diff --git a/api/src/executor/job.js b/api/src/executor/job.js
index 77ecbfe..2aff1be 100644
--- a/api/src/executor/job.js
+++ b/api/src/executor/job.js
@@ -17,22 +17,15 @@ let gid = 0;
 
 class Job {
 
-    constructor({ runtime, files, args, stdin, timeouts, main, alias }) {
+    constructor({ runtime, files, args, stdin, timeouts, alias }) {
         this.uuid =  uuidv4();
         this.runtime = runtime;
         this.files = files;
         this.args = args;
         this.stdin = stdin;
         this.timeouts = timeouts;
-        this.main = main;
         this.alias = alias;
 
-        let file_list = this.files.map(f => f.name);
-
-        if (!file_list.includes(this.main)) {
-            throw new Error(`Main file "${this.main}" will not be written to disk`);
-        }
-
         this.uid = config.runner_uid_min + uid;
         this.gid = config.runner_gid_min + gid;
 
@@ -171,7 +164,7 @@ class Job {
 
         const run = await this.safe_call(
             path.join(this.runtime.pkgdir, 'run'),
-            [this.main, ...this.args],
+            [this.files[0].name, ...this.args],
             this.timeouts.run
         );
 
diff --git a/api/src/executor/routes.js b/api/src/executor/routes.js
index 3cb4fe2..2bcd0d7 100644
--- a/api/src/executor/routes.js
+++ b/api/src/executor/routes.js
@@ -1,4 +1,4 @@
-// {"language":"python","version":"3.9.1","files":{"code.py":"print('hello world')"},"args":[],"stdin":"","compile_timeout":10, "run_timeout":3, "main": "code.py"}
+// {"language":"python","version":"3.9.1","files":{"code.py":"print('hello world')"},"args":[],"stdin":"","compile_timeout":10, "run_timeout":3}
 // {"success":true, "run":{"stdout":"hello world", "stderr":"", "error_code":0},"compile":{"stdout":"","stderr":"","error_code":0}}
 
 const { get_latest_runtime_matching_language_version } = require('../runtime');
@@ -55,8 +55,7 @@ module.exports = {
             timeouts: {
                 run: req.body.run_timeout,
                 compile: req.body.compile_timeout
-            },
-            main: req.body.main
+            }
         });
 
         await job.prime();
diff --git a/cli/commands/execute.js b/cli/commands/execute.js
index b4baf35..6adaf7e 100644
--- a/cli/commands/execute.js
+++ b/cli/commands/execute.js
@@ -52,7 +52,6 @@ exports.handler = async function(argv){
         language: argv.language,
         version: argv['language-version'],
         files: files,
-        main: path.basename(argv.file),
         args: argv.args,
         stdin,
         compile_timeout: argv.ct,
diff --git a/readme.md b/readme.md
index 190464e..08f15da 100644
--- a/readme.md
+++ b/readme.md
@@ -194,10 +194,9 @@ Content-Type: application/json
 This endpoint requests execution of some arbitrary code.
 - `language` (**required**) The language to use for execution, must be a string and must be installed.
 - `version` (**required**) The version of the language to use for execution, must be a string containing a SemVer selector for the version or the specific version number to use.
-- `files` (**required**) An array of files containing code or other data that should be used for execution.
+- `files` (**required**) An array of files containing code or other data that should be used for execution. The first file in this array is considered the main file.
 - `files[].name` (**required**) The name of the file to upload, must be a string containing no path.
 - `files[].content` (**required**) The content of the files to upload, must be a string containing text to write.
-- `main` (**required**) The name of one of the files provided that should be considered the main source file which will be used as the entrypoint, must be a string and be the name of a file in `files`.
 - `stdin` (**required**) The text to pass as stdin to the program. Must be a string, can be left blank.
 - `args` (**required**) The arguments to pass to the program. Must be an array.
 - `compile_timeout` (**required**) The maximum time allowed for the compile stage to finish before bailing out in milliseconds. Must be a number.
@@ -213,7 +212,6 @@ This endpoint requests execution of some arbitrary code.
             "content": "console.log(process.argv)"
         }
     ],
-    "main": "my_cool_code.js",
     "stdin": "",
     "args": [
         "1",