rig_core/providers/openai/wire/

route.rs

//! Dispatches completion requests to Chat Completions or Responses wires.
//! Explicit configuration routes override model-specific hooks and dialect defaults.
//!
//! ```
//! use rig_core::providers::openai::{OpenAI, OpenAIConfig, Route};
//! let provider: OpenAI = OpenAIConfig::new("key").with_route(Route::Chat).client();
//! let model = provider.completion("gpt-5.2");
//! ```

use serde::{Deserialize, Serialize};

use crate::completion::CompletionRequest;
use crate::error::{EncodeError, ProviderError};
use crate::operation::Completion;
use crate::providers::openai::responses_api::streaming::{ResponsesDecoder, ResponsesEvent};
use crate::providers::openai::responses_api::wire::Responses;
use crate::providers::openai::responses_api::{
    ResponsesToolDefinition, SystemInstructionsPlacement,
};
use crate::wire::{Decoder, Descriptor, Encoded, Flow, Mode, Out, Wire, WireEvent, WireFrame};

use super::OpenAIConfig;
use super::chat::{Chat, ChatDecoder, ChatEvent};

/// Dispatch a shared expression to the selected route.
macro_rules! on_route {
    ($chosen:expr, $wire:ident => $ask:expr) => {
        match $chosen {
            Self::Chat($wire) => $ask,
            Self::Responses($wire) => $ask,
        }
    };
}

/// Which completion endpoint a configuration serves.
#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize)]
pub enum Route {
    /// `POST /chat/completions`: the one endpoint every dialect serves.
    Chat,
    /// `POST /responses`: the flagship of OpenAI, xAI and ChatGPT.
    Responses,
}

/// A completion wire selected by configuration, model hook, or dialect default.
/// Route-specific options are no-ops on the other route.
#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
pub enum OpenAiWire {
    /// The chat-completions wire.
    Chat(Chat),
    /// The Responses wire.
    Responses(Responses),
}

impl OpenAiWire {
    /// The wire for `model` on `provider`'s
    /// [`completion_route`](OpenAIConfig::completion_route).
    pub fn new(provider: OpenAIConfig, model: impl Into<String>) -> Self {
        let model = model.into();
        let route = provider.route.unwrap_or_else(|| {
            provider
                .dialect
                .quirks
                .hooks
                .and_then(|hooks| hooks.model_route)
                .map_or_else(|| provider.completion_route(), |route| route(&model))
        });
        match route {
            Route::Chat => Self::Chat(Chat::new(provider, model)),
            Route::Responses => Self::Responses(Responses::new(provider, model)),
        }
    }

    /// A wrapper owning the envelope replaces the dialect's envelope here,
    /// before either encoder consumes the completion request.
    pub(crate) fn encode_with_headers(
        &self,
        request: CompletionRequest,
        mode: Mode,
        headers: impl FnOnce(
            &OpenAIConfig,
            &CompletionRequest,
            http::request::Builder,
        ) -> http::request::Builder,
    ) -> Result<Encoded, EncodeError> {
        on_route!(self, wire => wire.encode_with_headers(request, mode, headers))
    }

    /// The configuration this wire speaks to.
    pub fn provider(&self) -> &OpenAIConfig {
        on_route!(self, wire => &wire.provider)
    }

    /// Sanitize tool schemas for OpenAI's strict mode on whichever route
    /// this is.
    pub fn with_strict_tools(self) -> Self {
        self.on_chat(Chat::with_strict_tools)
            .on_responses(Responses::with_strict_tools)
    }

    /// Serialize tool-result content as arrays: a chat-completions shape,
    /// so a no-op on the Responses route, whose request has one content
    /// encoding.
    pub fn with_tool_result_array_content(self) -> Self {
        self.on_chat(Chat::with_tool_result_array_content)
    }

    /// Ask the provider to cache the prompt: an OpenRouter `cache_control`
    /// on the chat body, so a no-op on the Responses route.
    pub fn with_prompt_caching(self) -> Self {
        self.on_chat(Chat::with_prompt_caching)
    }

    /// Add a provider-side tool to every request: a Responses shape, so a
    /// no-op on the chat route, which carries no wire-level tools.
    pub fn with_tool(self, tool: impl Into<ResponsesToolDefinition>) -> Self {
        self.on_responses(|wire| wire.with_tool(tool))
    }

