🎵 strands-strudel

Live coding music with real-time WebSocket playback using Strudel patterns.

A Strands Agents tool for algorithmic music composition with a beautiful mobile-friendly player UI.

Features

• 🎧 Real-time WebSocket streaming - Send patterns to connected players instantly
• 📱 Mobile-friendly player - Glass morphism UI accessible from any device on your network
• 🎹 13 preset styles - Techno, ambient, DnB, house, acid, lofi, and more
• 📜 Pattern history - Timeline of all played patterns with one-click replay
• 🔌 Multi-client support - Broadcast to multiple players simultaneously

Installation

pip install strands-strudel

Quick Start

With Strands Agent

from strands import Agent
from strands_strudel import strudel

agent = Agent(tools=[strudel])

# Start the server and open player
agent("Start strudel and open the browser")

# Play a beat
agent("Play a techno beat")

# Create custom pattern
agent("Play s('bd*4') with some hi-hats")

Direct Tool Usage

from strands_strudel import strudel

# Start server and open player in browser
strudel(action="start", open_browser=True)

# Play by style
strudel(action="play", style="techno")

# Play custom code
strudel(action="play", code='s("bd sd hh sd")')

# Stop playback
strudel(action="hush")

# Check status
strudel(action="status")

# List available styles
strudel(action="styles")

# Stop server
strudel(action="stop")

Actions

Action	Description
start	Start WebSocket + HTTP servers, optionally open browser
play	Send pattern code or preset style to connected players
hush	Stop all playback
stop	Stop servers
status	Show server status and connected players
styles	List available preset styles

Available Styles

Style	Description
techno	Four-on-the-floor kick with classic drums
ambient	Atmospheric pads with reverb and delay
dnb	Fast drum and bass patterns (140 BPM feel)
house	Classic house groove with bass
acid	303-style acid basslines with filter sweeps
lofi	Lo-fi hip hop beats
minimal	Sparse minimal techno
breakbeat	Syncopated breakbeat patterns
dub	Dubby rhythms with heavy delay
trance	Uplifting trance with supersaw
jungle	Fast jungle/breakcore patterns
chillout	Relaxed downtempo vibes
industrial	Distorted industrial sounds

Architecture

┌─────────────────┐     WebSocket      ┌─────────────────┐
│  Strands Agent  │ ────────────────▶  │  Browser Player │
│                 │    Port 9999       │  (Strudel.js)   │
└─────────────────┘                    └─────────────────┘
                                              │
                          HTTP                │
                        Port 10000            ▼
                    ┌─────────────────────────────┐
                    │  Mobile / Other Browsers   │
                    │  http://<your-ip>:10000    │
                    └─────────────────────────────┘

Configuration

Environment variables:

Variable	Default	Description
STRUDEL_WS_PORT	9999	WebSocket server port
STRUDEL_WS_HOST	0.0.0.0	WebSocket bind address

Strudel Pattern Syntax

Sound Sources

Samples (from dirt-samples):

s("bd")           // bass drum
s("sd")           // snare drum
s("hh")           // hi-hat
s("cp")           // clap
s("808")          // 808 sounds
s("piano")        // piano
s("bd:0 bd:1")    // sample variations

Synthesizers (built-in):

note("c4").sound("sine")       // sine wave
note("c4").sound("sawtooth")   // sawtooth wave
note("c4").sound("triangle")   // triangle wave
note("c4").sound("square")     // square wave
note("c4").sound("supersaw")   // detuned saws

Mini-Notation

"a b c d"       // sequence (4 equal parts)
"[a b] c"       // subdivide: a and b share one slot
"a*4"           // repeat 4 times
"a/2"           // play every 2 cycles
"~"             // rest/silence
"a?"            // 50% chance
"<a b c>"       // one per cycle
"a,b,c"         // play simultaneously (chord)
"a(3,8)"        // Euclidean: 3 hits over 8 steps

Effects

.lpf(1000)      // lowpass filter
.hpf(200)       // highpass filter
.gain(0.8)      // volume
.pan(0.5)       // stereo position
.room(0.5)      // reverb
.delay(0.5)     // delay amount
.distort(2)     // distortion
.speed(2)       // playback speed

Example Patterns

Basic Beat:

stack(
  s("bd*4"),
  s("~ sd ~ sd"),
  s("hh*8").gain(0.6)
)

Melodic:

n("0 2 4 <5 7>")
  .scale("C:minor")
  .sound("sawtooth")
  .lpf(800)

Ambient:

note("<[c3,e3,g3] [d3,f3,a3]>")
  .sound("triangle")
  .lpf(sine.range(400, 2000).slow(8))
  .room(0.8)

Links

• Strudel REPL - Browser-based live coding
• Strudel Docs - Full documentation
• TidalCycles - The original Haskell version
• Strands Agents - Strands Agents SDK

License

MIT