> This page is for NeMo Relay, version v0.8.4.
> For other versions, use one of these documentation indexes:
> - Latest (v0.10.0) (default): https://docs.nvidia.com/nemo/relay/latest/llms.txt
> - dev: https://docs.nvidia.com/nemo/relay/dev/llms.txt
> - v0.10.0: https://docs.nvidia.com/nemo/relay/v0.10.0/llms.txt
> - v0.9.4: https://docs.nvidia.com/nemo/relay/v0.9.4/llms.txt
> - v0.8.4: https://docs.nvidia.com/nemo/relay/v0.8.4/llms.txt
> - v0.7.3: https://docs.nvidia.com/nemo/relay/v0.7.3/llms.txt
> - v0.6.0: https://docs.nvidia.com/nemo/relay/v0.6.0/llms.txt
> - v0.5.0: https://docs.nvidia.com/nemo/relay/v0.5.0/llms.txt

> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.nvidia.com/nemo/relay/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.nvidia.com/nemo/relay/_mcp/server.

# Module capability

> Capability registry tracking per-backend and per-model-family supported features.

Generated from `cargo doc --no-deps -p nemo-relay -p nemo-relay-adaptive -p nemo-relay-pii-redaction -p nemo-relay-ffi -p nemo-relay-types -p nemo-relay-plugin -p nemo-relay-worker-proto -p nemo-relay-worker`.

Capability registry tracking per-backend and per-model-family supported features.

The registry provides feature discovery so the policy engine knows which optimization intents can be expressed on which backend/model combinations.

## Two-Level Feature Lookup

[`BackendCapabilities`](/reference/api/rust-library-reference/nemo-relay-adaptive/acg/capability/struct-backendcapabilities) stores backend-level defaults plus per-model-family overrides via [`ModelFamilyCapabilities`](/reference/api/rust-library-reference/nemo-relay-adaptive/acg/capability/struct-modelfamilycapabilities). Feature lookups check the model family first, falling back to backend-level if the family is not registered.

## Built-in Defaults

[`CapabilityRegistry::with_defaults()`](/reference/api/rust-library-reference/nemo-relay-adaptive/acg/capability/struct-capabilityregistry) returns a registry pre-populated with known Anthropic and OpenAI capabilities.

## Structs

* [BackendCapabilities](/reference/api/rust-library-reference/nemo-relay-adaptive/acg/capability/struct-backendcapabilities): Capabilities of a specific backend provider.
* [CacheEconomics](/reference/api/rust-library-reference/nemo-relay-adaptive/acg/capability/struct-cacheeconomics): Provider/model-specific cache economics used by the internal planner.
* [CapabilityRegistry](/reference/api/rust-library-reference/nemo-relay-adaptive/acg/capability/struct-capabilityregistry): Registry holding capabilities for all known backends.
* [ModelFamilyCapabilities](/reference/api/rust-library-reference/nemo-relay-adaptive/acg/capability/struct-modelfamilycapabilities): Per-model-family capability overrides within a backend.

## Enums

* [ProviderFeature](/reference/api/rust-library-reference/nemo-relay-adaptive/acg/capability/enum-providerfeature): Feature that a backend or model family may support.