SSH Remote — a DeepSeek Harness plugin

English | Русский

Operate any number of VPS servers over SSH from inside DeepSeek Harness: a server registry, the /ssh command, ssh_run / ssh_put / ssh_get, four read-only navigation tools, a destructive-command guard, secret redaction, and an action log.

Authentication is by key where one is configured, and by a stored password otherwise. The plugin ships no server addresses: you add your own, so one installation works with any number of machines.

Status: 0.1.0, tested against Harness 0.2.1-rc.3 and allowed on >=0.2.1-rc.3 <0.3.0 (declared in engines.dsh). DSH is a developer preview and breaks compatibility between releases, so pin the Harness version you run.

Why this one

Most SSH tooling for an agent makes the whole session remote: the shell, the file tools and the editor are replaced by their remote counterparts, and you pick one host per workspace. This plugin is the other shape:

• Several hosts at once. ssh_run with host: "web1", then host: "db1", in the same session. Local bash/read/edit keep working on local files.
• Zero dependencies. It drives the system ssh/scp instead of reimplementing the protocol, so ~/.ssh/config, known_hosts and the agent all behave exactly as they do in a terminal.
• Guardrails on by default. Catastrophic commands never run, irreversible ones ask first, secrets are cut from output before the model sees it, and every call lands in an audit log.
• Small enough to read. Six source files, no client bundle, no build step.

If you want a full remote workspace — remote file editing, a terminal panel, LSP — use dsh-ssh, dsh-remote-ssh or dsh-ssh-ops instead. They are larger and solve a different problem.

Install

# from npm, once published
dsh plugin --profile web add dsh-plugin-ssh-remote

# from a local checkout
plugin_manager action=install_bundle target=<absolute path to this folder>

Then add servers with /ssh sync (import from ~/.ssh/config) or /ssh add.

Quick start

/ssh add                # add a server by hand
/ssh pass web1 <pass>   # only if no key is installed on that server yet
/ssh test web1          # check the connection

Then just ask the agent: "check disk usage on web1", "tail the nginx error log on web1", "copy ./dist.tar.gz to web1 and unpack it in /srv/app".

Tools

Tool	What it does	Limits
ssh_run	Run a command, return stdout, stderr and exit code.	Command policy, timeoutMs, tty, detached, logPath.
ssh_read	Read a file by line window.	offset (1-based), limit ≤ 2000; says when lines continue.
ssh_ls	List a directory.	200 entries, long: false for names only.
ssh_grep	Search file contents.	glob, maxMatches ≤ 1000, binary files skipped.
ssh_glob	Find files by name.	maxResults ≤ 2000, pattern as in find -name.
ssh_put / ssh_get	Upload or download one file.	Local path is not sandboxed (see Limits).
ssh_hosts / ssh_host_add / ssh_host_remove	Manage the registry.	Every change asks for confirmation first.

/ssh commands

/ssh                  # list servers; pick one from the list
/ssh web1             # test a server (does NOT change the default)
/ssh default web1     # make a server the default
/ssh status           # what is allowed, how login works, which server is default
/ssh add              # add a server manually
/ssh sync             # import from ~/.ssh/config
/ssh pass web1 <pass> # store a password (only for a server without a key)
/ssh nopass web1      # forget the password
/ssh lock web1        # block every operation with this server
/ssh unlock web1      # allow it again
/ssh remove web1      # drop it from the registry

Configuration

profile-patch-snippet.yml restates every key: a patch replaces the row's whole config instead of merging, so a profile-level patch must list every key it wants to keep.

Key	Default	Meaning
registryPath	$DSH_HOME/ssh-remote-hosts.json	Server registry.
secretsPath	$DSH_HOME/ssh-remote-secrets.json	Saved passwords.
auditLogPath	$DSH_HOME/ssh-remote-audit.jsonl	Action log.
askpassDir	$DSH_HOME/ssh-remote-askpass	Scratch directory for the password helper.
sshConfigPath	~/.ssh/config	Source for /ssh sync.
allowRawHosts	false	Accept an address that is not in the registry (turns the allowlist off).
sshPath / scpPath	platform default	OpenSSH clients; on Windows %SystemRoot%\System32\OpenSSH\.
connectTimeoutMs	10000	Connection timeout.
defaultTimeoutMs	120000	Default command deadline.
maxTimeoutMs	1800000	Ceiling any timeoutMs is clamped to.
maxOutputChars	60000	Per-stream output ceiling; head and tail are kept.
commandPolicy	standard	standard asks about irreversible commands; off stops asking (catastrophic ones are still refused).
multiplex	false	OpenSSH connection sharing; needs a POSIX local endpoint.

Safety model

• The registry is the allowlist. A connection needs a registered name. allowRawHosts is off by default, and even when on, an address is never substituted silently.
• Host-key checking is never relaxed. Always StrictHostKeyChecking=yes, including in password mode; a changed key stops the command and asks you to verify the fingerprint yourself.
• No interactive prompts. Key auth uses BatchMode=yes; password auth allows exactly one attempt, so a command can never hang waiting for input.
• Catastrophic commands are refused before the process starts. rm -rf /, mkfs, dd to a device, shutdown and similar are blocked even when wrapped in sudo, nohup or sh -c. Irreversible but legitimate commands (rm -rf on an absolute path, apt purge, docker system prune, DROP DATABASE) ask once, with the command, the server and the working directory shown. No answerer means no execution.
• Secrets are cut before the model sees them. Private-key blocks, AWS keys, sk-…, JWTs, password=/token=/api_key=, Authorization: Bearer … and credentials in URLs are replaced with redacted:<kind>, and the report says how many were removed.
• Every call is logged. One JSON line per client call in ssh-remote-audit.jsonl, command already redacted, rotated at 10 MB.

The command policy reads text, it does not evaluate it. rm -rf $(echo /), find / -delete, or a script uploaded with ssh_put and run afterwards are not caught. The real boundary is a dedicated server user without sudo; keep root for manual work.

Limits

• No multiplexing on Windows. Each call is a new connection, which shows up as latency. multiplex: true works only on a POSIX local endpoint.
• Local paths are not sandboxed. ssh_put can send any file your user can read. Every transfer is logged, but the local sandbox does not apply.
• No terminal, no remote editing, no LSP. These are tools, not a workspace. Use one of the plugins linked above for that.
• No ProxyJump. The registry has no jump-chain support; put the hops in ~/.ssh/config and sync, or connect to the bastion and hop manually.
• The registry is per profile. One file per $DSH_HOME; concurrent writes are serialized inside the plugin, but a manual edit during a run is picked up on the next operation.
• /ssh sync does not expand Include, Match or * patterns. Such blocks are listed as skipped rather than guessed.
• Editing the installed code needs a Harness restart. Node caches ES modules by URL, so toggling the bundle does not reload changed code.
• The /ssh interface speaks Russian. Tool descriptions — what the model reads — are English, but the /ssh output, prompts and picker labels are Russian. An English locale is the next planned change.

Tests

npm install          # one peer dependency, @deepseek-ai/schemastery, for the tests
npm test             # both suites

node test-args.mjs   # argv, failures, command policy, redaction, registry,
                     # ssh-config parser, passwords, ACL, audit, atomic writes
node test-host.mjs   # tools, policy gate, confirmation, /ssh, guard

No network, no real server: the host half runs against a fake subprocess. node test-live.mjs <name> is the optional live checklist (40 checks) against a registered server.

License

MIT. Not affiliated with DeepSeek AI.