How it works

SIGIL

Sound-design instrument. A synth with six ways to make sound that plays in a browser tab or inside your DAW. Hunt breeds new patches from the ones you keep, so you find sounds by ear.

Invite-only for now · demos publicVisit the site ↗

Fig.A sound-design instrument: six engines, in a browser tab or inside your DAW.

Architecture

APlay· 4Browser tab · MIDI · keyboard · Your DAW · Claude
- Browser tabNext.js 16 · ReactUI
  UI · Next.js 16 · React
  The instrument in a browser. The public build keeps everything in the browser, with no accounts and nothing stored on a server.
  Talks to
  → React UI
  → Server routes (gate)
- MIDI · keyboardWebMIDI · computer keysUI
  UI · WebMIDI · computer keys
  Play from a controller or the computer keyboard, in a chosen key and scale. Every browser API is optional; missing ones fail quietly.
  Talks to
  → React UI (notes)
- Your DAWVST3 · standaloneEXTERNAL
  EXTERNAL · VST3 · standalone
  Ableton or any VST3 host, on Apple Silicon, loading the plugin build.
  Talks to
  ← Bounce · record (drag WAV)
  ← JUCE plugin (VST3)
- ClaudeMCP clientEXTERNAL
  EXTERNAL · MCP client
  Claude can list engines and presets, make and change patches, and write chord progressions.
  Talks to
  → MCP endpoint (MCP)
BInterface· 5Bounce · record · React UI · Hunt · Names & glyphs · MCP endpoint
- Bounce · recordWAV · drag outSERVICE
  SERVICE · WAV · drag out
  Renders a sound offline to WAV, or records it, then lets you drag the file onto a DAW track (in Chrome) or download it.
  Talks to
  ← React UI
  → Your DAW (drag WAV)
- React UIone UI for bothUI
  UI · one UI for both
  The same interface in the browser and inside the plugin: engines, macros, the XY pad, presets and Hunt.
  Talks to
  ← Browser tab
  ← MIDI · keyboard (notes)
  ← Hunt (six takes)
  → AudioWorklet (params · notes)
  → Bounce · record
  → JUCE plugin (bundled)
- Huntmutate · breed · tasteSERVICE
  SERVICE · mutate · breed · taste
  Six variations at a time, judged by ear. Keeping some nudges the next generation toward them, within limits, and the nudge fades unless you keep choosing it.
  Talks to
  ← Presets (seeds)
  → Names & glyphs (name · mark)
  → React UI (six takes)
- Names & glyphsfrom parametersSERVICE
  SERVICE · from parameters
  A patch’s name and mark are computed from its parameters, so the same sound gets the same name everywhere, with nothing stored.
  Talks to
  ← Hunt (name · mark)
- MCP endpoint13 tools · JSON-RPCAI
  AI · 13 tools · JSON-RPC
  A plain HTTP POST endpoint. The protocol layer knows nothing about music; every tool body is a tested function.
  Talks to
  ← Claude (MCP)
  → Six engines (patches)
CSound· 4Presets · DSP core · Six engines · FX & character
- Presets84 across the banksSTORE
  STORE · 84 across the banks
  Starting points for every engine, plus a percussion bank.
  Talks to
  → Hunt (seeds)
- DSP coreTypeScript · referenceSERVICE
  SERVICE · TypeScript · reference
  The synthesis itself, in plain TypeScript: no browser APIs and no allocation in the render loops.
  Talks to
  ← AudioWorklet (renders)
  → Six engines
  → Parity check (goldens)
- Six enginesanalog · FM · physical …SERVICE
  SERVICE · analog · FM · physical …
  Analog, FM, physical modelling, granular, wavetable and sampler voices, under one voice manager.
  Talks to
  ← DSP core
  → FX & character
  ← MCP endpoint (patches)
- FX & charactertwo chainsSERVICE
  SERVICE · two chains
  An effects chain and a character chain, available on every engine.
  Talks to
  ← Six engines
DHosts· 3AudioWorklet · C++ engine · JUCE plugin
- AudioWorkletseparate realmREALTIME
  REALTIME · separate realm
  Runs the DSP on the browser’s audio thread. It is bundled on its own and only hears what the page posts to it.
  Talks to
  ← React UI (params · notes)
  → DSP core (renders)
- C++ enginehand portSERVICE
  SERVICE · hand port
  The same DSP in C++, kept in step with the TypeScript.
  Talks to
  ← JUCE plugin (process)
  → Parity check (compared)
- JUCE pluginWebView UI insideSERVICE
  SERVICE · WebView UI inside
  Wraps the C++ engine as a VST3 and serves the React UI from inside the binary. Parameters are only ever appended, so saved automation never moves.
  Talks to
  ← React UI (bundled)
  → C++ engine (process)
  → Your DAW (VST3)
EBuild· 3Server routes · PostgreSQL · Parity check
- Server routespasscode gate · sign-upsSERVICE
  SERVICE · passcode gate · sign-ups
  The private build sits behind a passcode; the public one has none. One setting decides, not a fork.
  Talks to
  ← Browser tab (gate)
  → PostgreSQL (SQL)
- PostgreSQLsign-upsSTORE
  STORE · sign-ups
  Email sign-ups from the landing page.
  Talks to
  ← Server routes (SQL)
- Parity check197 golden rendersJOB
  JOB · 197 golden renders
  Renders fresh goldens from the TypeScript and measures the C++ against them on every build.
  Talks to
  ← DSP core (goldens)
  ← C++ engine (compared)

