> This page is for NeMo Relay, version v0.9.4.
> 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 codec

> LLM codec types, traits, and built-in implementations.

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`.

LLM codec types, traits, and built-in implementations.

This module provides the type system and traits for bidirectional request codecs ([`traits::LlmCodec`](/reference/api/rust-library-reference/nemo-relay/codec/traits/trait-llmcodec) / [`request::AnnotatedLlmRequest`](/reference/api/rust-library-reference/nemo-relay/codec/request/struct-annotatedllmrequest)), the decode-only response codec ([`traits::LlmResponseCodec`](/reference/api/rust-library-reference/nemo-relay/codec/traits/trait-llmresponsecodec) / [`response::AnnotatedLlmResponse`](/reference/api/rust-library-reference/nemo-relay/codec/response/struct-annotatedllmresponse)), and the streaming response codec ([`streaming::StreamingCodec`](/reference/api/rust-library-reference/nemo-relay/codec/streaming/trait-streamingcodec)) used with the managed streaming LLM execution pipeline.

[`resolve`](/reference/api/rust-library-reference/nemo-relay/codec/resolve) is the detect-then-decode entry point for selecting a built-in provider codec from a raw payload when no codec annotation is present.

## Modules

* [anthropic](/reference/api/rust-library-reference/nemo-relay/codec/anthropic): Built-in codec for the Anthropic Messages API.
* [gemini\_generate\_content](/reference/api/rust-library-reference/nemo-relay/codec/gemini_generate_content): Built-in codec for the Gemini generateContent API.
* [model\_pricing](/reference/api/rust-library-reference/nemo-relay/codec/model_pricing): Data-driven LLM model pricing used to layer cost estimates onto usage.
* [oci\_genai](/reference/api/rust-library-reference/nemo-relay/codec/oci_genai): Built-in codec for the Oracle Cloud Infrastructure (OCI) Generative AI chat API.
* [openai\_chat](/reference/api/rust-library-reference/nemo-relay/codec/openai_chat): Built-in codec for the OpenAI Chat Completions API.
* [openai\_responses](/reference/api/rust-library-reference/nemo-relay/codec/openai_responses): Built-in codec for the OpenAI Responses API.
* [optimization](/reference/api/rust-library-reference/nemo-relay/codec/optimization): Re-exported plugin-neutral LLM optimization data types.
* [request](/reference/api/rust-library-reference/nemo-relay/codec/request): Re-exported normalized LLM request data types.
* [resolve](/reference/api/rust-library-reference/nemo-relay/codec/resolve): Provider-surface detection, best-effort normalization, and construction of the matching built-in codecs from a raw payload, surface, or codec name.
* [response](/reference/api/rust-library-reference/nemo-relay/codec/response): Re-exported normalized LLM response data types and core pricing helpers.
* [streaming](/reference/api/rust-library-reference/nemo-relay/codec/streaming): Streaming response codecs for the managed LLM execution pipeline.
* [traits](/reference/api/rust-library-reference/nemo-relay/codec/traits): LLM codec traits for bidirectional request translation.