plano/crates/brightstaff/src/handlers/llm.rs

701 lines
27 KiB
Rust

use bytes::Bytes;
use common::configuration::ModelAlias;
use common::consts::{
ARCH_IS_STREAMING_HEADER, ARCH_PROVIDER_HINT_HEADER, REQUEST_ID_HEADER, TRACE_PARENT_HEADER,
};
use common::llm_providers::LlmProviders;
use hermesllm::apis::openai_responses::{InputParam, Tool as ResponsesTool};
use hermesllm::clients::{SupportedAPIsFromClient, SupportedUpstreamAPIs};
use hermesllm::{ProviderRequest, ProviderRequestType};
use http_body_util::combinators::BoxBody;
use http_body_util::{BodyExt, Full};
use hyper::header::{self};
use hyper::{Request, Response, StatusCode};
use opentelemetry::global;
use opentelemetry::trace::get_active_span;
use opentelemetry_http::HeaderInjector;
use std::collections::{HashMap, HashSet};
use std::sync::Arc;
use tokio::sync::RwLock;
use tracing::{debug, info, info_span, warn, Instrument};
use crate::handlers::router_chat::{router_chat_get_upstream_model, RoutingResult};
use crate::handlers::utils::{
create_streaming_response, truncate_message, ObservableStreamProcessor,
};
use crate::router::llm_router::RouterService;
use crate::state::response_state_processor::ResponsesStateProcessor;
use crate::state::{
extract_input_items, retrieve_and_combine_input, StateStorage, StateStorageError,
};
use crate::tracing::{llm as tracing_llm, operation_component, set_service_name};
fn full<T: Into<Bytes>>(chunk: T) -> BoxBody<Bytes, hyper::Error> {
Full::new(chunk.into())
.map_err(|never| match never {})
.boxed()
}
pub async fn llm_chat(
request: Request<hyper::body::Incoming>,
router_service: Arc<RouterService>,
full_qualified_llm_provider_url: String,
model_aliases: Arc<Option<HashMap<String, ModelAlias>>>,
llm_providers: Arc<RwLock<LlmProviders>>,
state_storage: Option<Arc<dyn StateStorage>>,
) -> Result<Response<BoxBody<Bytes, hyper::Error>>, hyper::Error> {
let request_path = request.uri().path().to_string();
let request_headers = request.headers().clone();
let request_id: String = match request_headers
.get(REQUEST_ID_HEADER)
.and_then(|h| h.to_str().ok())
.map(|s| s.to_string())
{
Some(id) => id,
None => uuid::Uuid::new_v4().to_string(),
};
// Create a span with request_id that will be included in all log lines
let request_span = info_span!(
"llm",
component = "llm",
request_id = %request_id,
http.method = %request.method(),
http.path = %request_path,
llm.model = tracing::field::Empty,
llm.tools = tracing::field::Empty,
llm.user_message_preview = tracing::field::Empty,
llm.temperature = tracing::field::Empty,
);
// Execute the rest of the handler inside the span
llm_chat_inner(
request,
router_service,
full_qualified_llm_provider_url,
model_aliases,
llm_providers,
state_storage,
request_id,
request_path,
request_headers,
)
.instrument(request_span)
.await
}
#[allow(clippy::too_many_arguments)]
async fn llm_chat_inner(
request: Request<hyper::body::Incoming>,
router_service: Arc<RouterService>,
full_qualified_llm_provider_url: String,
model_aliases: Arc<Option<HashMap<String, ModelAlias>>>,
llm_providers: Arc<RwLock<LlmProviders>>,
state_storage: Option<Arc<dyn StateStorage>>,
request_id: String,
request_path: String,
mut request_headers: hyper::HeaderMap,
) -> Result<Response<BoxBody<Bytes, hyper::Error>>, hyper::Error> {
// Set service name for LLM operations
set_service_name(operation_component::LLM);
// Extract or generate traceparent - this establishes the trace context for all spans
let traceparent: String = match request_headers
.get(TRACE_PARENT_HEADER)
.and_then(|h| h.to_str().ok())
.map(|s| s.to_string())
{
Some(tp) => tp,
None => {
use uuid::Uuid;
let trace_id = Uuid::new_v4().to_string().replace("-", "");
let generated_tp = format!("00-{}-0000000000000000-01", trace_id);
warn!(
generated_traceparent = %generated_tp,
"TRACE_PARENT header missing, generated new traceparent"
);
generated_tp
}
};
let chat_request_bytes = request.collect().await?.to_bytes();
debug!(
body = %String::from_utf8_lossy(&chat_request_bytes),
"request body received"
);
