# The `fluksio` command

```sh
pip install fluksio
```

Installs the engine and the `fluksio` command. Python 3.12 or newer, Linux or
macOS.

There is a second, smaller distribution — `fluksio-worker` — for a machine that
should only *run nodes* for an engine elsewhere. It has none of the engine in
it. See [Remote workers](workers.md).

The command is two things at once: `serve`, `enroll` and `worker` *are* an
installation, while `login`, `sync`, `run`, `runs` and `sweep` talk to one that
may be anywhere.

## Where an installation lives

`.fluksio` beside your code, found the way `.git` is: from the working
directory, or any directory above it. Two repositories on one machine are
therefore two engines, with their own flows, runs and token. `fluksio serve`
makes one where there is none, and it ignores itself from within — a
`.gitignore` of `*`, so a database and a credential cannot be committed by
accident.

`--global` uses `~/.fluksio` instead, shared by every directory. `--data-dir`
(or `FLUKSIO_HOME`) names any directory outright and wins over both.

## `fluksio serve`

Runs the engine.

```sh
fluksio serve
```

On the first start it creates an admin account and prints its password **once**.
Nothing else has to be running: no database server, no message broker, no
Docker.

| Option | Default | What it does |
|---|---|---|
| `--data-dir PATH` | `./.fluksio` (or `$FLUKSIO_HOME`) | where this installation keeps everything |
| `--host HOST` | `127.0.0.1` | what to bind |
| `--port PORT` | `8000` | what to listen on |
| `--log-level LEVEL` | `info` | uvicorn's log level |
| `--admin-email ADDR` | `admin@example.com` | the account created on first run |
| `--admin-password PW` | generated | set it instead of having one generated |
| `--enroll CODE` | — | pair with a portal as part of coming up |
| `--portal URL` | — | the portal `--enroll` redeems at |

`--enroll` with `--portal` is the one-command setup: it pairs before the engine
starts, so the connection is dialled as part of coming up rather than needing a
restart. It is skipped if the installation is already enrolled.

!!! warning "One process"

    `fluksio serve` holds the flow engine. A second one is a *second engine* —
    duplicated subscriptions, duplicated cron ticks, two webhooks answering the
    same path. Run one, and distribute work with
    [workers](workers.md) instead.

!!! note "`$HOME` on a cluster"

    A login node's home directory is often NFS, where SQLite's write-ahead log
    does not work — the database would be locked or corrupt. `fluksio serve`
    warns when it notices; point `--data-dir` at local disk.

### What it prints

```text
Created the admin account admin@example.com
  password: k3Qm-8vTpLdX
  Shown once. Change it from the dashboard.
Fluksio 0.1.0 — data in /home/you/.fluksio
  API      http://127.0.0.1:8000/api/v1
  No portal. Pair this installation with:
    fluksio enroll <code>
```

An enrolled installation says which portal it is on instead, and notes that the
dashboard is served from there rather than here.

## `fluksio enroll`

Pairs an existing installation with a portal.

```sh
fluksio enroll ABCD-1234
```

| Option | What it does |
|---|---|
| `--portal URL` | a portal of your own, instead of `https://hub.fluksio.com` |
| `--as EMAIL` | the local account a portal session arrives as |
| `--data-dir PATH` | which installation, if not the one this directory is in |

Get the code from the portal under **Installations → Add installation**. It is
single-use and expires in fifteen minutes. `--as` matters when the installation
has several superusers — without it, enrolment refuses rather than guessing.

Afterwards, `fluksio serve` dials the portal as it comes up, and keeps dialling:
a portal that restarts, a wifi that changes, a laptop that suspends and wakes
somewhere else all end the same connection, and the link is put back up without
anybody noticing. A connection that stood up and then dropped is retried at
once; one that never stood up waits a little longer each time, up to half a
minute. See [Accounts and the portal](../interface/portal.md).

## `fluksio worker`

Runs nodes for an engine elsewhere. Everything after `worker` belongs to the
agent's own parser — it is the same program `fluksio-worker` installs, so the
two are interchangeable:

```sh
fluksio worker --url wss://api.example.com/api/v1/workers/attach \
               --token "$FLUKSIO_WORKER_TOKEN" --labels gpu
```

See [Remote workers](workers.md).

## Talking to an engine

The commands below are the client half: they run wherever you work, and
address an engine over its API rather than being one — except under `--local`,
which boots one inside the command instead.

### `fluksio login`

```sh
fluksio login --url https://api.example.com
```

For an engine somewhere *else*. One you started yourself needs no login:
`fluksio serve` writes the token as it comes up and says where it put it.

The token goes in this project's `.fluksio/client.json`, or with `--global` in
`~/.fluksio/client.json`. Every command below reads it from there — nearest
first, walking up from the working directory — or from `FLUKSIO_URL` and
`FLUKSIO_TOKEN`, or from its own `--url` and `--token`. A token an older
version wrote to `~/.config/fluksio/client.json` is still read.

