G-code from your own scripts

Everything the interface does is available over the API: upload the file, start generation, poll the status, download the G-code. Four calls, no account, no registration — the access token from your credit purchase is the API key.

Built for repeating work: part families with changing dimensions, batches out of a configurator, overnight runs. If you would rather have an AI assistant operate it, use the MCP server, which sits on this same interface.

Credits and the access token are available at www.step2gcode.com — no account, no subscription.

What you should know

No free quota: Over the API every new model costs one credit, charged at download. Uploading, generating, status polling and the image preview are free. The browser quota does not apply here — it is tied to a device, and a script has none.
What counts is the model, not the call: The same file with a different cutter, depth or origin costs one credit in total. A model already paid for stays free permanently, including in later months, so parameter sweeps do not get expensive.
Deterministic: The same file with the same settings always produces the same program. That is what makes the interface usable for automated workflows in the first place.

The four calls

POST /api/upload — CAD file as multipart/form-data, returns a file_id (free)
POST /api/generate — file_id plus settings (tool, depth, origin), returns a job_id (free)
GET /api/status/{job_id} — poll until completed or failed (free)
GET /api/preview-image/{job_id} — tool path as a PNG for visual checking (free)
GET /api/download/{job_id} — the finished program (1 credit per new model)
GET /api/pro/credits/{token} — credits left and models paid for (free)

Every parameter of POST /api/generate

The request object is nested: file_id sits at the top level, everything else lives in blocks. Every block is optional — whatever you leave out keeps its default. Unknown fields are dropped silently, so a typo in a field name does not come back as an error; it comes back as a result that does not match what you asked for.

`(top level)`

`file_id`	string, required		The id returned by POST /api/upload.
`nest_uniform_depth`	bool	false	Only when arranging several parts on one sheet: forces one cutting depth for all of them. Without it, STEP parts keep the depth from their 3D geometry while DXF and SVG parts use depth_override.

`tool` — Cutter

`bit_diameter`	number, mm	6.0	Cutter diameter. It has to fit the smallest inner radius of the part.
`cutting_length`	number, mm	empty	Usable flute length. When set, the depth per pass never exceeds it.
`tool_type`	'endmill' \| 'vbit'	'endmill'	End mill or V-bit. For laser jobs set laser.enabled instead.
`vbit_angle`	number, degrees	90	Included angle of the V-bit. Only used with tool_type "vbit".
`vbit_tip_diameter`	number, mm	0	Diameter of the flattened tip. 0 means pointed, no compensation.
`spindle_speed`	integer, rpm	10000	Spindle speed. Overridden by feed_rates when that block is sent.
`horizontal_speed`	number, mm/min	1200	Feed in the plane. Also overridden by feed_rates.
`vertical_speed`	number, mm/min	300	Plunge feed. Also overridden by feed_rates.

`feed_rates` — Cutting data

When this block is present, its values replace the three speeds from tool. Important for scripts: there is no server-side material automation — the cutting data you send is used exactly as sent.

`auto_calculate`	bool	true	Comes from the interface, where it drives the material preset. Over the API the field has no effect; set it to false for clarity when you send your own values.
`spindle_speed`	integer, rpm	18000	Spindle speed.
`horizontal_speed`	number, mm/min	1200	Feed in the plane.
`vertical_speed`	number, mm/min	400	Plunge feed.

`material` — Workpiece material

type string 'wood' Material, for example wood, hardwood, plywood, acrylic, aluminum, steel, brass. It only decides from which diameter holes are helically milled rather than drilled — spindle speed and feeds come from tool or feed_rates.

`depth` — Depth

`depth_override`	number, mm	empty = AUTO	Cutting depth. Empty means: derive it from the geometry (for STEP, the part height). DXF and SVG carry nothing to derive it from, so there the value is effectively required.
`step_down`	number, mm	empty = AUTO	Depth per pass. Note: while settings.optimize_passes is true, the value is only an upper bound and the actual step-down is optimised below it. For an exact step-down, set optimize_passes to false.
`final_depth_offset`	number, mm	0.1	How far the last pass goes below the underside of the part so a cut-out is severed cleanly.