Connections · 20

→ request · ⇢ webhook, queue or schedule

Browser tab → React UI
MIDI · keyboard → React UI · notes
Presets → Hunt · seeds
Hunt → Names & glyphs · name · mark
Hunt → React UI · six takes
React UI → AudioWorklet · params · notes
AudioWorklet → DSP core · renders
DSP core → Six engines
Six engines → FX & character
React UI → Bounce · record
Bounce · record → Your DAW · drag WAV
React UI → JUCE plugin · bundled
JUCE plugin → C++ engine · process
JUCE plugin → Your DAW · VST3
DSP core → Parity check · goldens
C++ engine → Parity check · compared
Claude → MCP endpoint · MCP
MCP endpoint → Six engines · patches
Browser tab → Server routes · gate
Server routes → PostgreSQL · SQL

Inside: the engines and Hunt

Each engine is a description plus a voice; the interface, the plugin parameters and Hunt are all built from the description. Hunt breeds sounds from a single seed, so a whole session can be replayed from one number.

ADescribe· 3Engine registry · Descriptors · Built interface
- Engine registryone line per engineSERVICE
  SERVICE · one line per engine
  Adding an engine is one line here plus its module. No app code changes.
  Talks to
  → Descriptors
- Descriptorsparams · ranges · groupsSTORE
  STORE · params · ranges · groups
  Every parameter with its range, default, curve and group. Linear and exponential parameters are normalised differently so a step means the same thing to the ear.
  Talks to
  ← Engine registry
  → Built interface (builds)
  → Voice manager (params)
- Built interfacefrom descriptorsUI
  UI · from descriptors
  The controls draw themselves from the descriptor.
  Talks to
  ← Descriptors (builds)
BVoices· 7Voice manager · Analog · FM · Physical · Granular · Wavetable · Sampler
- Voice managerpolyphonySERVICE
  SERVICE · polyphony
  Owns polyphony so engines never think about it. Every voice is allocated up front, so playing a note allocates nothing.
  Talks to
  ← Descriptors (params)
  → Analog (voices)
  ← Smoothing
  → Granular
- Analogantialiased saw · ladderSERVICE
  SERVICE · antialiased saw · ladder
  Subtractive voice with an antialiased sawtooth, so the top end sounds clean rather than harsh, into a ladder filter.
  Talks to
  ← Voice manager (voices)
- FMvelocity → brightnessSERVICE
  SERVICE · velocity → brightness
  Frequency modulation where playing harder opens the timbre, like a real tine, and nothing you do can push a preset past the brightness it was voiced at.
- Physicalmembrane · wood · metal · glassSERVICE
  SERVICE · membrane · wood · metal · glass
  A bank of resonant modes shaped like a drum head, a wooden bar, a bell or glass. Bowed excitation is bounded so it can never build up forever.
  Talks to
  → Effects chain (mix)
- Granularshared buffersSERVICE
  SERVICE · shared buffers
  Grain clouds panned across the field, sharing one buffer across voices instead of megabytes per note, with tapered windows so grains never click.
  Talks to
  ← Voice manager
- Wavetablesine → metallicSERVICE
  SERVICE · sine → metallic
  Tables that run from pure to complex: sine, triangle, soft organic, square, saw, two vocal formants and metallic.
- Sampleryour samplesSERVICE
  SERVICE · your samples
  Every voice plays one shared sample; swapping a 30 MB recording is a single reference swap between audio blocks.
