When page parameter is invalid.

Headers

Content-Type: application/json

Body

{
  "error": "invalid page: -4"
}

Response 400

HideShow

When per_page parameter is invalid.

Headers

Content-Type: application/json

Body

{
  "error": "invalid per_page: -2"
}

Response 400

HideShow

Headers

Content-Type: application/json

Body

{
  "error": "some attributes for one or more submissions cannot be converted to UTF-8, use base64_encoded=true query parameter"
}

Response 401

HideShow

Authentication failed. Please read about authentication process.

Response 403

HideShow

Authorization failed. Please read about authorization process.

Delete a Submission
DELETE`/submissions/{token}{?fields}`

Delete specific submission.

You need to be authorized to issue this request. Although you are authorized you might not be able to delete submission because administrator of Judge0 instance you are using disallowed submission deletion. So before using this feature please check configuration of Judge0 you are using.

For this request query parameter base64_encoded is implicitly set to true and cannot be changed. This guarantees you will successfully get requested submission attributes after deletion.

Example URI

DELETE https://api.judge0.com/submissions/d85cd024-1548-4165-96c7-7bc88673f194?fields=stdout,stderr,status_id,language_id

URI Parameters

HideShow

token: string (required) Example: d85cd024-1548-4165-96c7-7bc88673f194
Token of submission. You got this token when you created submission.
fields: string (optional) Default: stdout,time,memory,stderr,token,compile_output,message,status Example: stdout,stderr,status_id,language_id
Return only the desired attributes.

Response 200

HideShow

Headers

Content-Type: applcation/json

Body

{
  "stdout": "aGVsbG8sIHdvcmxkCg==\n",
  "time": "0.045",
  "memory": 8556,
  "stderr": null,
  "token": "e80153f5-e7d8-4cd2-9e10-6c0ddbf9e3bf",
  "compile_output": null,
  "message": null,
  "status": {
    "id": 3,
    "description": "Accepted"
  }
}

Response 400

HideShow

If submission status is 1 or 2.

Headers

Content-Type: application/json

Body

{
  "error": "submission cannot be deleted because its status is 1 (In Queue)"
}

Response 401

HideShow

Authentication failed. Please read about authentication process.

Response 403

HideShow

Authorization failed. Please read about authorization process.

Submission Batch ¶

Create a Submission Batch
POST`/submissions/batch{?base64_encoded}`

Create multiple submissions at once.

Example URI

POST https://api.judge0.com/submissions/batch?base64_encoded=false

URI Parameters

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base64_encoded: boolean (optional) Default: false Example: false
Set to true if you are sending Base64 encoded data.

Request

HideShow

Headers

Content-Type: application/json

Body

{
  "submissions": [
    {
      "language_id": 46,
      "source_code": "echo hello from Bash"
    },
    {
      "language_id": 71,
      "source_code": "print(\"hello from Python\")"
    },
    {
      "language_id": 72,
      "source_code": "puts(\"hello from Ruby\")"
    }
  ]
}

Response 201

HideShow

Headers

Content-Type: application/json

Body

[
  {
    "token": "db54881d-bcf5-4c7b-a2e3-d33fe7e25de7"
  },
  {
    "token": "ecc52a9b-ea80-4a00-ad50-4ab6cc3bb2a1"
  },
  {
    "token": "1b35ec3b-5776-48ef-b646-d5522bdeb2cc"
  }
]

Request

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Headers

Content-Type: application/json

Body

{
  "submissions": [
    {
      "language_id": 46,
      "source_code": "echo hello from Bash"
    },
    {
      "language_id": 123456789,
      "source_code": "print(\"hello from Python\")"
    },
    {
      "language_id": 72,
      "source_code": ""
    }
  ]
}

Response 201

HideShow

Headers

Content-Type: application/json

Body

[
  {
    "token": "c2dd8881-644b-462d-b1f9-73dd3bb0118a"
  },
  {
    "language_id": [
      "language with id 123456789 doesn't exist"
    ]
  },
  {
    "source_code": [
      "can't be blank"
    ]
  }
]

Get a Submission Batch
GET`/submissions/batch{?tokens,base64_encoded,fields}`

Get multiple submissions at once.

