---
gsd_state_version: 1.0
milestone: v1.0
milestone_name: milestone
status: Ready to execute
stopped_at: "Completed 02-02: OscillatorBank and stereo mixer"
last_updated: "2026-03-26T11:04:17.995Z"
progress:
  total_phases: 4
  completed_phases: 1
  total_plans: 7
  completed_plans: 6
---

# Project State

## Project Reference

See: .planning/PROJECT.md (updated 2026-03-24)

**Core value:** Network traffic patterns are instantly recognizable as distinct sounds — a ping sounds different from HTTPS noise, which sounds different from a port scan.
**Current focus:** Phase 02 — audio-synthesis-engine

## Current Position

Phase: 02 (audio-synthesis-engine) — EXECUTING
Plan: 3 of 3

## Performance Metrics

**Velocity:**

- Total plans completed: 0
- Average duration: —
- Total execution time: —

**By Phase:**

| Phase | Plans | Total | Avg/Plan |
|-------|-------|-------|----------|
| - | - | - | - |

**Recent Trend:**

- Last 5 plans: —
- Trend: —

*Updated after each plan completion*
| Phase 01 P01 | 4 | 2 tasks | 6 files |
| Phase 01 P03 | 8 | 2 tasks | 4 files |
| Phase 01-capture-and-classification P02 | 3min | 1 tasks | 4 files |
| Phase 01-capture-and-classification P04 | 15min | 2 tasks | 2 files |
| Phase 02 P01 | 15min | 2 tasks | 8 files |
| Phase 02 P02 | 10min | 2 tasks | 4 files |

## Accumulated Context

### Decisions

Decisions are logged in PROJECT.md Key Decisions table.
Recent decisions affecting current work:

- Use `github.com/gopacket/gopacket` v1.5.0 (community fork) — NOT `google/gopacket` which is unmaintained
- Use `github.com/packetcap/go-pcap` for live capture (pure Go, no CGo for capture layer)
- Use `github.com/sjzar/go-lame` v0.0.9 for MP3 encoding (embeds LAME C source, CGo required at build time only)
- Audio synthesis: hand-rolled additive sine oscillators + EMA amplitude smoothing (no external audio library)
- Frequency table: register-separated harmonics (low drones = bulk traffic, mid = control, high = interactive)
- [Phase 01]: Go installed to /home/dev/tools/go-install/go (no sudo); PATH export required each session
- [Phase 01]: Classifier uses ordered []Rule slice with first-match-wins; no switch statement (D-02)
- [Phase 01]: ICMP checked before TCP/UDP in Classify to handle packets with no port info
- [Phase 01]: DefaultWindowMs=500: 500ms windows balance temporal resolution against snapshot frequency for audio synthesis
- [Phase 01]: io.Writer injection in PrintSummary/PrintWindowLine enables test capture via bytes.Buffer and production use via os.Stderr
- [Phase 01-capture-and-classification]: Use net.Interfaces() for listing (go-pcap has no FindAllDevs equivalent); privileges not required for enumeration
- [Phase 01-capture-and-classification]: StartCapture uses 512-buffered channel with atomic drop counter to prevent backpressure blocking capture goroutine
- [Phase 01-capture-and-classification]: Dynamic link type detection via handle.LinkType() not hardcoded LinkTypeEthernet
- [Phase 01-04]: Cobra RunE + signal.NotifyContext for clean shutdown: context cancellation is the single stop signal propagating through all three pipeline stages
- [Phase 01-04]: Three-stage pipeline: capture -> classify goroutine -> aggregate via buffered channels; 1024-buffered classified channel absorbs burst processing
- [Phase 02]: go-lame v0.0.9 used for MP3 encoding (embedded LAME C source, no system library needed)
- [Phase 02]: go-audio/wav excluded — writing PCM bytes directly to LameWriter is simpler (per Claude's Discretion grant in CONTEXT.md)
- [Phase 02]: GainPerLayer applied in bank.go during mixing to ensure 11 max layers sum to 1.0 (D-10)
- [Phase 02]: int16 conversion uses float * 32767 to avoid positive overflow at exactly +1.0

### Pending Todos

None yet.

### Blockers/Concerns

- Phase 2: Frequency mapping requires subjective listening validation — specific Hz values not determined by research; must test during Phase 2
- Phase 3: Auto-clustering algorithm choice (hash-bucketing vs k-means) deferred until synthesis engine exists to evaluate perceptual results
- macOS privilege model (BPF device vs CAP_NET_RAW) not verified by research — flag if macOS is a target during Phase 1

## Session Continuity

Last session: 2026-03-26T11:04:17.988Z
Stopped at: Completed 02-02: OscillatorBank and stereo mixer
Resume file: None