One installation per project, and no login to reach it

Two things a local install should not have asked for.

`fluksio serve` now signs you in. Logging in to your own machine was a
formality — the password was printed by the same process that would have
checked it, and the database it authenticates against sits in the directory
the token goes into — so `serve` mints the token itself and says where it put
it. `fluksio login` is left for an engine somewhere else.

And an installation is `.fluksio` beside the code, found the way `.git` is,
rather than one `~/.fluksio` for the machine. A repository with its own venv
was already getting its own engine; it now gets its own flows, run history and
token too, instead of three repositories sharing one database and fighting
over one port. `--global` asks for the shared one, `--data-dir` still names
any directory, and when both exist the banner says which you are looking at
and how to reach the other.

The directory ignores itself from within — a `.gitignore` of `*`, the way uv
writes one into `.venv` — because it holds a credential and a database, and
neither belongs in anybody's history. The token is written mode 600. A login
an older version wrote to ~/.config/fluksio is still read, so nothing that
worked stops working.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012ue1tkFWB1bcGy3aWhCKpU

backend/README.md

@@ -9,8 +9,17 @@ pip install fluksio
 fluksio serve
 ```
 
+Then login once (the token is stored on your device) with the credentials shown after the previous command
+
+```sh
+fluksio login --url http://127.0.0.1:8000
+```
+
 and you're ready to go!
-Fluksio keeps a SQLite database, a git repository of your flows and an artifact store under `~/.fluksio`, and prints an admin password once upon start.
+
+Fluksio keeps a SQLite database, a git repository of your flows and an artifact
+store in a `.fluksio` beside your code — one installation per project, found
+the way `.git` is. It prints an admin password once, and signs you in itself.
 
 ## For data science
 
@@ -45,10 +54,9 @@ train = Flow("train", nodes=[prepare, fit, evaluate],
 ```
 
 Fluksio will automatically infer the order of nodes based on the inputs and outputs you defined.
-When everything is set, you can access a dashboard as follows:
+When everything is set, you can launch your first run as follows:
 
 ```sh
-fluksio login --url http://127.0.0.1:8000
 fluksio sync myresearch
 fluksio run train --lr 0.05 --wait
 ```

backend/fluksio/cli.py

@@ -20,6 +20,7 @@ import os
 import secrets
 import sys
 from pathlib import Path
+from typing import Any
 
 import fluksio
 
@@ -41,12 +42,37 @@ def _say(message: str = "") -> None:
     print(message, flush=True)
 
 
-def _data_dir(raw: str | None) -> Path:
+def _data_dir(raw: str | None, shared: bool = False) -> Path:
-    path = Path(raw).expanduser() if raw else DEFAULT_HOME.expanduser()
+    """Which installation this command is for.
+
+    A repository with its own venv wants its own engine too — its own flows,
+    its own run history, its own token — so the default is a `.fluksio` beside
+    the code, found the way `.git` is. `--global` asks for the shared one
+    instead, and `--data-dir` names any directory outright.
+    """
+    from fluksio.sdk.client import find_data_dir, ignore_self
+
+    if raw:
+        path = Path(raw).expanduser()
+    elif shared:
+        path = DEFAULT_HOME.expanduser()
+    else:
+        found = find_data_dir()
+        path = found if found is not None else Path.cwd() / ".fluksio"
     path.mkdir(parents=True, exist_ok=True)
+    ignore_self(path)
     return path.resolve()
 
 
+def _mention_other_installation(data_dir: Path) -> None:
+    """Say when there is a second engine, so neither goes looking lost."""
+    shared = DEFAULT_HOME.expanduser().resolve()
+    if data_dir == shared or not (shared / "fluksio.db").exists():
+        return
+    _say(f"  Note     {shared} holds another installation; this one is separate.")
+    _say("           `fluksio serve --global` runs that one instead.")
+
+
 def _warn_if_networked(path: Path) -> None:
     """A cluster's $HOME is often NFS, and SQLite's WAL does not work there."""
     try:
@@ -161,8 +187,35 @@ def _print_new_admin(email: str, password: str) -> None:
     _say("  Shown once. Change it from the dashboard.")
 