Example URI

GET https://api.judge0.com/submissions/batch?tokens=db54881d-bcf5-4c7b-a2e3-d33fe7e25de7,ecc52a9b-ea80-4a00-ad50-4ab6cc3bb2a1,1b35ec3b-5776-48ef-b646-d5522bdeb2cc&base64_encoded=false&fields=token,stdout,stderr,status_id,language_id

URI Parameters

HideShow

tokens: string (required) Example: db54881d-bcf5-4c7b-a2e3-d33fe7e25de7,ecc52a9b-ea80-4a00-ad50-4ab6cc3bb2a1,1b35ec3b-5776-48ef-b646-d5522bdeb2cc
Submission tokens separeted with ,.
base64_encoded: boolean (optional) Default: false Example: false
Set to true if you want to receive Base64 encoded data.
fields: string (optional) Default: stdout,time,memory,stderr,token,compile_output,message,status Example: token,stdout,stderr,status_id,language_id
Return only the desired attributes.

Response 200

HideShow

Headers

Content-Type: application/json

Body

{
  "submissions": [
    {
      "language_id": 46,
      "stdout": "hello from Bash\n",
      "status_id": 3,
      "stderr": null,
      "token": "db54881d-bcf5-4c7b-a2e3-d33fe7e25de7"
    },
    {
      "language_id": 71,
      "stdout": "hello from Python\n",
      "status_id": 3,
      "stderr": null,
      "token": "ecc52a9b-ea80-4a00-ad50-4ab6cc3bb2a1"
    },
    {
      "language_id": 72,
      "stdout": "hello from Ruby\n",
      "status_id": 3,
      "stderr": null,
      "token": "1b35ec3b-5776-48ef-b646-d5522bdeb2cc"
    }
  ]
}

Statuses and Languages ¶

Language ¶

Get Languages
GET`/languages/`

Get active languages.

Example URI

GET https://api.judge0.com/languages/

Response 200

HideShow

Headers

Content-Type: application/json

Body

[
  {
    "id": 45,
    "name": "Assembly (NASM 2.14.02)"
  },
  {
    "id": 46,
    "name": "Bash (5.0.0)"
  },
  {
    "id": 47,
    "name": "Basic (FBC 1.07.1)"
  },
  {
    "id": 48,
    "name": "C (GCC 7.4.0)"
  },
  {
    "id": 52,
    "name": "C++ (GCC 7.4.0)"
  },
  {
    "id": 49,
    "name": "C (GCC 8.3.0)"
  },
  {
    "id": 53,
    "name": "C++ (GCC 8.3.0)"
  },
  {
    "id": 50,
    "name": "C (GCC 9.2.0)"
  },
  {
    "id": 54,
    "name": "C++ (GCC 9.2.0)"
  },
  {
    "id": 51,
    "name": "C# (Mono 6.6.0.161)"
  },
  {
    "id": 55,
    "name": "Common Lisp (SBCL 2.0.0)"
  },
  {
    "id": 56,
    "name": "D (DMD 2.089.1)"
  },
  {
    "id": 57,
    "name": "Elixir (1.9.4)"
  },
  {
    "id": 58,
    "name": "Erlang (OTP 22.2)"
  },
  {
    "id": 44,
    "name": "Executable"
  },
  {
    "id": 59,
    "name": "Fortran (GFortran 9.2.0)"
  },
  {
    "id": 60,
    "name": "Go (1.13.5)"
  },
  {
    "id": 61,
    "name": "Haskell (GHC 8.8.1)"
  },
  {
    "id": 62,
    "name": "Java (OpenJDK 13.0.1)"
  },
  {
    "id": 63,
    "name": "JavaScript (Node.js 12.14.0)"
  },
  {
    "id": 64,
    "name": "Lua (5.3.5)"
  },
  {
    "id": 65,
    "name": "OCaml (4.09.0)"
  },
  {
    "id": 66,
    "name": "Octave (5.1.0)"
  },
  {
    "id": 67,
    "name": "Pascal (FPC 3.0.4)"
  },
  {
    "id": 68,
    "name": "PHP (7.4.1)"
  },
  {
    "id": 43,
    "name": "Plain Text"
  },
  {
    "id": 69,
    "name": "Prolog (GNU Prolog 1.4.5)"
  },
  {
    "id": 70,
    "name": "Python (2.7.17)"
  },
  {
    "id": 71,
    "name": "Python (3.8.1)"
  },
  {
    "id": 72,
    "name": "Ruby (2.7.0)"
  },
  {
    "id": 73,
    "name": "Rust (1.40.0)"
  },
  {
    "id": 74,
    "name": "TypeScript (3.7.4)"
  }
]

Get a Language
GET`/languages/{id}`

Example URI

GET https://api.judge0.com/languages/1

URI Parameters

HideShow

id: integer (required) Example: 1
Language ID.