### `fluksio sync`

```sh
fluksio sync [PATH_OR_MODULE ...]        # default: the current directory
```

Imports what you name, collects the flows the decorators declared, and uploads
each one with a generated import shim per node. A directory that is a package
is walked; a dotted name is imported as it stands; nothing is loaded from a
file path, because the shim has to import the same way.

| Flag | What it does |
|---|---|
| `--dry-run` | print the flow documents and shims, upload nothing |
| `--no-publish` | leave the upload as a draft |
| `--force` | overwrite a flow, or a node body, that was edited on the canvas |

Every sync retires the engine's workers, including one that had nothing to
upload — a worker holds your package in memory, so an edit to it is invisible
until the process goes. See
[Getting started: data science](../getting-started/data-science.md).

### `fluksio run`

```sh
fluksio run train --lr 0.05 --seed 7 [--wait]
```

Syncs the working directory, then submits a run — so the command after an edit
is this one and nothing else. Flags that are not its own are the flow's
inputs, typed by what the flow declares them as. `--wait` blocks until the run
finishes and exits non-zero if it failed. `--follow` waits as well, and prints
the numbers the run reports as they arrive:

```text
  train.loss[14] = 3.40295e-06
```

Ctrl-C while either is waiting cancels the run on the engine rather than only
stopping the watching, and exits 130.

`--no-sync` runs what is already on the engine. Worth it in a tight loop where
you know nothing changed, since syncing retires the workers and the next call
pays its imports again. A directory that declares no flows syncs nothing and
says nothing — a flow drawn on the canvas is run the same way.

`--no-cache` executes every node, including one an earlier run already
answered. See [Stage caching](../concepts/runs.md#stage-caching).

`--local` boots the engine inside this process instead of talking to a served
one, so there is no `fluksio serve` terminal to keep open. It is the same
installation either way — the same `.fluksio`, the same database, artifacts
and run history — so a run made this way and a run made through a served
engine cache against each other. It always waits, because the engine it starts
lives exactly as long as the command. Starting one costs a few seconds of
worker pool and module reconcile, against the ~15 ms of submitting to an
engine that is already up: `--local` is for "I just want to run it", not for a
loop you are iterating in.

### `fluksio runs`

```sh
fluksio runs [--flow train] [--limit 20]
```

The runs an engine has recorded, newest first: id, status, flow, duration, the
commit of the repository it came from, and its parameters. Statuses are
coloured when a terminal is reading the output — `ok` green, `error` red,
`cached` cyan. `--local` reads the same history from an in-process engine,
without one having to be served.

### `fluksio sweep`

```sh
fluksio sweep train --param lr=0.1,0.01 --param epochs=10,50 --wait
```

Every combination of the parameter lists, submitted as one group — four runs
above, sharing a `group_id` and executing in parallel. Values are typed by the
flow's inputs, the same as `run`'s are, and `--seed`, `--no-sync`,
`--no-cache` and `--local` mean what they do there. `--wait` blocks until all
of them are finished and exits non-zero if any failed.

## What lives in the data directory

```text
.fluksio/               (or ~/.fluksio, with `--global`)
├── client.json         the token `serve` wrote, mode 600
├── .gitignore          `*` — a database and a credential, ignored from within
├── fluksio.db          SQLite: users, runs, metrics, observability, agents
├── flows/              a git repository — one directory per flow
│   ├── house/
│   │   ├── flow.json           the published structure
│   │   ├── nodes/*.py          the published node code
│   │   ├── flow.draft.json     unpublished edits, if any
│   │   └── nodes.draft/*.py
│   ├── _lib/           shared node sources
│   ├── _dashboards/    dashboards, drafts and all
│   └── requirements.txt        what the Modules screen installs
├── artifacts/          content-addressed bytes, two levels deep
├── user-venv/          the interpreter your node code runs on
├── secrets.enc         encrypted credentials, deliberately outside flows/
├── alerts.json         alert channels and rules
├── panels.json         wall-panel pairings
├── oauth-key.pem       signs agent tokens
├── cloud.json          the portal enrolment, if there is one
├── secret_key          signs sessions and derives the secrets key
└── env                 optional settings file
```

Two things follow from this layout and are worth internalising:

**`flows/` is a real git repository.** `git log` is the history of every change
anyone made to any flow. A run records the commit it ran at, so `git show` on
that hash is literally the code that produced the number.

**Backing up the data directory backs up the installation.** Everything else is
rebuildable. Copy it while the engine is stopped, or use SQLite's online backup
for the database if it is not.

## Settings

Settings come from the environment, or from an `env` file in the data
directory. The ones you are most likely to touch:

| Variable | Default | What it does |
|---|---|---|
| `DATA_DIR` | `./.fluksio` via the CLI; `~/.fluksio` with `--global` | everything below it derives from this |
| `DATABASE_URL` | SQLite in the data dir | any SQLAlchemy URL |
| `NODE_VENV` | `auto` | which interpreter node code runs on: `auto` adopts the venv Fluksio was installed into, `managed` builds one of its own, or name an interpreter |
| `REDIS_HOST` | unset | flow state in Redis instead of memory; survives a restart |
| `FRONTEND_HOST` | — | the address used in mails, OAuth metadata and panel links |
| `ENVIRONMENT` | `local` | `production` closes the interactive API schema |
| `MCP_ENABLED` | `false` | opens the [agent endpoint](agents.md) |
| `SECRET_KEY` | generated once | signs sessions, derives the secrets key |

The full list is in [Configuration](../reference/configuration.md).