Nemo Agent Config

NeMo Platform agent config

Create or edit the Platform-managed agent.yaml for a NeMo Agent. This skill owns the machine-readable config shape for nemo-agents-spec-v1; nemo-build-agent owns the full build/deploy/eval workflow.

Use product-facing Platform language. Do not ask users to write raw Fabric SDK configuration. Fabric is an implementation dependency behind the Platform-managed agent config.

Storage model

The local config lives next to the human-readable Ethos:

agents/<agent-name>-ethos/
  ETHOS.md
  agent.yaml

The platform stores the parsed agent.yaml contents in the Agent.config payload with:

config_format: nemo-agents-spec-v1

The canonical remote config location is derivable from workspace and agent name: <workspace>/<agent-name>-ethos#agent.yaml. Do not invent a separate ref field.

What you do

1. Confirm the agent name and config path. Default to agents/<agent-name>-ethos/agent.yaml.
2. Select one supported harness:
   • codex
   • hermes
   • deepagents
   • claude
3. Invoke nemo-model-selection to select and compatibility-test the model for the chosen harness. Configure models.default only after that skill returns a verified provider and exact model name. Add a harness-local model override only when that harness intentionally uses a different verified provider, model, credential env var, or base URL.
4. Start from references/templates/agent.yaml unless the user is editing an existing file. Write only the verified model fields returned in Step 3.
5. Remove every unselected harness block and every remaining placeholder. Keep an additional harness only when the user explicitly requests it and its model configuration has been separately verified.
6. Add system instructions under instructions.system.content.
7. Add optional skills, MCP servers, blocked tools, environment directories, and telemetry using only fields in the template.
8. Keep all local file paths relative to the directory containing agent.yaml.
9. Validate by running nemo agents create against the config. Do not treat a successful create as validation of an unused or untested harness.

For the standard subprocess or default-image deployment path, keep skills.paths empty. Registration validates relative skill paths against the authoring directory, but these deployment paths currently materialize only agent.yaml and do not stage the referenced directories.

When non-empty skills.paths are required, each path must be relative to agent.yaml, remain inside its packaging context, and contain SKILL.md. Require the explicit image-packaging path before deployment:

IMAGE_TAG="${AGENT_NAME}:local"
.venv/bin/nemo agents package \
  --agent "agents/$AGENT_NAME-ethos/agent.yaml" \
  --tag "$IMAGE_TAG"

Deploy that image with --mode docker --image "$IMAGE_TAG"; publish it first and use the published tag for Kubernetes. Do not use a subprocess or default-image deployment for an agent with relative skills.paths.

Migrating from legacy NAT workflow YAML

If the user has an existing NAT workflow YAML and wants the new Platform-managed agent.yaml format, treat the migration as best-effort authoring. Do not overwrite the original NAT YAML unless the user explicitly asks.

Map only fields with a clear Platform equivalent:

For a NAT codex_agent workflow, apply this mapping instead of copying the workflow fields into harnesses.codex.settings:

Treat the installed Fabric adapter descriptor's settings_schema as authoritative. Only place keys declared under its properties in harnesses.<name>.settings; do not preserve an unsupported NAT setting merely because it existed in the source workflow. Surface omitted behavior in the migration summary. For Codex, map never to deny_all only when settings_schema.properties.approval_mode.enum includes deny_all.

If behavior does not map cleanly, say so directly and choose one:

• Keep the agent on the NAT compatibility path.
• Preserve the original NAT YAML and create a partial agent.yaml starter for manual completion.
• Mark it as requiring a custom adapter or a manual harness-specific migration.

Never claim a mechanical one-to-one conversion for arbitrary NAT workflows.