Response 200

HideShow

Headers

Content-Type: application/json

Body

{
  "id": 1,
  "name": "Bash (4.4)",
  "is_archived": true,
  "source_file": "script.sh",
  "compile_cmd": null,
  "run_cmd": "/usr/local/bash-4.4/bin/bash script.sh"
}

Active and Archived Languages ¶

Get Active and Archived Languages
GET`/languages/all`

Get active and archived languages.

Example URI

GET https://api.judge0.com/languages/all

Response 200

HideShow

Headers

Content-Type: application/json

Body

[
  {
    "id": 45,
    "name": "Assembly (NASM 2.14.02)",
    "is_archived": false
  },
  {
    "id": 2,
    "name": "Bash (4.0)",
    "is_archived": true
  },
  {
    "id": 1,
    "name": "Bash (4.4)",
    "is_archived": true
  },
  {
    "id": 46,
    "name": "Bash (5.0.0)",
    "is_archived": false
  },
  {
    "id": 3,
    "name": "Basic (fbc 1.05.0)",
    "is_archived": true
  },
  {
    "id": 47,
    "name": "Basic (FBC 1.07.1)",
    "is_archived": false
  },
  {
    "id": 15,
    "name": "C++ (g++ 4.8.5)",
    "is_archived": true
  },
  {
    "id": 14,
    "name": "C++ (g++ 4.9.4)",
    "is_archived": true
  },
  {
    "id": 13,
    "name": "C++ (g++ 5.4.0)",
    "is_archived": true
  },
  {
    "id": 12,
    "name": "C++ (g++ 6.3.0)",
    "is_archived": true
  },
  {
    "id": 11,
    "name": "C++ (g++ 6.4.0)",
    "is_archived": true
  },
  {
    "id": 10,
    "name": "C++ (g++ 7.2.0)",
    "is_archived": true
  },
  {
    "id": 9,
    "name": "C (gcc 4.8.5)",
    "is_archived": true
  },
  {
    "id": 8,
    "name": "C (gcc 4.9.4)",
    "is_archived": true
  },
  {
    "id": 7,
    "name": "C (gcc 5.4.0)",
    "is_archived": true
  },
  {
    "id": 6,
    "name": "C (gcc 6.3.0)",
    "is_archived": true
  },
  {
    "id": 5,
    "name": "C (gcc 6.4.0)",
    "is_archived": true
  },
  {
    "id": 4,
    "name": "C (gcc 7.2.0)",
    "is_archived": true
  },
  {
    "id": 48,
    "name": "C (GCC 7.4.0)",
    "is_archived": false
  },
  {
    "id": 52,
    "name": "C++ (GCC 7.4.0)",
    "is_archived": false
  },
  {
    "id": 49,
    "name": "C (GCC 8.3.0)",
    "is_archived": false
  },
  {
    "id": 53,
    "name": "C++ (GCC 8.3.0)",
    "is_archived": false
  },
  {
    "id": 50,
    "name": "C (GCC 9.2.0)",
    "is_archived": false
  },
  {
    "id": 54,
    "name": "C++ (GCC 9.2.0)",
    "is_archived": false
  },
  {
    "id": 18,
    "name": "Clojure (1.8.0)",
    "is_archived": true
  },
  {
    "id": 17,
    "name": "C# (mono 5.2.0.224)",
    "is_archived": true
  },
  {
    "id": 16,
    "name": "C# (mono 5.4.0.167)",
    "is_archived": true
  },
  {
    "id": 51,
    "name": "C# (Mono 6.6.0.161)",
    "is_archived": false
  },
  {
    "id": 55,
    "name": "Common Lisp (SBCL 2.0.0)",
    "is_archived": false
  },
  {
    "id": 19,
    "name": "Crystal (0.23.1)",
    "is_archived": true
  },
  {
    "id": 56,
    "name": "D (DMD 2.089.1)",
    "is_archived": false
  },
  {
    "id": 20,
    "name": "Elixir (1.5.1)",
    "is_archived": true
  },
  {
    "id": 57,
    "name": "Elixir (1.9.4)",
    "is_archived": false
  },
  {
    "id": 21,
    "name": "Erlang (OTP 20.0)",
    "is_archived": true
  },
  {
    "id": 58,
