Run the Agent Optimizer
Use the Agent Optimizer to analyze a deployed agent and act on improvement suggestions. The optimizer inspects the agent’s config, the workspace model catalog, any prior optimizer snapshots, and optional evaluation baselines, then writes suggestions you can review from the CLI or hand off to a coding agent.
This page covers the main path: establish a baseline, generate optimization suggestions, apply a candidate change to a sibling agent, and review the evaluation result before promotion.
What the Optimizer Checks
Optimizer state is stored in the nemo-agent-optimizer fileset:
optimizer_suggestions.jsonl: one suggestion per line, including applied state.optimizer_snapshot.json: model and agent names from the latest run.
Security-oriented suggestions such as missing guardrails, PII exposure, or leaked secrets are covered in Secure Agents.
Prerequisites
Before running the optimizer, make sure you have:
- Local services running (
nemo services run). - The agents plugin installed. For local development from this repository:
- A workspace with at least one model provider and discovered model entities.
- At least one deployed platform-managed agent.
- An evaluation baseline before promoting a candidate agent.
If you need a demo agent, start the platform and create the ReAct example:
In another terminal:
The example agent uses nvidia-nemotron-3-nano-30b-a3b, so it can produce a
model optimization suggestion when the workspace model catalog contains a
smaller compatible model.
Optimize with Switchyard Routing
Switchyard is the inference middleware that lets a virtual model split traffic across multiple backend models. The common optimization pattern is to create a virtual model with a strong model and a weaker, cheaper model, then evaluate whether the route split preserves application quality.
Run nemo models list first and replace the placeholders below with model
entity names from your workspace that use the OPENAI_CHAT backend format.
CLI
Skill
Python SDK
The command below creates a virtual model that sends 80% of traffic to the strong model and 20% to the weak one.
Before wiring the virtual model to an agent, smoke-test the route by
making several minimal chat-completions calls and checking the returned
model name. The observed split should roughly match strong_probability.
Optimize Skills
Skill optimization applies when the agent depends on local skill files and has an evaluation suite. The loop runs evaluations, analyzes failures, lets the coding agent edit only the configured skills directory, reruns verification, and keeps the change only when the evaluation result improves.
CLI
Skill
Python SDK
Set open_pr: true in the YAML when you want the loop to prepare a
reviewable branch.
A sample .agent-improver.yml is in
plugins/nemo-agents/examples/agent-improver.example.yml.
Inspect Saved Results
Use the Files service to inspect what the optimizer saved:
Telemetry is optional. If agents use the nemo_files telemetry exporter, trace
files are written to nemo-agent-telemetry, and the optimizer samples the
largest JSONL file:
Run Prompt and Parameter Tuning
The nemo agents optimize command submits Fabric-backed numeric
optimization through agents.optimize (implementation in
nemo-optimization). Input must be a Fabric-native agent package
(schema_version: fabric.agent/v1alpha1). The golden-path harness is
Hermes (nvidia.fabric.hermes); see
plugins/nemo-optimization/examples/hermes-optimize/ (install steps live in
that README).
After uv sync --package nemo-agents-plugin (and activating .venv), invoke
nemo directly.
For CLI platform runs, keep the config and everything it references in one
directory — an optimize bundle — stage that bundle with prepare-fileset,
and pass --optimize-config as a path relative to the staged fileset root.
For local Python SDK runs, optimize_config must be an absolute host path;
paths inside the YAML (dataset, eval.fabric.base_dir, hook and MCP configs)
resolve against your current working directory.
Chat-only Hermes (no MCP)
CLI
Skill
Python SDK
MCP Hermes (phishing analyzer)
Point PHISHING_AGENT_SRC / PHISHING_MCP_BIN at an
email-phishing-analyzer-harnesses checkout (its own .venv after
uv sync). Do not pip-install that agent into the platform venv.
Full setup steps are in plugins/nemo-optimization/examples/hermes-optimize/README.md.
CLI
Python SDK
When --agent is a platform-managed agent name, the job fetches the stored
Fabric agent config, overlays the optimization settings, runs Inference Gateway
model preflight, and dispatches to the Tune backend. --agent must be a
workspace agent name (hermes-optimize-chatonly or
default/hermes-optimize-chatonly). Endpoint URLs and other URI forms
(http://..., https://..., file://...) are rejected — raw HTTP endpoint
optimize mode was removed. Use a platform-managed agent reference or an inline
Fabric agent package in --optimize-config.
Run a Study on the Platform
nemo agents optimize hands the study to the platform’s Jobs service, which
runs it on the platform host or cluster and therefore cannot read your
filesystem. The command accepts no host paths: it takes a fileset holding the
whole optimize bundle, plus a config path relative to that fileset’s root.
1. Stage the bundle
prepare-fileset validates before it uploads, and prints the matching
nemo agents optimize command on success. It checks that:
- the YAML parses and enables an optimizer with a non-empty search space;
- there is an Agent under Test — either an inline
schema_version: fabric.agent/v1alpha1package or a resolvable--agent; - every path the config references (dataset,
eval.fabric.base_dir,eval.run_hook.path/agent_src, MCPconfig_paths) is relative and present under--source; - no absolute host path would be shipped to the worker.
Use --dry-run to validate without uploading, and --no-check-models to skip
resolving the config’s models against the platform.
The upload is recursive. Delete local run output (artifacts/, .tmp/) from
the bundle before staging.
2. Run
--optimize-config-fileset is required: passing an absolute host path fails at
compile time with a pointer back to prepare-fileset. Add
--output <fileset-or-dir> to publish the study’s artifacts (optimized config,
trials dataframe, ATIF evidence) somewhere addressable when it finishes.
Where the study runs
OptimizeJob picks its executor from the execution profiles the platform
actually registered, for the requested profile (currently always default):
Subprocess wins when both are registered, because a study drives Fabric trials that often need the host’s Docker daemon and harness adapters. If neither is registered under the profile, compile fails and lists what is available.
Troubleshooting
No suggestions appear. Confirm the workspace has agents, model entities, and a model catalog entry smaller than the agent’s current model. New-model suggestions require a previous optimizer snapshot, so they do not appear on the first run.
The model evaluation fails. Confirm the judge model in the eval config is available through the workspace Inference Gateway. You can replace the eval files in <agent-name>-eval with your own evaluation config and dataset.
Data safety suggestions do not appear. Telemetry is optional. The optimizer only scans nemo-agent-telemetry when that fileset exists and contains JSONL trace files.
Next steps
- Agent overview: review how platform-managed agents are registered, deployed, invoked, evaluated, and optimized.
- Agent evaluation: configure agents as online evaluation targets and choose the right agent response mapping.
- CLI reference: look up complete command options and global CLI flags for scripted workflows.