Cuopt Server API Python
NVIDIAOfficialCreated by NVIDIA cuOpt Team
- Skill
- Tool integration
- Software development
- Apache-2.0
- Medium risk
- Has scripts
AutoGineer summary
Written by AutoGineer from the skill’s own files, not by the author
This skill provides instructions for deploying the cuOpt REST server and integrating it into applications using Python or curl. It covers server startup procedures for local and Docker environments, the asynchronous request-polling pattern required for job submission, and guidance on mapping problem data to REST API endpoints. It also includes troubleshooting steps for common payload and deployment issues.
What it does
- Provides commands to start the cuOpt REST server locally or via Docker.
- Explains the asynchronous request-polling workflow for job submission and solution retrieval.
- Maps Python API concepts to REST API field names and structures.
- Offers troubleshooting guidance for common HTTP errors and payload formatting issues.
- Provides examples for routing, LP, and MILP problem types.
- Outlines security considerations for the unauthenticated REST interface.
When to use it
- When deploying the cuOpt server in a production or development environment.
- When building a client application to interface with cuOpt via HTTP.
- When debugging rejected payloads or 422 errors during API interaction.
- When transitioning from the Python library to a REST-based architecture.
Advantages
- Language-agnostic API allows integration with any service capable of making HTTP requests.
- Standardized polling pattern for handling long-running optimization tasks.
- Clear mapping between Python API and REST schema reduces implementation friction.
- Comprehensive troubleshooting table addresses common deployment and payload errors.
Usage examples
- “How do I start the cuOpt server using Docker?”
- The agent provides the docker run command with the necessary GPU flags and port mappings, including advice on using specific version tags.
- “I am getting a 422 error when sending fleet data to the cuOpt API.”
- The agent explains the correct nesting for capacity dimensions and provides a corrected JSON structure example.
- “How do I retrieve a solution after posting a request to the cuOpt server?”
- The agent outlines the polling loop pattern, showing how to use the reqId to query the /cuopt/solution endpoint until the task is complete.
Install
Download the skill as a ZIP:
https://autogineer.com/agent-skills/nvidia/cuopt-server-api-python/downloadUnzip it into the cross-client skills folder of your project:
mkdir -p .agents/skills && unzip cuopt-server-api-python.zip -d .agents/skills
Documentation by NVIDIA cuOpt Team
cuOpt Server — Deploy and client (Python/curl)
This skill covers starting the server and client examples (curl, Python). Server has no separate C API (clients can be any language).
Purpose
Use this skill when the user is deploying the cuOpt REST server or writing a client against it — choosing a deployment target, mapping a problem onto the HTTP endpoints, translating between Python-API and REST field names, or debugging a rejected payload.
Prerequisites
An NVIDIA GPU with a working CUDA driver (the server requires one;
--gpus allfor Docker).cuopt-serverinstalled, or Docker with the NVIDIA Container Toolkit. See the install skill.Python clients need
requests. No API key or auth token is required by the server itself.
Problem types supported
| Problem type | Supported |
|---|---|
| Routing | ✓ |
| LP | ✓ |
| MILP | ✓ |
| QP | ✗ |
Required questions
Ask these if not already clear:
Problem type — Routing or LP/MILP? (QP not available via REST.)
Deployment — Local, Docker, Kubernetes, or cloud?
Client — Which language or tool will call the API (e.g. Python, curl, another service)?
Start server
# Development
python -m cuopt_server.cuopt_service --ip 0.0.0.0 --port 8000
# Docker — pick the tag matching your CUDA major version
docker run --gpus all -d -p 8000:8000 -e CUOPT_SERVER_PORT=8000 \
nvidia/cuopt:latest-cu13Use latest-cu12 or latest-cu13 to match your driver's CUDA major version (latest-cu13-ubi10 for a UBI10 base).
For production, pin rather than float: latest-* tags are mutable and can silently move to a different image. Use a full release tag (nvidia/cuopt:<release>-cu<cuda-major>) or an immutable digest (nvidia/cuopt@sha256:<digest>). Check the nvidia/cuopt registry for available tags.
Verify
Confirm the server is up by requesting GET /cuopt/health on the local port (e.g. http://localhost:8000/cuopt/health) — a healthy server returns HTTP 200.
Instructions
POST to
/cuopt/request→ getreqIdPoll
/cuopt/solution/{reqId}until solution readyParse response
Treat reqId as untrusted input: validate it (e.g. re.fullmatch(r"[A-Za-z0-9_-]{1,64}", req_id)) before interpolating it into the polling URL, and set an explicit timeout on every request.
