# Rextester API Rextester's API is a code snippet execution engine crafted over more than 15 years. Executing arbitrary code safely is not a trivial task. This API allows you to execute code snippets in a sandboxed environment while remaining cost-effective. The execution engine is designed to scale, so applications with high execution volume can increase their load without having to manage the underlying execution infrastructure themselves. ## Endpoint Run a code snippet using: ```http POST https://rextester.p.rapidapi.com/api/v1 ``` ## Request Body Example: ```json { "LanguageChoice": 24, "Program": "print (\"Hi\")", "Input": "", "CompilerArgs": "" } ``` ### Request Parameters | Field | Description | | ---------------- | ------------------------------------------------------------------------------------ | | `LanguageChoice` | Numeric identifier of the programming language to use. See the language table below. | | `Program` | Source code to compile and/or execute. | | `Input` | Text supplied to the standard input (`stdin`) of the running process. | | `CompilerArgs` | Compiler arguments, when required by the selected language. | ## Response Example response: ```json { "Result": "Hi\n", "Warnings": null, "Errors": null, "Stats": "Absolute running time: 0.15 sec, cpu time: 0.02 sec, memory peak: 8 Mb, absolute service time: 0.28 sec", "Files": null } ``` ### Response Fields | Field | Description | | ---------- | ------------------------------------------------------------------------------------ | | `Result` | Standard output produced by the executed program. | | `Warnings` | Compiler or runtime warnings, if any. | | `Errors` | Compilation or runtime errors, if any. | | `Stats` | Execution statistics such as running time, CPU time, memory usage, and service time. | | `Files` | Files generated by the program, when applicable. | --- # Supported Languages | Language | `LanguageChoice` | | ----------- | ---------------: | | C# | `1` | | F# | `3` | | Java | `4` | | Python | `5` | | C (gcc) | `6` | | C++ (gcc) | `7` | | PHP | `8` | | Pascal | `9` | | Objective-C | `10` | | Haskell | `11` | | Ruby | `12` | | Perl | `13` | | Lua | `14` | | Nasm | `15` | | JavaScript | `17` | | Lisp | `18` | | Prolog | `19` | | Go | `20` | | Scala | `21` | | Scheme | `22` | | Node.js | `23` | | Python 3 | `24` | | Octave | `25` | | C (clang) | `26` | | C++ (clang) | `27` | | D | `30` | | Tcl | `32` | | Bash | `38` | | Ada | `39` | | Erlang | `40` | | Elixir | `41` | | OCaml | `42` | | Kotlin | `43` | | Brainf*** | `44` | | Fortran | `45` | | Rust | `46` | | Clojure | `47` | --- # Compiler Arguments Some compiled languages require `CompilerArgs` to be supplied. The source filename and output filename must match the names shown in these examples. ## C (gcc) ```text -Wall -std=gnu17 -O2 -o a.out source_file.c ``` ## C++ (gcc) ```text -Wall -std=c++20 -O2 -o a.out source_file.cpp ``` ## Objective-C ```text -std=gnu11 -MMD -MP -DGNUSTEP -DGNUSTEP_BASE_LIBRARY=1 -DGNU_GUI_LIBRARY=1 -DGNU_RUNTIME=1 -DGNUSTEP_BASE_LIBRARY=1 -fno-strict-aliasing -fexceptions -fobjc-exceptions -D_NATIVE_OBJC_EXCEPTIONS -pthread -fPIC -Wall -DGSWARN -DGSDIAGNOSE -Wno-import -g -O2 -fgnu-runtime -fconstant-string-class=NSConstantString -I. -I /usr/include/GNUstep -I/usr/include/GNUstep -o a.out source_file.m -lobjc -lgnustep-base ``` ## Haskell ```text -o a.out source_file.hs ``` ## Go ```text -o a.out source_file.go ``` ## C (clang) ```text -Wall -std=gnu17 -O2 -o a.out source_file.c ``` ## C++ (clang) ```text -Wall -std=c++20 -stdlib=libc++ -O2 -o a.out source_file.cpp ``` ## D ```text source_file.d -ofa.out ``` --- # Program Examples The following examples can be used as initial values for the `Program` request field. ## C# **LanguageChoice:** `1` ```csharp // Microsoft (R) Visual C# Compiler version 4.8.0-7.25056.18 // Copyright (C) Microsoft Corporation. All rights reserved. using System; using System.Collections.Generic; using System.Linq; using System.Text.RegularExpressions; namespace Rextester { public class Program { public static void Main(string[] args) { // Your code goes here Console.WriteLine("Hello, world!"); } } } ``` ## F# **LanguageChoice:** `3` ```fsharp // Microsoft (R) F# Interactive version 12.9.101.0 for F# 9.0 printfn "Hello, World!" ``` ## Java **LanguageChoice:** `4` ```java // 'main' method must be in a class 'Rextester'. // openjdk 25 import java.util.