Conning

A control room for your agent's test machines. Your agent (Claude Code, Codex, Cursor...) stays on your own laptop. Conning holds the keys to your lab VMs and gives the agent four lean tools to run commands and move files there. The agent never sees a password, and you approve anything risky.

Status: pre-alpha (M2 done). Running commands, long jobs, remote file reads and transfers work over OpenSSH, with pinned host keys, password or key auth, approvals and leases. You can approve in the agent client, in conn watch or with conn approve; conn doctor checks your setup. Long jobs run detached on Linux, macOS and Windows targets, and conn mcp install sets up claude, codex, cursor, opencode or pi. See docs/design.md for every decision so far.

Why

Putting an agent harness inside every CLI on every remote machine is redundant. Developers already have a capable agent on their own machine. What's missing is a safe, token-lean way for that agent to reach the machines it tests on:

• No secrets in context. Targets hold references to the OS keychain, op:// or ssh-agent. Secrets are resolved inside Conning at the last moment and never returned by any tool.
• Lean results. Exit code first, output capped at 8 KB by default (the agent may ask for more, up to a ceiling), with a handle to page the rest. Fan-out to many targets collapses identical results.
• Guardrails in code, not in the prompt. Each target has a mode (observe, ask, lease). Commands outside the allowlist wait for your approval; "always allow" remembers two words, so systemctl status never lets through systemctl stop.
• Plain OpenSSH underneath. Linux and Windows (OpenSSH + PowerShell 7), pinned host keys, forwarding forced off.

Install

uv tool install conning        # or: pipx install conning
conn mcp install claude        # or codex, cursor, opencode, pi: adds the server and denies raw ssh/scp

The MCP server needs no install at all:

claude mcp add conning -- uvx conning mcp

The agent's four tools

Agents without MCP can use the same commands through the conn CLI; the output is identical.

For agents: CLI reference

This block is generated by conn help --markdown, so you don't need to call --help. A test keeps it in sync with the code.

conn targets [--check] [filter]
    List targets: name, OS, shell, user, tags, mode. Never hosts or secrets.

conn run [--wait WAIT] [--timeout TIMEOUT] [--cwd CWD] [--shell]
                [--max-bytes MAX_BYTES] [--grep GREP]
                target [argv ...]
    Run a command on one target, a list, or tag:<tag>. Exit code first.

conn read [--wait WAIT] [--range RANGE] [--grep GREP] [--signal {INT,TERM,KILL}]
                 [--max-bytes MAX_BYTES]
                 id
    Page a job (new lines only), a saved output, an approval, or a remote file.

conn transfer source dest
    Copy files: local:<path> to <target>:<path>, or back. sha256 checked.

conn add [--host HOST] [--user USER] [--like TARGET] [--port PORT]
                [--auth {ssh-agent,key,password}] [--secret SECRET] [--key KEY]
                [--os {linux,windows,darwin}] [--mode {observe,ask,lease}] [--tag TAG] [--retry]
                name
    Add a target. Without a terminal it is saved as pending until a human approves it.

conn approve [--always] what
    Human only: make a pending target live, or allow a pending command a:<id>.

conn import [--match MATCH]
    Import hosts from ~/.ssh/config as pending targets (unsafe options dropped).

conn rm name
    Remove a target and its pinned host key.

conn test name
    Probe a target: reachability, OS, shell, pinned host key.

conn lease [--minutes MINUTES] name
    Human only: give a target a full shell for a time box (1-60 minutes).

conn allow target [words ...]
    Human only: let a command run without asking (no words: list the rules).

conn deny target words [words ...]
    Remove an allow rule, so the command asks again.

conn watch [--history HISTORY] [--no-prompt]
    Live control room: every command on every target, job output, approval prompts.

conn doctor
    Check this machine's setup: config and state dirs, ssh, keychain, targets.

conn mcp [--approve-in-client | --no-approve-in-client] <serve|install> ...
    Run the MCP server on stdio, or install it into an agent client.

conn help [--markdown]
    Show this help; --markdown prints the block cached in README.md.

A target is one login on one machine. To use the same machine as another user, add it again: conn add lab-tester --like lab --user tester copies the host, port, OS and tags and asks for the new user's password. conn targets shows which user each target uses.

A target you add with conn add from an agent session is saved as pending. It does nothing until the human runs conn approve <name>, which shows the host, the pinned host-key fingerprint and where the secret comes from.

A command outside a target's allowlist returns status=pending_approval id=a:<id>, and a desktop notification tells the human. They answer in one of three places (allow once, always allow its first two words, or deny), and the agent picks up the result with read a:<id>:

• In the agent client: any MCP client that supports elicitation shows the question before the command is queued, and an approved command runs in the same call. Clients without it fall back to the two below. If a client would answer such prompts by itself instead of asking you, run the server as conn mcp --no-approve-in-client.
• In conn watch, which also shows every command and its output as it happens.
• With conn approve a:<id> in any terminal. When you run conn run yourself at a terminal, it just asks you there and prints the result.

Read-only commands such as uname, hostname, df, ps, ls, ip addr, systemctl status and journalctl run without asking on every target; each is checked so its changing forms (hostname x, ip addr add) still ask, and safe = false in a target's entry turns the list off. conn allow <target> make test lets another command run without asking from then on; conn deny takes it back. Every command, answer and rule change lands in a hash-chained audit log, and conn doctor checks your setup when something doesn't work.

Safety model

• No tool returns a secret, adds a live target or changes policy.
• Secrets travel over stdin or the SSH channel's env, never argv. Output is redacted before it is saved.
• Remote output is marked untrusted. Shell wrappers (sh -c, python -c, sudo...) and shell syntax (;, |, $(...)) always ask.
• conn mcp install also denies the agent raw ssh/scp, so it can't go around Conning (pi has no permission rules, so there it only adds the server).
• The audit log is hash-chained. It runs as your user, so it is tamper-evident, not tamper-proof.

Development

uv sync
uv run pytest --cov=conning      # CI requires 95% coverage on Linux
uv run ruff check && uv run ruff format --check

After changing the CLI, refresh the README block with uv run conn help --markdown.

Docs

• docs/design.md: the design and every decision, with its status.
• docs/build-log.html: how the design came together, as a blog post.

License

Apache-2.0