CS 264 (Fall 2026): GitHub classroom setup report

Prepared 16 September 2026 for Koushik Sen (GitHub ksenxx), organization Berkeley-CS-264.

1. Why this is not "GitHub Classroom"

GitHub retired GitHub Classroom on 28 August 2026; classroom.github.com now redirects to the retirement notice. GitHub names two successors: Codio (commercial, LMS integration) and Classroom 50 (free, open source, from the CS50 / Fifty Foundation team). Classroom 50 was chosen because it costs nothing, keeps all data inside your own GitHub organization, and reproduces the GitHub Classroom workflow: per-student private repositories created from a template, invite links, autograding through GitHub Actions, a submissions dashboard, CSV score export and inline feedback pull requests.

Classroom 50 has no server. Every piece of state is ordinary GitHub data in your organization:

Concept	Where it lives on GitHub
Classrooms, assignments, scores	Private repository `Berkeley-CS-264/classroom50` (`cs264/classroom.json`, `assignments.json`, `roster.csv`, `scores.json`)
Who is enrolled / who is staff	GitHub teams `classroom50-cs264`, `-teacher`, `-hta`, `-ta`
A student's submission	Commits and Releases in `Berkeley-CS-264/cs264-hw1-<username>`
The assignment list students read when accepting	GitHub Pages site of the `classroom50` repository

2. What was done

Step	Result
Verify `ksenxx` owns `Berkeley-CS-264`	Yes, role admin (owner)
Widen the `gh` CLI token to the scopes Classroom 50 needs (`admin:org`, `repo`, `workflow`)	Done (you authorized device code 7374-8780)
Install `gh teacher` and `gh student` extensions on this machine	Done
Create the fine-grained service token `classroom50-Berkeley-CS-264` (resource owner: the org; all repositories; Contents, Actions, Workflows, Administration read/write; org Members read; expires 16 Sep 2027)	Created in your Chrome session; stored as the encrypted Actions secret `CLASSROOM50_SERVICE_TOKEN` on `Berkeley-CS-264/classroom50`. Not written to disk.
`gh teacher init Berkeley-CS-264`: lock down org member privileges (base permission none, no repo deletion/transfer/visibility change by members), enable Actions, $0 Actions overage cap, allow Actions to open PRs, create the private `classroom50` repo with 5 workflows	Steps 1 to 8 done
`init` step 5 (org branch rulesets) and step 9 (GitHub Pages on the private repo)	Blocked by the Free plan (HTTP 403 "Upgrade to GitHub Team" and HTTP 422 "Your current plan does not support GitHub Pages"). See section 3.
Create classroom `cs264` ("CS 264: Implementation of Programming Languages", term Fall-2026) and its four teams	Done; `ksenxx` added to the teacher team
Register assignment `hw1` from template `Berkeley-CS-264/cs264-hw1`	Done; the student team was granted read on the private template
Autograding for `hw1`	Python 3.12 runner; step 1 installs `pysmt` and `z3-solver` (0 points); step 2 runs `python3 -m pytest -q` against the template's `tests/` (100 points); passing threshold 50%

What now exists in the organization. Solid boxes were created today. The dashed box is created on demand when a student accepts. The yellow box is the one component that cannot work until the organization is on the Team plan.

3. The one remaining blocker: the organization's plan

Berkeley-CS-264 is on GitHub Free for organizations. Classroom 50 publishes the assignment list that gh student accept and the accept link read from the private classroom50 repository through GitHub Pages, and GitHub only allows Pages on private repositories for organizations on the Team or Enterprise plan. Consequences today:

The three Publish Pages workflow runs in classroom50 failed ("Ensure GitHub Pages has been enabled"), so students cannot accept hw1 yet.
Organization rulesets (which stop students from force-pushing over their submission history and let TAs merge feedback PRs) could not be installed.
The web app at classroom50.org will list the organization as "Not supported".

GitHub Education status. Verified teachers get GitHub Team for their organizations at no cost. Your ksenxx account had no GitHub Education application when I checked. I pre-filled the teacher application in your Chrome (role Teacher, school University of California, Berkeley, email ksen@berkeley.edu), but after you replied "submitted" the page github.com/settings/education/benefits still showed Start an application rather than a pending application, so it likely did not go through. Please open that page, click Start an application, allow the browser location prompt, click Continue, and upload proof of faculty status (a photo of your Cal ID or an appointment letter). Approval usually takes a few days, sometimes up to two weeks.

