Atlas / MCP servers / xdarkzx / Reaper

ReaperBLOCK

Name: Reaper
Author: xdarkzx

mcp/xdarkzx/reaper-4

MCP server by xdarkzx · ai tools · audio editing · claude · Audited 2026-10-08

AI-powered music production and post-production in REAPER via MCP — 181 tools for composition, mixing, mastering, batch editing, audio QC, and ReaScript automation.

Verdict

BLOCK

Grade

Trust score

68 /100

Exposed tools

166 70r · 79w · 17d

Transport

stdio

License

Apache-2.0

Stars

Overview

From the repository's own README, as read at the audited commit. Badges and raw HTML are left out.

ReaperMCP

AI-powered music production in REAPER through the Model Context Protocol

Quick Start • Why ReaperMCP? • Features • Tools Reference • Architecture • Changelog • Contributing • Troubleshooting

ReaperMCP connects any MCP-compatible AI assistant to REAPER, giving it full control over music production. Talk to your AI assistant and it composes, mixes, masters, and measures your music in real-time — the A

Read from source at commit 6e579d8b1efeOBSERVED · 2026-10-08

Connect

Built from this server's own package name, version and transport as found in its source — not copied from anyone's documentation, so it cannot drift against a page we do not control.

claude-code

claude mcp add xdarkzx-reaper-mcp -- uvx xdarkzx-reaper-mcp

claude-desktop

{
  "mcpServers": {
    "xdarkzx-reaper-mcp": {
      "command": "uvx",
      "args": [
        "xdarkzx-reaper-mcp"
      ]
    }
  }
}

Exposed tools (166)

70 read · 79 write · 17 destructive. Blast radius: 17 tools can delete or overwrite — an agent that can be talked into calling a tool can be talked into calling this one.