*; import java.lang.*; class Rextester { public static void main(String args[]) { System.out.println("Hello, World!"); } } ``` ## Python **LanguageChoice:** `5` ```python # Python 2.7.18 print "Hello, world!" ``` ## C (gcc) **LanguageChoice:** `6` **CompilerArgs:** ```text -Wall -std=gnu17 -O2 -o a.out source_file.c ``` ```c // gcc 13.3.0 #include int main(void) { printf("Hello, world!\n"); return 0; } ``` ## C++ (gcc) **LanguageChoice:** `7` **CompilerArgs:** ```text -Wall -std=c++20 -O2 -o a.out source_file.cpp ``` ```cpp // g++ 13.3.0 #include int main() { std::cout << "Hello, world!\n"; } ``` ## PHP **LanguageChoice:** `8` ```php ``` ## Pascal **LanguageChoice:** `9` ```pascal // fpc 3.2.2 program HelloWorld; begin writeln('Hello, world!'); end. ``` ## Objective-C **LanguageChoice:** `10` **CompilerArgs:** ```text -std=gnu11 -MMD -MP -DGNUSTEP -DGNUSTEP_BASE_LIBRARY=1 -DGNU_GUI_LIBRARY=1 -DGNU_RUNTIME=1 -DGNUSTEP_BASE_LIBRARY=1 -fno-strict-aliasing -fexceptions -fobjc-exceptions -D_NATIVE_OBJC_EXCEPTIONS -pthread -fPIC -Wall -DGSWARN -DGSDIAGNOSE -Wno-import -g -O2 -fgnu-runtime -fconstant-string-class=NSConstantString -I. -I /usr/include/GNUstep -I/usr/include/GNUstep -o a.out source_file.m -lobjc -lgnustep-base ``` ```objective-c // gcc 13.3.0 #import int main(int argc, const char *argv[]) { NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; NSLog(@"Hello, World!"); [pool drain]; return 0; } ``` ## Haskell **LanguageChoice:** `11` **CompilerArgs:** ```text -o a.out source_file.hs ``` ```haskell -- ghc 9.4.7 main = print $ "Hello, world!" ``` ## Ruby **LanguageChoice:** `12` ```ruby # ruby 3.2.3 puts "Hello, world!" ``` ## Perl **LanguageChoice:** `13` ```perl # perl v5.38.2 print "Hello World\n"; ``` ## Lua **LanguageChoice:** `14` ```lua -- Lua 5.4.6 print("Hello, World!") ``` ## Nasm **LanguageChoice:** `15` ```nasm ; NASM version 2.16.01, 64-bit BITS 64 default rel section .data hello: db 'Hello world!',10 helloLen: equ $-hello section .text global _start _start: mov eax,4 mov ebx,1 mov ecx,hello mov edx,helloLen int 80h mov eax,1 mov ebx,0 int 80h ``` ## JavaScript **LanguageChoice:** `17` ```javascript // Rhino 1.7.14-2.1 print("Hello, world!"); ``` ## Lisp **LanguageChoice:** `18` ```lisp ; GNU CLISP 2.49.93+ (print "Hello, world!") ``` ## Prolog **LanguageChoice:** `19` ```prolog % Commands to the interpreter are submitted from stdin. % 'halt.' will be automatically appended to stdin input. % swi-prolog 9.0.4 program :- write('Hello, world!'). :- program. ``` ## Go **LanguageChoice:** `20` **CompilerArgs:** ```text -o a.out source_file.go ``` ```go // go version go1.22.2 package main import "fmt" func main() { fmt.Printf("Hello, world!\n") } ``` ## Scala **LanguageChoice:** `21` ```scala // 'Rextester' class is the entry point for your code. // Don't declare a package. // scala 2.11.12 object Rextester extends App { println("Hello, World!") } ``` ## Scheme **LanguageChoice:** `22` ```scheme ; guile 3.0.9 (display "Hello, World!") ``` ## Node.js **LanguageChoice:** `23` ```javascript // nodejs v18.19.1 console.log("Hello, World!"); ``` ## Python 3 **LanguageChoice:** `24` ```python # python 3.12.3 print("Hello, world!") ``` Example complete request: ```json { "LanguageChoice": 24, "Program": "print(\"Hello, world!\")", "Input": "", "CompilerArgs": "" } ``` ## Octave **LanguageChoice:** `25` ```matlab % To view plots after plot-producing commands, export the current % plot to PNG so that it can be returned by the service. % GNU Octave version 8.4.0 set(0, "defaultfigurevisible", "off"); warning("off", "all"); x = 1:0.1:10; plot(x, sin(x)); print -dpng some_name.png; ``` ## C (clang) **LanguageChoice:** `26` **CompilerArgs:** ```text -Wall -std=gnu17 -O2 -o a.out source_file.c ``` ```c // clang 18.1.3 #include int main(void) { printf("Hello, world!\n"); return 0; } ``` ## C++ (clang) **LanguageChoice:** `27` **CompilerArgs:** ```text -Wall -std=c++20 -stdlib=libc++ -O2 -o a.out source_file.cpp ``` ```cpp // clang 18.1.3 #include int main() { std::cout << "Hello, world!