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Status - ttps://www.githubstatus.com

Command palette (Command+K) - https://docs.github.com/en/get-started/using-github/github-command-palette

Code search:

Locking down your GitHub-hosted Domains - https://news.ycombinator.com/item?id=32435134

Desktop app: https://desktop.github.com - https://github.com/desktop/desktop

View raw commit/patch: add .patch to the commit URL, eg https://github.com/AlbertVilaCalvo/Android-Udacity-Popular-Movies/commit/5c1218db157fc6ce5dfd9c9e98f0522c67241963.patch

List of cool features of Git and GitHub - https://github.com/tiimgreen/github-cheat-sheet

Hub CLI - https://github.com/mislav/hub

SSH​

https://docs.github.com/en/authentication/connecting-to-github-with-ssh

To test if SSH is set up correctly run ssh -T git@github.com. It should say:

Hi AlbertVilaCalvo! You've successfully authenticated, but GitHub does not provide shell access.

If it says "git@github.com: Permission denied (publickey).", it's not.

Doing cat ~/.ssh/config should show:

Host *.github.com
  AddKeysToAgent yes
  UseKeychain yes
  IdentityFile ~/.ssh/github_personal

or

Host github.com bitbucket.org
  AddKeysToAgent yes
  UseKeychain yes
  IdentityFile ~/.ssh/id_ed25519

Misc​

If you haven't used your SSH key for a year, then GitHub will automatically delete your inactive SSH key as a security precaution. For more information, see Deleted or missing SSH keys.

Add new SSH key​

Do this when you set up a new Mac.

If you already have an SSH key, you can use it - see Checking for existing SSH keys. If you don't have a key or you don't want to use it, you need to generate a new key, add the private key (eg id_rsa) to the SSH agent, and add the public key (eg id_rsa.pub) to the account on GitHub.

You can optionally require a passphrase:

With SSH keys, if someone gains access to your computer, the attacker can gain access to every system that uses that key. To add an extra layer of security, you can add a passphrase to your SSH key.

When you generate an SSH key, you can add a passphrase to further secure the key. Whenever you use the key, you must enter the passphrase. If your key has a passphrase and you don't want to enter the passphrase every time you use the key, you can add your key to the SSH agent. The SSH agent manages your SSH keys and remembers your passphrase.

See Working with SSH key passphrases.

See detailed instructions for adding a new key at https://docs.github.com/en/authentication/connecting-to-github-with-ssh/generating-a-new-ssh-key-and-adding-it-to-the-ssh-agent#generating-a-new-ssh-key

Create a new SSH key, using the email as a comment (a label):

ssh-keygen -t ed25519 -C "your_email@example.com" # default name is id_ed25519
ssh-keygen -t ed25519 -C "your_email@example.com" -f github_personal
# If Ed25519 is not supported use
ssh-keygen -t rsa -b 4096 -C "your_email@example.com" -f github_personal

Start the ssh-agent in the background:

eval "$(ssh-agent -s)" # Agent pid 38878

Add the following to ~/.ssh/config (omitting UseKeychain if there's no passphrase):

Host github.com
  AddKeysToAgent yes
  UseKeychain yes
  IdentityFile ~/.ssh/id_ed25519

Add the private key to the ssh-agent and, if there's a passphrase, store the passphrase in the keychain with --apple-use-keychain (you are prompted to enter the passphrase then):

# No passphrase
ssh-add ~/.ssh/id_ed25519
# With passphrase
ssh-add --apple-use-keychain ~/.ssh/id_ed25519

It will say "Identity added: /Users/albert/.ssh/id_ed25519 (your_email@example.com)". For more info, see How can I permanently add my SSH private key to Keychain so it is automatically available to ssh?.

Finally, add the public key to GitHub.com. See instructions at https://docs.gzithub.com/en/authentication/connecting-to-github-with-ssh/adding-a-new-ssh-key-to-your-github-account. Go to https://github.com/settings/keys and click 'New SSH key'. Give it a name, choose 'Authentication Key' (we are not signing commits) and paste the public key:

pbcopy < ~/.ssh/id_ed25519.pub

Multiple SSH keys (for different GitHub accounts) on the same computer​

Eg if we have a work GitHub account and want to commit on a personal repository on the work computer.

Resources followed:

Here I assume that I already have the SSH setup for the work GitHub account.

Note that this approach does not use add multiple entries to the ~/.ssh/config file. It's for specific repositories. It has the advantage that you don't need to change how you git clone a repository.

Create the new SSH key for the personal account: ssh-keygen -t ed25519 -C "mypersonal@email.com" -f github_personal. (If Ed25519 is not supported, use ssh-keygen -t rsa -b 4096 -C "mypersonal@email.com" -f github_personal.)

Copy github_personal.pub with pbcopy < github_personal.pub and add it at the GitHub website at https://github.com/settings/keys.

Add the SSH to keychain permanently with ssh-add --apple-use-keychain github_personal if there's a passphrase, otherwise use ssh-add github_personal. You'll need to type the passphrase if there's one. It will say "Identity added: github_personal (mypersonalemail@gmail.com)"

Update: to avoid the error "ERROR: Permission to AlbertVilaCalvo/XYZ.git denied to AlbertWork. fatal: Could not read from remote repository. Please make sure you have the correct access rights and the repository exists." I've had to add this line to the ~/.zshrc: ssh-add --apple-use-keychain ~/.ssh/github_personal.

