JobLine G-Code Intelligence

Read, check, and preview CNC programs before they reach the machine. Hover explanations, live diagnostics, a formatter, a program sidebar, and a 3D toolpath visualizer for Fanuc, Haas, Siemens, Mazak, and Okuma G-code, with machine presets, probing and Macro B awareness, and tap drill checks. Built by machinists at JobLine.ai.

Runs locally. Your programs are never uploaded.

Get started

1. Install the extension (VS Code 1.85 or newer) and open an NC program: .nc, .gcode, .ngc, .tap, .cnc, .mpf, .spf, .min, .prg, .eia and 50+ more extensions.
2. Click the machine in the status bar, or run JobLine: Switch Machine, and pick or create a machine preset. It is remembered per workspace.
3. Open the JobLine icon in the Activity Bar to see operations, tools, offsets, cycles, probing, macros, and warnings for the open program.
4. Run Show Toolpath Visualizer (or the eye icon in the editor title bar) to review the path in 3D.
5. Fix what the Problems panel flags, then JobLine: Format G-Code to clean up spacing and case.

Features

Hover explanations

Hover any G-code, M-code, or address word for a plain-language card: what it does, its parameters, and what to check. Drilling and motion codes include diagrams. Siemens CYCLE calls (for example CYCLE83, CYCLE840) show their positional parameters. JobLine: Open Plain Language Explanation narrates the whole program line by line.

Live diagnostics

Problems are underlined as you type and listed in the Problems panel. JobLine: Validate Program re-runs the checks and reports error and warning counts.

• Canned cycles missing Z depth or R plane, peck cycles (G73/G83) without Q or I/J/K, tapping cycles without F
• Tool changes (M06) with no safe-Z retract (G28, G30, or G53 Z) before them
• G02/G03 arcs whose endpoint does not match the center offset, in G17, G18, and G19 (tolerance set by jobline.validation.arcTolerance)
• Spindle or coolant possibly left on at program end
• Moves beyond the active machine's travel limits
• Macro expressions that cannot be resolved are tracked, never flagged as false errors

Formatter

JobLine: Format G-Code (or VS Code's Format Document) applies word spacing (G01X1.5 to G01 X1.5), uppercase G/M codes, and optional fixed decimal places.

Program sidebar

The JobLine Activity Bar panel updates as you edit:

Previous / next buttons step through operations, tools, cycles, probes, macros, and alarms. M98 P subprogram calls are links: Go to Definition jumps to the matching O number in the same file or the workspace.

Toolbox

Insert, remove, or renumber N-lines; strip comments; uppercase G/M codes; add or remove block skip (/); remove dwells; scale or clamp feeds and scale spindle speeds; shift X, Y, or Z; add a safety header, program end (M30 + %), safe-Z before tool changes, coolant on/off, or blank lines between operations; find the next tool change or canned cycle.

3D toolpath visualizer

• Linear and circular moves (G00 to G03) in G17, G18, and G19, G20/G21 units, G90/G91 coordinates; rapids and feeds drawn differently
• Play, pause, step, seek, speed control (0.25x to 4x), and jump to the highlighted source line
• Stock (box or cylinder), cutting tool and holder (ISO insert-aware mill and lathe tools), fixtures and jaws
• Import target models: STL, tessellated STEP (bundled OpenCascade runtime), and Fusion 360 F3D setup metadata (stock, model dimensions, G54)
• Seven camera presets and a ViewCube, per-layer visibility, opacity, and color
• Program review panel with setup findings, including the tap drill check

Tap drill check

When a tool comment names a thread (T3 M06 (1/4-20 TAP), M8 X 1.25 FORM TAP), the program review checks that an earlier tool drills a matching tap drill (75%, 50%, or STI size) and tells you the right size if none does. Sizes come from the JobLine shop reference (jobline-shop-reference.json v1.2.1: UNC, UNF, and metric tap drills, roll-tap drills, number/letter/fraction drill sizes, NPT, and cutting speeds), the same data behind the tap drill chart on jobline.ai.

Machine presets

A preset stores one machine: control and model, machine type, units, axis travel, spindle limit, options (4th/5th axis, live tooling, probing, sub-spindle), workholding, and CAM post. Pick it once and every program is read against it. If a program does not fit (turning codes on a mill, rotary moves on a 3-axis, a robot program on a CNC control), JobLine offers to switch.

• JobLine: New Machine Setup walks through name, control, machine type, units, and travel (X30 Y16 Z20).
• Presets are .jblmachine files, shared with jobline.ai-CAM, with schema validation and completion when you edit one.
• JobLine reads presets from the workspace (commit them with the job), jobline.presets.sharedFolders (a shop network share), and jobline.presets.libraryPath (default ~/.jobline/machines), plus built-in starting points for each control. The workspace copy wins, then shared folders, then your library.