 
+#: How long the token `serve` writes for its own machine is good for. Long,
+#: because the thing it saves you from is logging in again, and it is rewritten
+#: on every start anyway — an engine left running for a year is the only case
+#: this has to cover.
+LOCAL_TOKEN_DAYS = 365
+
+
+def _sign_in(admin_id: Any, url: str, data_dir: Path) -> Path:
+    """Write the credential for the engine this command is about to start.
+
+    Logging in to your own machine is a formality: the password was printed by
+    this same process, and the database it authenticates against is in the
+    directory the token goes into. So it costs nothing to be honest about it
+    and hand the client a token, rather than asking somebody to type back
+    something we just told them.
+    """
+    from datetime import timedelta
+
+    from fluksio.core import security
+    from fluksio.sdk.client import write_config
+
+    token = security.create_access_token(
+        admin_id, expires_delta=timedelta(days=LOCAL_TOKEN_DAYS)
+    )
+    return write_config(url, token, data_dir)
+
+
 def cmd_serve(args: argparse.Namespace) -> int:
-    data_dir = _data_dir(args.data_dir)
+    data_dir = _data_dir(args.data_dir, args.shared)
     _prepare(data_dir)
 
     from sqlmodel import Session
@@ -175,8 +228,9 @@ def cmd_serve(args: argparse.Namespace) -> int:
         admin, generated = ensure_superuser(
             session, email=args.admin_email, password=args.admin_password
         )
+        admin_id, admin_email = admin.id, admin.email
         if generated:
-            _print_new_admin(admin.email, generated)
+            _print_new_admin(admin_email, generated)
 
     if args.enroll:
         if not args.portal:
@@ -194,9 +248,15 @@ def cmd_serve(args: argparse.Namespace) -> int:
     from fluksio.flow import modules
     from fluksio.main import app
 
+    # The client talks to this engine, and 0.0.0.0 is not an address to talk
+    # to — it is a statement about which interfaces to listen on.
+    reachable = "127.0.0.1" if args.host in ("0.0.0.0", "::", "") else args.host
+    url = f"http://{reachable}:{args.port}"
+    token_path = _sign_in(admin_id, url, data_dir)
+
     config = cloud_config.load()
     _say(f"Fluksio {fluksio.__version__} — data in {data_dir}")
-    _say(f"  API      http://{args.host}:{args.port}{'/api/v1'}")
+    _say(f"  API      {url}/api/v1")
     # Which environment node code imports from is the thing a data scientist
     # most needs to know at this moment, and the answer differs depending on
     # how Fluksio was installed. Saying it costs one line.
@@ -215,6 +275,9 @@ def cmd_serve(args: argparse.Namespace) -> int:
     else:
         _say("  No portal. Pair this installation with:")
         _say("    fluksio enroll <code> --portal https://hub.example.com")
+    _say(f"  Signed in as {admin_email}")
+    _say(f"           token in {token_path}")
+    _mention_other_installation(data_dir)
 
     # One process: it holds the flow engine, and a second worker would be a
     # second engine — duplicated subscriptions, cron ticks and webhooks.
@@ -223,7 +286,7 @@ def cmd_serve(args: argparse.Namespace) -> int:
 
 
 def cmd_enroll(args: argparse.Namespace) -> int:
-    data_dir = _data_dir(args.data_dir)
+    data_dir = _data_dir(args.data_dir, args.shared)
     _prepare(data_dir)
     result = _enroll(args.portal, args.code, args.as_email)
     if result == 0:
@@ -248,7 +311,13 @@ def _parser() -> argparse.ArgumentParser:
         sub.add_argument(
             "--data-dir",
             default=os.environ.get("FLUKSIO_HOME"),
-            help=f"where this installation keeps everything (default {DEFAULT_HOME})",
+            help="where this installation keeps everything (default: ./.fluksio)",
+        )
+        sub.add_argument(
+            "--global",
+            dest="shared",
+            action="store_true",
+            help=f"use the shared installation at {DEFAULT_HOME} instead",
         )
 
