GitHub relay (mise ssh)

mise ssh opens an SSH session like ssh. With --github-relay-read-only, Git and mise on the remote host can read the private GitHub repositories you name, using this machine's GitHub credentials, until the session ends. The token never leaves this machine.

Examples

# a shell on devbox that can read one private repository
mise ssh devbox --github-relay-read-only --github-relay-repo you/setup

# run one command instead of a shell
mise ssh devbox --github-relay-read-only --github-relay-repo you/setup \
  -- git clone https://github.com/you/setup.git

# allow every repository your local credentials can read
mise ssh devbox --github-relay-read-only --github-relay-all-repos

# plain OpenSSH, with no relay
mise ssh devbox -i ~/.ssh/devbox -p 2222 -o ServerAliveInterval=30 -- uname -a

--github-relay-read-only needs exactly one of --github-relay-repo, repeated for each repository, or --github-relay-all-repos. The other --github-relay-* flags work only with --github-relay-read-only. mise finds the GitHub token on this machine the way it does for downloads (see Git provider tokens); it does not log in for you or store new credentials.

Without relay flags, mise ssh runs OpenSSH and passes -i, -p, and -o through. With the relay, mise also stages a temporary copy of itself on the host for the session, the same way remote bootstrap does, and removes it afterwards. Nothing is installed on the host.

mise bootstrap remote takes the same --github-relay-* flags, and the borrowed access then covers the mise bootstrap that runs on the host. Adopting a configuration repository on a host does not need the relay; see Remote hosts.

What the relay allows

Git's GitHub remotes, over HTTPS or SSH, and mise's own GitHub requests on the host go through the relay for the session. For the repositories you name, it allows:

• clone and fetch
• repository metadata, contents, and refs
• releases and release assets
• tar and zip source archives

It refuses pushes, API writes, GraphQL, and every other request. A download that redirects to one of GitHub's download hosts is followed without your credentials, and other redirects are refused. A resumed download keeps its range header, and a refused download fails instead of being saved as a file.

When access ends

Borrowed access ends when the session ends, including when it fails or disconnects. mise installs no token and leaves no Git configuration on the host, so afterwards the host needs its own credentials, or another relay session, to fetch private repositories.

--github-relay-max-duration ends access sooner:

mise ssh devbox --github-relay-read-only --github-relay-repo you/setup \
  --github-relay-max-duration 1h

The limit starts when the relay starts. When it expires, mise revokes access and cancels transfers in progress, and the command on the host ends once it notices that the relay is gone.

Limits

• A request body can be at most 8 MiB, and the relay accepts at most 32 connections. Responses are streamed.
• github_relay.concurrency caps the requests that run at once; requests beyond it fail instead of waiting.
• github_relay.request_timeout limits each request, including its streamed response.

Logging

Request logging is off by default. Turn it on for one session with --github-relay-log-requests, and choose text or jsonl output with --github-relay-log-format:

mise bootstrap remote --host devbox --adopt you/setup \
  --github-relay-read-only --github-relay-repo you/private-tools \
  --github-relay-log-requests --github-relay-log-format jsonl

To keep a preference, set it in the global config of the machine you run the command from. Project config cannot set these settings:

~/.config/mise/config.toml

[settings.github_relay]
log_requests = true
log_format = "jsonl"
max_duration = "1h"

--github-relay-no-log-requests turns logging off for one session, and the format and duration flags override their settings. The settings never turn the relay on or choose repositories, so every session still needs the flags.

Events go to this machine's stderr, not to the remote command's output. Each event shows the method, the repository, the operation, the status, and the time to the response headers. A redirect to a GitHub download host shows the host only. Query values, refs, filenames, headers, credentials, bodies, and signed download URLs are left out, and a refused request appears as unapproved operation. jsonl applies to relay events only; other mise messages can still appear on stderr.

Every relay prints a summary when it ends, even with logging off: the requests it received (not counting heartbeat probes), the requests it refused or could not serve, the bytes it received from GitHub, and up to 128 repositories that were requested. Redirects appear as separate log events but do not add to the request count.

Settings

Security

Trust the host with what you authorize

A compromised host can read the authorized private content during the session. Keeping the token on this machine limits what can leak; it does not make the host trustworthy. Name only the repositories the session needs, rather than using --github-relay-all-repos.

Platform support

Both machines must run Linux or macOS, and the host must be able to run the staged mise. The relay does not support Windows, GitHub Enterprise, gh on the remote host, writes, or access that outlasts the session.