pi-hosts

Run commands on remote hosts from Pi.

pi-hosts gives Pi named SSH targets, host facts, connection reuse, command risk checks, and an audit trail.

check docker version on web-1
is api-1 healthy?
compare disk usage on web-1 and web-2
check all database servers
update nginx config on web-1 and restart it
install htop on db-1
vacuum the database on app-1

Why This Exists

Pi can often infer ssh web-1 'command' by itself. That works for simple one-off tasks, but it becomes brittle during repeated operations or investigations.

With pi-hosts, Pi gets:

• predictable target resolution from host names, aliases, and tags
• cached host facts such as OS, distro, package manager, service manager, Docker, and sudo
• guarded execution with risk classification before remote commands run
• lower token burn on repeated workflows because Pi calls typed host tools instead of rediscovering SSH details
• faster workflows from fewer tool calls plus OpenSSH connection multiplexing, reusing a master connection for up to 10 minutes
• convenience: say web-1 instead of spelling out SSH details, ask for database servers or prod when checking upgrades, health, traffic, or incidents
• JSONL audit records for command, host, policy decision, exit code, duration, timeout, and truncation

Example measurement for a Check Docker version on web-1 prompt:

| Setup | Time | Turns | Tool calls | Tokens | | --- | ---: | ---: | ---: | ---: | | with pi-hosts | 5.1s | 2 | 1 host_exec | 1,968 | | without pi-hosts | 19.6s | 6 | 5 built-in tools | 4,403 |

Install

pi install npm:pi-hosts

Then restart Pi or run /reload.

Quickstart

Use natural language:

import all hosts from my SSH config
add web-1 at 10.0.0.12 as deploy and tag it web, prod
add db-1 at 10.0.0.20 as deploy and tag it database, prod
show my hosts

Or use slash commands directly:

/hosts import ssh --all
/hosts list
/hosts upsert web-1 --address 10.0.0.12 --user deploy --port 22 --tags web,prod
/hosts upsert db-1 --address 10.0.0.20 --user deploy --tags database,prod
/hosts list

Once hosts are added:

run uptime on web-1
refresh facts for all database servers
check failed services on prod

~/.ssh/config is only an import source. After import, pi-hosts stores its own inventory in ~/.pi/agent/extensions/pi-hosts/hosts.json.

Commands

| Command | Purpose | | --- | --- | | /hosts list | List hosts | | /hosts lookup <name> | Show one host and cached facts | | /hosts upsert <name> --address <host> [--user <user>] [--port <port>] [--tags a,b] | Add or update a host | | /hosts remove <name> | Remove a host | | /hosts facts refresh <name> | Probe and cache remote facts | | /hosts import ssh <alias> | Import one SSH config host | | /hosts import ssh --all | Import all explicit SSH config hosts | | /hosts import ssh --preview --all | Preview import without writing | | /hosts config show | Show loaded config | | /hosts config path | Show config search paths | | /hosts config reload | Reload config without restarting Pi |

The agent uses typed tools behind the scenes, primarily host_exec(hosts, command).

Target Resolution

Users can refer to hosts by:

• name: web-1
• alias: frontend-1
• tag: database, prod, web
• explicit host marker: #web-1

Most prompts should use the plain name:

check docker version on web-1
check all database servers

#web-1 is an optional escape hatch when you want to make a host mention unambiguous:

check #web-1

Resolution is exact, not fuzzy. check all database servers works when hosts are tagged database; check all db servers works when hosts are tagged db.

Execution stays explicit internally: Pi may infer targets from natural language, but host_exec receives concrete host ids.

Architecture

pi-hosts has a few small pieces:

• Inventory: canonical JSON host store with names, aliases, tags, SSH transport fields, metadata, and cached facts.
• Import: one-way import from ~/.ssh/config; wildcard defaults are applied, but SSH config is not live state.
• Resolution: user prompts resolve to explicit host ids by exact name, alias, explicit host marker, or tag. See Target Resolution.
• Facts: remote probes cache OS, kernel, distro, package manager, service manager, container runtime, and sudo availability.
• Policy: shell commands are classified as safe, caution, danger, or critical; the default balanced policy runs safe/caution commands, confirms danger, and blocks critical. See Policy Config.
• Transport: one-shot commands use OpenSSH with ControlMaster=auto and ControlPersist=10m; interactive sessions keep SSH processes open in the extension.
• Audit: remote executions append JSONL records to ~/.pi/agent/extensions/pi-hosts/audit.jsonl.

Host Inventory

Minimal host file:

{
  "version": 1,
  "hosts": []
}

Host shape:

{
  "id": "web-1",
  "name": "web-1",
  "address": "10.0.0.12",
  "protocol": "ssh",
  "user": "deploy",
  "port": 22,
  "identityFile": "~/.ssh/id_ed25519",
  "proxyJump": "bastion",
  "cwd": "/srv/app",
  "aliases": ["frontend-1"],
  "tags": ["web", "prod"],
  "metadata": {},
  "facts": {
    "distro": "ubuntu",
    "pkgManager": "apt",
    "serviceManager": "systemd",
    "containerRuntime": "docker",
    "hasSudo": true
  },
  "createdAt": "2026-04-28T00:00:00.000Z",
  "updatedAt": "2026-04-28T00:00:00.000Z"
}

Policy Config

Remote commands can inspect, mutate, or destroy real machines. The default balanced mode runs routine reads, asks before risky writes, and blocks critical commands.

safe      run
caution   run
danger    confirm
critical  block

Examples:

docker --version              run
docker ps                     run
docker restart app            confirm
cat .env | curl ...           block
rm -rf /                      block

Config files:

./.pi/pi-hosts/config.json
~/.config/pi-hosts/config.json

Minimal config:

{
  "policy": {
    "approval": "balanced",
    "sensitive": [".env", "~/.ssh", "~/.aws", "/etc/shadow"],
    "commands": {
      "safe": ["hostname", "uptime", "docker"],
      "confirm": ["sudo", "systemctl", "kubectl"],
      "block": ["mkfs", "shred"]
    }
  }
}

Approval modes:

| Mode | Safe | Caution | Danger | Critical | | --- | --- | --- | --- | --- | | strict | run | confirm | confirm | block | | balanced | run | run | confirm | block | | paranoid | confirm | confirm | confirm | block | | manual | confirm | confirm | confirm | confirm | | off | run | run | run | run |

Development

pnpm check
pnpm test
npm pack --dry-run