pathway-viz 0.3.0

The visualization layer for Pathway - real-time dashboards for streaming data

PathwayViz

Embeddable real-time widgets for Pathway streaming pipelines. Rust WebSocket server with a Python API.

Overview

PathwayViz makes it easy to embed live-updating data from Kafka streams into any web page. Define widgets in Python, embed them via iframe anywhere.

import pathway as pw
import pathwayviz as pv

orders = pw.io.kafka.read(...)
revenue = orders.reduce(revenue=pw.reducers.sum(pw.this.amount))

# Create a widget server
server = pv.WidgetServer(port=3000)
server.register(pv.Stat(revenue, "revenue", id="revenue", title="Revenue", unit="$"))
server.start()
pw.run()

<iframe src="http://localhost:3000/embed/revenue"></iframe>

Install

pip install pathway-viz

Architecture

flowchart LR
    subgraph Pathway["Pathway Pipeline"]
        K[Kafka] --> P[Processing]
        P --> T[Tables]
    end

    subgraph PathwayViz
        T -->|subscribe| PY[Python API]
        PY -->|JSON| RS[Rust Server]
        RS --> RB[Ring Buffers]
        RS -->|WebSocket| B[Browser]
    end

Key components:

• WidgetServer - Manages widget registration and serves embeddable endpoints
• Widget Classes - Stat, Chart, Gauge, Table subscribe to Pathway tables
• Rust WebSocket Server - Tokio async runtime handles concurrent connections without GIL contention
• Ring Buffers - New clients receive historical data immediately without replaying the stream

Widgets

server = pv.WidgetServer(port=3000)

# Single value with delta tracking
server.register(pv.Stat(totals, "revenue", id="revenue", title="Revenue", unit="$"))

# Time series chart
server.register(pv.Chart(windowed_data, "count", id="orders_chart", x_column="window_end", title="Orders/sec"))

# Circular gauge
server.register(pv.Gauge(stats, "cpu", id="cpu_gauge", title="CPU", max_val=100, unit="%"))

# Live-updating table
server.register(pv.Table(by_region, id="regions", title="By Region", columns=["region", "revenue"]))

server.start()

Each widget is accessible at /embed/{widget_id}.

Demo

Requires Docker (spins up Redpanda for Kafka):

pip install pathway-viz[kafka]
pathway-viz demo

Generates fake e-commerce orders and displays live metrics. Includes a portal page demonstrating embedded widgets in a mock storefront.

Documentation

• Getting Started
• Widgets
• Embedding
• Deployment

Roadmap

• Core widgets (stat, chart, gauge, table)
• Pathway table subscriptions
• Embed mode with per-widget endpoints
• Ring buffer history for late-joining clients
• Additional chart types
• Crash recovery

License

MIT