     serve = subparsers.add_parser("serve", help="run the engine")

backend/fluksio/sdk/cli.py

@@ -17,9 +17,10 @@ from typing import Any
 
 from fluksio.sdk import FLOWS, Flow, SyncError
 from fluksio.sdk.client import (
+    GLOBAL_DATA_DIR,
     ApiError,
     Client,
-    config_path,
+    data_dir,
     login,
     origin_of,
     repo_root,
@@ -104,13 +105,15 @@ def discover(targets: list[str]) -> list[Flow]:
 
 
 def cmd_login(args: argparse.Namespace) -> int:
+    """Only needed for an engine somewhere else — `serve` signs you in here."""
     email = args.email or input("Email: ")
     password = args.password or getpass.getpass("Password: ")
+    directory = GLOBAL_DATA_DIR.expanduser() if args.shared else data_dir()
     try:
-        login(args.url, email, password)
+        path = login(args.url, email, password, directory=directory)
     except ApiError as exc:
         return _fail(f"could not log in: {exc.detail}")
-    _say(f"Logged in to {args.url}; the token is in {config_path()}.")
+    _say(f"Logged in to {args.url}; the token is in {path}.")
     return 0
 
 
@@ -263,10 +266,18 @@ def add_parsers(subparsers: Any) -> None:
         )
         sub.add_argument("--token", default="", help="override the stored token")
 
-    parser = subparsers.add_parser("login", help="store a token for an engine")
+    parser = subparsers.add_parser(
+        "login", help="store a token for an engine elsewhere"
+    )
     parser.add_argument("--url", default="http://localhost:8000")
     parser.add_argument("--email", default="")
     parser.add_argument("--password", default="")
+    parser.add_argument(
+        "--global",
+        dest="shared",
+        action="store_true",
+        help="store it for the machine rather than this project",
+    )
     parser.set_defaults(func=cmd_login)
 
     parser = subparsers.add_parser(

backend/fluksio/sdk/client.py

@@ -17,21 +17,72 @@ from typing import Any
 
 from fluksio.sdk import MARKER, Flow, SyncError
 
-__all__ = ["Client", "RunHandle", "SyncReport", "config_path", "login", "sync"]
+__all__ = [
+    "Client",
+    "RunHandle",
+    "SyncReport",
+    "config_path",
+    "data_dir",
+    "find_data_dir",
+    "ignore_self",
+    "login",
+    "sync",
+    "write_config",
+]
 
 API = "/api/v1"
 #: A run is over when it reaches one of these.
 DONE = frozenset({"ok", "error", "cancelled", "abandoned"})
 
 
-def config_path() -> Path:
+#: What a project-local installation is called, beside `.venv` and `.git`.
-    """Where ``fluksio login`` leaves the engine it talked to."""
+DATA_DIR_NAME = ".fluksio"
+
+#: The shared one, for a machine that wants a single engine rather than one
+#: per repository. `fluksio serve --global` is how you ask for it.
+GLOBAL_DATA_DIR = Path("~/.fluksio")
+
+
+def find_data_dir(start: Path | None = None) -> Path | None:
+    """The nearest project-local installation, walking up from ``start``.
+
+    The same search `.git` and `.venv` get, and for the same reason: which
+    installation you mean is a fact about where you are standing, not about
+    which machine you are on. Several repositories on one device each keep
+    their own flows, runs and token this way rather than sharing one.
+    """
+    directory = (start or Path.cwd()).resolve()
+    for candidate in (directory, *directory.parents):
+        local = candidate / DATA_DIR_NAME
+        if local.is_dir():
+            return local
+    return None
+
+
+def data_dir(start: Path | None = None) -> Path:
+    """The installation this working directory belongs to."""
+    found = find_data_dir(start)
+    return found if found is not None else GLOBAL_DATA_DIR.expanduser()
+
+
+def config_path(directory: Path | None = None) -> Path:
+    """Where the token for an installation lives — beside the data it opens.
+
+    Not a single file per machine: a token is for one engine, and with an
+    installation per repository there is more than one. Keeping it inside the
+    data directory means the client finds the credential for the engine whose
+    directory it is standing in, without either having to be told.
+    """
+    return (directory or data_dir()) / "client.json"
+
+
+def _legacy_config_path() -> Path:
+    """Where `fluksio login` used to write, before installations were local."""
     base = os.environ.get("XDG_CONFIG_HOME") or str(Path.home() / ".config")
     return Path(base) / "fluksio" / "client.json"
 