let mut client_request = match ProviderRequestType::try_from((
&chat_request_bytes[..],
&SupportedAPIsFromClient::from_endpoint(request_path.as_str()).unwrap(),
)) {
Ok(request) => request,
Err(err) => {
warn!(
error = %err,
"failed to parse request as ProviderRequestType"
);
let err_msg = format!("Failed to parse request: {}", err);
let mut bad_request = Response::new(full(err_msg));
*bad_request.status_mut() = StatusCode::BAD_REQUEST;
return Ok(bad_request);
}
};
// === v1/responses state management: Extract input items early ===
let mut original_input_items = Vec::new();
let client_api = SupportedAPIsFromClient::from_endpoint(request_path.as_str());
let is_responses_api_client = matches!(
client_api,
Some(SupportedAPIsFromClient::OpenAIResponsesAPI(_))
);
let requires_native_responses_tools =
responses_request_uses_non_function_tools(&client_request);
// If model is not specified in the request, resolve from default provider
let model_from_request = client_request.model().to_string();
let model_from_request = if model_from_request.is_empty() {
match llm_providers.read().await.default() {
Some(default_provider) => {
let default_model = default_provider.name.clone();
info!(default_model = %default_model, "no model specified in request, using default provider");
client_request.set_model(default_model.clone());
default_model
}
None => {
let err_msg = "No model specified in request and no default provider configured";
warn!("{}", err_msg);
let mut bad_request = Response::new(full(err_msg.to_string()));
*bad_request.status_mut() = StatusCode::BAD_REQUEST;
return Ok(bad_request);
}
}
} else {
model_from_request
};
// Model alias resolution: update model field in client_request immediately
// This ensures all downstream objects use the resolved model
let temperature = client_request.get_temperature();
let is_streaming_request = client_request.is_streaming();
let alias_resolved_model = resolve_model_alias(&model_from_request, &model_aliases);
// Validate that the requested model exists in configuration
// This matches the validation in llm_gateway routing.rs
if llm_providers
.read()
.await
.get(&alias_resolved_model)
.is_none()
{
let err_msg = format!(
"Model '{}' not found in configured providers",
alias_resolved_model
);
warn!(model = %alias_resolved_model, "model not found in configured providers");
let mut bad_request = Response::new(full(err_msg));
*bad_request.status_mut() = StatusCode::BAD_REQUEST;
return Ok(bad_request);
}
// Handle provider/model slug format (e.g., "openai/gpt-4")
// Extract just the model name for upstream (providers don't understand the slug)
let model_name_only = if let Some((_, model)) = alias_resolved_model.split_once('/') {
model.to_string()
} else {
alias_resolved_model.clone()
};
// Extract tool names and user message preview for span attributes
let tool_names = client_request.get_tool_names();
let user_message_preview = client_request
.get_recent_user_message()
.map(|msg| truncate_message(&msg, 50));
let span = tracing::Span::current();
if let Some(temp) = temperature {
span.record(tracing_llm::TEMPERATURE, tracing::field::display(temp));
}
if let Some(tools) = &tool_names {
let formatted_tools = tools
.iter()
.map(|name| format!("{}(...)", name))
.collect::<Vec<_>>()
.join("\n");
span.record(tracing_llm::TOOLS, formatted_tools.as_str());
}
if let Some(preview) = &user_message_preview {
span.record(tracing_llm::USER_MESSAGE_PREVIEW, preview.as_str());
}
// Extract messages for signal analysis (clone before moving client_request)
let messages_for_signals = Some(client_request.get_messages());
// Set the model to just the model name (without provider prefix)
// This ensures upstream receives "gpt-4" not "openai/gpt-4"
client_request.set_model(model_name_only.clone());
if client_request.remove_metadata_key("plano_preference_config") {
debug!("removed plano_preference_config from metadata");
}
// === v1/responses state management: Determine upstream API and combine input if needed ===
// Do this BEFORE routing since routing consumes the request
