Keypairs

SSH keypairs are used to securely access compute instances.

A keypair has two parts:

Public key, uploaded to redu.cloud
Private key, kept on your machine

Never upload or share your private key.

With an agent (MCP)

Connect the redu MCP, then just ask your agent. Your agent can run ssh-keygen locally if you do not already have a key, then call import_keypair to register the public key on redu. It can also list_keypairs to check what exists and delete_keypair to remove old ones.


Set up an SSH key for me if I do not have one, and register it on redu.

1. Generate an SSH key

If you already have an SSH keypair, you can reuse it. Otherwise, generate a new one.

Linux / macOS


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

Windows PowerShell


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

Your public key file usually ends with .pub.

Example:


~/.ssh/id_ed25519.pub

2. Add an SSH key

Go to:

Menu → Compute → Virtual Machines → SSH Keypairs

Click Add SSH key, then choose one of these modes:

Mode	Use it when	Required input
Import public key	You already control the matching private key	SSH key name and the complete public key
Generate Keypair	You need a new keypair	SSH key name

When importing a key, paste only the single-line public key. Public keys usually start with ssh-ed25519, ssh-rsa, or ecdsa-sha2-. Never paste a private key into the console.

When generating a keypair, redu creates an RSA key and shows the private .pem file once. Download or copy it before closing the window; it cannot be retrieved later.

The SSH keys list shows the name, fingerprint, key type, creation date, and available actions. Only public-key registrations are stored there.

Keep private keys outside the repository and restrict their filesystem permissions. Anyone with the private key may be able to access instances launched with its public key.

3. Use a keypair when creating an instance

When creating an instance:

Enable SSH access
Select your keypair
Launch the instance

After the instance is ready, use the SSH command shown in the UI.

Example:


ssh -p <port> ubuntu@<host>

You can copy the command from:

Compute → Virtual Machines → Actions → Copy SSH

The command uses the correct public host, mapped port, and image username. If Copy SSH is unavailable, wait until the instance is active and confirm that it has a public DNS entry.

If your private key has a passphrase, SSH will ask for it.

4. Import via API or MCP

You can also manage keypairs programmatically.

REST API


# Import a keypair
curl -X POST https://api.redu.cloud/v1/keypairs \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "my-keypair",
    "publicKey": "ssh-ed25519 AAAA..."
  }'
 
# List keypairs
curl https://api.redu.cloud/v1/keypairs \
  -H "x-api-key: YOUR_API_KEY"
 
# Delete a keypair
curl -X DELETE https://api.redu.cloud/v1/keypairs/my-keypair \
  -H "x-api-key: YOUR_API_KEY"

MCP (Claude Code)

With the redu.cloud MCP server connected, ask Claude:


Import my SSH key, here it is: ssh-ed25519 AAAA...

your agent will call import_keypair and confirm the name. You can then create instances immediately:


Create a medium Ubuntu instance using that keypair.

This is the recommended flow for AI-driven deployments. The check_agent_prerequisites tool will remind you to import a keypair if none are found.

5. Delete a keypair (UI)

Only delete keypairs that are no longer needed.

Go to:

Menu → Compute → Virtual Machines → SSH Keypairs

Then:

Open Actions for the SSH key
Choose Delete SSH key
Confirm the deletion

Deleting the registration prevents it from being selected for future launches. It does not remove the key from instances that were already created, so make sure those instances have another access path before deleting it.

Troubleshooting

Permission denied publickey

Check that:

You selected the correct keypair when creating the instance
You are using the correct username for the image, such as ubuntu
Your security group allows SSH on port 22
Your private key permissions are correct


chmod 600 ~/.ssh/id_ed25519

Invalid public key format

The public key must be a single line starting with ssh-ed25519 or ssh-rsa.

Lost private key

Private keys cannot be recovered from redu.cloud.

Generate a new keypair and use it for new instances.