Struct ApiPrompt 

pub struct ApiPrompt { /* private fields */ }

A prompt formatter for API-based language models that follow OpenAI’s message format.

ApiPrompt handles formatting messages into the standard role/content pairs used by API-based LLMs. It manages token counting specific to these models, including per-message and per-name token overhead.

The struct maintains thread-safe interior mutability for built messages and token counts, rebuilding them as needed when the prompt content changes.

Implementations

impl ApiPrompt

pub fn new( tokenizer: Arc<dyn PromptTokenizer>, tokens_per_message: Option<u32>, tokens_per_name: Option<i32>, ) -> ApiPrompt

pub fn get_built_prompt(&self) -> Result<Vec<HashMap<String, String>>, Error>

Retrieves the built prompt messages in OpenAI API format.

Returns the messages as a vector of hashmaps, where each message contains a “role” key (system/user/assistant) and a “content” key with the message text.

Returns

Returns Ok(Vec<HashMap<String, String>>) containing the formatted messages.

Errors

Returns an error if the prompt has not been built yet.

pub fn get_total_prompt_tokens(&self) -> Result<u64, Error>

Gets the total number of tokens in the prompt, including any model-specific overhead.

The total includes the base tokens from all messages plus any additional tokens specified by tokens_per_message and tokens_per_name. This count is useful for ensuring prompts stay within model context limits.

Returns

Returns Ok(u64) containing the total token count.

Errors

Returns an error if the prompt has not been built yet.

Trait Implementations

impl Clone for ApiPrompt

fn clone(&self) -> ApiPrompt

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Display for ApiPrompt

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Serialize for ApiPrompt

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.