// Only process state if state_storage is configured
let mut should_manage_state = false;
if is_responses_api_client {
if let (
ProviderRequestType::ResponsesAPIRequest(ref mut responses_req),
Some(ref state_store),
) = (&mut client_request, &state_storage)
{
// Extract original input once
original_input_items = extract_input_items(&responses_req.input);
// Get the upstream path and check if it's ResponsesAPI
let upstream_path = get_upstream_path(
&llm_providers,
&alias_resolved_model,
&request_path,
&alias_resolved_model,
is_streaming_request,
)
.await;
let upstream_api = SupportedUpstreamAPIs::from_endpoint(&upstream_path);
// Only manage state if upstream is NOT OpenAIResponsesAPI (needs translation)
should_manage_state = !matches!(
upstream_api,
Some(SupportedUpstreamAPIs::OpenAIResponsesAPI(_))
);
if should_manage_state {
// Retrieve and combine conversation history if previous_response_id exists
if let Some(ref prev_resp_id) = responses_req.previous_response_id {
match retrieve_and_combine_input(
state_store.clone(),
prev_resp_id,
original_input_items, // Pass ownership instead of cloning
)
.await
{
Ok(combined_input) => {
// Update both the request and original_input_items
responses_req.input = InputParam::Items(combined_input.clone());
original_input_items = combined_input;
info!(
items = original_input_items.len(),
"updated request with conversation history"
);
}
Err(StateStorageError::NotFound(_)) => {
// Return 409 Conflict when previous_response_id not found
warn!(previous_response_id = %prev_resp_id, "previous response_id not found");
let err_msg = format!(
"Conversation state not found for previous_response_id: {}",
prev_resp_id
);
let mut conflict_response = Response::new(full(err_msg));
*conflict_response.status_mut() = StatusCode::CONFLICT;
return Ok(conflict_response);
}
Err(e) => {
// Log warning but continue on other storage errors
warn!(
previous_response_id = %prev_resp_id,
error = %e,
"failed to retrieve conversation state"
);
// Restore original_input_items since we passed ownership
original_input_items = extract_input_items(&responses_req.input);
}
}
}
} else {
debug!("upstream supports ResponsesAPI natively");
}
}
}
// OpenAI Responses API rejects some tool fields that Codex may emit (e.g. domains on web_search).
// Strip those unsupported fields before serializing.
if matches!(
client_api,
Some(SupportedAPIsFromClient::OpenAIResponsesAPI(_))
) {
if let ProviderRequestType::ResponsesAPIRequest(ref mut responses_req) = client_request {
let mut stripped_domains_fields = 0usize;
if let Some(tools) = responses_req.tools.as_mut() {
for tool in tools.iter_mut() {
if let ResponsesTool::WebSearchPreview { domains, .. } = tool {
if domains.is_some() {
*domains = None;
stripped_domains_fields += 1;
}
}
}
}
if stripped_domains_fields > 0 {
debug!(
stripped_domains_fields = stripped_domains_fields,
"removed unsupported web_search domains fields for OpenAI Responses API"
);
}
}
}
// Serialize request for upstream BEFORE router consumes it
let client_request_bytes_for_upstream = ProviderRequestType::to_bytes(&client_request).unwrap();
// Determine routing using the dedicated router_chat module
// This gets its own span for latency and error tracking
let routing_span = info_span!(
"routing",
component = "routing",
http.method = "POST",
http.target = %request_path,
model.requested = %model_from_request,
model.alias_resolved = %alias_resolved_model,
route.selected_model = tracing::field::Empty,
routing.determination_ms = tracing::field::Empty,
);
let routing_result = match async {
set_service_name(operation_component::ROUTING);
router_chat_get_upstream_model(
router_service,
client_request, // Pass the original request - router_chat will convert it
&traceparent,
&request_path,
&request_id,
)
.await
}
.instrument(routing_span)
.await
{
Ok(result) => result,
Err(err) => {
// Codex /v1/responses can include tools (e.g. web_search) that cannot be
// converted to ChatCompletions for routing. Fall back to alias-resolved model
// instead of failing the full request.
