Command line (ics)

ics works on the same project folders as the desktop app. Use it for scripting, batch runs and CI; ics mcp also runs the MCP server for AI agents. The release installer puts it on the PATH. From source, build it with cargo build --release -p ics-cli (binary target/release/ics) or run it with cargo run -p ics-cli -- <args>.

• <CELL> is lib/cell or just the cell name (the first cell with that name is used).
• Exit code 0 means success. Errors print error: <message> to stderr and exit with 1.
• ics --help and ics <command> --help describe every option.

Commands

Details

Schematic from a netlist

ics schematic reads a flat SPICE netlist (R, C, L, V, I, D and M lines, and X lines for PDK MOS subcircuits) and draws it as the cell’s schematic: every pin gets a net label (node 0 or gnd gets a ground symbol) and devices are laid out in rows (PMOS, NMOS, passives, sources). Analysis lines (.op, .dc, .ac dec, .tran) and .temp set the cell’s simulation setup; other dot lines (.model, .include, .param, .ic, .meas) become its extra lines. Lengths are SPICE metres (w=2u); a bare w=2 is read as µm with a warning. The cell is created in library work unless lib/cell is given. It prints the generated deck and saves the project.

ics schematic myproj ota ota.cir && ics route myproj ota --place && ics lvs myproj ota

Simulation

ics sim uses the analyses, temperature, extra lines and backend saved for the cell in the app. --backend overrides the backend (auto picks ngspice only when the built-in engine would not evaluate the deck as written, see Backends); --parasitics adds layout parasitics (also enabled when the saved setup has them on). Without --json, it prints each dataset’s title and point count, operating-point values and device regions, and the vector names of sweeps. The backend and any warnings about what the built-in engine approximates go to stderr.

With --json, the full results go to stdout:

{
  "backend": "built-in",
  "elapsed_ms": 3.1,
  "warnings": [],
  "datasets": [
    { "analysis": "tran", "title": "...", "vectors": { "time": [0, 1e-11], "v(out)": [0, 0.01] } }
  ]
}

AC vectors are { "re": [...], "im": [...] }.

ics spice deck.cir simulates any SPICE file with the analyses in the file (default backend built-in).

--compare runs the deck on ngspice (the reference) and on the built-in engine and prints the worst disagreement of every vector; it exits with 1 when the largest relative error is above --tol (default 0.05). See Built-in engine versus ngspice.

ics mc runs the cell’s analyses --runs times (default 100, reproducible with --seed) with a global threshold and transconductance shift per polarity (--vto-sigma default 20m V, --kp-sigma default 0.03) and per-device mismatch σ(ΔVth) = avt / √(W L), σ(Δβ/β) = abeta / √(W L) (--avt default 5n = 5 mV·µm, --abeta default 10n = 1 %·µm). Each --measure is an analysis and a calculator expression with a scalar result; the command prints mean, sigma, min and max of each. The same runs from the app’s Monte Carlo window.

ics mc demo ota5t --runs 200 --measure "op:v(out)" --measure "ac:bandwidth(v(out))"

GDS

• ics import-gds adds layers the technology lacks, unless --skip-unknown-layers is given. The library name defaults to the file name. By default the library is stored as one GDS file in the project; --json stores one JSON folder per cell instead (editable, diff-friendly, larger). ics lib-storage converts an existing library between the two.
• ics gds and ics import-gds apply the technology’s stream layer map when it has one.
• ics gds-info reads a GDS file without writing anything and prints the top cells with their sizes and the read / parse / index times.

Verification and routing

• ics drc prints each rule with its violation count and up to 50 marker boxes in µm. --deck FILE uses a deck file instead of the technology’s deck. --fix first applies verified quick fixes to the cell’s top-level geometry and saves the project, then reports what is left.
• ics lvs prints the device and net pairs and the differences.
• ics route --place first places the schematic devices missing from the layout (schematic-driven layout), then routes, then saves the project.

Layout editing

• ics compact slides the cell’s top-level items toward each --dir in turn (left, right, down, up; default left,down) until the rules stop them, and saves. Fixed items stay, constraints hold and moves that would add DRC violations are undone. Symmetry constraints are first inferred from the schematic’s matched devices unless --no-infer is given.
• ics diff XORs the cell’s flattened layout per layer against the version at a git revision of the project (--rev, default HEAD) or against the same cell in another project directory (--against DIR), and prints the differences.
• ics place-like matches the cell’s devices by circuit topology to a finished reference cell (--from) and places them like it, sized from the cell’s own schematic; --route then routes it.

Optimizer

ics optimize uses the cell’s specs (sim.sweep.specs) and optimizer variables (sim.optimize), as set up in the app (Tools > Optimizer…). It prints each evaluation on stderr and the best values and spec results on stdout (--json: one object with passed, evaluations, vars and specs). --post-layout places, routes and extracts every candidate first; --apply writes the best values into the schematic and saves.

SKILL scripts

ics skill runs a Cadence SKILL (.il) file against the project (layout calls such as dbOpenCellViewByType, dbCreateRect and dbCreateInst, coordinates in µm). It prints what the script printed, lists the modified cells on stderr, and saves the project unless --no-save is given. With --json, stdout is one object:

{ "output": "...", "value": "t", "modified": ["work/inv_layout"] }

On a SKILL error it prints the script output, then error: <file>:<line>: <message>, exits with 1 and does not save.

Examples

ics new demo --template demo
ics info demo
ics netlist demo cmos_inverter
ics sim demo rc_lowpass --json > rc.json
ics sim demo nand2 --backend ngspice
ics sim demo cmos_inverter --compare
ics sim demo ring_osc5 --parasitics
ics drc demo nand2 && ics lvs demo nand2
ics extract demo inv_chain
ics gds demo inv_tiles -o tiles.gds
ics def export demo inv_chain -o chain.def --lef chain.lef
ics import-gds demo chip.gds --lib chip
ics import-tech demo sky130A.lyp --lyt sky130A.lyt
ics skill demo make_pads.il --json
ics drc demo cmos_inverter --fix
ics diff demo nand2 --rev HEAD~1

A CI check of a cell:

ics drc myproj work/opamp && ics lvs myproj work/opamp