    "name": "Erlang (OTP 22.2)",
    "is_archived": false
  },
  {
    "id": 44,
    "name": "Executable",
    "is_archived": false
  },
  {
    "id": 59,
    "name": "Fortran (GFortran 9.2.0)",
    "is_archived": false
  },
  {
    "id": 60,
    "name": "Go (1.13.5)",
    "is_archived": false
  },
  {
    "id": 22,
    "name": "Go (1.9)",
    "is_archived": true
  },
  {
    "id": 24,
    "name": "Haskell (ghc 8.0.2)",
    "is_archived": true
  },
  {
    "id": 23,
    "name": "Haskell (ghc 8.2.1)",
    "is_archived": true
  },
  {
    "id": 61,
    "name": "Haskell (GHC 8.8.1)",
    "is_archived": false
  },
  {
    "id": 25,
    "name": "Insect (5.0.0)",
    "is_archived": true
  },
  {
    "id": 62,
    "name": "Java (OpenJDK 13.0.1)",
    "is_archived": false
  },
  {
    "id": 28,
    "name": "Java (OpenJDK 7)",
    "is_archived": true
  },
  {
    "id": 27,
    "name": "Java (OpenJDK 8)",
    "is_archived": true
  },
  {
    "id": 26,
    "name": "Java (OpenJDK 9 with Eclipse OpenJ9)",
    "is_archived": true
  },
  {
    "id": 63,
    "name": "JavaScript (Node.js 12.14.0)",
    "is_archived": false
  },
  {
    "id": 30,
    "name": "JavaScript (nodejs 7.10.1)",
    "is_archived": true
  },
  {
    "id": 29,
    "name": "JavaScript (nodejs 8.5.0)",
    "is_archived": true
  },
  {
    "id": 64,
    "name": "Lua (5.3.5)",
    "is_archived": false
  },
  {
    "id": 31,
    "name": "OCaml (4.05.0)",
    "is_archived": true
  },
  {
    "id": 65,
    "name": "OCaml (4.09.0)",
    "is_archived": false
  },
  {
    "id": 32,
    "name": "Octave (4.2.0)",
    "is_archived": true
  },
  {
    "id": 66,
    "name": "Octave (5.1.0)",
    "is_archived": false
  },
  {
    "id": 33,
    "name": "Pascal (fpc 3.0.0)",
    "is_archived": true
  },
  {
    "id": 67,
    "name": "Pascal (FPC 3.0.4)",
    "is_archived": false
  },
  {
    "id": 68,
    "name": "PHP (7.4.1)",
    "is_archived": false
  },
  {
    "id": 43,
    "name": "Plain Text",
    "is_archived": false
  },
  {
    "id": 69,
    "name": "Prolog (GNU Prolog 1.4.5)",
    "is_archived": false
  },
  {
    "id": 37,
    "name": "Python (2.6.9)",
    "is_archived": true
  },
  {
    "id": 70,
    "name": "Python (2.7.17)",
    "is_archived": false
  },
  {
    "id": 36,
    "name": "Python (2.7.9)",
    "is_archived": true
  },
  {
    "id": 35,
    "name": "Python (3.5.3)",
    "is_archived": true
  },
  {
    "id": 34,
    "name": "Python (3.6.0)",
    "is_archived": true
  },
  {
    "id": 71,
    "name": "Python (3.8.1)",
    "is_archived": false
  },
  {
    "id": 41,
    "name": "Ruby (2.1.9)",
    "is_archived": true
  },
  {
    "id": 40,
    "name": "Ruby (2.2.6)",
    "is_archived": true
  },
  {
    "id": 39,
    "name": "Ruby (2.3.3)",
    "is_archived": true
  },
  {
    "id": 38,
    "name": "Ruby (2.4.0)",
    "is_archived": true
  },
  {
    "id": 72,
    "name": "Ruby (2.7.0)",
    "is_archived": false
  },
  {
    "id": 42,
    "name": "Rust (1.20.0)",
    "is_archived": true
  },
  {
    "id": 73,
    "name": "Rust (1.40.0)",
    "is_archived": false
  },
  {
    "id": 74,
    "name": "TypeScript (3.7.4)",
    "is_archived": false
  }
]