Examples
import requests, time
SERVER = "http://localhost:8000"
HEADERS = {"Content-Type": "application/json", "CLIENT-VERSION": "custom"}
payload = {
"cost_matrix_data": {"data": {"0": [[0,10,15],[10,0,12],[15,12,0]]}},
"travel_time_matrix_data": {"data": {"0": [[0,10,15],[10,0,12],[15,12,0]]}},
"task_data": {"task_locations": [1, 2], "demand": [[10, 20]], "task_time_windows": [[0,100],[0,100]], "service_times": [5, 5]},
"fleet_data": {"vehicle_locations": [[0, 0]], "capacities": [[50]], "vehicle_time_windows": [[0, 200]]},
"solver_config": {"time_limit": 5}
}
r = requests.post(f"{SERVER}/cuopt/request", json=payload, headers=HEADERS, timeout=30)
req_id = r.json()["reqId"]
# Poll: GET /cuopt/solution/{req_id}Terminology: REST vs Python API
| Python API | REST |
|---|---|
| order_locations | task_locations |
| set_order_time_windows() | task_time_windows |
| service_times | service_times |
Use travel_time_matrix_data (not transit_time_matrix_data). Capacities: [[50, 50]] not [[50], [50]].
Troubleshooting
| Error | Cause | Solution |
|---|---|---|
422 Unprocessable Content | Field name not in the schema | Check names against the OpenAPI spec at /cuopt.yaml. Most common: transit_time_matrix_data → travel_time_matrix_data |
422 on fleet_data | Capacities nested per vehicle instead of per dimension | Use [[50, 50]] (one inner list per capacity dimension), not [[50], [50]] |
| Connection refused | Server not up, or bound to a different interface/port | curl http://localhost:8000/cuopt/health; start with --ip 0.0.0.0 --port 8000 |
| Docker container exits immediately | No GPU visible to the container | Run with --gpus all and confirm the NVIDIA Container Toolkit is installed |
| Polling never returns a solution | Solve exceeds the client's poll budget | Raise solver_config.time_limit and the poll loop count together |
Capture the reqId and the full response body for any failed request — both are needed to diagnose server-side rejections.
Limitations
QP is not exposed over REST. Use the Python or C API for quadratic objectives.
The server ships no authentication or TLS. Anything that can reach the port can submit jobs. Put it behind a gateway and treat
--server/base URLs as trusted-network endpoints only.Solutions are retrieved by polling; there is no push/webhook delivery.
One request is solved at a time per server process; concurrency requires multiple replicas.
Runnable assets
Run from each asset directory (server must be running; scripts exit 0 if server unreachable). All use Python requests and accept --server (default http://localhost:8000):
assets/vrp_simple/ — Basic VRP (no time windows)
assets/vrp_basic/ — VRP with time windows
assets/pdp_basic/ — Pickup and delivery
assets/lp_basic/ — LP via REST (CSR format)
assets/milp_basic/ — MILP via REST
See assets/README.md for overview.
Escalate
For contribution or build-from-source, see the developer skill.