    /// Add provider-side tools to every request: a no-op on the chat
    /// route, which carries no wire-level tools.
    pub fn with_tools<I, Tool>(self, tools: I) -> Self
    where
        I: IntoIterator<Item = Tool>,
        Tool: Into<ResponsesToolDefinition>,
    {
        self.on_responses(|wire| wire.with_tools(tools))
    }

    /// Put Rig's system instructions somewhere other than the dialect's
    /// default placement: a no-op on the chat route, where a system message
    /// has one place to go.
    pub fn with_system_instructions_placement(
        self,
        placement: SystemInstructionsPlacement,
    ) -> Self {
        self.on_responses(|wire| wire.with_system_instructions_placement(placement))
    }

    /// Send Rig's system instructions as `system` messages in `input`: a
    /// no-op on the chat route, which sends them that way already.
    pub fn with_system_instructions_as_messages(self) -> Self {
        self.on_responses(Responses::with_system_instructions_as_messages)
    }

    /// Apply a chat-route option; the Responses route is left as it is.
    fn on_chat(self, option: impl FnOnce(Chat) -> Chat) -> Self {
        match self {
            Self::Chat(wire) => Self::Chat(option(wire)),
            responses => responses,
        }
    }

    /// Apply a Responses-route option; the chat route is left as it is.
    fn on_responses(self, option: impl FnOnce(Responses) -> Responses) -> Self {
        match self {
            Self::Responses(wire) => Self::Responses(option(wire)),
            chat => chat,
        }
    }
}

impl From<Chat> for OpenAiWire {
    fn from(wire: Chat) -> Self {
        Self::Chat(wire)
    }
}

impl From<Responses> for OpenAiWire {
    fn from(wire: Responses) -> Self {
        Self::Responses(wire)
    }
}

impl Wire for OpenAiWire {
    type Op = Completion;
    type Payload = crate::wire::Encoded;
    type Frame = crate::wire::WireFrame;
    type Decoder<'id> = OpenAiDecoder<'id>;

    fn describe(&self) -> Descriptor<'_> {
        on_route!(self, wire => wire.describe())
    }

    fn encode(&self, request: CompletionRequest, mode: Mode) -> Result<Encoded, EncodeError> {
        on_route!(self, wire => wire.encode(request, mode))
    }

    fn decoder<'id>(&self) -> OpenAiDecoder<'id> {
        match self {
            Self::Chat(wire) => OpenAiDecoder::Chat(wire.decoder()),
            Self::Responses(wire) => OpenAiDecoder::Responses(wire.decoder()),
        }
    }
}

/// One classified frame of whichever route is answering.
pub enum OpenAiEvent {
    /// A chat-completions frame.
    Chat(ChatEvent),
    /// A Responses frame.
    Responses(ResponsesEvent),
}

/// The chosen route's decoder.
pub enum OpenAiDecoder<'id> {
    /// The chat-completions state machine.
    Chat(ChatDecoder<'id>),
    /// The Responses state machine.
    Responses(ResponsesDecoder<'id>),
}

impl<'id> Decoder<'id, Completion> for OpenAiDecoder<'id> {
    type Event = OpenAiEvent;

    fn classify(&self, frame: WireFrame) -> WireEvent<OpenAiEvent> {
        match self {
            Self::Chat(decoder) => decoder.classify(frame).map(OpenAiEvent::Chat),
            Self::Responses(decoder) => decoder.classify(frame).map(OpenAiEvent::Responses),
        }
    }

    fn decode(
        &mut self,
        event: OpenAiEvent,
        out: Out<'id, Completion>,
    ) -> Result<Flow, ProviderError> {
        match (self, event) {
            (Self::Chat(decoder), OpenAiEvent::Chat(event)) => decoder.decode(event, out),
            (Self::Responses(decoder), OpenAiEvent::Responses(event)) => decoder.decode(event, out),
            // The driver feeds each decoder only events from its own
            // classifier.
            (Self::Chat(_), OpenAiEvent::Responses(_))
            | (Self::Responses(_), OpenAiEvent::Chat(_)) => Ok(Flow::More),
        }
    }

    fn eof(&mut self, out: Out<'id, Completion>) -> Result<Flow, ProviderError> {
        on_route!(self, decoder => decoder.eof(out))
    }
}

#[cfg(test)]
mod tests;