Update 2: instead of adding ssh-add ... to ~/.zshrc, this error may be fixed by having a ~/.ssh/config file with:

Host github.com
  AddKeysToAgent yes
  UseKeychain yes
  IdentityFile ~/.ssh/github_personal

Clone the personal repository you want to contribute to. If you get the error "Please make sure you have the correct access rights and the repository exists", clone the repo with a specific SSH key with GIT_SSH_COMMAND="ssh -i ~/.ssh/github_personal" git clone git@github.com:AlbertVilaCalvo/zshrc.git. source

Once the repo is cloned, configure it to use the personal SSH key: git config core.sshCommand 'ssh -i ~/.ssh/github_personal'. I took this from https://stackoverflow.com/a/50746763/4034572

Important: don't forget to set the personal email on that repository, otherwise the work account will appear as a contributor on the personal repository: git config --local user.email mypersonal@email.com

Hide personal email address​

tip

Change the author of the last commit with git commit --amend --reset-author.

Check "Block command line pushes that expose my email" in https://github.com/settings/emails.

To change the email for a particular repository (not globally), go to https://github.com/settings/emails, copy the GitHub-provided noreply email address and then do:

git config user.email "{ID}+{username}@users.noreply.github.com "

You can check the current email with git config [--global] user.email.

Docs:

Trending repositories this week: https://github.com/trending?since=weekly&spoken_language_code=en

Alternatives (from https://news.ycombinator.com/item?id=32681319):

Shortcuts​

https://docs.github.com/en/get-started/accessibility/keyboard-shortcuts

Press ? to view the shortcuts.

Browse code in web editor​

Docs: https://docs.github.com/en/codespaces/the-githubdev-web-based-editor

CLI​

https://cli.github.com/

https://docs.github.com/en/github-cli

https://github.com/cli/cli

Markdown​

It does not accept inline styles (style="margin-right: 10px;"), see https://github.com/github/markup

The HTML is sanitized, aggressively removing things that could harm you and your kin—such as script tags, inline-styles, and class or id attributes.

Alerts:

Repository settings​

General​

Pull requests

[ ] Allow merge commits
[✓] Allow squash merging
Default commit message: Pull request title and commit details → With this setting you need to copy-paste the PR description to the commit message, which is a bit annoying, but you get all the commit history.
[✓] Allow rebase merging

[✓] Always suggest updating pull request branches

[✓] Allow auto-merge → This is only enabled for public repositories or if you have GitHub Pro/Team/etc.

[✓] Automatically delete head branches

Advanced Security​

TODO

Rulesets​

Prebuilt rulesets ready to import - https://github.com/github/ruleset-recipes

Define whether collaborators can delete or force push to the branch and set requirements for any pushes to the branch, such as passing status checks or a linear commit history.

There are two ways to make a branch protected:

  1. Classic branch protection rules. See About protected branches.
  2. Rulesets (new). See About rulesets.

The advantages of rulesets over branch protection rules are listed at About rulesets and protected branches.

There are two types of rulesets: branch and tag.

Protect main branch ruleset​

GitHub Branch Protection Setup: Securing Your Main Branch with the New UI - https://tech-bridge-log.com/blog/github-branch-protection-setup

When you create a new repository, you'll see an alert with a button:

info

Your main branch isn't protected Protect this branch from force pushing or deletion, or require status checks before merging. View documentation.

Protect this branch

To fix the issue, go to Settings → Rules → Rulesets and click "New ruleset". Select "New branch ruleset". Set this:

  • Ruleset name: Protect main branch
  • Enforcement status: Active
  • Target branches: Include default branch
  • Branch rules. Check the following:
    • Restrict deletions (checked by default)
    • Require linear history
    • Require a pull request before merging
      • Require conversation resolution before merging
      • Allowed merge methods: Squash and Rebase
    • Block force pushes (checked by default)

This creates the following JSON:

{
  "id": 15207640,
  "name": "Protect main branch",
  "target": "branch",
  "source_type": "Repository",
  "source": "AlbertVilaCalvo/RecipeManager",
  "enforcement": "active",
  "conditions": {
    "ref_name": {
      "exclude": [],
      "include": ["~DEFAULT_BRANCH"]
    }
  },
  "rules": [
    {
      "type": "deletion"
    },
    {
      "type": "non_fast_forward"
    },
    {
      "type": "required_linear_history"
    },
    {
      "type": "pull_request",
      "parameters": {
        "required_approving_review_count": 0,
        "dismiss_stale_reviews_on_push": false,
        "required_reviewers": [],
        "require_code_owner_review": false,
        "require_last_push_approval": false,
        "required_review_thread_resolution": true,
        "allowed_merge_methods": ["squash", "rebase"]
      }
    }
  ],
  "bypass_actors": []
}

Status checks and path filters​

From https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks#handling-skipped-but-required-checks and https://docs.github.com/en/actions/reference/workflows-and-actions/workflow-syntax#example-including-paths

If a workflow is skipped due to path filtering, branch filtering or a commit message, then checks associated with that workflow will remain in a "Pending" state. A pull request that requires those checks to be successful will be blocked from merging.

Due to path filtering, a pull request that only changes a file in the root of the repository will not trigger this workflow and is blocked from merging. On the pull request, you would see "Waiting for status to be reported."

Allow required checks to pass/skip, not fail, when using path filtering - https://github.com/orgs/community/discussions/44490

Path filtering on required pull request checks - https://github.com/orgs/community/discussions/26857

How can I handle a required check that isn't always triggered? - https://stackoverflow.com/questions/77996177/how-can-i-handle-a-required-check-that-isnt-always-triggered

Branch protection: status checks for workflows with path conditions - https://stackoverflow.com/questions/79348923/branch-protection-status-checks-for-workflows-with-path-conditions

Merge queue​

https://humanwhocodes.com/blog/2026/04/improving-developer-velocity-github-merge-queue/