About

Use this section when you want to package reusable NeMo Relay behavior as a plugin that can be activated from configuration.

Plugins are the configuration-driven packaging layer for shared runtime behavior. A plugin can validate component-local config, register middleware and subscribers through a component-scoped context, and rely on the plugin system to report diagnostics and roll back partial setup when activation fails.

Plugins prevent repeated registration code for policies, request transforms, exporters, and related runtime components. They give shared behavior a stable kind name, a structured config document, and a clear activation lifecycle.

NeMo Relay also ships built-in plugin components for shared runtime behavior. For example, the pricing component installs model-pricing sources that response codecs can use to annotate managed LLM responses with cost estimates. Applications, eval harnesses, custom agents, and framework integrations can activate that component through the same plugin APIs they use for custom plugins; the nemo-relay CLI is only one host that can load plugin configuration from files.

Start Here When

Use these signals to decide whether this documentation path matches your current task.

• Ship policy bundles across applications
• Install observability exporters consistently
• Install pricing sources for cost estimates across applications, harnesses, or agent integrations
• Package framework-agnostic request transforms
• Validate operator-supplied config before runtime behavior changes

If the behavior applies to only one request or tenant, consider scope-local middleware before turning it into a process-level plugin.

Guides

Use these guide links to move from the overview into task-specific instructions.

• Define a Plugin explains plugin kinds, shape, runtime ownership, and the activation lifecycle.
• Validate Plugin Configuration covers JSON-compatible config, validation rules, and structured diagnostics.
• Plugin Configuration Files documents plugins.toml file discovery, precedence, merge behavior, and editor controls for the CLI gateway.
• Register Plugin Behavior shows how to initialize config and install subscribers or middleware through PluginContext.
• Design Plugin Configuration covers validation rules, advanced configuration patterns, rollout controls, and PluginContext usage.
• NeMo Guardrails Plugin documents the built-in first-party nemo_guardrails component.
• Code Examples provides patterns for dynamic header injection, subscriber-oriented export, multi-surface bundles, and framework-facing plugins.

Start by deciding which runtime surfaces the plugin owns: middleware, subscribers, or a combination of related runtime behavior. Define the smallest JSON-compatible config that can drive that behavior, validate it before registration, and keep external objects or callables out of the config document.

Use plugins for reusable process-level behavior. Keep request-specific behavior scope-local so it is cleaned up with the owning scope.