git@github.com: Permission Denied (publickey)

git@github.com: Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

Git tried to talk to GitHub over SSH, and GitHub didn't recognise any key your computer offered. It's an authentication problem, not a problem with your code or repository.

Step 1: Test the connection

ssh -T git@github.com

Hi yourname! You've successfully authenticated → SSH works. Skip to "SSH works but push still fails."
Permission denied (publickey) → keep going.

For details on what's happening, add -v:

ssh -vT git@github.com

Look for lines like Offering public key: /Users/you/.ssh/id_ed25519. If no key is offered, you don't have one or the agent isn't loading it.

Step 2: Do you have a key?

ls ~/.ssh

You're looking for a pair like id_ed25519 and id_ed25519.pub. If there's nothing, create one:

ssh-keygen -t ed25519 -C "you@example.com"

Press Enter to accept the default location; a passphrase is recommended. (SSH keys explained)

Step 3: Add the public key to GitHub

Copy the public key (the .pub file — never the other one):

cat ~/.ssh/id_ed25519.pub

On GitHub: Settings → SSH and GPG keys → New SSH key, paste it, save. Then test again with ssh -T git@github.com.

Step 4: Make sure the agent offers it

If the key has a non-default name or a passphrase, the SSH agent may not have it loaded:

eval "$(ssh-agent -s)"
ssh-add ~/.ssh/id_ed25519

On macOS, add --apple-use-keychain to remember the passphrase. To make it permanent, tell SSH which key to use for GitHub in ~/.ssh/config:

Host github.com
  User git
  IdentityFile ~/.ssh/id_ed25519
  IdentitiesOnly yes

(The SSH config file explained)

SSH works but push still fails

If ssh -T greets you but push says "permission denied" or "repository not found":

Wrong account. The greeting shows which GitHub user you authenticated as. If you have a personal and a work account, you may be using the key for the wrong one. Use separate keys and host aliases in ~/.ssh/config.
No access to the repo. You need to be a collaborator (or a member of the org with access). Private repos return "not found" rather than "forbidden" when you lack access.
Org requires SSO. Some organisations require you to authorise your SSH key for SSO in GitHub's key settings.
Deploy keys only work for the one repository they were added to.

On a server or in an AI agent's environment

The same error on a remote server or container usually means the server has no key of its own. Options:

Create a key on the server and add it to GitHub (as a deploy key for one repo, or to a bot account).
Use SSH agent forwarding from your machine (ssh -A), so the server borrows your key without storing it.

Don't copy your personal private key onto shared servers.

Or use HTTPS instead

Check which URL your repo uses:

git remote -v

git@github.com:... is SSH; https://github.com/... is HTTPS. HTTPS with the GitHub CLI is often simplest:

gh auth login
git remote set-url origin https://github.com/you/app.git

Note: GitHub doesn't accept your account password over HTTPS ("Support for password authentication was removed"). Use gh auth login, a credential manager, or a personal access token.

The summary

Test with ssh -T git@github.com.
Create a key if you have none; add the .pub file to GitHub.
Load it into the agent, or point to it in ~/.ssh/config.
If SSH works but push fails, check which account you are and whether you have access.
HTTPS with gh auth login is a fine alternative.

EasySpawn gives each server its own Git setup, so Claude Code can clone, pull and push without you copying personal keys around. See how it works or join the waitlist.

"Permission Denied (publickey)" on GitHub: How to Fix It