Build a Plugin

Build a Plugin

Use this skill when a user wants to package reusable NeMo Relay runtime behavior behind plugin configuration. Keep reusable plugin behavior separate from one-off application startup code.

Use This When

Use this skill when the behavior should be activated by shared config and reused across applications, teams, or process startup paths.

Common cases:

• Register subscribers, guardrails, intercepts, or a small bundle of related runtime behavior.
• Validate operator-supplied config before changing runtime behavior.
• Give reusable behavior a stable plugin kind and activation lifecycle.
• Package behavior that should be enabled, disabled, or rolled out through plugin config rather than repeated application startup code.

Do Not Use This When

Do not build a plugin when a narrower NeMo Relay surface is enough:

• One request or tenant needs temporary behavior -> use scope-local middleware.
• The user only needs first-time scopes, tool calls, or LLM calls -> nemo-relay-instrument-calls.
• The user only needs to choose an exporter path -> nemo-relay-plugin-observability.
• The behavior depends on live callables, provider clients, file handles, credentials, or framework objects inside config.

Choose A Delivery Model

Choose the delivery model before designing config or registration:

• Embedded component: Use the shared plugin document when behavior ships with the Relay host application. Follow the embedded component model below.
• Discoverable dynamic package: Use a relay-plugin.toml manifest when the plugin ships independently of the host. Use rust_dynamic for a trusted