Controls and languages

The CNC controls share one ISO / Fanuc-style engine; picking a control sets the dialect used for parsing and validation and shows it in the status bar. This is not full controller emulation.

Machine types: mill, lathe, mill-turn, and grinder. Lathe programs get diameter-mode X, T-word decoding, and turning cycle lists.

Free machining calculators at jobline.ai/tools

The same team publishes free, no-signup shop calculators and charts:

• Speed and feed calculator: RPM from SFM, feed, chip load, chip thinning, MRR
• Drill and tap calculator: drilling speeds and feeds, point allowance, tap drill sizes
• Thread size chart: UNC, UNF, and metric, TPI to pitch, single-point threading feed
• Machinist shop math: tolerance stackup, surface finish Ra, hardness conversion, right triangles
• Reference charts: tap drill, roll tap, STI/Helicoil, drill size, NPT, cutting speed
• G-Code Academy: learn and quiz yourself on codes

All free tools

Run your shop on JobLine

JobLine.ai is shift handoff and job tracking software for machine shops: notes, counts, and issues for every station, handed off cleanly between shifts. See JobLine for shops. Machinists and programmers can also create a free talent profile.

Commands

Open the Command Palette (Ctrl+Shift+P / Cmd+Shift+P) and type JobLine, G-Code, or Toolpath.

Machine presets

Check, explain and format

Toolpath visualizer and simulation

Toolbox (program edits)

Sidebar navigation and tools

69 commands, generated from package.json for v0.3.13.

Settings

Find these under Settings > Extensions > JobLine G-Code.

16 settings, generated from package.json for v0.3.13.

Supported files

Opened as G-code automatically: .nc .gcode .ngc .tap .cnc .g .min .prg .mpf .spf .eia .iso .ncc .ncp .ncf .nc1 .5ax .fgc .dnc .apt .cls .cyc .tab .ptp .src .sub .lib .cmx (any case), plus any file whose first line looks like a program (%, O1234, N10 G..). Fanuc Robot: .ls .tp. ABB RAPID: .mod .pgf. Machine presets: .jblmachine. Add shop-specific extensions with jobline.additionalExtensions.

Known issues

• Robot programs are basic. Fanuc TP and ABB RAPID files get a language mode, highlighting from the shared G-code grammar, and control/preset checks. Hover cards, diagnostics, the sidebar, and the visualizer are built for G-code and do not model robot instructions or kinematics yet.
• Playback is step-based. Smooth time-based G00/G01 interpolation is not done yet, and the visualizer draws the path; it does not simulate material removal. It is a review aid, not collision certification.
• Reported visual bugs still open: cutting color can stay green during air rapids, and tool size may not reset when switching between large and small programs.
• N-numbers are not maintained automatically while you type. Use the Toolbox insert / remove / renumber commands.
• Dialect coverage varies. Controller-specific cycles, macro and subprogram execution, and rotary motion need broader coverage; generic ISO tests do not certify every control.
• Fusion F3D import gives stock, model dimensions, and setup metadata, not a full reconstruction of the CAD solid. Parasolid targets are shown as a bounds envelope.
• Choosing the Okuma control applies lathe conventions (turret T-words, turning review rules) even to Okuma mill programs. Use the Fanuc control for Okuma machining centers for now.
• .mod is also used by other languages. If another extension claims it, use Change Language Mode > ABB RAPID.
• Machine connectivity / DNC transfer is not included.

Roadmap

Shipped so far: diagnostics and Validate Program (0.2), formatter (0.3), M98 subprogram navigation, the 3D visualizer with STL / STEP / Fusion imports, the Toolbox, probing and macro views, machine presets, and tap drill checks.

Next:

• Smooth linear playback and fixes for the open visualizer bugs above, with rendered regression tests
• Automatic N-number maintenance
• Broader controller-specific cycle, macro/subprogram, rotary, and robot coverage
• Optional JobLine sign-in to link activity to a free talent profile
• Send a reviewed program and tool list to a JobLine shop job or work order, with revision and sender recorded
• Machine Connect: controlled program transfer and shop-floor feedback (planned, not started in this extension)

Feedback

Report problems on GitHub Issues. Include the extension version, control and machine type, units, a short NC example, what you expected, and a screenshot for visual problems.

• Changelog
• Source and contributor setup
• Test coverage and known gaps

Set jobline.ui.showLinks to false to hide the optional JobLine links in the sidebar and hover cards. Built by WeCr8 Solutions, LLC. Extension code is MIT-licensed; bundled dependencies (three.js, OpenCascade / occt-import-js, fzstd) keep their own licenses.