Conning

# Conning

<!-- mcp-name: io.github.EranYonai/conning -->

<p align="center"><img src="docs/brand/handler-hero.svg" alt="Handler, the Conning mascot: a friendly cartoon glove working puppet strings on three lab VMs" width="360"></p>

**A light, local SSH controller for humans and agents.** Conning is one small CLI and MCP server on
your own machine. It runs commands, long jobs and file copies on your test machines over plain
OpenSSH. You drive it from a terminal; your agent (Claude Code, Codex, Cursor...) gets the same four
commands as MCP tools, with identical output. Conning holds the keys, so the agent never sees a
password, and you approve anything risky.

```sh
conn targets add lab --host 10.0.0.5 --user tester   # asks for the rest, pins the host key
conn run lab uname -a                                 # exit code first, then the output
conn run -t lab apt upgrade                           # you, at a terminal: live, like ssh -t
conn targets mode lab auto                            # optional: let the agent run anything there
```

> **Status: early (0.6).** Linux, macOS and Windows targets work, with long jobs, transfers, jump
> hosts and approvals. See [docs/design.md](docs/design.md) for every decision so far.

## What it is

- **Light.** One Python package and no daemon: the MCP server runs on stdio when your agent starts it.
  Four tools cost about 1k tokens a turn. Results lead with the exit code and are capped at 8 KB by
  default, with a handle to page the rest; fan-out to many targets collapses identical results.
- **Local.** It runs next to you and your agent. Targets only need inbound SSH, and nothing gets
  installed on them. Secrets stay where they are (OS keychain, `op://`, ssh-agent): the target file
  holds references, and no tool ever returns a secret.
- **SSH.** Plain OpenSSH underneath, never your `~/.ssh/config`: a generated config per target, pinned
  host keys, forwarding off, jump hosts. Windows targets need OpenSSH and PowerShell 7.
- **For humans and agents.** Each target has a mode, `ask` or `auto`. In `ask`, read-only commands and
  your allow rules run, and anything else waits for you; "always allow" remembers two words, so
  `systemctl status` never lets through `systemctl stop`. Only you grant trust: in the agent
  client's prompt, in `conn watch` or at your terminal.

## Install

```sh
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
```

For Tab completion that reads the target (its files, commands and shell history), run
`conn completion install` once; it adds one line to your bash, zsh or fish rc file, and `conn doctor`
reminds you if it's missing. Set `history = false` on a target to keep its shell history out (D53).

The MCP server needs no install at all:

```sh
claude mcp add conning -- uvx conning mcp
```

### Or run the server in Docker

```sh
docker run -i --rm --network host \
  -v ~/.config/conning:/conning \
  -v "$SSH_AUTH_SOCK":/ssh-agent -e SSH_AUTH_SOCK=/ssh-agent \
  ghcr.io/eranyonai/conning:latest
```

The image carries Python, the OpenSSH client and Conning, and nothing else. Targets, pinned host
keys and job output live on the `/conning` volume, and `conn` runs as that folder's owner, so files it
writes there stay yours on the host. On Docker Desktop for Mac, forward the agent with
`-v /run/host-services/ssh-auth.sock:/ssh-agent` instead. Two things stay on your machine (D46):

- **Approving.** `conn targets add`, `conn approve`, `conn allow` and turning on `auto` need your terminal. Install
  the CLI on the host and point it at the same folder: `CONNING_HOME=~/.config/conning conn approve a:1`.
  Approving in the agent client works from the container as usual.
- **Secrets.** The OS keychain is not reachable from a container, so use `env:` or `op://`
  references, or forward your ssh-agent as above and use a key. `docker run --rm ... conning doctor`
  checks the rest.

Targets on a lab LAN or VPN need `--network host` (Linux) or a route the container can use.

## The agent's four tools

| Tool | What it does |
|---|---|
| `targets(filter?, check?)` | One line per target: name, OS, shell, user, tags, mode. Never a host or secret. |
| `run(target, cmd \| argv, wait=30, max_bytes=8192, ...)` | Runs on one target, a list or `tag:<tag>`. Exit code first. Still running after `wait` seconds: returns a job id (`wait=0` is async). |
| `read(id, wait?, range?, grep?, signal?)` | Long-polls a job for new lines, pages a saved output, or reads a remote file. |
| `transfer(source, dest)` | Copies files between `local:<path>` and `<target>:<path>`, checked by sha256. |

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-help:start -->
```
# Agent commands (same output as the MCP tools)

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] [-t]
                [--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.

# Targets (conn targets <verb>)

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

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

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

conn targets mode target [{ask,auto}]
    Show or set ask or auto; auto runs anything without asking and needs a human.

conn targets rename old new
    Human only: rename a target; its host keys, password and pending work follow.

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

# Trust

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

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 (no terminal needed).

# This machine

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 completion {bash,zsh,fish,install}
    Tab completion that reads the target; conn completion install turns it on in your shell.

conn help [--markdown]
    Show this help; --markdown prints the block cached in README.md.
```
<!-- conn-help:end -->

A target is one login on one machine. To use the same machine as another user, add it again:
`conn targets 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 behind a bastion names it as its jump host: add the bastion as a target first, then
`conn targets add lab --host 10.0.0.5 --user tester --jump gw`. Every hop gets its own login and its own pinned
host key, and `conn targets import` keeps a `ProxyJump` to another host it imports. The bastion is a target the
agent can see too; in `ask` mode it can only run read-only commands there without you.

A target you add with `conn targets 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

| Mode | What the agent can do | Default for |
|---|---|---|
| `ask` | The built-in read-only