keboola-data-app

name

keboola-data-app

description

Build Streamlit-based Keboola Data Apps with Storage Files API integration. Use when creating data applications that run on Keboola platform, need to read/write files to Keboola Storage, require OIDC user authentication via proxy headers, or build multi-step wizards with session state. Triggers: "Keboola app", "data app", "Streamlit app for Keboola", "read from Keboola Storage", "save to Keboola Files".

Keboola Data App

Build Streamlit applications that integrate with Keboola Storage Files API.

Quick Start

Minimal Keboola Data App structure:

import streamlit as st
import os
from dotenv import load_dotenv

load_dotenv()

# Keboola config
KBC_URL = os.environ.get("KBC_URL", "https://connection.keboola.com")
KBC_TOKEN = os.environ.get("KBC_TOKEN", "")

def get_authenticated_user():
    """Get user from Keboola OIDC proxy or dev override."""
    dev_email = os.environ.get("DEV_USER_EMAIL")
    if dev_email:
        return dev_email
    try:
        return st.context.headers.get("X-Kbc-User-Email")
    except Exception:
        return None

st.set_page_config(page_title="My App", page_icon="📊")
user = get_authenticated_user()
st.write(f"Hello, {user or 'Guest'}!")

Environment Variables

Variable	Description
KBC_URL or KBC_API_URL	Keboola connection URL
KBC_TOKEN or KBC_API_TOKEN	Storage API token
DEV_USER_EMAIL	Local dev override for OIDC

Keboola Storage Files API

Initialize Client

from kbcstorage.files import Files

def get_files_client(show_errors: bool = True):
    if not KBC_TOKEN:
        if show_errors:
            st.error("Keboola token not configured. Set KBC_TOKEN environment variable.")
        return None
    try:
        return Files(KBC_URL, KBC_TOKEN)
    except Exception as e:
        if show_errors:
            st.error(f"Failed to connect to Keboola Storage: {e}")
        return None

List & Download Files by Tag

def load_file_by_tags(tags: list[str], show_errors: bool = True) -> dict | None:
    """Load file that has ALL specified tags."""
    client = get_files_client(show_errors=show_errors)
    if not client:
        return None

    try:
        files_list = client.list(tags=[tags[0]], limit=1000)

        for file_info in files_list:
            file_tags = file_info.get("tags", [])
            tag_names = [t.get("name") if isinstance(t, dict) else t for t in file_tags]

            if all(tag in tag_names for tag in tags):
                file_id = file_info.get("id")
                file_name = file_info.get("name")

                with tempfile.TemporaryDirectory() as tmp_dir:
                    client.download(file_id, tmp_dir)
                    with open(os.path.join(tmp_dir, file_name), "r") as f:
                        return json.load(f)
        return None
    except Exception as e:
        if show_errors:
            st.error(f"Failed to load file from Keboola Storage: {e}")
        return None

Upload File with Tags

def save_file_with_tags(filename: str, data: dict, tags: list[str], show_errors: bool = True) -> bool:
    """Upload JSON file to Keboola Storage with tags."""
    client = get_files_client(show_errors=show_errors)
    if not client:
        return False

    try:
        with tempfile.TemporaryDirectory() as tmp_dir:
            local_path = os.path.join(tmp_dir, filename)

            with open(local_path, "w") as f:
                json.dump(data, f, indent=2, ensure_ascii=False)

            client.upload_file(
                file_path=local_path,
                tags=tags,
                is_permanent=True,
                is_public=False
            )
            return True
    except Exception as e:
        if show_errors:
            st.error(f"Failed to save file to Keboola Storage: {e}")
        return False

Delete Files by Tag

def delete_files_by_tags(tags: list[str]) -> bool:
    """Delete all files matching ALL tags."""
    client = get_files_client()
    if not client:
        return False

    files_list = client.list(tags=[tags[0]], limit=1000)

    for file_info in files_list:
        file_tags = file_info.get("tags", [])
        tag_names = [t.get("name") if isinstance(t, dict) else t for t in file_tags]

        if all(tag in tag_names for tag in tags):
            client.delete(file_info.get("id"))

    return True

Streamlit Patterns

Session State for Multi-Step Wizard

def init_session_state():
    if "current_step" not in st.session_state:
        st.session_state.current_step = 0
    if "answers" not in st.session_state:
        st.session_state.answers = {}
    if "submitted" not in st.session_state:
        st.session_state.submitted = False

Widget State Sync Pattern

def init_widget_state(widget_key: str, answer_key: str):
    """Initialize widget from answers if not set."""
    if widget_key not in st.session_state:
        st.session_state[widget_key] = st.session_state.answers.get(answer_key, "")

def sync_answer(widget_key: str, answer_key: str):
    """Sync widget value back to answers."""
    st.session_state.answers[answer_key] = st.session_state.get(widget_key, "")

# Usage
answer_key = "q1"
widget_key = "input_q1"
init_widget_state(widget_key, answer_key)

st.text_area(
    "Your answer",
    key=widget_key,
    on_change=sync_answer,
    args=(widget_key, answer_key)
)

Navigation with Progress

def render_progress(current: int, total: int):
    st.progress((current + 1) / total)
    st.markdown(f"Step {current + 1} of {total}")

def render_navigation(current: int, total: int):
    col1, _, col3 = st.columns([1, 1, 1])

    with col1:
        if current > 0 and st.button("← Previous"):
            st.session_state.current_step -= 1
            st.rerun()

    with col3:
        if current < total - 1:
            if st.button("Next →", type="primary"):
                st.session_state.current_step += 1
                st.rerun()
        else:
            if st.button("Submit ✓", type="primary"):
                st.session_state.submitted = True
                st.rerun()

File Naming Convention

Convert email to safe filename:

def email_to_filename(email: str) -> str:
    """[e-mail] -> petr_keboola.com.json"""
    return f"{email.replace('@', '_')}.json" if email else "anonymous.json"

def filename_to_email(filename: str) -> str:
    """petr_keboola.com.json -> [e-mail]"""
    name = filename.replace(".json", "")
    parts = name.split("_", 1)
    return f"{parts[0]}@{parts[1]}" if len(parts) == 2 else name

Requirements

streamlit
python-dotenv
kbcstorage

References

• For Google Sheets export integration: See references/google_sheets.md
• For advanced Streamlit patterns: See references/streamlit_patterns.md