`origin` — Origin and orientation

The short spelling xy and z is accepted as well and means the same as origin_xy and origin_z.

`origin_xy`	'TL' \| 'TR' \| 'BL' \| 'BR' \| 'C'	'TL'	Origin in the plane: top left, top right, bottom left, bottom right or centre.
`origin_z`	'top' \| 'spoilboard'	'top'	Z zero on the stock surface or on the spoilboard.
`rotation_z`	number, degrees	0	Rotates the part in the plane, for instance to lay it out better on the sheet.
`rotation_x`	number, degrees	0	Tilts the model around X, for parts that are not lying flat in CAD.
`rotation_y`	number, degrees	0	Tilts the model around Y.
`work_coordinate_system`	'G54' … 'G59'	'G54'	Work coordinate system selected in the program.

`operations` — Operations

`contour`	bool	true	Cut the outer contour.
`inner_contour`	bool	true	Inner contours and cut-outs that are not round holes.
`holes`	bool	true	Round holes.
`pockets`	bool	true	Pockets. The depth information for them lives in the STEP geometry; DXF and SVG do not carry it.
`pocket_step_over`	integer, %	50	Overlap between clearing passes.
`pocket_start_at`	'Edge' \| 'Center'	'Edge'	Clear from the outside in, or from the inside out.
`dogbone`	bool	false	Dogbone corners so square counterparts fit into inside corners.
`ramp_entry`	bool	true	Enter on a ramp instead of plunging straight down.
`cylindrical_hole_mode`	'auto' \| 'helix' \| 'normal'	'auto'	How round holes are made: helical milling, drilling, or decided automatically from diameter and material.
`order`	list of strings	empty	Custom operation order, e.g. ["facing","pockets","holes","inner","contour","other"]. Empty means the internal default order.

`settings` — Job behaviour

`holding_tabs`	bool	true	Master switch for holding tabs. Their geometry lives in tags.
`holding_tabs_outer`	bool	true	Tabs on the outer contour.
`holding_tabs_inner`	bool	true	Tabs on inner contours.
`ramp_entry`	bool	true	Ramp entry, as in operations.
`dogbone`	bool	false	Dogbone corners, as in operations.
`optimize_passes`	bool	true	Distributes the depth over even passes on its own and treats depth.step_down as an upper bound only. Set it to false when the step-down has to be honoured exactly.

`tags` — Holding tabs

Only takes effect when tabs are enabled through settings.holding_tabs. Empty dimensions mean AUTO: derived from part size and cutter diameter.

`enabled`	bool	false	Create tabs.
`width`	number, mm	empty = AUTO	Width of one tab.
`height`	number, mm	empty = AUTO	Height of one tab, usually a fraction of the cutting depth.
`length`	number, mm	empty = AUTO	Length of one tab along the contour.
`angle`	number, degrees	45	Flank angle of the tabs.
`spacing`	number, mm	empty = AUTO	Distance between two tabs along the contour.

`facing` — Facing

`enabled`	bool	false	Face the surface before machining.
`depth`	number, mm	0.5	Layer to be removed.
`step_over`	integer, %	50	Path overlap.
`pattern`	'ZigZag' \| 'Offset'	'ZigZag'	Path pattern.
`zigzag_angle`	number, degrees	0	Direction of the zigzag passes.
`add_to_depth`	bool	true	true: the faced layer is added to the stock thickness. false: it is subtracted from the cutting depth.
`extension`	number, mm	empty = half the cutter	Overshoot beyond the workpiece edge. 0 turns the overshoot off.

