Name: Loenn
Author: Magedeline

Loenn MCP

Celeste map editor for AI agents: read, edit, validate, preview and generate .bin maps.

Grade A Local · stdio No auth needed 31 tools v7.2.0 MIT

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93/100

trust score

tools declared

local

runs on your machine

downloads

What it does

Celeste map editor for AI agents: read, edit, validate, preview and generate .bin maps.

Quickstart

Install it the way its author documents:

1. Download loenn-mcp-7.2.0.mcpb and open it in Claude Desktop or another client that installs MCP bundles (.mcpb) 2. Its sha256 is 99aa5f3cd18d0bcc9fc9016683aa7a10b29beaa868161cb40f45f640fe2a90f5

The full guide: https://github.com/Magedeline/loenn-mcp/releases/download/v7.2.0/loenn-mcp-7.2.0.mcpb

Publisher

Magedeline1 server

1 category

All 1 server

Tool surface

What the model actually sees. Descriptions are diffed on every release — see version history.

Only tools that write or reach the network

Read from its source code. A server that builds its tool list when it starts can list more tools than this.

List all .bin map files in the project.

Parameter	Type	Required	Notes
subdir	string	no	Subdirectory to search (default: "Maps")

Parse a .bin map file and return a summary of rooms and structure.

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file (relative to workspace or absolute)

Get detailed data for a specific room: tiles, entities, triggers.

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file
room_name	string	yes	Room name (with or without 'lvl_' prefix)

Get the complete tile grid for a room as text.

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file
room_name	string	yes	Room name
layer	string	no	"fg" for foreground (solids), "bg" for background

Add an entity to a room and save the map.

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file
room_name	string	yes	Room name
entity_name	string	yes	Entity type (e.g. "player", "MaggyHelper/KirbyBoss")
x	integer	yes	X position in pixels
y	integer	yes	Y position in pixels
entity_id	integer	no	Entity ID (-1 to auto-assign)
width	integer	no	Entity width (0 if inapplicable)
height	integer	no	Entity height (0 if inapplicable)
properties	string	no	JSON object string of extra properties

Remove an entity from a room by its ID.

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file
room_name	string	yes	Room name
entity_id	integer	yes	Entity ID to remove

Set tile data for a room. Each row is a line of characters ('0'=air).

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file
room_name	string	yes	Room name
tiles	string	yes	Tile data (newline-separated rows, 1 char per tile)
layer	string	no	"fg" for foreground (solids), "bg" for background

Add a new empty room to a map.

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file
room_name	string	yes	Room name (prefixed with 'lvl_' if needed)
x	integer	no	Room X position in pixels
y	integer	no	Room Y position in pixels
width	integer	no	Room width in pixels (multiple of 8)
height	integer	no	Room height in pixels (multiple of 8)
dark	boolean	no	Whether the room is dark
space	boolean	no	Whether the room has space physics

Remove a room from a map.

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file
room_name	string	yes	Room name to remove

Create a new empty Celeste .bin map file.

Parameter	Type	Required	Notes
map_path	string	yes	Path for the new file (relative to workspace)
package_name	string	no	Map package name (e.g. "Maggy/PCG/MyMap")

List available Lönn entity definitions from the project.

Parameter	Type	Required	Notes
filter_text	string	no	Optional text to filter filenames

Read a Lönn entity Lua definition and extract its properties.

Parameter	Type	Required	Notes
entity_file	string	yes	Filename (e.g. "kirbyBoss" or "kirbyBoss.lua")

List available Lönn trigger definitions.

Parameter	Type	Required	Notes
filter_text	string	no	Optional text to filter filenames

List available Lönn effect definitions.

Parameter	Type	Required	Notes
filter_text	string	no	Optional text to filter filenames

Get detailed statistics about a map file.

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file

Generate an ASCII visualization of all room positions in a map.

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file

Generate an ASCII preview of a map section, like a Lönn mini-map.

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file
prefix	string	no	Only show rooms whose name starts with this (e.g. "g-", "h-")
center_room	string	no	Center the view on this room name
cols	integer	no	Terminal width for the preview (default 140)
rows	integer	no	Terminal height for the preview (default 60)

Render an interactive HTML map preview with zoom, pan, search, and detail panel.

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file
prefix	string	no	Only show rooms matching this prefix (e.g. "g-", "w-")
output_file	string	no	Output HTML filename (default: map_preview.html in Temp/)

Get all editable settings for a room (music, physics, wind, camera, flags).

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file
room_name	string	yes	Room name (with or without 'lvl_' prefix)

Update room-level properties (music, dark, wind, etc.).

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file
room_name	string	yes	Room name (with or without lvl_ prefix)
settings	string	yes	JSON object of properties to update. Example: '{"dark": true, "windPattern": "Left"}'

Read the map-level metadata block (Everest/celeste.yaml meta settings).

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file

Set map-level metadata properties (Everest meta block).

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file
settings	string	yes	JSON object of meta key/value pairs to set, e.g. '{"Wipe": "Mountain", "Dreaming": true}'

List all decals in a room (foreground or background).

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file
room_name	string	yes	Room name
layer	string	no	"fg" for foreground decals, "bg" for background decals

Add a decal to a room.

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file
room_name	string	yes	Target room
texture	string	yes	Decal texture path (e.g. "decals/1-forsakencity/flag_a00")
x	integer	yes	X position
y	integer	yes	Y position
layer	string	no	"fg" or "bg"
scale_x	number	no	Horizontal scale (default 1.0)
scale_y	number	no	Vertical scale (default 1.0)

Remove a decal by index.

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file
room_name	string	yes	Room name
index	integer	yes	Decal index (from list_decals output)
layer	string	no	"fg" or "bg"

List all stylegrounds (foreground + background effects) in a map.