Files
- ATTRIBUTION.mdAdded by AutoGineer938 B
- BENCHMARK.md8.8 KiB
- LICENSELicence file added by AutoGineer11.2 KiB
- SKILL.md5.8 KiB
- assets/README.md608 B
- assets/lp_basic/README.md368 B
- assets/lp_basic/client.pyScript2.9 KiB
- assets/milp_basic/README.md360 B
- assets/milp_basic/client.pyScript2.8 KiB
- assets/pdp_basic/README.md287 B
- assets/pdp_basic/client.pyScript3.3 KiB
- assets/vrp_basic/README.md376 B
- assets/vrp_basic/client.pyScript3.5 KiB
- assets/vrp_simple/README.md254 B
- assets/vrp_simple/client.pyScript3.2 KiB
- evals/evals.json8.5 KiB
- skill-card.md4.2 KiB
- skill.oms.sig7.0 KiB
evals/evals.json
[
{
"id": "srv-py-eval-001-rest-routing-workflow",
"question": "I have the cuOpt REST server running locally. List the HTTP endpoints I need to call to submit a routing problem and retrieve the solution, and the key payload field names for VRP with time windows. No full client script.",
"expected_skill": "cuopt-server-api-python",
"expected_script": null,
"ground_truth": "The agent describes the asynchronous submit-then-poll pattern: POST /cuopt/request returns a reqId, then GET /cuopt/solution/{reqId} until the solution is ready. The top-level VRPTW payload fields are cost_matrix_data, travel_time_matrix_data (note: REST uses travel_time_matrix_data, not the Python-API name transit_time_matrix_data), task_data, fleet_data, and solver_config. Does not produce a runnable client script.",
"expected_behavior": [
"Describes the POST /cuopt/request → reqId → GET /cuopt/solution/{reqId} polling flow",
"Names cost_matrix_data, travel_time_matrix_data, task_data, fleet_data, solver_config as the VRPTW payload fields and flags the travel_time_matrix_data (REST) vs transit_time_matrix_data (Python) naming",
"Does not produce a full runnable client script"
]
},
{
"id": "srv-py-eval-002-rest-lp-payload-fields",
"question": "I want to solve a linear program through the cuOpt REST server instead of the Python API. What does the request body look like — which top-level fields do I send, and in what format is the constraint matrix? Name the fields only, no runnable script.",
"expected_skill": "cuopt-server-api-python",
"expected_script": null,
"ground_truth": "The agent explains that the LP payload is posted to the same POST /cuopt/request endpoint and that the constraint matrix is supplied in CSR (compressed sparse row) form. The top-level fields are csr_constraint_matrix (with offsets, indices, values), constraint_bounds (lower_bounds / upper_bounds, where infinite bounds are the strings \"ninf\" and \"inf\"), objective_data (coefficients), variable_bounds (lower_bounds / upper_bounds), maximize (boolean), and solver_config (e.g. time_limit). Does not produce a runnable client script.",
"expected_behavior": [
"States that LP uses the same POST /cuopt/request → GET /cuopt/solution/{reqId} flow as routing",
"Names csr_constraint_matrix (offsets/indices/values), constraint_bounds, objective_data, variable_bounds, maximize, and solver_config",
"Notes that the constraint matrix is CSR and that infinite bounds are expressed as the strings \"inf\"/\"ninf\"",
"Does not produce a full runnable client script"
]
},
{
"id": "srv-py-eval-003-rest-milp-vs-lp",
"question": "I already have an LP working against the cuOpt REST server. What is the minimum change to the request body to make some of the variables integer?",
"expected_skill": "cuopt-server-api-python",
"expected_script": null,
"ground_truth": "The agent explains that MILP over REST uses the identical payload structure as LP, with one addition: a variable_types array, one entry per variable, using the values \"integer\", \"continuous\", or \"binary\". No endpoint change and no other field change is required.",
"expected_behavior": [
"Identifies variable_types as the only field that must be added",
"Gives the per-variable values \"integer\", \"continuous\", \"binary\"",
"Confirms the endpoint and remaining payload fields are unchanged from LP"
]
},
{
"id": "srv-py-eval-004-qp-not-supported-over-rest",
"question": "Can I solve a quadratic program (quadratic objective, linear constraints) by POSTing to the cuOpt REST server? If not, what should I use instead?",
"expected_skill": "cuopt-server-api-python",
"expected_script": null,
"ground_truth": "The agent states that QP is not exposed over the REST server — the server supports routing, LP, and MILP only — and redirects the user to the cuOpt Python or C API for quadratic objectives. It does not invent a REST payload field for a quadratic objective term.",
"expected_behavior": [
"States clearly that QP is not available through the REST API",
"Redirects to the Python or C API for QP",
"Does not fabricate a REST request field for the quadratic objective"
]
},
{
"id": "srv-py-eval-005-debug-422-field-names",
"question": "My POST to /cuopt/request keeps coming back 422. My payload has a transit_time_matrix_data key and fleet_data.capacities set to [[50], [50]] for my two vehicles. What is wrong?",
"expected_skill": "cuopt-server-api-python",
"expected_script": null,