Tool	Risk	Description
`add_markers_batch`	write	Batch add markers/regions.
`analyze_chop_set`	write	Inspect a list of chops and classify each by duration.
`analyze_clipping`	read	Count samples at or above a clipping threshold (default -0.1 dBFS).
`analyze_frequency_spectrum`	read	Bass / mid / treble energy split and spectral centroid.
`analyze_loudness`	read	Measure integrated loudness (LUFS), true peak, loudness range, and crest factor.
`analyze_peaks`	read	Find click/pop candidates — short transients that spike well above the local baseline.
`analyze_region_qc`	write	Per-region silence + peak/click candidate report — the post-production QC pass.
`analyze_score`	read	Dump current MIDI data: per-track notes, CCs, timing stats.
`analyze_silence`	read	Find candidate silence spans — amplitude at/below threshold_db for at least min_duration.
`analyze_stereo_field`	read	Stereo correlation, mid/side balance, and width estimate.
`arrange_chops_to_chord_tones`	read	[NICHE] Retune each chop to a chord tone.
`bounce_stems`	read	Render the given tracks as individual audio stems (in-project).
`configure_tracks`	write	Batch set volume_db, pan, color, mute, solo, name on multiple tracks.
`detect_common_bpm`	read	Given a JSON array of file paths, return the most common BPM
`edit_section`	destructive	Clear+replace notes/CCs in a time range. For CC-only fixes, use rewrite_cc instead.
`envelope_add_points`	write	Batch-insert automation points into an envelope.
`envelope_clear_range`	destructive	Delete all envelope points in a time range.
`envelope_get_points`	read	Read automation points from a track or FX parameter envelope.
`fx_disable`	write	Bypass an FX plugin.
`fx_enable`	write	Enable an FX plugin.
`fx_get_chain`	read	Get FX chain for a track (names, enabled, presets, param counts).
`fx_get_instrument`	read	Find VSTi instrument on track. Returns index + params, or -1 if none.
`fx_get_params`	read	Get all parameters of an FX plugin (names, values, formatted display).
`fx_get_pin_mappings`	read	Read-only inspection of an FX plugin
`fx_get_preset`	read	Get current preset name and count.
`fx_list_installed`	read	List every FX plugin installed in REAPER, grouped by category.
`fx_move`	write	Move FX to different position in chain.
`fx_navigate_preset`	read	Step to next/previous preset.
`fx_remove_batch`	destructive	Remove one FX, several, or a whole chain, across one or many tracks, in one call.
`fx_rename`	write	Rename an FX instance
`fx_scan_params`	read	On-demand fallback: sweep a plugin
`fx_set_preset`	write	Load preset by name. Returns the resulting preset, not the parameters.
`fx_show_ui`	read	Open FX plugin UI window.
`get_track_instruments`	read	List all tracks with detected VSTi names and item counts.
`item_create_midi`	write	Create an empty MIDI item on a track. Returns the item
`item_delete`	destructive	Delete an item. Prefer items_apply for multiple.
`item_duplicate`	read	Copy an item N times at fixed spacing.
`item_get_all`	read	Get all media items. Filter by track or -1 for all.
`item_get_info`	read	Get detailed info for one item.
`item_insert_media`	write	Insert audio/MIDI file into track.
`item_move`	write	Move item to new position. Prefer items_apply for multiple.
`item_move_to_track`	write	Move item to different track.
`item_select`	read	Select/deselect an item.
`item_set_fade`	write	Set fade in/out. -1=unchanged. Prefer items_apply for multiple.
`item_set_length`	write	Set item length. Prefer items_apply for multiple.
`item_set_mute`	write	Mute/unmute item. Prefer items_apply for multiple.
`item_set_volume`	write	Set item volume in dB. Prefer items_apply for multiple.
`item_split`	read	Split item at position.
`item_split_at_positions`	read	Slice an item at a list of absolute project-time positions.
`item_split_at_transients`	read	Slice an audio item at every detected transient.
`item_take_add`	write	Add a new empty take to an item. Returns the new take
`item_take_delete_active`	destructive	Delete the currently active take from an item.
`item_take_list`	read	List all takes on an item with their active status.
`item_take_set_active`	write	Switch which take plays back on an item.
`items_apply`	destructive	Batch set position/length/volume_db/mute/fade_in/fade_out, or delete, across many items in one call.
`list_audio_subfolders`	read	List the subfolder structure under a folder — fast, no per-file
`marker_add`	write	Add marker. Prefer add_markers_batch for multiple.
`marker_add_region`	write	Add region. Prefer add_markers_batch for multiple.
`marker_delete`	destructive	Delete marker/region. Prefer markers_apply for multiple.
`marker_edit`	write	Edit marker/region. Prefer markers_apply for multiple, or to also edit a region
`marker_get_all`	read	Get all markers and regions. For just the region list plus a cheap
`marker_go_to`	write	Move cursor to marker.
`markers_apply`	destructive	Batch edit (name/position/start/end/color) or delete markers and regions in one call.
`midi_count_events`	read	Count notes, CCs, and sysex events in item.
`midi_delete_all_notes`	destructive	Clear all notes from a MIDI item.
`midi_delete_cc`	destructive	Delete a CC event.
`midi_delete_note`	destructive	Delete a note.
`midi_get_note_names`	read	Get MIDI note number to name mapping (C4=60, etc.).
`midi_get_notes`	read	Get notes in a MIDI item (capped at max_results to limit context size).
`midi_humanize`	write	Add random timing + velocity jitter to all notes in a MIDI item.
`midi_insert_cc`	write	Insert single CC event. For whole curves use the `ccs` array of rewrite_cc or compose_arrangement.
`midi_insert_note`	write	Insert single note into existing item. For composing use compose_arrangement.
`midi_insert_notes_batch`	write	Batch-insert notes into a MIDI item. Primary tool for writing MIDI.
`midi_insert_program_change`	write	Insert a MIDI Program Change, optionally preceded by Bank Select.
`midi_list_programs`	read	List the MIDI program names a track
`midi_quantize`	read	Quantize notes in a MIDI item to a time grid.
`midi_select_notes`	read	Select/deselect all notes in item.
`midi_set_item_extents`	write	Set MIDI item boundaries in quarter notes.
`midi_set_note`	write	Edit existing note. -1 keeps current value.
`midi_sort`	read	Sort MIDI events by time.