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file

Add a styleground effect to a map.

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file
effect_name	string	yes	Effect type (e.g. "parallax", "2.5DHelper/VoidBg", "WhiteholeBg", "apply" for a group element)
layer	string	no	"bg" / "background" / "backgrounds" (default), or "fg" / "foreground" / "foregrounds"
index	integer	no	Position to insert at (-1 appends to the end)
properties	string	no	JSON object of effect properties (e.g. '{"texture": "bgs/01/bg", "only": "lvl_a-01"}')

Update properties of a styleground by index.

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file
layer	string	yes	"fg"/"foregrounds" or "bg"/"backgrounds"
index	integer	yes	0-based index of the styleground in that layer
properties	string	yes	JSON object of properties to merge in

Remove a styleground from a map by its index in the layer.

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file
layer	string	yes	"fg"/"foregrounds" or "bg"/"backgrounds"
index	integer	yes	0-based index of the styleground in that layer

Add a trigger to a room and save the map.

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file
room_name	string	yes	Room name
trigger_name	string	yes	Trigger type (e.g. "everest/dialogTrigger", "2.5DHelper/StarterFlagTrigger")
x	integer	yes	X position in pixels
y	integer	yes	Y position in pixels
width	integer	no	Trigger width in pixels (default 16)
height	integer	no	Trigger height in pixels (default 16)
trigger_id	integer	no	Trigger ID (-1 to auto-assign)
properties	string	no	JSON object string of extra properties (e.g. '{"dialog_id": "MAP_INTRO"}')
nodes	string	no	JSON array of {\"x\": int, \"y\": int} objects for triggers that need path/target nodes (e.g. cameraTargetTrigger). Default "[]"

Remove a trigger from a room by its ID.

Parameter	Type	Required	Notes
map_path	string	yes	Path to the .bin file
room_name	string	yes	Room name
trigger_id	integer	yes	Trigger ID to remove

Free

$0 forever

Every tool, no call limit
No card, and mcprush charges nothing for it
Source published under MIT
Runs on your machine — nothing of it reaches our gateway
Nothing to cap, because mcprush bills nothing

Nothing here is billable: mcprush charges nothing to install Loenn or to call it, at any volume.

ATrust score 93 / 100

Release 7.2.0 · scanned 28 Oct 2026

Two independent axes, because powerful and malicious are different questions. The grade is threat only. The capability level is blast radius, and it is never a penalty on the grade — it is priced as one subtract-only term in the score, where you can see it.

Threat score100

Client score93

Findings9 threat · 0 capability

Capabilityhigh

Coveragesource

Verificationrepo

Surface digest9ae59fa933ba96e0897b8576de2576b2a6126746f9528b8f620cb487356f2fa2

Score vectorthreat 100 → client 93

Term	Level	What it prices	Points
capability-exposure	high	capability blast radius (high) — client exposure if the model is manipulated	−6
verification-discount	repo	publisher verification (public source) — no provenance, but the source is public and inspectable	−1
coverage-honesty	source	inspection depth (source) — how much of the target the scan could see	−0

score = clamp(round(threatScore − E_cap − E_ver − E_cov), 0, 100). No model, no opinion, no network call at scoring time: the same methodology version against the same bytes always produces this number, and every line above is a field of the report rather than a summary of it.

What the scan could actually read

A grade is only as meaningful as its coverage, so the scanner publishes its own depth before it publishes its result.

Tool surfaceread

Implementation sourceread

Package metadataread

Live transportnot available

Tools were statically extracted from the published source (31 recovered), not enumerated from a running server. Tool-poisoning, Unicode-smuggling, capability and toxic-flow analysis ran on this inferred surface, but a mis-parsed registration could be missed or mis-attributed, so tool-derived findings are capped below “confirmed”. To grade the real runtime surface, scan the running server: --command "npx -y <package>".

Capability — what it could do if the model were manipulated

Tags derived from each tool’s schema and the implementation, not from what the tool calls itself. high is the level these add up to.

Tool	Capability tags	Why the tag was assigned
list_maps	no tags
read_map_overview	no tags
read_room	no tags
get_room_tiles	no tags
add_entity	no tags
remove_entity	no tags
set_room_tiles	no tags
add_room	no tags
remove_room	no tags
create_map	no tags
list_entity_definitions	no tags
get_entity_definition	no tags
list_trigger_definitions	no tags
list_effect_definitions	no tags
analyze_map	no tags
visualize_map_layout	no tags
preview_map_section	no tags
render_map_html	no tags
get_room_settings	no tags
update_room_settings	no tags
get_map_metadata	no tags
set_map_metadata	no tags
list_decals	no tags
add_decal	no tags
remove_decal	no tags
list_stylegrounds	no tags
add_styleground	no tags
update_styleground	no tags
remove_styleground	no tags
add_trigger	no tags
remove_trigger	no tags

Toxic-flow graph

The lethal trifecta, checked as a graph rather than as a checklist: untrusted input, a sensitive source and an external sink have to meet before there is a path worth worrying about.

The public result for this release does not print the flow graph, so there is nothing to show here. That is not the same as "no paths were found": what the scan did read is above, under coverage.

Supply chain and provenance

Integrityfirst-seen

Surface digest9ae59fa933ba96e0

Scanned2026-10-28

This is the first scan of this surface here, so there is nothing yet to compare it against.

Every result on this tab comes from one deterministic pass over the published package — offline, rule by rule, and auditable line by line above. Same methodology version, same bytes, same score.

Where are you running it?

Tool surface

Release history

Loenn MCP

What it does

Quickstart

Where are you running it?

Tool surface

What counts against your monthly calls

What the scan could actually read

Capability — what it could do if the model were manipulated

Toxic-flow graph

Supply chain and provenance

Release history

See also