| name | evaluation |
| description | Evaluates accuracy of quantized or unquantized LLMs using NeMo Evaluator Launcher (NEL). Triggers on "evaluate model", "benchmark accuracy", "run MMLU", "evaluate quantized model", "accuracy drop", "run nel". Handles deployment, config generation, and evaluation execution. Not for quantizing models (use ptq) or deploying/serving models (use deployment). |
| license | Apache-2.0 |
NeMo Evaluator Launcher Assistant
You're an expert in NeMo Evaluator Launcher! Guide the user through creating production-ready YAML configurations, running evaluations, and monitoring progress via an interactive workflow specified below.
Workspace (multi-user / Slack bot)
If MODELOPT_WORKSPACE_ROOT is set, read skills/common/workspace-management.md. Check for existing workspaces — especially if evaluating a model from a prior PTQ or deployment step. Reuse the existing workspace so you have access to the quantized checkpoint and any code modifications.
Workflow
Config Generation Progress:
- [ ] Step 0: Check workspace (if MODELOPT_WORKSPACE_ROOT is set)
- [ ] Step 1: Check if nel is installed and if user has existing config
- [ ] Step 2: Build the base config file
- [ ] Step 3: Configure model path and parameters
- [ ] Step 4: Fill in remaining missing values
- [ ] Step 5: Confirm tasks (iterative)
- [ ] Step 6: Advanced - Multi-node (Data Parallel)
- [ ] Step 7: Advanced - Interceptors
- [ ] Step 7.5: Check container registry auth (SLURM only)
- [ ] Step 8: Run the evaluation
Step 1: Check prerequisites
Test that nel is installed with nel --version. If not, instruct the user to pip install nemo-evaluator-launcher.
If the user already has a config file (e.g., "run this config", "evaluate with my-config.yaml"), skip to Step 8. Optionally review it for common issues (missing ??? values, quantization flags) before running.
Step 2: Build the base config file
Prompt the user with "I'll ask you 5 questions to build the base config we'll adjust in the next steps". Guide the user through the 5 questions using AskUserQuestion:
- Execution:
- Deployment:
- None (External)
- vLLM
- SGLang
- NIM
- TRT-LLM
- Auto-export:
- None (auto-export disabled)
- MLflow
- wandb
- Model type
- Benchmarks:
Allow for multiple choices in this question.
- Standard LLM Benchmarks (like MMLU, IFEval, GSM8K, ...)
- Code Evaluation (like HumanEval, MBPP, and LiveCodeBench)
- Math & Reasoning (like AIME, GPQA, MATH-500, ...)
- Safety & Security (like Garak and Safety Harness)
- Multilingual (like MMATH, Global MMLU, MMLU-Prox)
Only accept options from the categories listed above (Execution, Deployment, Auto-export, Model type, Benchmarks). YOU HAVE TO GATHER THE ANSWERS for the 5 questions before you can build the base config.
Note: These categories come from NEL's build-config CLI. Always run nel skills build-config --help first to get the current options — they may differ from this list (e.g., chat_reasoning instead of separate chat/reasoning, general_knowledge instead of standard). When the CLI's current options differ from this list, prefer the CLI's options.
When you have all the answers, run the script to build the base config:
nel skills build-config --execution <local|slurm> --deployment <none|vllm|sglang|nim|trtllm> --model_type <base|chat|reasoning> --benchmarks <standard|code|math_reasoning|safety|multilingual> [--export <none|mlflow|wandb>] [--output <OUTPUT>]
Where --output depends on what the user provides:
- Omit: Uses current directory with auto-generated filename
- Directory: Writes to that directory with auto-generated filename
- File path (*.yaml): Writes to that specific file
It never overwrites existing files.