`project_backup`	write	Save a snapshot copy to `path` WITHOUT changing this project
`project_export_audio`	read	Render project to audio file(s) on disk.
`project_get_change_count`	read	Cheap check for whether the project has changed since you last looked.
`project_get_info`	read	Get project info (name, BPM, time sig, tracks, length, markers, render settings).
`project_get_metadata`	read	Get project render metadata (title, author, album, comment, etc.).
`project_get_notes`	read	Get the project notes/description text.
`project_get_notes_info`	read	Get the Title and Author fields of the Project Settings -> Notes tab.
`project_get_overview`	write	One cheap call for post-production awareness: counts, region list, change_count, and a selection summary.
`project_new`	write	Create a new empty REAPER project. Returns the new project info.
`project_open`	read	Open .rpp project file.
`project_redo`	read	Redo the last undone step, or the last several in one call.
`project_save`	write	Save the current project. Returns project info confirming the save.
`project_save_as`	write	Save project to new path. This project
`project_set_grid`	write	Set grid division (1.0=quarter, 0.5=eighth, 0.25=sixteenth).
`project_set_metadata`	write	Set project render metadata fields. Non-empty fields are written.
`project_set_notes`	write	Set the project notes/description text.
`project_set_notes_info`	write	Set the Title and Author fields of the Project Settings -> Notes tab.
`project_set_ripple_mode`	write	Set REAPER
`project_undo`	read	Undo the last step, or the last several steps in one call.
`project_undo_group`	write	Undo every step of the most recent multi-command tool run.
`reset_composition`	destructive	Unlock compose_arrangement without deleting MIDI. Use wipe_all_midi to also delete.
`rewrite_cc`	read	Replace CC automation in a time range, leaving notes untouched.
`scan_audio_folder`	read	Walk a folder for audio loops and parse metadata from filenames.
`script_list`	read	List ReaScripts (.lua/.eel only) found in REAPER
`script_run`	write	Run a ReaScript from REAPER
`selection_deselect_all_items`	read	Deselect all media items.
`selection_deselect_all_tracks`	read	Deselect all tracks.
`selection_get_selected_items`	read	Get a list of all currently selected media items with their full info.
`selection_get_selected_tracks`	read	Get a list of all currently selected tracks with their full info.
`selection_get_time`	read	Get current time selection. If you also need track/item counts or
`selection_select_all_items`	read	Select all items.
`selection_select_all_tracks`	read	Select all tracks.
`selection_set_loop`	write	Set loop points.
`selection_set_time`	write	Set time selection.
`send_create`	write	Create send between tracks. Prefer setup_routing for batch.
`send_get_all`	write	Get all sends/receives on a track.
`send_get_routing_diagram`	write	Get full project routing diagram (sends, receives, outputs).
`send_remove`	destructive	Remove a send.
`send_set_midi_channel`	write	Set MIDI source/destination channel on an existing send.
`send_set_mute`	write	Mute/unmute send.
`send_set_pan`	write	Set send pan.
`send_set_volume`	write	Set send volume.
`set_fx_preferences`	write	Save user FX preferences — per-category plugin overrides.
`setup_effect_bus`	write	Create effect return bus (track + FX + sends) in one call.
`setup_fx_chain`	write	Add and/or configure FX — the only tool for this, for one plugin
`setup_routing`	write	Batch create sends with optional volume/pan.
`take_set_pitch`	write	Pitch-shift a take by N semitones (no time change).
`take_set_playrate`	write	Time-stretch a take by changing its playrate.
`take_set_reversed`	write	Reverse an item
`tempo_add_marker`	write	Add a tempo and/or time-signature marker at a given time.
`tempo_clear_all`	destructive	Delete every tempo/time-sig marker — resets the project to its base tempo.
`tempo_delete_marker`	destructive	Delete a tempo/time-sig marker by its index (from `tempo_list_markers`).
`tempo_list_markers`	read	List all tempo + time-signature markers in the project.
`track_create`	write	Create new track.
`track_delete_batch`	destructive	Delete one track, several, or all of them, in one call.
`track_freeze`	read	Freeze a track to stereo audio (pre-fader render of FX + VSTi).
`track_get_all`	read	Get all tracks with properties (name, volume, pan, mute, solo, FX, items, routing).
`track_get_info`	read	Get detailed info for one track.
`track_get_mixer_state`	read	Get mixer state for all tracks (volumes, pans, mutes, solos, sends).
`track_get_peak`	read	Read instantaneous peak level from a track
`track_rename`	write	Rename a track.
`track_select`	read	Select/deselect a track.
`track_set_color`	write	Set track color (RGB 0-255). Prefer configure_tracks for batch.
`track_set_folder`	write	Set folder state. 0=normal, 1=folder parent, -1=last in folder.
`track_set_input`	write	Set recording input. 0-1023=mono (0=first input), +1024=stereo, 4096+=MIDI, -1=MIDI all inputs/channels.
`track_set_mute`	write	Mute/unmute a track.
`track_set_pan`	write	Set track pan. Prefer configure_tracks for batch.
`track_set_record_arm`	write	Arm/disarm track for recording.
`track_set_solo`	write	Solo/unsolo a track.
`track_set_volume`	write	Set track volume. Prefer configure_tracks for batch.
`track_template_apply`	write	Apply a saved template to a track — replaces its FX chain + settings.
`track_template_delete`	destructive	Delete a saved track template.
`track_template_list`	read	List all saved track templates.
`track_template_save`	write	Save a track
`track_unfreeze`	read	Unfreeze a track, restoring its original FX chain and MIDI state.
`transport_get_state`	read	Get transport state (play/record status, position, BPM, time sig, repeat).
`transport_pause`	read	Toggle pause.
`transport_play`	write	Start playback.
`transport_record`	write	Start recording.
`transport_set_bpm`	write	Set project tempo.
`transport_set_playrate`	write	Set playback speed.
`transport_set_position`	write	Set cursor position.
`transport_set_time_signature`	write	Set time signature.
`transport_stop`	write	Stop playback/recording.
`transport_toggle_metronome`	read	Toggle metronome.
`transport_toggle_repeat`	read	Toggle repeat/loop mode.

