Fix · GitHub and Git

Permission denied (publickey) when pushing over SSH

Blocks your workNot checked against the vendor's current screens

What you may see

The push says permission denied (publickey)
It says could not read from the remote repository
I just got a new computer or changed my key

Most likely cause

GitHub does not know the SSH key of this computer, or the key is not loaded.

Check first (about two minutes)

Run ssh -T git@github.com and read the answer; a greeting with your user name means the key works.
Run ssh-add -l to see if a key is loaded.

The fix prompt

What you type here never leaves your browser. The search runs on this page, and nothing is sent to a server or to an AI.

The exact error or what you see

What you did before it happened

Kept only in this browser, on this device. Keys and passwords are removed before anything is saved.

Prompt language

You are a patient senior engineer who knows Git and GitHub very well and explains them to people who are not developers. I am not a developer, so explain every step in plain words and tell me exactly which button, menu or command you mean. If you are not sure about something, say so; do not guess.

Menu and button names change over time. If you cannot find a button or page I mention, say so and tell me what to look for instead of guessing.

THE PROBLEM
Permission denied (publickey) when pushing over SSH

THE EXACT ERROR OR WHAT I SEE
[paste the exact error here]

WHAT I DID BEFORE IT HAPPENED
[write in a few words what you did before it happened]

MOST LIKELY CAUSE
GitHub does not know the SSH key of this computer, or the key is not loaded.

DO THESE STEPS, IN THIS ORDER
1. Run ssh -T git@github.com and ssh-add -l and show me the output.
2. If no key exists, create one with ssh-keygen -t ed25519 -C "my label" and a passphrase, and load it with ssh-add.
3. Show me ONLY the public key (the file ending in .pub) so I can add it in my GitHub account under the settings page for SSH keys (the page may be labelled differently).
4. Test again with ssh -T git@github.com, then retry the push.
Stop and tell me if what you see does not match a step. Do not skip ahead.

CHECK THAT IT WORKED
- ssh -T git@github.com greets me by my GitHub user name.
Tell me exactly what I should see on the screen when it works.

DO NOT CHANGE
- Do not open, print or copy the private key file (the one without .pub).
- Anything I did not ask about: the design, the text, other pages, other settings or the data.
- Do not delete files, data or branches, do not reset or force-push, and do not rewrite history, unless you first show me exactly what would be lost and I say yes.
- Do not paste, print or ask me to paste a password or secret key into this chat. If one is needed, tell me which settings page of the right service to store it in.

WHEN YOU FINISH
Explain in simple words what you changed (file by file or setting by setting), why you changed it, and how I can undo it.

Paste it into Claude, ChatGPT, Gemini or Cursor, then follow what it says.

After you tried it, did it work?

Steps

Run ssh -T git@github.com and ssh-add -l and show me the output.
If no key exists, create one with ssh-keygen -t ed25519 -C "my label" and a passphrase, and load it with ssh-add.
Show me ONLY the public key (the file ending in .pub) so I can add it in my GitHub account under the settings page for SSH keys (the page may be labelled differently).
Test again with ssh -T git@github.com, then retry the push.

Do not do this

Never send the private key to anyone or paste it anywhere.
Do not switch off host key checks to "get past" the error.
Do not open, print or copy the private key file (the one without .pub).

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