CSignal· 3Smoothing · Effects chain · Character chain
- Smoothingevery parameterSERVICE
  SERVICE · every parameter
  Every parameter passes through a smoother. Unsmoothed changes cause zipper noise, the most common reason a digital synth sounds cheap.
  Talks to
  → Voice manager
- Effects chainchorus · delay · reverbSERVICE
  SERVICE · chorus · delay · reverb
  Where the signal becomes stereo. Each unit is skipped when its mix is silent.
  Talks to
  ← Physical (mix)
  → Character chain
- Character chainbounded ±1.2SERVICE
  SERVICE · bounded ±1.2
  Effects that make a listener ask what that was, allocation-free and guarded against denormals, and bounded so nothing can push the output past ±1.2.
  Talks to
  ← Effects chain
DHunt· 6Seed · Mutate · Breed · Taste · Lineage · Name & glyph
- Seedone numberSERVICE
  SERVICE · one number
  A deterministic generator: the same seed gives the same hunt on every machine, so a session can be shared as a single number.
  Talks to
  → Mutate
- Mutatesix distinct takesSERVICE
  SERVICE · six distinct takes
  Walks the current patch to six variations, retrying until they sound distinct from each other.
  Talks to
  ← Seed
  ← Breed
  → Lineage (what changed)
- Breedtwo kept parentsSERVICE
  SERVICE · two kept parents
  Crosses two patches you kept, with a little jitter.
  Talks to
  → Mutate
  ← Taste (bias)
- Tastebounded · blended · fadingSERVICE
  SERVICE · bounded · blended · fading
  Turns what you keep into a direction for the next generation: capped so it can’t pin a parameter, blended so one odd keep doesn’t define you, and fading unless you keep choosing it.
  Talks to
  → Breed (bias)
- Lineage“brighter”, “looser”SERVICE
  SERVICE · “brighter”, “looser”
  Names the one or two things that changed in a player’s words, and keeps the trail of moves that found a sound.
  Talks to
  ← Mutate (what changed)
  → Name & glyph
- Name & glyphfrom parametersSERVICE
  SERVICE · from parameters
  Computed from the parameter values, so the same sound always has the same name and mark.
  Talks to
  ← Lineage

Connections · 13

→ request · ⇢ webhook, queue or schedule

Engine registry → Descriptors
Descriptors → Built interface · builds
Descriptors → Voice manager · params
Voice manager → Analog · voices
Smoothing → Voice manager
Voice manager → Granular
Physical → Effects chain · mix
Effects chain → Character chain
Seed → Mutate
Breed → Mutate
Taste → Breed · bias
Mutate → Lineage · what changed
Lineage → Name & glyph

Two flows

Finding a sound

Walk through it and each step lights the parts it runs through in the drawings above.

By count

engines: 6
presets: 84
actions Claude can take in it: 13

Notes

N.1A patch’s name and glyph come from how it sounds. The same sound is called the same thing on every machine, and a heavy dark patch can’t come out called Bright Tide.
N.2Hunt shows no knobs. You choose by ear, and each patch keeps the moves that found it, written the way a player would say them.
N.3The plugin and the browser make the same sound, so a patch you find in a tab sounds identical in your DAW.

Built by

I design, architect and build software products like this one.

naram@hey.com·See the rest of my work

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