Working At Reaper

Bridge Setup

At the start of every session, copy invoke.py from the skill to a working path:

Copy-Item "C:\Users\slyle\agents\reaper-producer\.agents\skills\working-at-reaper\references\invoke.py" `
          "C:\Users\slyle\agents\reaper-producer\bridge\invoke.py"

Then invoke actions with the Bash tool:

echo '{"action":"query_project_state","params":{}}' | python bridge/invoke.py

invoke.py handles notes-compact conversion, result polling (5 s timeout, 50 ms interval), and stale-result clearing automatically. See references/bridge-architecture.md for full details.

Engineering Tools (reaper-producer-tools)

The reaper-producer-tools repository is a pre-installed CLI available to all agents. Think of it as the engineering team's toolbox that's already on the system.

For Producer, Guitarist, Drummer

• Use the existing tools — don't reinvent the wheel
• The CLI is at: C:\Users\slyle\agents\reaper-producer\reaper-producer-tools
• Available via: bun run reaper-producer-tools/src/index.ts <command>
• Check if a tool exists before asking for something new

Requesting New Tools

If you need a new script, automation, or CLI command:

1. Ask @engineer — they're the ones who build and maintain the tools
2. Don't modify the repo yourself — that's the engineer's job
3. Explain what you need — "I need a way to batch-export stems" or "I need a script that auto-colors tracks by type"

Example Workflow

You need: "Export all tracks to separate WAV files"
Action: Delegate to @engineer: "Hey @engineer, I need a batch stem export script"

You need: "Quickly check session BPM"
Action: Use MCP tool directly: `query_project_state`

What You Can Control

Through MCP tools, you can:

• Query project state (name, BPM, play state code, cursor position, play position, track count)
• Control transport (play, stop, record)
• Save the project
• Get current position in bar/beat format
• Set project tempo
• List tracks with mute state, armed state, FX counts, volume (dB), pan, and peak levels (dB)
• Add tracks with name, position, and color
• Set track volume, pan, mute, and input monitoring
• Drop markers at cursor or specific positions
• Get all markers and navigate to markers
• List media items (takes) on a track
• Mute/unmute media items and rename takes
• List FX on any track
• Set FX parameters by track/FX/param (name or index)
• Create MIDI items with note data
• Quantize MIDI items
• Insert preset FX chains (basic_vocal, basic_drum, basic_drum_bus, drum_instrument)
• Arm tracks and start recording
• Render rough mixes with most recent render settings
• Reload MCP_Handler.lua mid-session via reload_handler (hot-reload without REAPER restart)
• Log explanatory messages to the REAPER console with explain_change
• Trigger a VST plugin rescan via rescan_vst (REAPER action 4161) — use after installing new VST3 plugins so REAPER discovers them without a restart
• Delete media items from a track via delete_item (takes track_name_or_index + item_index; delete highest index first when removing multiple items)

What You Cannot Control (Yet)

These operations are not exposed through the current MCP tools:

• Time signature changes (only tempo is settable)
• Solo tracks (mute is available, but solo is not)
• Undo/redo operations
• Loop/repeat settings
• Punch in/out configuration
• Track routing and sends
• Track record input selection
• Envelope automation beyond FX params

Bridge Architecture Summary

See references/bridge-architecture.md for the complete architecture. Key points:

• Active bridge: invoke.py (from skill, run via Bash) + MCP_Handler.lua (Lua, inside REAPER)
• Transport: ExtState via REAPER Web Interface on port 8080
• Transport helper: reaper_web_bridge.py (in skill + bridge/) for raw SET/GET debugging
• Legacy bridge (dead code): server.py (Python MCP server), reaper_bridge.py (Python TCP), reaper_bridge.eel (EEL2 TCP)

FX Chains

See references/fx-chains.md for built-in FX chain definitions, comprehensive ReaPlugs parameter reference (every Cockos plugin with full parameter tables), sidechaining setup, and FX routing (serial/parallel, containers).

REAPER Concepts

See references/reaper-concepts.md for REAPER domain knowledge relevant to session production. Includes:

• Tracks, items, takes, markers, FX, tempo, recording
• Fixed media item lanes and comping (REAPER 7+)
• Track folders and submixes
• Record modes and dual-disk recording paths
• Metering (gain reduction, LUFS, RMS)
• Essential keyboard shortcuts

ReaScript API Reference

See references/reascript-api.md for the key REAPER API functions used by the bridge.

Extensions (SWS + ReaPack)

See references/extensions.md for the key REAPER extensions:

• SWS/S&M Extension: auto-color, snapshots, notes, region playlist, ReaConsole, cycle actions, startup actions, cue buss, loudness tools, additional ReaScript API
• ReaPack: community package manager with ~1300+ scripts, effects, and themes

Hardware Reference

See references/scarlett-solo-4th-gen.md for Focusrite Scarlett Solo 4th Gen setup, hardware features, gain staging, ASIO driver setup, and common gotchas.

Workflow

1. Always call query_project_state first to orient yourself.
2. Reference song structure markers when giving position callouts.
3. Use name-based lookups for tracks and FX when possible (more readable than indices).
4. Save before destructive operations.
5. Confirm with the artist before deleting anything.
6. Log significant changes to the REAPER console with explain_change.
7. After installing a new VST3 plugin on disk, call rescan_vst before attempting to use that plugin via insert_fx_chain or list_fx_on_track.

Known Good Configuration

See references/known-good-config.md for the verified project state as of April 2026 (tracks, FX, installed plugins, bridge wiring, hardware).

Maintenance

The skillz subagent is responsible for maintaining this skill.

• After discovering new durable facts about REAPER or the bridge, delegate to skillz.
• Keep SKILL.md focused on intent, rules, and workflow.
• Put concrete technical details in the appropriate reference file.
• When the bridge gains new capabilities, update references/bridge-architecture.md.

When Not To Use This Skill

• For general OpenCode configuration (use working-at-home or working-at-opencode)
• For tasks unrelated to REAPER or audio production
• For mixing/mastering decisions (those are artist/engineer territory unless explicitly asked)