Config shape

Use this structure. Keep unknown fields out of the YAML; the Platform validator rejects unsupported fields instead of passing arbitrary execution config through.

config_format: nemo-agents-spec-v1
name: <agent-name>
description: <short description>

instructions:
  system:
    content: <system instructions>

default_harness: codex

harnesses:
  codex:
    kind: codex
    settings:
      sandbox: workspace-write
      reasoning_effort: high

models:
  default:
    provider: <verified-provider>
    model: <verified-platform-model-name>
    api_key_env: <credential-env-var-if-needed>

skills:
  paths: []

mcp:
  servers: {}

tools:
  blocked: []

environment:
  workspace: ./workspace
  artifacts: ./artifacts

telemetry:
  enabled: false
  provider: relay
  output_dir: ./artifacts/relay
  project: <agent-name>

Harness overrides

Use a harness-local model only when that harness should override the default.

harnesses:
  hermes:
    kind: hermes
    model:
      provider: <verified-provider>
      model: <verified-model-name>
      api_key_env: <credential-env-var-if-needed>
      base_url: <provider-base-url-if-needed>
      temperature: 0.0
    settings:
      max_tokens: 512
      reasoning_config:
        effort: none

If base_url is needed, put it directly in the model block, not under settings.

Use nemo-model-selection for every harness. It must verify the exact model against that harness's model contract before returning it: Responses for codex, the selected provider's chat path for hermes and deepagents, and the native Anthropic provider contract for claude. Do not route Claude through Platform IGW. Do not write or finalize agent.yaml if model selection cannot establish a compatible model. For Platform-routed models, availability, provider metadata, config validation, and Fabric planning do not replace a valid inference request through the required wire API.

Validate and register

Before registering, validate the YAML shape with the Platform create path. Immediately before running nemo agents create, show the command to the user, ask for explicit confirmation, and wait for approval.

.venv/bin/nemo agents create \
  --name "$AGENT_NAME" \
  --agent-config "agents/$AGENT_NAME-ethos/agent.yaml"

If validation fails, fix the named field in agent.yaml and retry. Do not silence validation errors by moving unknown fields into settings.

Deploy and invoke

After create succeeds, show the nemo agents deploy command to the user, ask for explicit confirmation, and wait for approval before running it.

.venv/bin/nemo agents deploy \
  --agent "$AGENT_NAME" \
  --name "$AGENT_NAME-deployment"

The deploy command waits for running by default. After it succeeds, invoke the same explicitly named deployment without another confirmation:

.venv/bin/nemo agents invoke \
  --agent-deployment "$AGENT_NAME-deployment" \
  --input "<test prompt>"

For local one-shot validation without registering an Agent entity, use this only when the selected model already has a directly usable provider endpoint and credentials. Platform IGW normalization is applied by the registered deployment path, not this local path:

.venv/bin/nemo agents invoke \
  --agent-config "agents/$AGENT_NAME-ethos/agent.yaml" \
  --input "<test prompt>"

For a local persistent server, bind to loopback by default. Use an externally accessible host only when the user explicitly asks to expose the server:

.venv/bin/nemo agents run \
  --agent-config "agents/$AGENT_NAME-ethos/agent.yaml" \
  --host 127.0.0.1 \
  --port 8080

If validation fails

Hard rules

• Keep config_format: nemo-agents-spec-v1.
• Keep paths relative to the agent.yaml directory.
• Put system instructions under instructions.system.content.
• Do not use prompts for the default path; top-level prompts are not translated yet.
• Do not create profile files. Profiles are not the Platform authoring contract.
• Do not expose Fabric SDK object names as user-authored YAML fields.
• Do not emit arbitrary adapter settings unless the selected harness documents them.

Gotchas

• Default model vs harness model. A harness-local model always wins over models.default.
• Registration validates and normalizes. nemo agents create is the user-facing validation command.
• agent.yaml is the implementation config, not the Ethos. ETHOS.md explains what the agent should do; agent.yaml tells the Platform how to run it.
• NAT workflow YAML is a compatibility path. If the user explicitly asks for legacy NAT, route to nemo-build-agent and use its NAT template.