orcaslicer-mcpCAUTION
OrcaSlicer MCP — drive OrcaSlicer from Claude or any MCP client: load models, tune settings, slice, analyze
Overview
From the repository's own README, as read at the audited commit. Badges and raw HTML are left out.
[](https://pypi.org/project/orcaslicer-mcp/) [](https://pypi.org/project/orcaslicer-mcp/) [](LICENSE) [](https://lobehub.com/mcp/maxellis-orcaslicer-mcp) [](https://buymeacoffee.com/maxellis)
Let Claude work alongside you in a real, running OrcaSlicer. It loads models, arranges the plate, tunes settings, slices, and reads the result back as numbers you can question: which feature ate the print time, what a setting actually does, whether a profile breaks your printer's physics. Every change lands in the GUI while you watch, so the slicer stays yours and you get better at it as you go.
This package is an MCP server: it bundles no model and talks to nothing but OrcaSlicer, at an address you configure, localhost by default. The model comes from your MCP client. If that client uses a hosted one, your conversation goes there as any chat does; your models, profiles, and gcode stay on the machine running the slicer. Point the client at a local model and nothing leaves at all.
What it can do
Knowing what the settings mean
An offline settings reference ships with the package, carrying the authoritative label, tooltip, type, range, enum, and default for each key, so describe_setting, search_settings, and compare_settings answer from OrcaSlicer's own source instead of guessing. consult composes curated slicing knowledge and your saved notes by topic, symptom, or goal.
check_profile_physics is a deterministic gate. It overlays proposed changes on the live config, runs flow, temperature, geometry, and cooling math, then returns ok, warnings, or blocked. Accelerations your p
f513fb7e20cbOBSERVED · 2026-10-08Connect
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. Replace the environment placeholders with a token scoped to the least it needs.
claude mcp add orcaslicer-mcp --env ORCA_API_TOKEN=${ORCA_API_TOKEN} -- uvx orcaslicer-mcp==0.1.14Exposed tools (40)
29 read · 9 write · 2 destructive. Blast radius: 2 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 |
|---|---|---|
apply_and_slice | write | Apply config overrides and then slice in one step, returning {applied, errors, result} |
arrange_plate | read | Auto-arrange all objects on the plate (async job; poll get_job_status until idle). |
auto_orient | read | Auto-orient all objects for printing (async job; poll get_job_status until idle). |
cancel_slice | read | Abort a running slice, or unwedge a stale |
check_placement | read | Estimate whether every object (plus its skirt/brim ring) fits inside the printable |
check_profile_physics | write | Deterministic pre-save gate: fetches the live config, overlays optional |
compare_settings | read | For each value of `key`, slice and collect stats/warnings; restore the original when done. |
compare_slices | read | Slice the current plate under several named variants and compare the cost of each. |
consult | read | Retrieve curated slicing knowledge + saved context notes for a topic, |
delete_object | destructive | Remove one object from the current plate by id. This is permanent within the session |
delete_preset | destructive | Delete a USER preset (system presets and the currently-selected one are refused). |
describe_plate | read | Machine-readable plate facts from the last slice |
describe_setting | read | Authoritative definition of one OrcaSlicer setting: label, tooltip, type, unit, valid |
diagnose_plate | read | One-call plate diagnosis: app/slice status, objects on the plate, bed + active |
duplicate_object | read | Duplicate an object on the plate by id (adds a copy, offset from the original). |
edit_preset | write | Edit a named preset |
find_config_keys | read | Find config keys containing `substring` (helps discover among the ~600 keys). |
get_config | read | Read merged config values (optionally filtered to `keys`). |
get_gcode | read | Retrieve the last successful slice |
get_job_status | read | Whether the plate |
get_preset_config | read | Read the full settings of a named preset without selecting it. |
get_slice_breakdown | read | Per-feature breakdown of the last slice + a stateless predicted-vs-observed flow check. |
get_slice_status | read | State of the current or most recent slice: state (slicing, done, error, or idle), stats |
get_slice_warnings | read | Just the warnings/errors from the last (or current) slice, plus validity - the |