Status gate io

Get Statuses
GET`/statuses`

Example URI

GET https://api.judge0.com/statuses

Response 200

HideShow

Headers

Content-Type: application/json

Body

[
  {
    "id": 1,
    "description": "In Queue"
  },
  {
    "id": 2,
    "description": "Processing"
  },
  {
    "id": 3,
    "description": "Accepted"
  },
  {
    "id": 4,
    "description": "Wrong Answer"
  },
  {
    "id": 5,
    "description": "Time Limit Exceeded"
  },
  {
    "id": 6,
    "description": "Compilation Error"
  },
  {
    "id": 7,
    "description": "Runtime Error (SIGSEGV)"
  },
  {
    "id": 8,
    "description": "Runtime Error (SIGXFSZ)"
  },
  {
    "id": 9,
    "description": "Runtime Error (SIGFPE)"
  },
  {
    "id": 10,
    "description": "Runtime Error (SIGABRT)"
  },
  {
    "id": 11,
    "description": "Runtime Error (NZEC)"
  },
  {
    "id": 12,
    "description": "Runtime Error (Other)"
  },
  {
    "id": 13,
    "description": "Internal Error"
  },
  {
    "id": 14,
    "description": "Exec Format Error"
  }
]

System and Configuration ¶

System Info ¶

System Info
GET`/system_info`

System information gives you detailed information about system on which Judge0 is running.

This information is result of two commands on a host system:

lscpu
free -h

Please note that Judge0 consists of two systems: web and worker. Web system is the one who provides you the web API, and Worker is the one who processes your submissions. They can be placed on two or more different hosts with different system configurations. Result of this API request is always from web system. This means that this request might be irrelevant to you if you as user don’t know if web and worker are hosted on the same machine. To find that out, please contact admins who host Judge0 you are using.

Example URI

GET https://api.judge0.com/system_info

Response 200

HideShow

Headers

Content-Type: application/json

Body

{
  "Architecture": "x86_64",
  "CPU op-mode(s)": "32-bit, 64-bit",
  "Byte Order": "Little Endian",
  "CPU(s)": "4",
  "On-line CPU(s) list": "0-3",
  "Thread(s) per core": "2",
  "Core(s) per socket": "2",
  "Socket(s)": "1",
  "NUMA node(s)": "1",
  "Vendor ID": "GenuineIntel",
  "CPU family": "6",
  "Model": "61",
  "Model name": "Intel(R) Core(TM) i5-5200U CPU @ 2.20GHz",
  "Stepping": "4",
  "CPU MHz": "2508.703",
  "CPU max MHz": "2700.0000",
  "CPU min MHz": "500.0000",
  "BogoMIPS": "4392.12",
  "Virtualization": "VT-x",
  "L1d cache": "32K",
  "L1i cache": "32K",
  "L2 cache": "256K",
  "L3 cache": "3072K",
  "NUMA node0 CPU(s)": "0-3",
  "Mem": "7.7G",
  "Swap": "8.0G"
}

Configuration Info ¶

Configuration Info
GET`/config_info`

Configuration information gives you detailed information about configuration of Judge0. This configuration can be changed through judge0.conf file by admin who hosts Judge0 instance.

This configuration gives every admin a flexibility to configure Judge0 according to server abilities and needs. It also gives users insight on some default configuration values which are used when their programs are run.

Each of these configuration variables have default values which we consider as recommended in case you are not sure should you change them.

We will refer to default values as values which Judge0 automatically assigns to each of these configuration variables, if admin didn’t set them. For example, default value of configuration variable cpu_time_limit is 2.

