{ "openapi": "3.1.1", "info": { "title": "Ambience Generator (rain, wind, stream, fire, hum, drone) API", "version": "1.0.0", "summary": "Synthesize rain, wind, water, fire, room hum or a drone as a seamless-loop WAV.", "description": "Every endpoint performs the same calculation as the human page and returns inputs, result, units, assumptions, sources, warnings and computedAt. MCP endpoint: /mcp." }, "servers": [ { "url": "https://soundscapeambiencegenerator.usefulweb.site" } ], "paths": { "/api/v1/calculate": { "post": { "operationId": "calculate", "summary": "Synthesize rain, wind, water, fire, room hum or a drone as a seamless-loop WAV.", "description": "Creates procedural background sound — rain with individual drops, gusty wind, a bubbling stream, a crackling campfire, room tone with mechanical hum, or an evolving drone — as a seamless-loop WAV. Every layer is synthesized from seeded noise and oscillators (no samples), with intensity, brightness and character controls and an optional room reverb.\n\nMethodology:\n- Rain: a pink-noise bed band-limited by the brightness, plus raindrops as a Poisson process (rate = drops per second × intensity), each a short decaying, slightly falling sine with a click, at a random stereo position.\n- Wind: pink noise through a band-pass filter whose centre frequency, sharpness and level follow a gust envelope made from three smoothed random curves (about 8 s, 2.5 s and 0.8 s), plus low rumble; the right channel hears each gust 0.25 s later.\n- Stream: four noise bands (≈300 Hz–4 kHz, lower for larger water) with fast random level changes, plus bubbles: short sines with rising pitch, as in physically based liquid-sound models.\n- Fire: low brown-noise roar and airy hiss with flicker, plus clusters of very short noise bursts (crackles) and occasional low pops. Hum: fundamental and harmonics with a 1/k^p roll-off (odd harmonics stronger) over low-passed pink room tone. Drone: band-limited (polyBLEP) sawtooth voices on root, fifth and octave, detuned, through a low-pass filter moved by slow LFOs.\n- Seamless loops: noise-like parts are rendered longer and the tail is crossfaded (equal power) onto the start; periodic parts (hum, drone, LFOs) are rounded to whole cycles per loop so they repeat exactly. Optional room reverb (Freeverb structure) is applied before looping, with a warm-up so the loop start is already reverberant.\n\nThese are synthesized impressions of natural sounds, not field recordings. Start playback quietly.", "tags": [ "apps" ], "x-mcp-tool": "soundscape_ambience_generator", "x-owner-app": "soundscape", "requestBody": { "required": true, "content": { "application/json": { "schema": { "$ref": "#/components/schemas/SoundscapeAmbienceGeneratorInput" }, "examples": { "example1": { "summary": "Steady rain, 6 s seamless loop", "value": { "kind": "rain", "duration": 6, "sampleRate": "44100", "intensity": 0.6, "density": 150, "brightness": 0.5, "seed": "1" } }, "example2": { "summary": "Gusty wind in an open forest, 6 s", "value": { "kind": "wind", "duration": 6, "sampleRate": "32000", "intensity": 0.7, "gustiness": 0.8, "pitch": 0.4, "room": "forest", "seed": "storm" } }, "example3": { "summary": "Campfire with lots of crackles, 5 s mono", "value": { "kind": "fire", "duration": 5, "sampleRate": "44100", "channels": "mono", "intensity": 0.6, "detail": 0.8, "seed": "7" } }, "example4": { "summary": "Server-room hum on 60 Hz mains, 4 s", "value": { "kind": "hum", "duration": 4, "sampleRate": "22050", "frequency": 120, "partials": 10, "brightness": 0.6, "roomToneDb": -18, "seed": "1" } }, "example5": { "summary": "Evolving drone in a hall, 8 s", "value": { "kind": "drone", "duration": 8, "sampleRate": "32000", "frequency": 55, "partials": 5, "detuneCents": 12, "motion": 0.6, "lfoRate": 0.25, "room": "hall", "seed": "1" } } } } } }, "responses": { "200": { "description": "Calculation result envelope.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/SoundscapeAmbienceGeneratorResult" } } } }, "400": { "description": "Malformed JSON body.", "content": { "application/problem+json": { "schema": { "$ref": "#/components/schemas/Problem" } } } }, "422": { "description": "Invalid input (see errors[]).", "content": { "application/problem+json": { "schema": { "$ref": "#/components/schemas/Problem" } } } }, "429": { "description": "Rate limit exceeded (see Retry-After).", "content": { "application/problem+json": { "schema": { "$ref": "#/components/schemas/Problem" } } } } } } }, "/api/v1/tool": { "get": { "operationId": "getToolDefinition", "summary": "Inputs, output schema and examples for this tool", "responses": { "200": { "description": "Tool definition.", "content": { "application/json": { "schema": { "type": "object" } } } } } } } }, "components": { "schemas": { "Problem": { "type": "object", "description": "RFC 9457 problem details. 