G-code Slicer Tool

What it does

When your agent uses it

• Slicing an STL or 3MF model into G-code for a given printer profile
• Checking whether a mesh is ready to slice
• Finding which slicer backends are installed locally
• Validating generated G-code against printer bounds before handoff

Example prompts

• “Slice ./models/bracket.stl with the profile in ./profiles/printer.json, and do a dry run first.”
• “Which slicers are installed on this machine?”
• “Check whether ./models/vase.3mf is ready to slice.”
• “Validate /tmp/bracket.gcode against my printer profile.”

Requirements

• Python, to run scripts/gcode_tool.py
• A local slicer CLI such as OrcaSlicer
• A wrapper profile JSON that points to a native slicer profile

Workflow steps

7 steps, taken from the first numbered list in SKILL.md.

1. 1Confirm the input is a supported mesh: .stl, .obj, unsliced .3mf, .ply, .glb, or .gltf.
2. 2Require an explicit printer/profile wrapper JSON. Do not invent real-printer profiles.
3. 3Discover slicer backends when the backend is unknown
4. 4Inspect the input
5. 5Dry-run the slicer command before executing
6. 6Execute only after the dry-run command and profile are appropriate
7. 7Validate the generated G-code

What it can do on your machine

Read from SKILL.md and the folder at commit 54a1f1b. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Ships 1 file in scripts/ (Python), which the agent can run.

  Shell commands in SKILL.md call:

  • python
  • brew

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  Links to these hosts (documentation or services it may open):

  • github.com

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

G-code Slicer Tool loads about 1.5k tokens when it runs, and up to ~3k if it reads all its reference files. Until then it costs about 97 tokens; SKILL.md has 590 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~97

When it runs · the whole SKILL.md, loaded when a task matches

~1.5k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~3k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); the scripts in this folder are not scanned.

SKILL.md

The full file from autonomous-ai/openharness at commit 54a1f1b, republished under its MIT licence (© autonomous-ai). 590 words, ~1,521 tokens.

name

gcode

description

Generate, inspect, dry-run, and statically validate plain FDM `.gcode` from 3D mesh files by orchestrating real slicer CLIs. Use when Codex needs to slice `.stl`, `.obj`, unsliced `.3mf`, `.ply`, `.glb`, or `.gltf` into printer-profiled G-code, discover local slicer backends, inspect whether a mesh is slice-ready, or validate generated G-code before any printer-specific handoff.

python scripts/gcode_tool.py discover

python scripts/gcode_tool.py inspect --input path/to/model.stl --json

python scripts/gcode_tool.py slice \
  --input path/to/model.stl \
  --output /tmp/model.gcode \
  --profile path/to/profile.json \
  --backend auto \
  --dry-run

python scripts/gcode_tool.py slice \
  --input path/to/model.stl \
  --output /tmp/model.gcode \
  --profile path/to/profile.json \
  --backend auto \
  --execute

python scripts/gcode_tool.py validate \
  --gcode /tmp/model.gcode \
  --profile path/to/profile.json \
  --json

{
  "backend": "orcaslicer",
  "native_config": "/absolute/path/to/native-slicer-profile",
  "machine": {
    "name": "Example Printer",
    "bed_size_mm": [180, 180],
    "z_height_mm": 180,
    "motion_bounds_mm": {
      "x": [0, 180],
      "y": [0, 180],
      "z": [0, 180]
    }
  },
  "filament": {
    "type": "PLA",
    "nozzle_temp_c": 220,
    "bed_temp_c": 65
  }
}

{
  "backend": "orcaslicer",
  "native_config": "/absolute/path/to/machine-or-process.json",
  "native_settings": [
    "/absolute/path/to/machine.json",
    "/absolute/path/to/process.json"
  ],
  "native_filaments": [
    "/absolute/path/to/filament.json"
  ],
  "machine": {
    "name": "Example Printer",
    "bed_size_mm": [180, 180],
    "z_height_mm": 180
  },
  "filament": {
    "type": "PLA",
    "nozzle_temp_c": 220,
    "bed_temp_c": 65
  }
}

© autonomous-ai, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 5 other files (scripts, references) in store/agents/text-to-cad/skills/gcode of autonomous-ai/openharness.

• SKILL.md
• LICENSE
• agents/openai.yaml
• references/gcode-validation.md
• references/slicer-backends.md
• scripts/gcode_tool.py

Open the folder on GitHubat commit 54a1f1b