if request_path == "/v1/responses" && err.message.contains("Unsupported conversion") {
warn!(
request_id = %request_id,
error = %err.message,
"routing conversion unsupported for responses request; falling back to validated model"
);
RoutingResult {
model_name: "none".to_string(),
}
} else {
let mut internal_error = Response::new(full(err.message));
*internal_error.status_mut() = err.status_code;
return Ok(internal_error);
}
}
};
// Determine final model to use
// Router returns "none" as a sentinel value when it doesn't select a specific model
let router_selected_model = routing_result.model_name.clone();
let resolved_model = if router_selected_model != "none" {
// Router selected a specific model via routing preferences
router_selected_model.clone()
} else {
// Router returned "none" sentinel, use validated resolved_model from request
alias_resolved_model.clone()
};
let resolved_model = if requires_native_responses_tools {
match select_capability_compatible_model(
&llm_providers,
&resolved_model,
is_streaming_request,
)
.await
{
Some(compatible_model) => {
if compatible_model != resolved_model {
warn!(
request_id = %request_id,
selected_model = %resolved_model,
compatible_model = %compatible_model,
"selected model cannot serve responses web/file/computer tools; rerouting to compatible model"
);
}
compatible_model
}
None => {
let err_msg = "No configured model can serve OpenAI Responses API requests with non-function tools".to_string();
warn!(request_id = %request_id, error = %err_msg, "capability-aware routing failed");
let mut bad_request = Response::new(full(err_msg));
*bad_request.status_mut() = StatusCode::BAD_REQUEST;
return Ok(bad_request);
}
}
} else {
resolved_model
};
tracing::Span::current().record(tracing_llm::MODEL_NAME, resolved_model.as_str());
let span_name = if model_from_request == resolved_model {
format!("POST {} {}", request_path, resolved_model)
} else {
format!(
"POST {} {} -> {}",
request_path, model_from_request, resolved_model
)
};
get_active_span(|span| {
span.update_name(span_name.clone());
});
debug!(
url = %full_qualified_llm_provider_url,
provider_hint = %resolved_model,
upstream_model = %model_name_only,
"Routing to upstream"
);
request_headers.insert(
ARCH_PROVIDER_HINT_HEADER,
header::HeaderValue::from_str(&resolved_model).unwrap(),
);
request_headers.insert(
header::HeaderName::from_static(ARCH_IS_STREAMING_HEADER),
header::HeaderValue::from_str(&is_streaming_request.to_string()).unwrap(),
);
// remove content-length header if it exists
request_headers.remove(header::CONTENT_LENGTH);
// Inject current LLM span's trace context so upstream spans are children of plano(llm)
global::get_text_map_propagator(|propagator| {
let cx = tracing_opentelemetry::OpenTelemetrySpanExt::context(&tracing::Span::current());
propagator.inject_context(&cx, &mut HeaderInjector(&mut request_headers));
});
// Capture start time right before sending request to upstream
let request_start_time = std::time::Instant::now();
let _request_start_system_time = std::time::SystemTime::now();
let llm_response = match reqwest::Client::new()
.post(&full_qualified_llm_provider_url)
.headers(request_headers)
.body(client_request_bytes_for_upstream)
.send()
.await
{
Ok(res) => res,
Err(err) => {
let err_msg = format!("Failed to send request: {}", err);
let mut internal_error = Response::new(full(err_msg));
*internal_error.status_mut() = StatusCode::INTERNAL_SERVER_ERROR;
return Ok(internal_error);
}
};
// copy over the headers and status code from the original response
let response_headers = llm_response.headers().clone();
let upstream_status = llm_response.status();
let mut response = Response::builder().status(upstream_status);
let headers = response.headers_mut().unwrap();
for (header_name, header_value) in response_headers.iter() {
headers.insert(header_name, header_value.clone());
}
// Build LLM span with actual status code using constants
let byte_stream = llm_response.bytes_stream();
// Create base processor for metrics and tracing
let base_processor = ObservableStreamProcessor::new(
operation_component::LLM,
span_name,
request_start_time,
messages_for_signals,
);
// === v1/responses state management: Wrap with ResponsesStateProcessor ===
// Only wrap if we need to manage state (client is ResponsesAPI AND upstream is NOT ResponsesAPI AND state_storage is configured)
let streaming_response = if let (true, false, Some(state_store)) = (
should_manage_state,
original_input_items.is_empty(),
state_storage,
) {
// Extract Content-Encoding header to handle decompression for state parsing
let content_encoding = response_headers
.get("content-encoding")
.and_then(|v| v.to_str().ok())
.map(|s| s.to_string());
// Wrap with state management processor to store state after response completes
let state_processor = ResponsesStateProcessor::new(
base_processor,
state_store,
original_input_items,
alias_resolved_model.clone(),
resolved_model.clone(),
is_streaming_request,
false, // Not OpenAI upstream since should_manage_state is true
content_encoding,
request_id,
);
create_streaming_response(byte_stream, state_processor, 16)
} else {
// Use base processor without state management
create_streaming_response(byte_stream, base_processor, 16)
};
match response.body(streaming_response.body) {
Ok(response) => Ok(response),
Err(err) => {
let err_msg = format!("Failed to create response: {}", err);
let mut internal_error = Response::new(full(err_msg));
*internal_error.status_mut() = StatusCode::INTERNAL_SERVER_ERROR;
Ok(internal_error)
}
}
}
/// Resolves model aliases by looking up the requested model in the model_aliases map.