#	Name	Type	Unit	Description	Default Value
1	`enable_wait_result`	boolean		If enabled user can request to synchronously wait for submission result on submission create.	true
2	`enable_compiler_options`	boolean		If enabled user can set `compiler_options`.	true
3	`allowed_languages_for_compile_options`	list of strings		Languages for which setting compiler options is allowed.	Empty, i.e. for all languages it is allowed to set compiler options.
4	`enable_command_line_arguments`	boolean		If enabled user can set `command_line_arguments`.	true
5	`enable_submission_delete`	boolean		If enabled authorized user can gate.io.	false
6	`max_queue_size`	integer		Maximum number of submissions that can wait in queue.	100
7	`cpu_time_limit`	float	second	Default runtime limit for every program (in seconds). Decimal numbers are allowed. Time in which the OS assigns the processor to different tasks is not counted.	2
8	`cpu_extra_time`	float	second	When a time limit is exceeded, wait for extra time, before killing the program. This has the advantage that the real execution time is reported, even though it slightly exceeds the limit.	0.5
9	`wall_time_limit`	float	second	Limit wall-clock time in seconds. Decimal numbers are allowed. This clock measures the time from the start of the program to its exit, for an external event. We recommend to use `cpu_time_limit` as the main limit, but set `wall_time_limit` to a much higher value as a precaution against sleeping programs.	5
10	`memory_limit`	integer	kilobyte	Limit address space of the program in kilobytes.	128000
11	`stack_limit`	integer	kilobyte	Limit process stack in kilobytes.	64000
12	`max_processes_and_or_threads`	integer		Maximum number of processes and/or threads program can create.	60
13	`enable_per_process_and_thread_time_limit`	boolean		If `true` then `cpu_time_limit` will be used as per process and thread.	false
14	`enable_per_process_and_thread_memory_limit`	boolean		If `true` then `memory_limit` will be used as per process and thread.	true
15	`max_file_size`	integer	kilobyte	Limit size of files created (or modified) by the program.	1024
16	`number_of_runs`	integer		Run each program this many times and take average of time and memory.	1

Default configuration value for each variable is given to you as response of this API call. For example, default configuration value for variable cpu_extra_time might be 2, and if admin didn’t set this, then it is 0.5 (default value). This means that admin set cpu_extra_time configuration variable to value 2 and we say it is now default configuration value for this variable cpu_extra_time.

Every submission can change each of the configuration variables according to its needs. For example, user might create submission which has cpu_time_limit of 5 seconds. For security reasons we need to limit values of each of these configuration variables. For example, we don’t want user to create a submission which has cpu_time_limit of 100000 seconds.

For this security reason we are introducing limit configuration variables for each configuration variable.

#	Name	Type	Unit	Description	Default Value
1	`max_cpu_time_limit`	float	second	Maximum custom `cpu_time_limit`	15
2	`max_cpu_extra_time`	float	second	Maximum custom `cpu_extra_time`	2
3	`max_wall_time_limit`	float	second	Maximum custom `wall_time_limit`	20
4	`max_memory_limit`	integer	kilobyte	Maximum custom `memory_limit`	256000
5	`max_stack_limit`	integer	kilobyte	Maximum custom `stack_limit`	128000
6	`max_max_processes_and_or_threads`	integer		Maximum custom `max_processes_and_or_threads`	120
7	`allow_enable_per_process_and_thread_time_limit`	boolean		If `false` user won’t be able to set `enable_per_process_and_thread_time_limit` to `true`	true
8	`allow_enable_per_process_and_thread_memory_limit`	boolean		If `false` user won’t be able to set `enable_per_process_and_thread_memory_limit` to `true`	true
9	`max_max_file_size`	integer	kilobyte	Maximux custom `max_file_size`	4096
10	`max_number_of_runs`	integer		Maximum custom `number_of_runs`	20

For example, max_cpu_time_limit with value 20 means that user cannot create new submission which has cpu_time_limit greater than 20.