 
-def _stored() -> dict[str, str]:
+def _read(path: Path) -> dict[str, str]:
-    path = config_path()
     if not path.exists():
         return {}
     try:
@@ -41,6 +92,15 @@ def _stored() -> dict[str, str]:
     return data if isinstance(data, dict) else {}
 
 
+def _stored() -> dict[str, str]:
+    """The nearest credential: this project's, then the machine's."""
+    for path in (config_path(), _legacy_config_path()):
+        found = _read(path)
+        if found:
+            return found
+    return {}
+
+
 class ApiError(Exception):
     """The engine refused, with what it said."""
 
@@ -247,7 +307,37 @@ class RunHandle:
         return f"RunHandle({self.id!r}, status={self.status!r})"
 
 
-def login(url: str, email: str, password: str, timeout: float = 30.0) -> str:
+def ignore_self(directory: Path) -> None:
+    """Keep an installation out of the repository it sits in.
+
+    It holds a token and a database, neither of which belongs in anybody's
+    history. A `.gitignore` of `*` inside the directory ignores it from within,
+    so nothing has to be added to the project's own — the same thing `uv` does
+    for the venv it builds.
+    """
+    marker = directory / ".gitignore"
+    if not marker.exists():
+        directory.mkdir(parents=True, exist_ok=True)
+        marker.write_text("# A Fluksio installation: a database, and a token.\n*\n")
+
+
+def write_config(url: str, token: str, directory: Path | None = None) -> Path:
+    """Store the credential for an engine, readable only by its owner."""
+    path = config_path(directory)
+    path.parent.mkdir(parents=True, exist_ok=True)
+    ignore_self(path.parent)
+    path.write_text(json.dumps({"url": url.rstrip("/"), "token": token}, indent=2))
+    path.chmod(0o600)
+    return path
+
+
+def login(
+    url: str,
+    email: str,
+    password: str,
+    timeout: float = 30.0,
+    directory: Path | None = None,
+) -> Path:
     """Exchange credentials for a token and remember the engine."""
     import httpx
 
@@ -258,12 +348,7 @@ def login(url: str, email: str, password: str, timeout: float = 30.0) -> str:
     )
     if response.status_code >= 400:
         raise ApiError(response.status_code, _detail(response))
-    token = str(response.json()["access_token"])
+    return write_config(url, str(response.json()["access_token"]), directory)
-    path = config_path()
-    path.parent.mkdir(parents=True, exist_ok=True)
-    path.write_text(json.dumps({"url": url.rstrip("/"), "token": token}, indent=2))
-    path.chmod(0o600)
-    return token
 