After approval, in this order:

Go to github.com/education/teachers and upgrade Berkeley-CS-264 to GitHub Team using the education benefit (no charge).
Re-run the setup; it is idempotent and will finish the skipped steps (Pages, rulesets, branch protection, workflow permissions) without touching the stored secret:
```
gh teacher init Berkeley-CS-264 --yes
gh teacher audit Berkeley-CS-264
```
Apply the four settings GitHub has no API for, at organization Settings, Member privileges: App access requests to Members only; uncheck Allow repository admins to install GitHub Apps; Projects base permission No access; uncheck Allow repository administrators to rename branches protected by organization rules.
Confirm the service token end to end: gh workflow run probe-token.yaml --repo Berkeley-CS-264/classroom50 (a green run means every permission is in place).

If you would rather not wait for verification, the Team plan can also be paid for directly (per user per month) from the organization's billing page; the education benefit can replace it later.

4. Day-to-day commands

All of these run on this machine, where gh is authenticated as ksenxx. The same actions are available in the web app at classroom50.org once the plan is upgraded.

Add students

# one student by GitHub username (sends the org invitation and enrolls them)
gh teacher roster add Berkeley-CS-264 cs264 <username> --first-name Ada --last-name Lovelace --email ada@berkeley.edu

# whole class from a CSV with header: username,first_name,last_name,email,section
gh teacher roster import Berkeley-CS-264 cs264 roster.csv

# students whose GitHub usernames you do not know yet: invite by email, one address per line
gh teacher roster invite Berkeley-CS-264 cs264 --file emails.txt
gh teacher roster sync Berkeley-CS-264 cs264 --write     # later: record who accepted

gh teacher roster list Berkeley-CS-264 cs264

GitHub limits organizations on the Free plan (or younger than one month) to 50 invitations per day, 500 otherwise.

Add TAs

gh teacher staff add Berkeley-CS-264 cs264 <username> --role ta     # or --role hta for a head TA

Add the next homework

gh teacher assignment add Berkeley-CS-264 cs264 hw2 \
  --name "Homework 2" \
  --template Berkeley-CS-264/cs264-hw2 \
  --due 2026-10-15T23:59:00-07:00 \
  --runtime reports/cs264-classroom/hw1-runtime.json \
  --tests   reports/cs264-classroom/hw1-tests.json

The template repository must have the Template repository flag set (as cs264-hw1 already does) and must not contain .github/workflows/autograde.yaml. To add a due date to hw1, re-run its assignment add with --due, re-passing --template, --runtime and --tests (a re-add rebuilds the whole entry).

Collect and download

gh workflow run collect-scores.yaml --repo Berkeley-CS-264/classroom50   # refresh cs264/scores.json
gh teacher download Berkeley-CS-264 cs264 hw1                           # clone every student repo locally

Control grading cost

The default grades every push to main; each run bills at least one Actions minute against the organization's quota (2,000 minutes per month on Free, 3,000 on Team) and the $0 overage cap set today means grading simply stops when the quota is exhausted. To grade only explicit submissions:

gh teacher assignment submission-mode Berkeley-CS-264 cs264 hw1 --tag

5. What students do

A copy-ready handout is in reports/cs264-classroom/student-instructions.md. In short:

gh extension install foundation50/gh-student
gh student login
gh student accept Berkeley-CS-264 cs264 hw1        # creates Berkeley-CS-264/cs264-hw1-<username>
# ... work, commit ...
gh student submit                                  # or plain git push to main

Browser alternative: classroom50.org/Berkeley-CS-264/cs264/assignments/hw1/accept. Scores appear as a Release on the student's repository (tag submit/<timestamp>-<sha>) and as a commit status.

6. Things to know

Students can read the template. Accept works by granting the student team read access to cs264-hw1, including its history. Never commit a solution (or a commit that once contained one) to a template repository.
Grading files are tamper-proof, not secret. Anything you put in classroom50/cs264/autograders/hw1/ is served by the organization's Pages site. Keep reference solutions out of it, and use failure-details: actual-only on tests whose expected output would give the answer away.
The autograder for hw1 runs the template's own tests/. Students receive those tests, so they can see exactly what is checked. For hidden tests, put them under cs264/autograders/hw1/ in the classroom50 repository and run python3 -m pytest -q "$CLASSROOM50_BUNDLE_DIR".
The service token expires 16 September 2027. Rotate with gh teacher rotate-service-token Berkeley-CS-264.
Students cannot see scores inside the web app (a GitHub cross-origin limitation); point them at their repository's Releases page.
Renaming a student repository breaks tracking. Tell students not to.

7. Files produced

reports/cs264-classroom/index.html: this report
reports/cs264-classroom/student-instructions.md: handout for students
reports/cs264-classroom/hw1-runtime.json, hw1-tests.json: the grading configuration registered for hw1, reusable for later homeworks

Sources

GitHub Classroom retirement notice (28 Aug 2026)
Classroom 50 wiki: Prerequisites, How Classroom 50 Works, CLI Teacher Guide, Assignment Templates, Autograding Basics, Known Limitations, GitHub Integration
Apply to GitHub Education as a teacher and GitHub's plans
EECS course page for CS 264