> 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.

# Function nemo_relay_register_llm_request_intercept

> Register an LLM request intercept. The callback can transform the `LlmRequest` before it reaches the LLM provider.

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`.

<pre />

Register an LLM request intercept. The callback can transform the `LlmRequest` before it reaches the LLM provider.

## Parameters

* `name`: Unique intercept name.
* `priority`: Execution priority (lower runs first).
* `break_chain`: If true, stop processing further intercepts after this one.
* `cb`: LLM request transform callback (receives/returns `FfiLLMRequest`).
* `user_data`: Opaque pointer passed to `cb`.
* `free_fn`: Optional destructor for `user_data`.

The callback is fallible. To signal failure, call [`crate::error::nemo_relay_set_last_error_message`](/reference/api/rust-library-reference/nemo-relay-ffi/error/fn-nemo-relay-set-last-error-message) from C and return null.

## Safety

`name` must be a valid C string. `cb` must be a valid function pointer.