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Walkthrough — Stage 8: Push to GitHub ​

Command: git push -u origin main ​

bash
git push -u origin main

What's happening:

Four tokens, each with a job:

  • git push — the command. It uploads commits from your local branch to a remote branch.
  • -u — the "set upstream" flag. It tells Git to remember a default mapping between your local main and the remote's main on origin. After this one-time flag, you can just run git push or git pull with no arguments.
  • origin — the remote to push to. This is the name you gave in Stage 7 when you ran git remote add origin ....
  • main — the local branch to push. You are pushing your main to the remote's main.

Everything you have ever committed to main now exists on GitHub.

What the -u flag actually does ​

Without -u, Git has no default for git push or git pull on this branch — you would have to type the remote and branch every time. With -u, Git writes a small block to .git/config:

[branch "main"]
    remote = origin
    merge = refs/heads/main

From then on, Git knows that main is linked to origin/main. You only set this up once per branch, the first time you push it.

Authentication on the first push ​

The first git push on a new machine triggers an authentication prompt. Modern GitHub does not accept account passwords over HTTPS — you need a personal access token (PAT).

How to create one:

  1. On github.com, go to Settings → Developer settings → Personal access tokens → Tokens (classic).
  2. Click Generate new token (classic).
  3. Give it a name like "box-runner tutorial."
  4. Check the repo scope.
  5. Generate and copy the token (it starts with ghp_).
  6. When Git asks for your password during push, paste the token.

Your operating system's credential helper usually caches the token, so you only do this once.

Reading the push output ​

A successful push prints something like:

Enumerating objects: 12, done.
Counting objects: 100% (12/12), done.
...
To https://github.com/<your-username>/box-runner.git
 * [new branch]      main -> main
branch 'main' set up to track 'origin/main'.

The last two lines are the important ones:

  • [new branch] main -> main — a brand-new branch was created on the remote.
  • branch 'main' set up to track 'origin/main' — the -u flag did its job.