import sys

print(f"Python:  {sys.executable}")
print(f"Version: {sys.version.split()[0]}")

try:
    import fiftyone as fo
    print(f"FiftyOne: {fo.__version__}")
    print(f"Database: {fo.config.database_name}")
    print(f"DB URI:   {fo.config.database_uri or '(internal MongoDB)'}")
except ImportError:
    print("ERROR: fiftyone not installed — check Python environment, if needed run: pip install fiftyone")
    sys.exit(1)

try:
    print(f"Datasets: {fo.list_datasets()}")
    print("Connection: OK")
except Exception as e:
    print(f"Connection ERROR: {e}")
    print("→ Match this error to the Issue Index below")

import fiftyone as fo
import tempfile, os

TEST_NAME = "_fo_health_check"

try:
    # Clean up any debris from a previous failed check
    if TEST_NAME in fo.list_datasets():
        fo.delete_dataset(TEST_NAME)

    # Non-persistent: auto-removed if Python exits before cleanup
    dataset = fo.Dataset(TEST_NAME, persistent=False)
    dataset.add_sample(fo.Sample(
        filepath=os.path.join(tempfile.gettempdir(), "health_check.jpg")
    ))
    assert len(dataset) == 1, "Sample write failed"

    # Verify connection round-trip
    assert TEST_NAME in fo.list_datasets(), "Dataset not listed"

    print(f"OK — FiftyOne {fo.__version__} on database '{fo.config.database_name}'")

finally:
    # Always clean up, even on failure
    if TEST_NAME in fo.list_datasets():
        fo.delete_dataset(TEST_NAME)

import fiftyone as fo

> If the dataset is already gone from `fo.list_datasets()`, it cannot be recovered through FiftyOne — re-import from source files.

---

session = fo.launch_app(dataset)
session.wait()  # keeps the process alive

if __name__ == "__main__":
    session = fo.launch_app(dataset)
    session.wait()

session = fo.launch_app(dataset, port=<alternative-port>)  # e.g. 5152, 5153

pkill -f "fiftyone"

sample["my_field"] = "new_value"
sample.save()  # required

dataset.info["description"] = "Updated"
dataset.save()  # required

dataset.set_values("my_field", [v1, v2, ...])

import fiftyone.utils.video as fouv

---

undefined

---

fo.app_config.proxy_url = "http://your-server:<app-port>/proxy/<app-port>"
session = fo.launch_app(dataset)

undefined

---

pip install plotly
jupyter labextension install jupyterlab-plotly

import plotly.offline as pyo
pyo.init_notebook_mode(connected=True)

ps aux | grep mongod     # is MongoDB running?
df -h                    # is disk full?

pkill -f "fiftyone.*mongod"   # kill stale process, then re-import fiftyone

// ~/.fiftyone/config.json
{ "database_uri": "mongodb://localhost:27017" }

ls -la ~/.fiftyone/          # show what will be deleted
rm -rf ~/.fiftyone/var/      # only after user confirms

fo.list_plugins()

**Fix:**
```python
fo.download_plugin("voxel51/fiftyone-plugins", plugin_names=["@voxel51/brain"])
fo.enable_plugin("@voxel51/brain")

| Operator prefix | Plugin |
|----------------|--------|
| `@voxel51/brain/*` | `@voxel51/brain` |
| `@voxel51/io/*` | `@voxel51/io` |
| `@voxel51/utils/*` | `@voxel51/utils` |
| `@voxel51/evaluation/*` | `@voxel51/evaluation` |
| `@voxel51/zoo/*` | `@voxel51/zoo` |

---

launch_app()              # 1. launch app first

---

writable = fo.load_dataset("read-only-dataset").clone("my-writable-dataset")
writable.persistent = True

undefined

---

dataset.reload()

Browser: `Cmd+Shift+R` (macOS) / `Ctrl+Shift+R` (Windows/Linux).

---

pip install fiftyone==X.Y.Z
python -c "import fiftyone as fo; fo.migrate_database_if_necessary()"

OSError: You must have fiftyone>=X.Y.Z to migrate from vX.Y.Z to vA.B.C

undefined

**Fix A — Isolate the environment (recommended, no data loss):**

Give the affected env its own database so it never conflicts with other installs.

```bash

Then run the Health Check.

> ⚠️ After applying this fix, **restart any running FiftyOne App or Python processes** — env var changes only affect new processes. Check for stale processes: `ps aux | grep fiftyone`. Confirm with user before killing them.

**Fix B — Per-session (no file changes):**
```bash
FIFTYONE_DATABASE_NAME=fiftyone-<your-project> python your_script.py

pip install "fiftyone>=X.Y.Z"

// ~/.fiftyone/config.json
{ "database_name": "fiftyone-<your-project>" }

ConnectionError: Cannot connect to database type 'fiftyone' with client type 'fiftyone-teams'

import fiftyone as fo
print(fo.__version__)
print(fo.config.database_name)
print(fo.config.database_uri or "(internal MongoDB)")
try:
    fo.list_datasets()
except Exception as e:
    print(e)

ACTIVATE=$(python -c "import sys; print(sys.prefix)")/bin/activate
echo $ACTIVATE   # confirm before editing
echo '

**Fix — Inspect Teams config if the error is unexpected:**
```bash
cat ~/.fiftyone/config.json 2>/dev/null || echo "(no config)"
python -c "import fiftyone as fo; import json; print(json.dumps(fo.config.serialize(), indent=2))"