get_status | read | Snapshot of the current OrcaSlicer session: app and project info, the active |
list_objects | read | List objects on the current plate: id (stable), name, size_mm, and transform (offset/rotation/scale). |
list_presets | read | List print/filament/printer presets with system/selected/visible flags. |
load_model | read | Load a model file (path on the OrcaSlicer host) onto the current plate. |
recall_prints | read | How did past prints of THIS model actually turn out? Matches the current plate by geometry |
remember | read | Persist a context fact for future sessions. scope: |
render_plate | read | Render a PNG picture of the current plate so you can SEE it. |
save_gcode | write | Save the last successful slice |
save_preset | write | Save the currently edited settings as a named user preset (create or update, |
search_settings | read | Search settings by keyword across key/label/tooltip; returns compact matches (key, label, category, short tooltip), ranked key/label first. Offline. |
set_layer_height | write | Variable layer height for one object. mode= |
set_object_config | write | Set per-object config overrides on an object by id, e.g. { |
slice | write | Start slicing the current plate in the background and return immediately, without waiting |
slice_and_wait | read | Slice the current plate and block until it finishes, then return the final stats and |
transform_object | write | Move/rotate/scale an object by id. translate=[dx,dy,dz] mm (relative), rotate=[rx,ry,rz] degrees (relative), scale=[sx,sy,sz] absolute factor. Provide at least one. |
watch_events | read | Collect live events (slice.*/config.changed/project.opened) over a bounded window. |
Trust audit
CAUTIONgrade B · trust 89/100 Install with care. The audit found things worth knowing before you trust its output.
| Layer | What it checks | Result |
|---|---|---|
| L0 | Provenance & inventory | PASS |
| L1 | Static analysis of the code | WARN |
| L2 | Instruction surface (what it tells the agent) | PASS |
| L3 | Class-specific surface | WARN |
| L4 | Behavioural (sandbox) | SKIPPED |
What the source does
- Filesystem
- UNDECLARED (1 observation(s))
- Network
- declared (8 observation(s))
- Shell
- none-observed
- Dependencies
- pinned
- Secrets in source
- none-found
Findings (10)
BASE = os.environ.get("ORCA_BASE", "http://127.0.0.1:13131")base_url = os.environ.get("ORCA_API_URL", "http://127.0.0.1:13130").rstrip("/")delete_object, delete_preset
body4_corner_x3_support.gcode.xz
cube20_flat.gcode.xz
return hashlib.sha1("|".join(sorted(parts)).encode()).hexdigest()[:16]h = hashlib.sha1()
`ORCA_API_URL` defaults to `http://127.0.0.1:13130`. Set it only if you changed the port, or if OrcaSlicer runs on another machine with LAN access enabled there.
assert s("http://192.0.2.5") == "http://192.0.2.5"Install [uv](https://docs.astral.sh/uv/getting-started/installation/) first, because it provides the `uvx` command that runs the server. One line does it: `curl -LsSf https://astral.sh/uv/install.sh |
Gates applied: no_behavioural_pass.
f513fb7e20cbfull audit observations/trust-audit/mcp-server/maxellis__orcaslicer-mcp.json · Report an issue / request a re-scanAudit 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 | f513fb7e20cb | CAUTION | B | 89 | first audit |
Questions
What is the orcaslicer-mcp MCP server?
OrcaSlicer MCP — drive OrcaSlicer from Claude or any MCP client: load models, tune settings, slice, analyze
What tools does orcaslicer-mcp expose?
40 in total: 29 read-only, 9 that write, and 2 that can delete or overwrite (delete_object, delete_preset). Every one is listed on this page with its risk.
Is orcaslicer-mcp safe to connect to an agent?
With care. The audit graded it B (89/100) and found 10 things worth knowing before you trust this server, listed below with the exact line each was found on. Separately from the audit: 2 of its tools can destroy data, so scope the token you give it to what you actually need.
What credentials does orcaslicer-mcp need?
It reads ORCA_API_TOKEN, ORCA_MCP_ALLOW_KEYS and ORCA_TOKEN from the environment. Give it a token scoped to the least it needs — an agent that can be talked into calling a tool can be talked into calling it with your credentials.
How does orcaslicer-mcp run?
It speaks stdio, so it runs as a local process your client starts. It is published on PyPI as orcaslicer-mcp.
How current is this page?
The grade is for one exact copy of the source (f513fb7e20cb), read on 2026-10-08. The repository is watched and re-audited when it changes.