Trust audit

BLOCKgrade D · trust 68/100 Do not install this without reading the findings. The audit found something that could harm you or your machine.

Layer	What it checks	Result
L0	Provenance & inventory	PASS
L1	Static analysis of the code	FAIL
L2	Instruction surface (what it tells the agent)	FAIL
L3	Class-specific surface	WARN
L4	Behavioural (sandbox)	SKIPPED

What the source does

Filesystem: declared (8 observation(s))
Network: declared (1 observation(s))
Shell: declared (2 observation(s))
Dependencies: pinned
Secrets in source: none-found

Findings (13)

HIGHFilesystem / path · fs.credential_store · CWE-22, CWE-59

reaper_mcp_shared/path_safety.py:49

".npmrc", ".netrc", ".pgpass", "id_rsa", "id_ed25519", "id_ecdsa",

Why it matters. touches a credential store

HIGHFilesystem / path · fs.credential_store · CWE-22, CWE-59

reaper_mcp_shared/path_safety.py:50

"known_hosts", "authorized_keys", "credentials.json", "secrets.json",

Why it matters. touches a credential store

HIGHPrompt injection · prompt.hide_from_user · CWE-94, CWE-1427

reaper_mcp/instructions/00_core.md:251

"worth checking," don't tell the user something is definitely broken.

Why it matters. asks the agent to act without the user's knowledge

HIGHPrompt injection · prompt.hide_from_user · CWE-94, CWE-1427

reaper_mcp/instructions/50_postproduction.md:31

"worth checking," don't tell the user something is definitely broken.