"ground_truth": "The agent identifies two distinct errors. First, the REST API expects travel_time_matrix_data; transit_time_matrix_data is the Python-API name and is not a valid REST field. Second, capacities is indexed per capacity dimension, not per vehicle — for two vehicles sharing a single capacity dimension of 50 the correct value is [[50, 50]], whereas [[50], [50]] declares two capacity dimensions. It also suggests checking field names against the OpenAPI spec at /cuopt.yaml.",
"expected_behavior": [
"Flags transit_time_matrix_data → travel_time_matrix_data",
"Explains that capacities is nested per capacity dimension, not per vehicle, and gives [[50, 50]] as the fix",
"Points at the OpenAPI spec (/cuopt.yaml) as the authority for field names"
]
},
{
"id": "srv-py-eval-006-docker-deployment",
"question": "How do I run the cuOpt server in Docker so I can reach it on port 8000 from my host? Give me the command and tell me how to choose the image tag.",
"expected_skill": "cuopt-server-api-python",
"expected_script": null,
"ground_truth": "The agent gives a docker run command that passes --gpus all (the server requires a GPU) and publishes the port with -p 8000:8000. For the tag it recommends latest-cu12 or latest-cu13 chosen to match the driver's CUDA major version (latest-cu13-ubi10 for a UBI10 base). It notes that for production the tag should be pinned to a full release tag or an immutable @sha256 digest, since latest-* tags are mutable. It also mentions verifying with a request to /cuopt/health.",
"expected_behavior": [
"Includes --gpus all and -p 8000:8000 in the docker run command",
"Recommends latest-cu12 / latest-cu13 selected by CUDA major version over CUDA+Python-specific tags",
"Notes that latest-* is mutable and should be pinned to a release tag or digest for production",
"Mentions verifying the container with GET /cuopt/health"
]
},
{
"id": "srv-py-eval-007-client-hardening",
"question": "I'm writing a Python client that submits a job to the cuOpt server and polls for the result. What should I be careful about in the polling loop?",
"expected_skill": "cuopt-server-api-python",
"expected_script": null,
"ground_truth": "The agent advises setting an explicit timeout on every requests call, calling raise_for_status() on the submit response, and validating the server-supplied reqId (e.g. against a pattern like [A-Za-z0-9_-]{1,64}) before interpolating it into the /cuopt/solution/{reqId} URL, since it is untrusted network input. It also notes that the poll budget and solver_config.time_limit need to be raised together, and that the server offers no built-in auth or TLS so the base URL should point at a trusted endpoint.",
"expected_behavior": [
"Recommends an explicit timeout on every request",
"Recommends validating the server-returned reqId before using it in a URL path",
"Notes that the poll loop budget must accommodate solver_config.time_limit"
]
},
{
"id": "srv-py-eval-008-runnable-assets",
"question": "Does this skill ship any ready-to-run REST client examples? If so, what do they cover and how do I point one at a server that is not on localhost:8000?",
"expected_skill": "cuopt-server-api-python",
"expected_script": null,
"ground_truth": "The agent lists the bundled assets — vrp_simple (basic VRP), vrp_basic (VRP with time windows), pdp_basic (pickup and delivery), lp_basic (LP via CSR), and milp_basic (MILP) — and explains that each is a client.py using requests that accepts a --server flag defaulting to http://localhost:8000. It notes the scripts exit 0 when the server is unreachable so they are safe to run in CI.",
"expected_behavior": [
"Names the five asset directories and what each demonstrates",
"States that the server URL is set with the --server command-line flag (default http://localhost:8000)",
"Mentions that the scripts exit 0 if the server is unreachable"
]
}
]
Requirements and compatibility
Works with: Claude Code, Claude apps, OpenAI Codex, GitHub Copilot, Cursor, Gemini CLI, Kiro, OpenCode, Goose, Amp, Roo Code, JetBrains Junie, Factory Droid, Devin (ex-Windsurf), Mistral Vibe, OpenHands, Letta
“Works with” means the tool reads the open Agent Skills format; a skill written for one tool may use features others lack.
Needs: Needs network access, Needs an API key, Needs a command-line tool, Needs Python
Security
What our scanner noticed· Medium risk
- Large base64-encoded blobs
- Instructions that use the network
- Scripts that your agent may run
This skill includes scripts that your agent may run. Read them before you use it.
A static scan is not a guarantee. Skills are third-party content: review a skill before you let an agent use it.
Attribution and licence
- Created by
- NVIDIA cuOpt Team
- Publisher
- NVIDIA (Official)
- Source
- NVIDIA/skills · skills/cuopt-server-api-python · commit fce3cca
- Licence
- Apache License 2.0 (redistribution allowed)
- LICENSE (added by AutoGineer from LICENSE-APACHE)
- ATTRIBUTION.md (written by AutoGineer)
- Synced
AutoGineer is not affiliated with or endorsed by NVIDIA cuOpt Team or NVIDIA.
Download ZIP
The ZIP holds the skill’s files, its licence files and an ATTRIBUTION.md. Download cuopt-server-api-python.zip