`chamfer` — Chamfer, engraving and 2D direct mode

`enabled`	bool	false	Run a chamfer with the V-bit.
`depth`	number, mm	2.0	Depth of the chamfer.
`hole_depth`	number, mm	empty	Different chamfer depth at holes. Empty means: same as depth.
`engraving`	bool	false	Engraving mode: follows the contour without cutter radius compensation, even with a flattened tip.
`dxf_direct`	bool	false	2D direct mode: G-code straight from the DXF paths, without going through an extrusion.
`controller_compensation`	bool	false	Leave radius compensation to the controller (G41/G42) instead of baking it into the path.

`vshape_adaptive` — V-carving

`enabled`	bool	false	V-carving with adaptive depth instead of a constant chamfer depth.
`max_depth`	number, mm	0 = unlimited	Upper bound for the carving depth.
`depth_step`	number, mm	0.5	Depth increment per pass.
`nesting_mode`	'inner' \| 'outer'	'inner'	Contour selection: carve inside the inner contours, or clear the outer areas and leave holes out. Not to be confused with arranging several parts.

`laser` — Laser

`enabled`	bool	false	Laser job instead of a milling job.
`power`	number, %	100	Power.
`speed`	number, mm/min	1000	Speed.
`passes`	integer	1	Number of passes.
`mode`	'cut' \| 'engrave'	'cut'	Cutting or engraving.
`kerf`	number, mm	0	Kerf width the path is offset by.
`kerf_enabled`	bool	false	Switches the compensation on. Without this flag kerf has no effect.
`nesting`	'all' \| 'outer' \| 'inner'	'all'	Contour selection: all contours, outer only, or inner only.

`postprocessor` — Output format

GET /api/postprocessors returns the full list of names.

`name`	string	'grbl_post'	Controller dialect, e.g. grbl_post, linuxcnc_post, mach3_mach4_post, uccnc_post, marlin_post, fanuc_post, heidenhain_post, estlcam_post.
`custom_preamble`	string	empty	Your own G-code lines before all operations.
`custom_postamble`	string	empty	Your own G-code lines after all operations.

Verification stays your job

The generated G-code is a machine-produced proposal. Verify tool paths, depths of cut, feed rates and clearances before every run, and do an air pass without a workpiece when in doubt. Uploaded files are deleted after 24 hours at the latest.

Frequently asked questions

How do I authenticate?

With the access token from your credit purchase, as the header Authorization: Bearer YOUR-TOKEN. If that header is already taken — behind some corporate proxies or an upstream basic auth — use X-Api-Token: YOUR-TOKEN instead. Both are equivalent.

What happens without credits?

Upload and generation still work; the download responds with status 402 and the reason no_credits. An invalid token is rejected at upload time with 401 and invalid_token.

Which settings can I pass?

The same ones the interface offers, as a nested object. Every field with its type, default and effect is listed above under "Every parameter of POST /api/generate" — each block is optional, whatever you leave out keeps its default. Three traps are worth knowing: depth.step_down only acts as an upper bound while settings.optimize_passes is true; laser.kerf additionally needs kerf_enabled; and a material name sets no cutting data, that comes from tool or feed_rates.

Are there limits?

Yes, a rate limit per IP address so the service stays available for everyone. A valid access token raises the limit. Bulk requests without a token are not permitted under the terms of service.

How long do jobs stay available?

Uploaded files and results are deleted after 24 hours at the latest, and a service restart can invalidate job ids earlier. So download the G-code promptly.

What if I would rather let an assistant drive it?

Then use the MCP server: it sits on this same interface and turns it into tools for Claude, ChatGPT, the Gemini CLI and other clients.

MCP server: the same interface inside an AI assistant

G-code from your own scripts

What you should know

The four calls

Every parameter of POST /api/generate

(top level)

tool — Cutter

feed_rates — Cutting data

material — Workpiece material

depth — Depth

origin — Origin and orientation

operations — Operations

settings — Job behaviour

tags — Holding tabs

facing — Facing

chamfer — Chamfer, engraving and 2D direct mode

vshape_adaptive — V-carving

laser — Laser

postprocessor — Output format