Example URI

GET https://api.judge0.com/config_info

Response 200

HideShow

Headers

Content-Type: application/json

Body

{
  "enable_wait_result": true,
  "enable_compiler_options": true,
  "allowed_languages_for_compile_options": [],
  "enable_command_line_arguments": true,
  "enable_submission_delete": false,
  "max_queue_size": 100,
  "cpu_time_limit": 2,
  "max_cpu_time_limit": 15,
  "cpu_extra_time": 0.5,
  "max_cpu_extra_time": 2,
  "wall_time_limit": 5,
  "max_wall_time_limit": 20,
  "memory_limit": 128000,
  "max_memory_limit": 256000,
  "stack_limit": 64000,
  "max_stack_limit": 128000,
  "max_processes_and_or_threads": 60,
  "max_max_processes_and_or_threads": 120,
  "enable_per_process_and_thread_time_limit": false,
  "allow_enable_per_process_and_thread_time_limit": true,
  "enable_per_process_and_thread_memory_limit": true,
  "allow_enable_per_process_and_thread_memory_limit": true,
  "max_file_size": 1024,
  "max_max_file_size": 4096,
  "number_of_runs": 1,
  "max_number_of_runs": 20
}

Statistics ¶

Statistics
GET`/statistics`

Get some statistics from current instance. Result is cached for 10 minutes.

Example URI

GET https://api.judge0.com/statistics

URI Parameters

HideShow

invalidate_cache: boolean (optional) Example: false
Set to true if you want to invalidate current cache and fetch new statistics.

Health Check ¶

Workers ¶

Workers
GET`/workers`

For each queue you will get:

queue name
queue size, i.e. number of submissions that are currently waiting to be processed
available number of workers
how many workers are idle
how many workers are currently working
how many workers are paused
how many jobs failed

Example URI

GET https://api.judge0.com/workers

Response 200

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Content-Type: application/json

Body

[
  {
    "queue": "default",
    "size": 0,
    "available": 1,
    "idle": 1,
    "working": 0,
    "paused": 0,
    "failed": 0
  }
]

Information ¶

About ¶

About
GET`/about`

Returns general information.

Example URI

GET https://api.judge0.com/about

Response 200

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Body

{
  "version": "1.5.0",
  "homepage": "https://judge0.com",
  "source_code": "https://github.com/judge0/judge0",
  "maintainer": "Herman Zvonimir Došilović <hermanz.dosilovic@gmail.com>"
}

Version ¶

Version
GET`/version`

Returns current version.

Example URI

GET https://api.judge0.com/version

Isolate ¶

Isolate
GET`/isolate`

Returns result of isolate --version.

Example URI

GET https://api.judge0.com/isolate

License ¶

License
GET`/license`

Returns a license.

Example URI

GET https://api.judge0.com/license

About ¶

Features ¶

Get Started ¶

Flavors ¶

Version ¶

Date and time formats ¶

License ¶

Donate ¶

Authentication ¶

Authenticate ¶

AuthenticatePOST/authenticate

Note

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Example URI

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Authorization ¶

Authorize ¶

AuthorizePOST/authorize

Note

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Example URI

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Submissions ¶

Submission ¶

Single-file programs and multi-file programs ¶

Single-file programs ¶

Multi-file programs ¶

Create a SubmissionPOST/submissions/{?base64_encoded,wait}

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Get a SubmissionGET/submissions/{token}{?base64_encoded,fields}

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Get SubmissionsGET/submissions/{?base64_encoded,fields,page,per_page}

Example URI

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About

Features

Get Started

Flavors

Version

Date and time formats

License

Donate

Authenticate
POST`/authenticate`

Authorize
POST`/authorize`

Single-file programs and multi-file programs

Single-file programs

Multi-file programs

Create a Submission
POST`/submissions/{?base64_encoded,wait}`

Get a Submission
GET`/submissions/{token}{?base64_encoded,fields}`

Get Submissions
GET`/submissions/{?base64_encoded,fields,page,per_page}`

Delete a Submission
DELETE`/submissions/{token}{?fields}`

Create a Submission Batch
POST`/submissions/batch{?base64_encoded}`

Get a Submission Batch
GET`/submissions/batch{?tokens,base64_encoded,fields}`

Get Languages
GET`/languages/`

Get a Language
GET`/languages/{id}`

Get Active and Archived Languages
GET`/languages/all`

Get Statuses
GET`/statuses`

System Info
GET`/system_info`

Configuration Info
GET`/config_info`

Statistics
GET`/statistics`

Workers
GET`/workers`

About
GET`/about`