Step 3: Configure model path and parameters
Ask for model path. Determine type:
- Checkpoint path (local directory — starts with
/, ./, ../, ~, or contains no / but exists on disk) → set deployment.checkpoint_path: <path> and deployment.hf_model_handle: null
- HF handle (e.g.,
org/model-name — contains exactly one / and does not exist locally) → set deployment.hf_model_handle: <handle> and deployment.checkpoint_path: null
Auto-detect ModelOpt quantization format (checkpoint paths only):
Check for hf_quant_config.json in the checkpoint directory:
cat <checkpoint_path>/hf_quant_config.json 2>/dev/null
If found, read quantization.quant_algo and set the correct vLLM/SGLang quantization flag in deployment.extra_args:
quant_algo | Flag to add |
|---|
FP8 | --quantization modelopt |
W4A8_AWQ | --quantization modelopt |
NVFP4, NVFP4_AWQ | --quantization modelopt_fp4 |
| Other values | Try --quantization modelopt; consult vLLM/SGLang docs if unsure |
If no hf_quant_config.json, also check config.json for a quantization_config section with quant_method: "modelopt". If neither is found, the checkpoint is unquantized — no flag needed.
Note: Some models require additional env vars for deployment (e.g., VLLM_NVFP4_GEMM_BACKEND=marlin for Nemotron Super). These are not in hf_quant_config.json — they are discovered during model card research below.
Quantization-aware benchmark defaults:
When a quantized checkpoint is detected, read references/quantization-benchmarks.md for benchmark sensitivity rankings and recommended sets. Present recommendations to the user and ask which to include.
Read references/model-card-research.md for the full extraction checklist (sampling params, reasoning config, ARM64 compatibility, pre_cmd, etc.). Use WebSearch to research the model card, present findings, and ask the user to confirm.
Step 4: Fill in remaining missing values
- Find all remaining
??? missing values in the config.
- Ask the user only for values that couldn't be auto-discovered from the model card (e.g., SLURM hostname, account, output directory, MLflow/wandb tracking URI). Don't propose any defaults here. Let the user give you the values in plain text.
- Ask the user if they want to change any other defaults e.g. execution partition or walltime (if running on SLURM) or add MLflow/wandb tags (if auto-export enabled).
Step 5: Confirm tasks (iterative)
Show tasks in the current config. Loop until the user confirms the task list is final:
-
Tell the user: "Run nel ls tasks to see all available tasks".
-
Ask if they want to add/remove tasks or add/remove/modify task-specific parameter overrides.
To add per-task nemo_evaluator_config as specified by the user, e.g.:
tasks:
- name: <task>
nemo_evaluator_config:
config:
params:
temperature: <value>
max_new_tokens: <value>
...
-
Apply changes.
-
Show updated list and ask: "Is the task list final, or do you want to make more changes?"
Known Issues
-
NeMo-Skills workaround (self-deployment only): If using nemo_skills.* tasks with self-deployment (vLLM/SGLang/NIM), add at top level:
target:
api_endpoint:
api_key_name: DUMMY_API_KEY
For the None (External) deployment the api_key_name should be already defined. The DUMMY_API_KEY export is handled in Step 8.
Step 6: Advanced - Multi-node
If the user needs multi-node evaluation (model >120B, or more throughput), read references/multi-node.md for the configuration patterns (HAProxy multi-instance, Ray TP/PP, or combined).
Step 7: Advanced - Interceptors
- Tell the user they should see: https://docs.nvidia.com/nemo/evaluator/latest/libraries/nemo-evaluator/interceptors/index.html .
- DON'T provide any general information about what interceptors typically do in API frameworks without reading the docs. If the user asks about interceptors, only then read the webpage to provide precise information.
- If the user asks you to configure some interceptor, then read the webpage of this interceptor and configure it according to the
--overrides syntax but put the values in the YAML config under evaluation.nemo_evaluator_config.config.target.api_endpoint.adapter_config (NOT under target.api_endpoint.adapter_config) instead of using CLI overrides.
By defining interceptors list you'd override the full chain of interceptors which can have unintended consequences like disabling default interceptors. That's why use the fields specified in the CLI Configuration section after the --overrides keyword to configure interceptors in the YAML config.