Why it matters. asks the agent to act without the user's knowledge

MEDIUMCode injection · code.dynamic_import · CWE-78, CWE-94, CWE-95

reaper_mcp/tool_registry.py:298

module = importlib.import_module(f"reaper_mcp.tools.{name}")

MEDIUMCode injection · code.dynamic_import · CWE-78, CWE-94, CWE-95

reaper_mcp/tool_registry.py:341

importlib.import_module(f"reaper_mcp.tools.{name}")

MEDIUMFilesystem / path · mcp.destructive_tools · CWE-22, CWE-59

edit_section, envelope_clear_range, fx_remove_batch, item_delete, item_take_delete_active, items_apply, marker_delete, markers_apply, midi_delete_all_notes, midi_delete_cc, midi_delete_note, reset_com

Why it matters. 17 tool(s) can delete or overwrite

Fix. prefer a read-only mode or scoped tokens; the page states the blast radius

LOWCode injection · code.dynamic_import · CWE-78, CWE-94, CWE-95

tests/test_tool_registry.py:23

module = __import__(f"reaper_mcp.tools.{name}", fromlist=["register"])

LOWFilesystem / path · fs.credential_store · CWE-22, CWE-59

tests/test_path_safety.py:113

@pytest.mark.parametrize("name", [".env", ".ENV", "id_rsa", "known_hosts", ".netrc"])

Why it matters. touches a credential store

LOWFilesystem / path · fs.credential_store · CWE-22, CWE-59

tests/test_path_safety.py:117

@pytest.mark.parametrize("name", ["Kick_140bpm.wav", "environment.wav", "id_rsa.wav"])

Why it matters. touches a credential store

LOWFilesystem / path · fs.traversal · CWE-22, CWE-59

tests/test_script_tools.py:49

_validate_script_path("../../../etc/passwd")

LOWFilesystem / path · fs.traversal · CWE-22, CWE-59

tests/test_script_tools.py:53

_validate_script_path("sub/../../escape.lua")

LOWPrompt injection · prompt.transfer_instruction · CWE-94, CWE-1427

SECURITY.md:7

Instead, use GitHub's private reporting: go to the [Security tab](https://github.com/xDarkzx/Reaper-MCP/security) → **Report a vulnerability**. This opens a private conversation only you and the maint

Why it matters. an instruction to move sensitive data to an outside destination

Fix. remove; a skill never needs the user's secrets off the machine

Gates applied: instruction_override, no_behavioural_pass.

Audited 2026-10-08 · audit v0.4.1 · source sha 6e579d8b1efefull audit observations/trust-audit/mcp-server/xdarkzx__reaper-4.json · Report an issue / request a re-scan

Audit history

Every audit this server has had. A grade with a past is a grade somebody is still checking.

Date	Source	Verdict	Grade	Score	Change
2026-10-08	`6e579d8b1efe`	BLOCK	D	68	first audit

Questions

What is the Reaper MCP server?

AI-powered music production and post-production in REAPER via MCP — 181 tools for composition, mixing, mastering, batch editing, audio QC, and ReaScript automation.

What tools does Reaper expose?

166 in total: 70 read-only, 79 that write, and 17 that can delete or overwrite (edit_section, envelope_clear_range, fx_remove_batch, item_delete, item_take_delete_active). Every one is listed on this page with its risk.

Is Reaper safe to connect to an agent?

No — not without reading the findings first. The audit graded it D (68/100) and found 4 critical or high issues in the source. Each one is listed on this page with the file and line it is on. Separately from the audit: 17 of its tools can destroy data, so scope the token you give it to what you actually need.

What credentials does Reaper need?

No credential environment variables were found in its source, so it appears to need none.

How does Reaper run?

It speaks stdio, so it runs as a local process your client starts. It is published on PyPI as xdarkzx-reaper-mcp.

How current is this page?

The grade is for one exact copy of the source (6e579d8b1efe), read on 2026-10-08. The repository is watched and re-audited when it changes.

Source	xdarkzx/reaper-mcp
PyPI	`xdarkzx-reaper-mcp`
Transports	stdio
License	Apache-2.0
Activity	pushed 3d ago