 
 # ---------------------------------------------------------------------------

backend/tests/sdk/test_paths.py

@@ -0,0 +1,91 @@
+"""Which installation a command is for, and where its token lives.
+
+A repository with its own venv gets its own engine, so "which one" is a fact
+about the working directory rather than about the machine.
+"""
+
+import json
+from pathlib import Path
+
+import pytest
+
+from fluksio.sdk import client
+
+
+@pytest.fixture
+def elsewhere(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> Path:
+    """A working directory with no installation above it."""
+    monkeypatch.chdir(tmp_path)
+    monkeypatch.setenv("XDG_CONFIG_HOME", str(tmp_path / "xdg"))
+    monkeypatch.setattr(client, "GLOBAL_DATA_DIR", tmp_path / "home" / ".fluksio")
+    return tmp_path
+
+
+def test_a_project_local_installation_is_found_from_below(elsewhere: Path):
+    (elsewhere / ".fluksio").mkdir()
+    deep = elsewhere / "src" / "pkg" / "sub"
+    deep.mkdir(parents=True)
+
+    assert client.find_data_dir(deep) == elsewhere / ".fluksio"
+    assert client.config_path(client.data_dir(deep)).parent.name == ".fluksio"
+
+
+def test_the_nearest_one_wins(elsewhere: Path):
+    """An installation inside another belongs to the directory it is in."""
+    (elsewhere / ".fluksio").mkdir()
+    inner = elsewhere / "inner"
+    (inner / ".fluksio").mkdir(parents=True)
+
+    assert client.find_data_dir(inner) == inner / ".fluksio"
+
+
+def test_with_none_above_it_the_shared_one_answers(elsewhere: Path):
+    assert client.find_data_dir() is None
+    assert client.data_dir() == elsewhere / "home" / ".fluksio"
+
+
+def test_a_token_is_written_only_for_its_owner(elsewhere: Path):
+    path = client.write_config("http://127.0.0.1:8000", "abc", elsewhere / ".fluksio")
+
+    assert json.loads(path.read_text()) == {
+        "url": "http://127.0.0.1:8000",
+        "token": "abc",
+    }
+    # It is a credential sitting in somebody's project directory.
+    assert path.stat().st_mode & 0o077 == 0
+    # And one nothing can commit by accident.
+    assert (path.parent / ".gitignore").read_text().endswith("*\n")
+
+
+def test_the_credential_beside_the_data_is_the_one_used(elsewhere: Path):
+    client.write_config("http://127.0.0.1:8131", "local", elsewhere / ".fluksio")
+
+    assert client._stored()["token"] == "local"
+
+
+def test_a_login_from_before_installations_were_local_still_works(elsewhere: Path):
+    """`fluksio login` wrote to XDG once; that must not stop answering."""
+    legacy = client._legacy_config_path()
+    legacy.parent.mkdir(parents=True)
+    legacy.write_text(json.dumps({"url": "http://elsewhere:8000", "token": "old"}))
+
+    assert client._stored()["token"] == "old"
+
+
+def test_a_local_credential_wins_over_the_legacy_one(elsewhere: Path):
+    legacy = client._legacy_config_path()
+    legacy.parent.mkdir(parents=True)
+    legacy.write_text(json.dumps({"url": "http://elsewhere:8000", "token": "old"}))
+    client.write_config("http://127.0.0.1:8131", "local", elsewhere / ".fluksio")
+
+    assert client._stored()["token"] == "local"
+
+
+def test_ignoring_itself_leaves_an_existing_gitignore_alone(elsewhere: Path):
+    directory = elsewhere / ".fluksio"
+    directory.mkdir()
+    (directory / ".gitignore").write_text("mine\n")
+
+    client.ignore_self(directory)
+
+    assert (directory / ".gitignore").read_text() == "mine\n"

backend/tests/test_cli.py

@@ -86,3 +86,33 @@ def test_run_arguments_are_typed_by_the_flow_they_are_for() -> None:
 
