Connecting Judge0
Judge0 is the code execution engine behind programming assignments. When a learner runs or submits code, Edmingle sends it to Judge0, which compiles it, runs it against your test cases, and reports what passed. Without it connected, programming assignments cannot run.
Judge0 is not included with Edmingle. You bring your own, and you pay the provider directly.
Getting a Judge0 instance
Judge0 is available through RapidAPI, where you subscribe to a plan and get a host address and an API key. You can also self-host it, in which case you supply your own address and key.
Either way you need two things before you start:
- The host address, for example
judge0-ce.p.rapidapi.com. - The API key for that subscription.
Edmingle sends your key with each request as a RapidAPI-style header, so a RapidAPI subscription works out of the box.
Pick your plan based on executions, not learners. Every Run and every Submit is a separate execution, and each test case in an assignment counts as one more. A 30-learner class submitting a 5-test-case assignment twice each is 300 executions, before anyone presses Run.
Connect it
- Go to Settings → Apps and open the Others tab.
- Find the Judge0 card and click Connect.
- Enter:
| Field | Required | Notes |
|---|---|---|
| Judge0 API Key | Yes | Hidden as you type. Use the eye icon to check it |
| Judge0 URL | Yes | The host address, without https:// |
- Click Save and Activate.
Edmingle checks the details against your Judge0 instance as you save. On success you see "Judge0 activated successfully" and the card shows an ACTIVE badge.
If the key or address is wrong, saving returns an error and programming assignments stay switched off. Fix the details and save again. There is no separate test button, so saving successfully is your confirmation that the connection works.
The URL field takes the host only. Do not paste a full URL with a path, and do not include a trailing slash.
What it unlocks
Once connected, Programming Assignment becomes usable as a material type inside any course module. See Creating a Programming Assignment.
The Programming Assignment tile is visible and clickable even when Judge0 is not connected, and nothing in the authoring screens warns you. You can build an entire assignment, publish it, and only discover the problem when a learner tries to run their code. Connect Judge0 first.
Changing or removing the connection
- Manage reopens the form so you can update the key or the address. The button then reads Save.
- Disconnect removes it. The confirmation says: "You can no longer use programming assignments . Are you sure you want to deactivate JudgeO Integration?"
[!Important] Disconnecting stops every programming assignment in every course immediately. Existing assignments and past submissions are not deleted, but learners cannot run or submit code until you reconnect.
What it costs
Judge0 is billed by your provider, not by Edmingle. Nothing is deducted from your Edmingle wallet when code runs.
The Coding Compiler box on the Utility Wallet screen shows Coming Soon and is not in use. Compiler usage is not metered or charged by Edmingle today.
Troubleshooting
| Symptom | What to check |
|---|---|
| Saving the integration fails | The key or host is wrong, or your Judge0 instance is unreachable. Test the host and key against your provider's dashboard |
| Learners see an error about an invalid key, but the key is correct | The same message appears when Judge0 is unreachable, over quota, or timing out. Check your provider's status and remaining quota before assuming the key is bad |
| Every learner suddenly scores zero on every test case | Almost always the compiler, not the code. Check that the integration is still active and that your Judge0 plan has quota left |
| A learner's submission seems to have vanished | If Judge0 is down at the moment of submitting, the attempt may not be recorded at all. Ask them to submit again once the connection is restored |
| Runs are slow or time out | Judge0 queues executions. A burst of submissions at a deadline can back the queue up, so check your plan's concurrency limits |
Before a graded assessment with a whole cohort, run one submission yourself and check your Judge0 quota. Most exam-day failures are a quota that ran out, not a broken integration.
What's next
Continue to Creating a Programming Assignment.