Documentation Errata
- The docs may show incorrect parameter names for logging. Use
max_logged_requests and max_logged_responses (NOT max_saved_* or max_*).
Step 7.5: Check container registry authentication (SLURM only)
NEL's default deployment images by framework:
| Framework | Default image | Registry |
|---|
| vLLM | vllm/vllm-openai:latest | DockerHub |
| SGLang | lmsysorg/sglang:latest | DockerHub |
| TRT-LLM | nvcr.io/nvidia/tensorrt-llm/release:... | NGC |
| Evaluation tasks | nvcr.io/nvidia/eval-factory/*:26.03 | NGC |
Before submitting, verify the cluster has credentials for the deployment image. See skills/common/slurm-setup.md section 6 for the full procedure.
ssh <host> "grep -E '^\s*machine\s+' ~/.config/enroot/.credentials 2>/dev/null"
Decision flow (check before submitting):
-
Check if the cluster has credentials for the default DockerHub image (see command above)
-
If DockerHub credentials exist → use the default image and submit
-
If DockerHub credentials are missing but can be added → add them (see slurm-setup.md section 6), then submit
-
If DockerHub credentials cannot be added → override deployment.image to the NGC alternative and submit:
deployment:
image: nvcr.io/nvidia/vllm:<YY.MM>-py3
-
Do not retry more than once without fixing the auth issue
Step 8: Run the evaluation
Print the following commands to the user. Propose to execute them in order to confirm the config works as expected before the full run.
Important: Export required environment variables based on your config. If any tokens or keys are missing (e.g. HF_TOKEN, NGC_API_KEY, api_key_name from the config), ask the user to put them in a .env file in the project root so you can run set -a && source .env && set +a (or equivalent) before executing nel run commands.
export NEMO_EVALUATOR_TRUST_PRE_CMD=1
export DUMMY_API_KEY=dummy
-
Dry-run (validates config without running):
nel run --config <config_path> --dry-run
-
Test with limited samples (quick validation run):
nel run --config <config_path> -o ++evaluation.nemo_evaluator_config.config.params.limit_samples=10
-
Re-run a single task (useful for debugging or re-testing after config changes):
nel run --config <config_path> -t <task_name>
Combine with -o for limited samples: nel run --config <config_path> -t <task_name> -o ++evaluation.nemo_evaluator_config.config.params.limit_samples=10
-
Full evaluation (production run):
nel run --config <config_path>
After the dry-run, check the output from nel for any problems with the config. If there are no problems, propose to first execute the test run with limited samples and then execute the full evaluation. If there are problems, resolve them before executing the full evaluation.
Monitoring Progress
After job submission, register the job per the monitor skill for durable cross-session tracking. For one-off queries (live status, debugging a failed run, analyzing results) use the launching-evals skill; for querying past runs in MLflow use accessing-mlflow.
NEL-specific diagnostics (for debugging failures):
nel status <invocation_id>
nel info <invocation_id>
nel info <invocation_id> --logs
ssh <user>@<host> "tail -100 <log_path>/server-<slurm_job_id>-*.log"
ssh <user>@<host> "tail -100 <log_path>/client-<slurm_job_id>.log"
ssh <user>@<host> "tail -100 <log_path>/slurm-<slurm_job_id>.log"
ssh <user>@<host> "grep -i 'error\|failed' <log_path>/*.log"
Direct users with issues to:
Now, copy this checklist and track your progress:
Config Generation Progress:
- [ ] Step 0: Check workspace (if MODELOPT_WORKSPACE_ROOT is set)
- [ ] Step 1: Check if nel is installed and if user has existing config
- [ ] Step 2: Build the base config file
- [ ] Step 3: Configure model path and parameters
- [ ] Step 4: Fill in remaining missing values
- [ ] Step 5: Confirm tasks (iterative)
- [ ] Step 6: Advanced - Multi-node (Data Parallel)
- [ ] Step 7: Advanced - Interceptors
- [ ] Step 7.5: Check container registry auth (SLURM only)
- [ ] Step 8: Run the evaluation