     with pytest.raises(SyncError, match="not an input of this flow"):
         _params(definition, ["--nonesuch", "1"])
+
+
+def test_serve_uses_the_installation_the_directory_belongs_to(
+    tmp_path: Path, monkeypatch
+) -> None:
+    """A repository with its own venv gets its own engine, not the machine's."""
+    from fluksio import cli
+
+    monkeypatch.chdir(tmp_path)
+    monkeypatch.setattr(cli, "DEFAULT_HOME", tmp_path / "home" / ".fluksio")
+
+    # Nothing above it yet: one is made here rather than in the home directory.
+    made = cli._data_dir(None)
+    assert made == (tmp_path / ".fluksio").resolve()
+    assert (made / ".gitignore").exists()
+
+    # And is then found again from anywhere below it.
+    deep = tmp_path / "src" / "deep"
+    deep.mkdir(parents=True)
+    monkeypatch.chdir(deep)
+    assert cli._data_dir(None) == made
+
+    # `--global` asks for the shared one even so.
+    assert (
+        cli._data_dir(None, shared=True) == (tmp_path / "home" / ".fluksio").resolve()
+    )
+
+    # And `--data-dir` still names any directory outright.
+    named = cli._data_dir(str(tmp_path / "named"))
+    assert named == (tmp_path / "named").resolve()

docs/code/cli.md

@@ -15,6 +15,18 @@ The command is two things at once: `serve`, `enroll` and `worker` *are* an
 installation, while `login`, `sync`, `run` and `runs` 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.
@@ -29,7 +41,7 @@ Docker.
 
 | Option | Default | What it does |
 |---|---|---|
-| `--data-dir PATH` | `~/.fluksio` (or `$FLUKSIO_HOME`) | where this installation keeps everything |
+| `--data-dir PATH` | `./.fluksio` (or `$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 |
@@ -112,13 +124,17 @@ address an engine over its API rather than being one.
 ### `fluksio login`
 
 ```sh
-fluksio login --url http://127.0.0.1:8000
+fluksio login --url https://api.example.com
 ```
 
-Asks for an email and password, and keeps the token it gets in
+For an engine somewhere *else*. One you started yourself needs no login:
-`~/.config/fluksio/client.json` (`$XDG_CONFIG_HOME` is honoured). Everything
+`fluksio serve` writes the token as it comes up and says where it put it.
-below reads it from there, or from `FLUKSIO_URL` and `FLUKSIO_TOKEN`, or from
+
-its own `--url` and `--token`.
+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`
 
@@ -164,7 +180,9 @@ commit of the repository it came from, and its parameters.
 ## What lives in the data directory
 
 ```text
-~/.fluksio/
+.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/
@@ -203,7 +221,7 @@ directory. The ones you are most likely to touch:
 
 | Variable | Default | What it does |
 |---|---|---|
-| `DATA_DIR` | `~/.fluksio` via the CLI | everything below it derives from this |
+| `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 |

docs/getting-started/data-science.md

@@ -6,36 +6,74 @@ answer to "what was the learning rate on the run that got 94%?", and the
 
 This page adds Fluksio to what you already have. It takes about five minutes,
 installs one Python package, and does not ask you to restructure anything.
-
 ## Install
 
 ```sh
+cd my-research
 pip install fluksio
 fluksio serve
 ```
 
 That is the whole installation. No Docker, no database server, no ports to
-open. The first run prints something like:
+open, and no login. The first run prints something like:
 
