Show HN: Audio Toolkit for Agents

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SAS Audio Processor A suite of 25 audio processing tools — trim, normalize, compress, EQ, reverb, pitch-shift, time-stretch, key detection, MIDI extraction, and more — exposed as MCP tools via DeclarAgent. What You Get Category Tools Processing trim, time-stretch, convert, mono, silence-remove, split-bars Effects normalize, gain, compress, eq, reverb, limit, filter, pitch-shift Analysis analyze, detect-key, loudness, onset-detect MIDI melody-to-midi Composite master-track, sample-prep, tempo-match, full-analysis, melody-extract Every tool accepts WAV files and outputs structured JSON. Quick Start (Claude Code) This is the primary use case — use these audio tools directly from Claude Code via MCP. 1. Install DeclarAgent go install github.com/stevehiehn/declaragent@latest 2. Install sas-audio-processor # From source git clone https://github.com/stevehiehn/sas-audio-processor.git cd sas-audio-processor python3 -m venv venv && source venv/bin/activate pip install -r requirements.txt && pip install -e . Or use the pre-built binary (macOS only): ./build.sh # Binary at dist/sas-processor/sas-processor 3. Add MCP config Add to ~/.claude/settings.json: { "mcpServers": { "sas-audio": { "command": "declaragent", "args": ["--plans-dir", "/path/to/sas-audio-processor/plans"] } } } 4. Use it Now Claude Code has access to all 25 audio tools. Example conversation: You: Analyze this drum loop and tell me the BPM Claude: [calls analyze tool] The drum loop is at 128 BPM, 44100 Hz, stereo, 8.2 seconds long. You: Trim it to 4 bars and normalize to -14 LUFS Claude: [calls trim tool, then normalize tool] Done — trimmed to 4 bars starting at the downbeat, normalized to -14 LUFS. You: Now master it Claude: [calls master-track tool] Applied normalize → compress → limit chain. Output saved. Quick Start (Other MCP Clients) Claude Desktop Add to claude_desktop_config.json: { "mcpServers": { "sas-audio": { "command": "declaragent", "args": ["--plans-dir", "/path/to/sas-audio-processor/plans"] } } } Cursor / Windsurf / Copilot Add the same MCP server config to your editor's MCP settings. The command and args are identical — only the config file location differs per editor. How It Works MCP Client (Claude Code, Claude Desktop, etc.) │ └─► DeclarAgent (reads YAML plan files from plans/) │ └─► sas-processor <subcommand> --input ... --output ... │ └─► stdout: JSON result Each YAML plan file in plans/ defines one MCP tool. DeclarAgent reads these at startup and exposes them to MCP clients. When a tool is called, DeclarAgent runs the sas-processor CLI under the hood. Available Tools Processing Tool Description trim Detect downbeat and trim audio to specified number of bars time-stretch Change tempo while preserving pitch convert Change sample rate and/or bit depth mono Convert stereo to mono silence-remove Trim silence from start and end split-bars Split audio into N-bar chunks Effects Tool Description normalize Normalize to target LUFS or peak level gain Apply volume change in dB compress Dynamics compression with threshold/ratio/attack/release eq Parametric EQ band (boost or cut at frequency) reverb Algorithmic reverb with room size and wet/dry mix limit Brick-wall limiter filter High-pass or low-pass filter pitch-shift Shift pitch by semitones Analysis Tool Description analyze Detect BPM, duration, sample rate, channels detect-key Detect musical key and mode (major/minor) loudness Measure integrated LUFS and peak dB onset-detect Detect onset/transient times MIDI Tool Description melody-to-midi Extract monophonic melody to MIDI file Composite (Multi-Step) Tool Description master-track normalize → compress → limit sample-prep analyze → trim → normalize → convert tempo-match analyze → time-stretch to target BPM full-analysis analyze + detect-key + loudness melody-extract normalize → melody-to-midi CLI Reference All subcommands output line-delimited JSON to stdout. Errors go to stderr as JSON. sas-processor <subcommand> [options] ping sas-processor ping Health check — returns version and status. analyze sas-processor analyze --input <file> Returns BPM, duration, sample rate, and channel count. trim sas-processor trim --input <file> --output <file> --bpm <float> --bars <int> [--meter 4] [--verbose] Detects the downbeat and trims audio to the specified number of bars. time-stretch sas-processor time-stretch --input <file> --output <file> --source-bpm <float> --target-bpm <float> Changes tempo while preserving pitch. normalize sas-processor normalize --input <file> --output <file> [--mode lufs|peak] [--target-lufs -14] [--target-peak -1] gain sas-processor gain --input <file> --output <file> --db <float> mono sas-processor mono --input <file> --output <file> convert sas-processor convert --input <file> --output <file> [--sample-rate <int>] [--bit-depth 16|24|32] silence-remove sas-processor silence-remove --input <file> --output <file> [--top-db 30] compress sas-processor compress --input <file> --output <file> [--threshold -20] [--ratio 4] [--attack 1.0] [--release 100] eq sas-processor eq --input <file> --output <file> --freq <float> --gain-db <float> [--q 1.0] reverb sas-processor reverb --input <file> --output <file> [--room-size 0.5] [--damping 0.5] [--wet-level 0.33] limit sas-processor limit --input <file> --output <file> [--threshold -1] filter sas-processor filter --input <file> --output <file> --type highpass|lowpass --cutoff-hz <float> pitch-shift sas-processor pitch-shift --input <file> --output <file> --semitones <float> detect-key sas-processor detect-key --input <file> Returns key, mode (major/minor), and confidence score. loudness sas-processor loudness --input <file> Returns integrated LUFS and peak dB. onset-detect sas-processor onset-detect --input <file> Returns onset count and onset times in seconds. split-bars sas-processor split-bars --input <file> --output-dir <dir> --bpm <float> [--bars-per-chunk 1] [--meter 4] melody-to-midi sas-processor melody-to-midi --input <file> --output <file.mid> Building from Source Prerequisites macOS 10.15+ Python 3.9+ Build Steps git clone https://github.com/stevehiehn/sas-audio-processor.git cd sas-audio-processor python3 -m venv venv && source venv/bin/activate pip install -r requirements.txt && pip install -e . # Build self-contained binary pyinstaller sas-processor.spec --clean --noconfirm # Output: dist/sas-processor/ Or use the build script: ./build.sh Cross-Architecture Builds Apple Silicon (ARM64): pyinstaller sas-processor.spec --clean --noconfirm mv dist/sas-processor dist/sas-processor-arm64 Intel (x86_64): arch -x86_64 /bin/bash -c " python3 -m venv venv-x64 source venv-x64/bin/activate pip install -r requirements.txt pyinstaller sas-processor.spec --clean --noconfirm " mv dist/sas-processor dist/sas-processor-x86_64 Running Tests source venv/bin/activate # All tests pytest tests/ -v # E2E subcommand tests only pytest tests/test_plans_e2e.py -v # With coverage pytest tests/ -v --cov=sas_processor JSON Output Format All subcommands output line-delimited JSON to stdout. Result (stdout) {"type": "<subcommand>", "success": true, "output": "/path/to/output.wav", ...} Progress Events (stdout, trim only) {"type": "progress", "stage": "loading", "percent": 0} {"type": "progress", "stage": "detecting", "percent": 30} {"type": "progress", "stage": "trimming", "percent": 60} {"type": "progress", "stage": "complete", "percent": 100} Errors (stderr) {"type": "error", "code": "FILE_NOT_FOUND", "message": "Input file not found: /path/to/file.wav", "severity": "fatal"} Limitations WAV only — no MP3, FLAC, or other formats macOS only — binary builds target macOS (CLI works anywhere Python runs) Binary size ~220MB — due to numpy/scipy/librosa dependencies License MIT