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COPT

What it is

COPT (Cardinal Optimizer) from Cardinal Operations is a newer commercial linear, mixed-integer, second-order cone, and semidefinite programming solver. Its Python API is intentionally Gurobi-shaped, so polar-high's COPT adapter mirrors the Gurobi adapter closely. FlexTool dispatches through polar-high; it never imports coptpy directly.

Official site: https://www.copt.de/ (Cardinal Operations product portal). Also https://www.shanshu.ai/ offers licensing options.

License options

  • Commercial. Cardinal Operations sells perpetual and floating-server licences directly and through resellers.
  • Academic. Free for academic users. Request through the Cardinal Operations academic programme on the official site.
  • Cloud / WLS-style token licences. Cardinal supports floating-licence servers and token discovery, similar to Gurobi's WLS model.
  • Trial / community. A free trial is typically offered; specifics change with release. Check the vendor site.

Installation

Install the Python wrapper:

pip install coptpy

polar-high's COPT adapter also requires scipy for the vectorised matrix load (same dependency as the Gurobi adapter); install it if missing:

pip install scipy

For licensing:

  1. Obtain copt.lic (node-locked) or floating-licence credentials from Cardinal Operations.
  2. Place copt.lic at the path indicated by the vendor installer, or set COPT_LICENSE_DIR to the directory containing it. Refer to the vendor's installation guide for the precise discovery order [FIXME: confirm URL].
  3. Floating-licence users configure the licence server endpoint per the COPT documentation; polar-high accepts a pre-built coptpy.Envr via the env= pass-through.

HiGHS / COPT process-coexistence warning

COPT 8.x ships native code (coptpy.coptcore) that conflicts with highspy when both are loaded into the same Python interpreter: highspy.Highs.run() can segfault once coptpy has been imported.

polar-high auto-detects this situation and transparently routes COPT solves through the MPS-file fallback (HiGHS writes an MPS, the copt_cmd CLI is invoked as a subprocess) so the in-process load does not happen. This requires the standalone copt_cmd binary on PATH. If it is missing, FlexTool surfaces a clear "binary not found" error. The binary ships with the COPT distribution.

In a FlexTool scenario that uses only COPT (no HiGHS solves anywhere in the run), the in-process direct path is used.

Verification

After installing coptpy, run:

python -c "from polar_high.solvers import available_solvers; print(available_solvers)"

Expected: 'copt' appears in the list.

['gurobi', 'cplex', 'xpress', 'copt', 'highs']

To verify the licence works:

python -c "import coptpy as cp; cp.Envr().createModel('test')"

A clean exit (no CoptError) means the licence is found.

Common errors

The error messages below are what FlexTool surfaces as FlexToolUserError. polar-high's COPT adapter classifies licence errors by both numeric errno and message keywords (because the published errno table is not as cleanly documented as Gurobi's).

  • No licence file found. CoptError with errno in the provisional licence range (2, 7, 8, 9) or a message containing "license", "licence", "token", or "expired". FlexTool shows: "Solver 'copt' is installed but its license check failed. Details: ...". Fix by placing copt.lic or setting COPT_LICENSE_DIR.
  • Licence expired. Same FlexTool message family with the vendor's expiry text. Renew through the Cardinal Operations licence portal.
  • scipy missing. FlexTool surfaces: "Solver 'copt' is not installed on this system. ..." with the cause "scipy is not installed (required by the COPT adapter for vectorized matrix load)". Install scipy with pip install scipy.
  • copt_cmd not on PATH (HiGHS-coexistence fallback). FlexTool shows: "Solver 'copt' returned an error: ..." with the cause naming the missing binary. Add the COPT distribution's bin directory to PATH, or run COPT solves from a process that does not also use HiGHS.

How to set it in FlexTool

On the solve entity:

solve_advanced.solver         = "copt"
solve_advanced.solver_mip_gap = 0.005
solve_advanced.solver_arguments:
  Presolve   = 1
  LpMethod   = 2

flextool <input_db_url> --solver-time-limit 60 --highs-threads 8

The convenience knobs translate to COPT's TimeLimit, RelGap, and Threads. Raw solver_arguments win on key collision.

Verified install on: [empty]