 ```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
+Fluksio 0.1.0 — data in /home/you/my-research/.fluksio
   API      http://127.0.0.1:8000/api/v1
+  Nodes    /home/you/my-research/.venv/bin/python
+           your environment, adopted. Add packages with pip.
   No portal. Pair this installation with:
     fluksio enroll <code> --portal https://hub.example.com
+  Signed in as admin@example.com
+           token in /home/you/my-research/.fluksio/client.json
 ```
 
-**Write that password down.** It is shown once and it is how you authenticate
+Read the last two lines: you are already signed in. Signing in to your own
-from here on.
+machine is a formality — the password was printed by the same process that
+would have checked it — so `serve` writes the token itself and every command
+below just works. `fluksio login` is for an engine somewhere *else*.
 
-Everything the installation owns lives in `~/.fluksio`: a SQLite database, a
+**Write that password down** anyway. It is shown once, and it is what the
-git repository holding your flows, the artifact store, and a virtual
+dashboard asks for.
-environment your node code runs in. Move it with `--data-dir`, which is worth
+
-doing on a cluster where `$HOME` is a network filesystem — SQLite's
+### One installation per project
-write-ahead log does not work on NFS, and `fluksio serve` warns you when it
+
-notices.
+`.fluksio` sits beside your code, and is found the way `.git` is — from the
+directory you are standing in, or any directory above it. So two repositories
+on one machine are two engines: separate flows, separate run history,
+separate token, and no chance of one experiment's graph turning up in the
+other's.
+
+```text
+~/research/protein-fold/
+  .venv/          torch, fluksio
+  .fluksio/       its own database, flows, artifacts, token
+  myresearch/
+
+~/research/climate-sim/
+  .venv/          jax, fluksio
+  .fluksio/       its own everything
+  climate/
+```
+
+It holds a database and a credential, so it ignores itself from within — a
+`.gitignore` of `*`, the same thing `uv` writes into `.venv`. Nothing to add
+to your project's own.
+
+Give them different ports (`--port`) if you want two running at once.
+
+!!! tip "One engine for the machine instead"
+
+    `fluksio serve --global` uses `~/.fluksio` — shared by every directory,
+    which is what you want for a personal server rather than a project. When
+    both exist, the banner says which one you are looking at and how to reach
+    the other. `--data-dir` still names any directory outright, which is worth
+    doing on a cluster where `$HOME` is a network filesystem: SQLite's
+    write-ahead log does not work on NFS, and `fluksio serve` warns you when
+    it notices.
 
 !!! tip "Keep it running"
 
@@ -44,25 +82,23 @@ notices.
     orchestrator spends before it does anything. Leave it in a `tmux` window,
     or write a small `systemd --user` unit for it.
 
-## Log in
+## Talking to it over HTTP
-
-```sh
-fluksio login --url http://127.0.0.1:8000
-```
-
-It asks for the email and password printed above and keeps the token in
-`~/.config/fluksio/client.json`, so nothing below needs credentials again.
 
 Everything the commands do is the HTTP API, and some of this page shows it
-directly. For that, grab the same token as a shell variable:
+directly. For that, take the token `serve` already wrote:
 
 ```sh
 export FLUKSIO=http://127.0.0.1:8000/api/v1
-export TOKEN=$(jq -r .token ~/.config/fluksio/client.json)
+export TOKEN=$(jq -r .token .fluksio/client.json)
 ```
 
 While you are experimenting, the interactive schema at
 <http://127.0.0.1:8000/docs> is the fastest way to see what is available.
+
+For an engine on another machine, `fluksio login --url https://…` asks for a
+password and stores the token the same way — in this project's `.fluksio`, or
+with `--global` in `~/.fluksio`.
+
 ## Your packages are already there
 
 If you installed Fluksio into the environment you work in — the venv that
@@ -492,7 +528,7 @@ every version of this thing I keep tweaking", note that **your flows are
 already a git repository**:
 
 ```sh
-cd ~/.fluksio/flows
+cd .fluksio/flows
 git log --oneline
 ```
 

docs/reference/configuration.md

@@ -14,7 +14,7 @@ Anything already exported wins over the file.
 
 | Variable | Default | Notes |
 |---|---|---|
-| `DATA_DIR` | `flow-data` (`~/.fluksio` via the CLI) | everything below derives from this |
+| `DATA_DIR` | `flow-data` (`./.fluksio` via the CLI; `~/.fluksio` with `--global`) | everything below derives from this |
 | `DATABASE_URL` | SQLite in `DATA_DIR` | any SQLAlchemy URL |
 | `FLOWS_DIR` | `$DATA_DIR/flows` | the git repository holding flows |
 | `SECRETS_FILE` | `$DATA_DIR/secrets.enc` | encrypted credentials, deliberately outside the repo |