422 responses include per-field `errors`.", "required": [ "type", "title", "status", "detail" ], "properties": { "type": { "type": "string" }, "title": { "type": "string" }, "status": { "type": "integer" }, "detail": { "type": "string" }, "code": { "type": "string" }, "errors": { "type": "array", "items": { "type": "object", "required": [ "field", "message" ], "properties": { "field": { "type": "string" }, "message": { "type": "string" } } } } } }, "SoundscapeAmbienceGeneratorInput": { "type": "object", "additionalProperties": false, "properties": { "kind": { "title": "Sound", "type": "string", "enum": [ "rain", "wind", "stream", "fire", "hum", "drone" ], "default": "rain" }, "duration": { "title": "Loop length", "description": "Up to 60 seconds (stereo up to 48 kHz). A seamless loop can be repeated as long as you like in any player that loops. The WAV file is kept on the server for about 2 hours so you can download it, then deleted.", "type": "number", "minimum": 1, "maximum": 60, "default": 20, "x-unit": "s" }, "sampleRate": { "title": "Sample rate", "type": "string", "enum": [ "8000", "16000", "22050", "32000", "44100", "48000", "96000" ], "default": "44100" }, "channels": { "title": "Channels", "type": "string", "enum": [ "stereo", "mono" ], "default": "stereo" }, "level": { "title": "Level (RMS)", "type": "number", "minimum": -60, "maximum": -6, "default": -20, "x-unit": "dBFS" }, "loop": { "title": "Seamless loop", "type": "boolean", "default": true }, "loopCrossfade": { "title": "Loop crossfade", "description": "Longer crossfades hide the seam better; at most a quarter of the loop length is used.", "type": "number", "minimum": 0.05, "maximum": 10, "default": 1, "x-unit": "s" }, "room": { "title": "Room", "type": "string", "enum": [ "none", "small-room", "living-room", "studio", "hall", "cathedral", "cave", "forest" ], "default": "none" }, "intensity": { "title": "Intensity (rain, wind strength, water flow, fire size)", "type": "number", "minimum": 0, "maximum": 1, "default": 0.5 }, "density": { "title": "Raindrops per second at full intensity (rain)", "type": "number", "minimum": 0, "maximum": 400, "default": 120 }, "brightness": { "title": "Brightness (rain, fire, hum, drone)", "type": "number", "minimum": 0, "maximum": 1, "default": 0.5 }, "gustiness": { "title": "Gustiness (wind)", "type": "number", "minimum": 0, "maximum": 1, "default": 0.5 }, "pitch": { "title": "Pitch (wind) or water size (stream: 0 brook … 1 river)", "type": "number", "minimum": 0, "maximum": 1, "default": 0.5 }, "detail": { "title": "Bubbles (stream) or crackles (fire)", "type": "number", "minimum": 0, "maximum": 1, "default": 0.5 }, "frequency": { "title": "Frequency (hum fundamental or drone root)", "description": "Empty = 100 Hz hum (transformer hum on 50 Hz mains; use 120 for 60 Hz mains) or a 55 Hz drone root.", "type": "number", "minimum": 20, "maximum": 1000, "x-unit": "Hz" }, "partials": { "title": "Harmonics (hum, 1–16) or voices (drone, 2–8)", "description": "Empty = 8 harmonics or 4 voices.", "type": "integer", "minimum": 1, "maximum": 16 }, "detuneCents": { "title": "Detune spread (drone)", "type": "number", "minimum": 0, "maximum": 50, "default": 8, "x-unit": "cents" }, "motion": { "title": "Slow movement (drone LFO depth, hum wobble)", "type": "number", "minimum": 0, "maximum": 1, "default": 0.5 }, "lfoRate": { "title": "LFO rate (drone)", "type": "number", "minimum": 0.01, "maximum": 1, "default": 0.08, "x-unit": "Hz" }, "roomToneDb": { "title": "Room tone level relative to the hum (hum)", "type": "number", "minimum": -60, "maximum": 0, "default": -24, "x-unit": "dB" }, "encoding": { "title": "File format", "type": "string", "enum": [ "pcm16", "float32" ], "default": "pcm16" }, "seed": { "title": "Seed", "description": "Same seed and settings = the same file. Change it for different drops, gusts and crackles.", "type": "string", "maxLength": 40, "default": "1" } }, "required": [] }, "SoundscapeAmbienceGeneratorResult": { "type": "object", "additionalProperties": false, "required": [ "schemaVersion", "tool", "computedAt", "inputs", "summary", "result", "units", "assumptions", "sources", "warnings", "presentation", "links" ], "properties": { "schemaVersion": { "type": "string", "const": "1.0" }, "tool": { "type": "object", "additionalProperties": false, "required": [ "id", "name", "version" ], "properties": { "id": { "type": "string" }, "name": { "type": "string" }, "version": { "type": "string" } } }, "computedAt": { "type": "string", "format": "date-time" }, "inputs": { "type": "object", "description": "Normalised inputs actually used, including applied defaults." }, "summary": { "type": "string" }, "result": { "type": "object", "additionalProperties": false, "required": [ "kind", "sampleRate", "channels", "durationSeconds", "frames", "loop", "room", "seed", "encoding", "parameters", "events", "quantisedFrequencyHz", "levelReduced", "spectrum", "seam", "artifact" ], "properties": { "kind": { "type": "string", "enum": [ "rain", "wind", "stream", "fire", "hum", "drone" ] }, "sampleRate": { "type": "integer" }, "channels": { "type": "integer" }, "durationSeconds": { "type": "number" }, "frames": { "type": "integer" }, "loop": { "type": "boolean" }, "room": { "type": "string" }, "seed": { "type": "string" }, "encoding": { "type": "string" }, "parameters": { "type": "object", "description": "All synthesis parameters after defaults and clamping (what was rendered)." }, "events": { "type": "integer", "description": "Raindrops, bubbles or crackles that were synthesized." }, "quantisedFrequencyHz": { "type": [ "number", "null" ], "description": "Hum fundamental or drone root after rounding to whole cycles per loop (looped files only)." }, "levelReduced": { "type": "boolean" }, "spectrum": { "type": "object", "additionalProperties": false, "required": [ "centroidHz", "rolloffHz", "slopeDbPerOctave", "peaks", "rmsDb", "peakDb", "crestDb", "octaveBands" ], "properties": { "centroidHz": { "type": "number", "description": "Power-weighted mean frequency (spectral centroid)." }, "rolloffHz": { "type": "number", "description": "Frequency below which 85 % of the power lies." }, "slopeDbPerOctave": { "type": "number", "description": "Least-squares slope of the 1/3-octave power spectrum between 100 Hz and min(10 kHz, sample rate / 4)." }, "peaks": { "type": "array", "items": { "type": "object", "additionalProperties": false, "required": [ "frequencyHz", "levelDb" ], "properties": { "frequencyHz": { "type": "number" }, "levelDb": { "type": "number" } } } }, "rmsDb": { "type": "number" }, "peakDb": { "type": "number" }, "crestDb": { "type": "number" }, "octaveBands": { "type": "array", "items": { "type": "object", "additionalProperties": false, "required": [ "centerHz", "relativeDb" ], "properties": { "centerHz": { "type": "number" }, "relativeDb": { "type": "number" } } } } } }, "seam": { "type": [ "object", "null" ], "additionalProperties": false, "required": [ "seamJump", "maxInnerJump" ], "properties": { "seamJump": { "type": "number" }, "maxInnerJump": { "type": "number" } } }, "artifact": { "type": "object", "additionalProperties": false, "required": [ "artifactId", "filename", "mime", "bytes", "sha256", "path" ], "properties": { "artifactId": { "type": "string" }, "filename": { "type": "string" }, "mime": { "type": "string" }, "bytes": { "type": "integer" }, "sha256": { "type": "string" }, "path": { "type": "string", "description": "Download path on the same site (valid for about 2 hours)." } } } } }, "units": { "type": "object", "additionalProperties": { "type": "string" } }, "assumptions": { "type": "array", "items": { "type": "string" } }, "sources": { "type": "array", "items": { "type": "object", "additionalProperties": false, "required": [ "title" ], "properties": { "title": { "type": "string" }, "url": { "type": "string" }, "publisher": { "type": "string" }, "retrievedAt": { "type": "string" }, "note": { "type": "string" } } } }, "warnings": { "type": "array", "items": { "type": "string" } }, "presentation": { "type": "array", "items": { "type": "object" }, "description": "Display blocks used by the human page (same data)." }, "links": { "type": "object", "additionalProperties": false, "required": [ "human", "api", "openapi", "methodology" ], "properties": { "human": { "type": "string", "format": "uri" }, "api": { "type": "string", "format": "uri" }, "openapi": { "type": "string", "format": "uri" }, "methodology": { "type": "string", "format": "uri" } } } } } } } }