/// Returns the target model if an alias is found, otherwise returns the original model.
fn resolve_model_alias(
model_from_request: &str,
model_aliases: &Arc<Option<HashMap<String, ModelAlias>>>,
) -> String {
if let Some(aliases) = model_aliases.as_ref() {
if let Some(model_alias) = aliases.get(model_from_request) {
debug!(
"Model Alias: 'From {}' -> 'To {}'",
model_from_request, model_alias.target
);
return model_alias.target.clone();
}
}
model_from_request.to_string()
}
fn responses_request_uses_non_function_tools(client_request: &ProviderRequestType) -> bool {
match client_request {
ProviderRequestType::ResponsesAPIRequest(req) => req
.tools
.as_ref()
.map(|tools| {
tools
.iter()
.any(|tool| !matches!(tool, ResponsesTool::Function { .. }))
})
.unwrap_or(false),
_ => false,
}
}
async fn model_supports_native_responses_api(
llm_providers: &Arc<RwLock<LlmProviders>>,
model_name: &str,
is_streaming: bool,
) -> bool {
let upstream_path = get_upstream_path(
llm_providers,
model_name,
"/v1/responses",
model_name,
is_streaming,
)
.await;
matches!(
SupportedUpstreamAPIs::from_endpoint(&upstream_path),
Some(SupportedUpstreamAPIs::OpenAIResponsesAPI(_))
)
}
async fn select_capability_compatible_model(
llm_providers: &Arc<RwLock<LlmProviders>>,
preferred_model: &str,
is_streaming: bool,
) -> Option<String> {
if model_supports_native_responses_api(llm_providers, preferred_model, is_streaming).await {
return Some(preferred_model.to_string());
}
let (default_candidate, ordered_candidates): (Option<String>, Vec<String>) = {
let providers = llm_providers.read().await;
let default_candidate = providers.default().map(|p| p.name.clone());
let mut seen = HashSet::new();
let mut candidates = Vec::new();
for (key, provider) in providers.iter() {
if key != &provider.name || provider.internal == Some(true) {
continue;
}
if seen.insert(provider.name.clone()) {
candidates.push(provider.name.clone());
}
}
(default_candidate, candidates)
};
if let Some(default_model) = default_candidate {
if model_supports_native_responses_api(llm_providers, &default_model, is_streaming).await {
return Some(default_model);
}
}
for candidate in ordered_candidates {
if model_supports_native_responses_api(llm_providers, &candidate, is_streaming).await {
return Some(candidate);
}
}
None
}
/// Calculates the upstream path for the provider based on the model name.
/// Looks up provider configuration, gets the ProviderId and base_url_path_prefix,
/// then uses target_endpoint_for_provider to calculate the correct upstream path.
async fn get_upstream_path(
llm_providers: &Arc<RwLock<LlmProviders>>,
model_name: &str,
request_path: &str,
resolved_model: &str,
is_streaming: bool,
) -> String {
let (provider_id, base_url_path_prefix) = get_provider_info(llm_providers, model_name).await;
// Calculate the upstream path using the proper API
let client_api = SupportedAPIsFromClient::from_endpoint(request_path)
.expect("Should have valid API endpoint");
client_api.target_endpoint_for_provider(
&provider_id,
request_path,
resolved_model,
is_streaming,
base_url_path_prefix.as_deref(),
)
}
/// Helper function to get provider info (ProviderId and base_url_path_prefix)
async fn get_provider_info(
llm_providers: &Arc<RwLock<LlmProviders>>,
model_name: &str,
) -> (hermesllm::ProviderId, Option<String>) {
let providers_lock = llm_providers.read().await;
// Try to find by model name or provider name using LlmProviders::get
// This handles both "gpt-4" and "openai/gpt-4" formats
if let Some(provider) = providers_lock.get(model_name) {
let provider_id = provider.provider_interface.to_provider_id();
let prefix = provider.base_url_path_prefix.clone();
return (provider_id, prefix);
}
// Fall back to default provider
if let Some(provider) = providers_lock.default() {
let provider_id = provider.provider_interface.to_provider_id();
let prefix = provider.base_url_path_prefix.clone();
(provider_id, prefix)
} else {
// Last resort: use OpenAI as hardcoded fallback
warn!("No default provider found, falling back to OpenAI");
(hermesllm::ProviderId::OpenAI, None)
}
}