\n"; } ``` ## D **LanguageChoice:** `30` **CompilerArgs:** ```text source_file.d -ofa.out ``` ```d // DMD64 D Compiler v2.111.0 import std.stdio; void main() { writeln("Hello, World!"); } ``` ## Tcl **LanguageChoice:** `32` ```tcl # tclsh 8.6 puts "Hello, world!" ``` ## Bash **LanguageChoice:** `38` ```bash #!/bin/bash # GNU bash, version 5.2.21(1) echo "Hello, world!" ``` ## Ada **LanguageChoice:** `39` ```ada -- GNAT 14.2.0 with Ada.Text_IO; use Ada.Text_IO; procedure Hello is begin Put_Line ("Hello, world!"); end Hello; ``` ## Erlang **LanguageChoice:** `40` ```erlang % Erlang/OTP 25 [erts-13.2.2.5] % Don't change the first 3 lines -module(source). -export([entry_point/0]). entry_point() -> io:fwrite("Hello, world\n"). ``` ## Elixir **LanguageChoice:** `41` ```elixir # Elixir 1.14.0 IO.puts "Hello, world!" ``` ## OCaml **LanguageChoice:** `42` ```ocaml (* The OCaml compiler, version 4.14.1 *) print_string "Hello, world!\n";; ``` ## Kotlin **LanguageChoice:** `43` ```kotlin // Kotlin version 2.2.21-release-469 // JRE 25+36-Ubuntu-124.04.2 fun main(args: Array) { println("Hello, world!") } ``` ## Brainf*** **LanguageChoice:** `44` ```text [Brainf*** interpreter version 20041219] ++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++++++..+++.>++.<<+++++++++++++++.>.+++.------.--------.>+.>. ``` ## Fortran **LanguageChoice:** `45` ```fortran ! gfortran, gcc version 13.3.0 program hello print *, "Hello World!" end program hello ``` ## Rust **LanguageChoice:** `46` ```rust // rustc 1.75.0 fn main() { println!("Hello, world!"); } ``` ## Clojure **LanguageChoice:** `47` ```clojure ;; clojure 1.11.1 (println "Hello world!") ``` --- # Example Requests ## Python 3 ```json { "LanguageChoice": 24, "Program": "print(\"Hello, world!\")", "Input": "", "CompilerArgs": "" } ``` ## C (gcc) ```json { "LanguageChoice": 6, "Program": "#include \n\nint main(void)\n{\n printf(\"Hello, world!\\n\");\n return 0;\n}", "Input": "", "CompilerArgs": "-Wall -std=gnu17 -O2 -o a.out source_file.c" } ``` ## C++ (gcc) ```json { "LanguageChoice": 7, "Program": "#include \n\nint main()\n{\n std::cout << \"Hello, world!\\n\";\n}", "Input": "", "CompilerArgs": "-Wall -std=c++20 -O2 -o a.out source_file.cpp" } ``` ## Go ```json { "LanguageChoice": 20, "Program": "package main\n\nimport \"fmt\"\n\nfunc main() {\n fmt.Printf(\"Hello, world!\\n\")\n}", "Input": "", "CompilerArgs": "-o a.out source_file.go" } ``` --- # Using Standard Input The `Input` field is passed to the running program through standard input (`stdin`). For example, a Python 3 program: ```python name = input() print("Hello, " + name) ``` Request: ```json { "LanguageChoice": 24, "Program": "name = input()\nprint(\"Hello, \" + name)", "Input": "Rextester", "CompilerArgs": "" } ``` Expected result: ```json { "Result": "Hello, Rextester\n", "Warnings": null, "Errors": null, "Stats": "...", "Files": null } ``` --- # RapidAPI Request Example A typical HTTP request should send the payload as JSON to: ```text https://rextester.p.rapidapi.com/api/v1 ``` Example with cURL: ```bash curl --request POST \ --url https://rextester.p.rapidapi.com/api/v1 \ --header 'Content-Type: application/json' \ --header 'X-RapidAPI-Host: rextester.p.rapidapi.com' \ --header 'X-RapidAPI-Key: YOUR_RAPIDAPI_KEY' \ --data '{ "LanguageChoice": 24, "Program": "print(\"Hello, world!\")", "Input": "", "CompilerArgs": "" }' ``` > Replace `YOUR_RAPIDAPI_KEY` with your RapidAPI key. --- # Notes * `LanguageChoice` must correspond to one of the supported language IDs listed above. * `Program` contains the complete source code that should be executed. * `Input` can be left as an empty string when the program does not read from standard input. * `CompilerArgs` can be left empty for languages that do not require explicit compiler arguments. * For languages requiring compiler arguments, use the expected source filename shown in the compiler argument examples. * Generated files, such as images produced by Octave, may be returned through the `Files` field. * Compilation failures and runtime failures are reported through `Errors`. * Compiler or runtime diagnostics that do not prevent execution may appear in `Warnings`. * Execution information is returned in `Stats`.